use crate::render::text::decoration_segments;
use crate::{
    math::{Bounds, Matrix, Rect},
    render::{default_font, DEFAULT_EMOJI_FONT},
    utils::Browser,
};

use core::f32;
use macros::ToJs;
use skia_safe::textlayout::{RectHeightStyle, RectWidthStyle};
use skia_safe::{
    self as skia,
    paint::{self, Paint},
    textlayout::Affinity,
    textlayout::ParagraphBuilder,
    textlayout::ParagraphStyle,
    textlayout::PlaceholderAlignment,
    textlayout::PlaceholderStyle,
    textlayout::PositionWithAffinity,
    textlayout::TextBaseline,
    Contains,
};

use std::borrow::Cow;
use std::cell::Cell;
use std::collections::HashSet;
use std::rc::Rc;

use super::FontFamily;
use crate::math::Point;
use crate::shapes::{self, merge_fills, Shape, Type, VerticalAlign};
use crate::utils::{get_fallback_fonts, get_font_collection};
use crate::Uuid;

// TODO: maybe move this to the wasm module?
pub type ParagraphBuilderGroup = Vec<ParagraphBuilder>;

/// True when the modifier changes the text layout container (resize), as opposed
/// to rotation/move where glyph layout can be reused.
pub fn modifier_changes_text_layout(base: &Shape, modifier: &Matrix) -> bool {
    let Type::Text(text_content) = &base.shape_type else {
        return false;
    };
    let before = oriented_container_bounds(base);
    let after = before.transform(modifier);
    match text_content.grow_type() {
        GrowType::AutoWidth => !crate::math::is_close_to(before.height(), after.height()),
        GrowType::AutoHeight | GrowType::Fixed => {
            !crate::math::is_close_to(before.width(), after.width())
        }
    }
}

fn oriented_container_bounds(shape: &Shape) -> Bounds {
    let selrect = shape.selrect();
    let mut bounds = Bounds::new(
        Point::new(selrect.x(), selrect.y()),
        Point::new(selrect.x() + selrect.width(), selrect.y()),
        Point::new(
            selrect.x() + selrect.width(),
            selrect.y() + selrect.height(),
        ),
        Point::new(selrect.x(), selrect.y() + selrect.height()),
    );
    if !shape.transform.is_identity() {
        let mut matrix = shape.transform;
        let center = shape.center();
        matrix.post_translate(center);
        matrix.pre_translate(-center);
        bounds.transform_mut(&matrix);
    }
    bounds
}

#[repr(u8)]
#[derive(Debug, PartialEq, Clone, Copy, ToJs)]
pub enum GrowType {
    Fixed = 0,
    AutoWidth = 1,
    AutoHeight = 2,
}

#[derive(Debug, PartialEq, Copy, Clone)]
pub struct TextContentSize {
    pub width: f32,
    pub height: f32,
    pub max_width: f32,
    pub normalized_line_height: f32,
}

const DEFAULT_TEXT_CONTENT_SIZE: f32 = 0.01;

/// Matches `marginRight: "1px"` on `.paragraph-set` in the HTML text renderer
/// (`frontend/src/app/main/ui/shapes/text/styles.cljs`). DOM `getBoundingClientRect`
/// includes that margin in auto-width measurements; Skia `longest_line()` does not.
const PARAGRAPH_SET_MARGIN_RIGHT: f32 = 1.0;

impl TextContentSize {
    pub fn default() -> Self {
        Self {
            width: DEFAULT_TEXT_CONTENT_SIZE,
            height: DEFAULT_TEXT_CONTENT_SIZE,
            max_width: DEFAULT_TEXT_CONTENT_SIZE,
            normalized_line_height: 0.0,
        }
    }

    pub fn new_with_size(width: f32, height: f32) -> Self {
        Self {
            width,
            height,
            max_width: DEFAULT_TEXT_CONTENT_SIZE,
            normalized_line_height: 0.0,
        }
    }

    pub fn new_with_normalized_line_height(
        width: f32,
        height: f32,
        max_width: f32,
        normalized_line_height: f32,
    ) -> Self {
        Self {
            width,
            height,
            max_width,
            normalized_line_height,
        }
    }

    pub fn set_size(&mut self, width: f32, height: f32) {
        self.width = width;
        self.height = height;
    }

    pub fn copy_finite_size(
        &mut self,
        size: TextContentSize,
        default_height: f32,
        default_width: f32,
    ) {
        if f32::is_finite(size.width) {
            self.width = size.width;
        } else {
            self.width = default_width;
        }
        if f32::is_finite(size.max_width) {
            self.max_width = size.max_width;
        } else {
            self.max_width = default_width
        }
        if f32::is_finite(size.height) {
            self.height = size.height;
        } else {
            self.height = default_height;
        }
        if f32::is_finite(size.normalized_line_height) {
            self.normalized_line_height = size.normalized_line_height;
        }
    }
}

#[derive(Debug, Clone, Copy, Default)]
pub struct TextPositionWithAffinity {
    pub position_with_affinity: PositionWithAffinity,
    pub paragraph: usize,
    pub offset: usize,
}

impl PartialEq for TextPositionWithAffinity {
    fn eq(&self, other: &Self) -> bool {
        self.paragraph == other.paragraph && self.offset == other.offset
    }
}

impl TextPositionWithAffinity {
    pub fn new(
        position_with_affinity: PositionWithAffinity,
        paragraph: usize,
        offset: usize,
    ) -> Self {
        Self {
            position_with_affinity,
            paragraph,
            offset,
        }
    }

    pub fn empty() -> Self {
        Self {
            position_with_affinity: PositionWithAffinity {
                position: 0,
                affinity: Affinity::Downstream,
            },
            paragraph: 0,
            offset: 0,
        }
    }

    pub fn new_downstream_affinity(paragraph: usize, offset: usize) -> Self {
        Self {
            position_with_affinity: PositionWithAffinity {
                position: offset as i32,
                affinity: Affinity::Downstream,
            },
            paragraph,
            offset,
        }
    }

    pub fn new_upstream_affinity(paragraph: usize, offset: usize) -> Self {
        Self {
            position_with_affinity: PositionWithAffinity {
                position: offset as i32,
                affinity: Affinity::Upstream,
            },
            paragraph,
            offset,
        }
    }

    pub fn reset(&mut self) {
        self.position_with_affinity.position = 0;
        self.position_with_affinity.affinity = Affinity::Downstream;
        self.paragraph = 0;
        self.offset = 0;
    }
}

#[derive(Debug)]
pub struct TextContentLayoutResult(
    Vec<ParagraphBuilderGroup>,
    Vec<Vec<skia::textlayout::Paragraph>>,
    TextContentSize,
);

/// Cached extrect stored as offsets from the selrect origin,
/// keyed by the selrect dimensions (width, height) and vertical alignment
/// used to compute it.
#[derive(Debug, Clone, Copy)]
struct CachedExtrect {
    selrect_width: f32,
    selrect_height: f32,
    valign: u8,
    left: f32,
    top: f32,
    right: f32,
    bottom: f32,
}

#[derive(Debug)]
pub struct TextContentLayout {
    pub paragraph_builders: Vec<ParagraphBuilderGroup>,
    /// Shared across shape clones (e.g. modifier transforms) so rotation/pan
    /// can paint without rebuilding Skia layout. Cleared builders on clone are OK.
    pub paragraphs: Rc<Vec<Vec<skia::textlayout::Paragraph>>>,
    cached_extrect: Cell<Option<CachedExtrect>>,
}

impl Default for TextContentLayout {
    fn default() -> Self {
        Self::new()
    }
}

impl Clone for TextContentLayout {
    fn clone(&self) -> Self {
        Self {
            paragraph_builders: vec![],
            paragraphs: Rc::clone(&self.paragraphs),
            cached_extrect: Cell::new(self.cached_extrect.get()),
        }
    }
}

impl PartialEq for TextContentLayout {
    fn eq(&self, _other: &Self) -> bool {
        true
    }
}

impl TextContentLayout {
    pub fn new() -> Self {
        Self {
            paragraph_builders: vec![],
            paragraphs: Rc::new(Vec::new()),
            cached_extrect: Cell::new(None),
        }
    }

    pub fn set(
        &mut self,
        paragraph_builders: Vec<ParagraphBuilderGroup>,
        paragraphs: Vec<Vec<skia::textlayout::Paragraph>>,
    ) {
        self.paragraph_builders = paragraph_builders;
        self.paragraphs = Rc::new(paragraphs);
        self.cached_extrect.set(None);
    }

    pub fn clear(&mut self) {
        self.paragraph_builders.clear();
        self.paragraphs = Rc::new(Vec::new());
        self.cached_extrect.set(None);
    }

    pub fn needs_update(&self) -> bool {
        self.paragraphs.is_empty()
    }
}

#[derive(Debug, Clone)]
pub struct TextDecorationSegment {
    #[allow(dead_code)]
    pub kind: skia::textlayout::TextDecoration,
    pub text_style: skia::textlayout::TextStyle,
    pub y: f32,
    pub thickness: f32,
    pub left: f32,
    pub width: f32,
}

impl TextDecorationSegment {
    /// The bar to paint, centered on `y`.
    pub fn rect(&self) -> Rect {
        Rect::new(
            self.left,
            self.y - self.thickness / 2.0,
            self.left + self.width,
            self.y + self.thickness / 2.0,
        )
    }
}

pub fn vertical_align_offset(container_h: f32, content_h: f32, valign: VerticalAlign) -> f32 {
    match valign {
        VerticalAlign::Center => (container_h - content_h) / 2.0,
        VerticalAlign::Bottom => container_h - content_h,
        _ => 0.0,
    }
}

fn intersects(paragraph: &skia_safe::textlayout::Paragraph, x: f32, y: f32) -> bool {
    if y < 0.0 || y > paragraph.height() {
        return false;
    }

    let pos = paragraph.get_glyph_position_at_coordinate((x, y));
    let idx = pos.position as usize;

    let rects =
        paragraph.get_rects_for_range(0..idx + 1, RectHeightStyle::Tight, RectWidthStyle::Tight);

    rects.iter().any(|r| r.rect.contains(&Point::new(x, y)))
}

fn paragraph_intersects<'a>(
    paragraphs: impl Iterator<Item = &'a skia::textlayout::Paragraph>,
    x_pos: f32,
    y_pos: f32,
) -> bool {
    paragraphs
        .scan(0.0_f32, |height, p| {
            let prev_height = *height;
            *height += p.height();
            Some((prev_height, p))
        })
        .any(|(height, p)| intersects(p, x_pos, y_pos - height))
}

// Performs a text auto layout without width limits.
// This should be the same as text_auto_layout.
pub fn build_paragraphs_from_paragraph_builders(
    paragraph_builders: &mut [ParagraphBuilderGroup],
    width: f32,
) -> Vec<Vec<skia::textlayout::Paragraph>> {
    let paragraphs = paragraph_builders
        .iter_mut()
        .map(|builders| {
            builders
                .iter_mut()
                .map(|builder| {
                    let mut paragraph = builder.build();
                    // For auto-width, always layout with infinite width first to get intrinsic width
                    paragraph.layout(width);
                    paragraph
                })
                .collect()
        })
        .collect();
    paragraphs
}

/// Calculate the normalized line height from paragraph builders
pub fn calculate_normalized_line_height(
    paragraph_builders: &mut [ParagraphBuilderGroup],
    width: f32,
) -> f32 {
    let mut normalized_line_height = 0.0;
    for paragraph_builder_group in paragraph_builders.iter_mut() {
        for paragraph_builder in paragraph_builder_group.iter_mut() {
            let mut paragraph = paragraph_builder.build();
            paragraph.layout(width);
            let baseline = paragraph.ideographic_baseline();
            if baseline > normalized_line_height {
                normalized_line_height = baseline;
            }
        }
    }
    normalized_line_height
}

#[derive(Debug, Clone)]
pub struct TextContent {
    pub paragraphs: Vec<Paragraph>,
    pub bounds: Rect,
    pub grow_type: GrowType,
    pub size: TextContentSize,
    pub layout: TextContentLayout,
    content_version: u64,
    layout_version: u64,
    layout_width: Option<f32>,
    /// Canvas origin used when absolute fill shaders (image/gradient) were baked
    /// into cached Skia paragraphs. Kept across move clones so paint can
    /// translate glyphs + shaders together. See `cached_layout_paint_offset`.
    layout_paint_origin: Option<Point>,
}

impl PartialEq for TextContent {
    fn eq(&self, other: &Self) -> bool {
        self.paragraphs == other.paragraphs
            && self.bounds == other.bounds
            && self.grow_type == other.grow_type
            && self.size == other.size
            && self.layout == other.layout
    }
}

impl TextContent {
    pub fn new(bounds: Rect, grow_type: GrowType) -> Self {
        Self {
            paragraphs: Vec::new(),
            bounds,
            grow_type,
            size: TextContentSize::default(),
            layout: TextContentLayout::new(),
            content_version: 0,
            layout_version: 0,
            layout_width: None,
            layout_paint_origin: None,
        }
    }

    pub fn new_bounds(&self, bounds: Rect) -> Self {
        let paragraphs = self.paragraphs.clone();
        let grow_type = self.grow_type;
        Self {
            paragraphs,
            bounds,
            grow_type,
            size: TextContentSize::new_with_size(bounds.width(), bounds.height()),
            layout: TextContentLayout::new(),
            content_version: 0,
            layout_version: 0,
            layout_width: None,
            layout_paint_origin: None,
        }
    }

    pub fn bounds(&self) -> Rect {
        self.bounds
    }

    /// Anchor used when painting from the layout cache. Absolute image/gradient
    /// shaders were built in this coordinate space; paint glyphs here and apply
    /// [`cached_layout_paint_offset`] on the canvas so both move together.
    pub fn cached_layout_paint_anchor(&self, selrect: &Rect) -> Point {
        self.layout_paint_origin
            .unwrap_or_else(|| Point::new(self.selrect_origin_x(selrect), selrect.y()))
    }

    /// Canvas translation from the baked paint origin to the current selrect.
    /// Zero when there is no recorded origin (fall back to painting at selrect).
    pub fn cached_layout_paint_offset(&self, selrect: &Rect) -> Point {
        match self.layout_paint_origin {
            Some(origin) => Point::new(
                self.selrect_origin_x(selrect) - origin.x,
                selrect.y() - origin.y,
            ),
            None => Point::new(0.0, 0.0),
        }
    }

    /// [`layout_origin_x`] for this content's own measured width.
    fn selrect_origin_x(&self, selrect: &Rect) -> f32 {
        self.layout_origin_x(selrect, self.size.width)
    }

    /// Text content for paint when [`Rect`] size may differ from stored bounds
    /// (e.g. modifier transform). Reuses `self` when width/height match; otherwise
    /// clones paragraphs into a rebound copy with an empty layout cache.
    pub fn paint_content_for_selrect<'a>(&'a self, selrect: Rect) -> Cow<'a, Self> {
        let stored_bounds = self.bounds();
        if (stored_bounds.width() - selrect.width()).abs() < 0.01
            && (stored_bounds.height() - selrect.height()).abs() < 0.01
        {
            Cow::Borrowed(self)
        } else {
            Cow::Owned(self.new_bounds(selrect))
        }
    }

    pub fn set_xywh(&mut self, x: f32, y: f32, w: f32, h: f32) {
        self.bounds = Rect::from_xywh(x, y, w, h);
    }

    /// Distinct font families referenced by this content's spans, in first-seen
    /// order.
    pub fn font_families(&self) -> Vec<FontFamily> {
        let mut seen: Vec<FontFamily> = Vec::new();
        for paragraph in &self.paragraphs {
            for span in paragraph.children() {
                if !seen.contains(&span.font_family) {
                    seen.push(span.font_family);
                }
            }
        }
        seen
    }

    pub fn add_paragraph(&mut self, mut paragraph: Paragraph) {
        let index = self.paragraphs.len() as u32;
        paragraph.set_span_positions(index);
        self.paragraphs.push(paragraph);
        self.content_version = self.content_version.wrapping_add(1);
    }

    pub fn reset_span_positions(&mut self) {
        for (index, paragraph) in self.paragraphs.iter_mut().enumerate() {
            paragraph.set_span_positions(index as u32);
        }
    }

    pub fn paragraphs(&self) -> &[Paragraph] {
        &self.paragraphs
    }

    pub fn has_non_ascii(&self) -> bool {
        self.paragraphs
            .iter()
            .flat_map(|p| p.children())
            .any(|span| !span.text.is_ascii())
    }

    pub fn paragraphs_mut(&mut self) -> &mut Vec<Paragraph> {
        self.content_version = self.content_version.wrapping_add(1);
        &mut self.paragraphs
    }

    pub fn width(&self) -> f32 {
        self.size.width
    }

    pub fn normalized_line_height(&self) -> f32 {
        self.size.normalized_line_height
    }

    pub fn grow_type(&self) -> GrowType {
        self.grow_type
    }

    pub fn set_grow_type(&mut self, grow_type: GrowType) {
        if self.grow_type != grow_type {
            self.grow_type = grow_type;
            self.content_version = self.content_version.wrapping_add(1);
        }
    }

    /// Non-empty and every paragraph RTL. Mixed content counts as LTR, mirroring
    /// `app.common.types.text/rtl-content?` on the ClojureScript side.
    pub fn is_rtl(&self) -> bool {
        !self.paragraphs.is_empty()
            && self
                .paragraphs
                .iter()
                .all(|paragraph| paragraph.text_direction() == TextDirection::RTL)
    }

    /// Left edge of the laid-out text of `width` inside `selrect`. RTL auto-width
    /// text anchors right so the box extends leftward as it grows.
    pub fn layout_origin_x(&self, selrect: &Rect, width: f32) -> f32 {
        if self.grow_type() == GrowType::AutoWidth && self.is_rtl() {
            selrect.right() - width
        } else {
            selrect.x()
        }
    }

    /// Compute a tight text rect from laid-out Skia paragraphs using glyph
    /// metrics (fm.top for overshoot, line descent for bottom, line left/width
    /// for horizontal extent).
    fn rect_from_paragraphs(&self, selrect: &Rect, valign: VerticalAlign) -> Option<Rect> {
        let paragraphs = &self.layout.paragraphs;
        let x = selrect.x();
        let base_y = selrect.y();

        let total_height: f32 = paragraphs
            .iter()
            .filter_map(|group| group.first())
            .map(|p| p.height())
            .sum();

        let vertical_offset = vertical_align_offset(selrect.height(), total_height, valign);

        let mut min_x = f32::MAX;
        let mut min_y = f32::MAX;
        let mut max_x = f32::MIN;
        let mut max_y = f32::MIN;
        let mut has_lines = false;
        let mut y_accum = base_y + vertical_offset;

        for group in paragraphs.iter() {
            if let Some(paragraph) = group.first() {
                let line_metrics = paragraph.get_line_metrics();
                for line in &line_metrics {
                    let line_baseline = y_accum + line.baseline as f32;

                    // Use per-glyph fm.top for tighter vertical bounds when
                    // available; fall back to line-level ascent for empty lines
                    // (where get_style_metrics returns nothing).
                    let style_metrics = line.get_style_metrics(line.start_index..line.end_index);
                    if style_metrics.is_empty() {
                        min_y = min_y.min(line_baseline - line.ascent as f32);
                    } else {
                        for (_start, style_metric) in &style_metrics {
                            let fm = &style_metric.font_metrics;
                            min_y = min_y.min(line_baseline + fm.top);
                        }
                    }

                    // Bottom uses line-level descent (includes descender space
                    // for the whole line, not just present glyphs).
                    max_y = max_y.max(line_baseline + line.descent as f32);
                    min_x = min_x.min(x + line.left as f32);
                    max_x = max_x.max(x + line.left as f32 + line.width as f32);
                    has_lines = true;
                }
                y_accum += paragraph.height();
            }
        }

        if has_lines {
            Some(Rect::from_ltrb(min_x, min_y, max_x, max_y))
        } else {
            None
        }
    }

    fn compute_and_cache_extrect(
        &self,
        shape: &Shape,
        selrect: &Rect,
        valign: VerticalAlign,
    ) -> Rect {
        // AutoWidth paragraphs are laid out with f32::MAX, so line metrics
        // (line.left) reflect alignment within that huge width and are
        // unusable for tight bounds.  Fall back to content_rect.
        if self.grow_type() == GrowType::AutoWidth {
            return self.content_rect(selrect, valign);
        }

        let layout_matches_container = self
            .layout_width
            .is_some_and(|w| w.ceil() == self.get_width(selrect.width()).ceil());

        let tight = if !self.layout.paragraphs.is_empty() && layout_matches_container {
            self.rect_from_paragraphs(selrect, valign)
        } else {
            let mut text_content = self.clone();
            text_content.update_layout(shape.selrect);
            text_content.rect_from_paragraphs(selrect, valign)
        }
        .unwrap_or_else(|| self.content_rect(selrect, valign));

        // Cache as offsets from selrect origin so it's position-independent.
        let sx = selrect.x();
        let sy = selrect.y();
        self.layout.cached_extrect.set(Some(CachedExtrect {
            selrect_width: selrect.width(),
            selrect_height: selrect.height(),
            valign: valign as u8,
            left: tight.left() - sx,
            top: tight.top() - sy,
            right: tight.right() - sx,
            bottom: tight.bottom() - sy,
        }));

        tight
    }

    pub fn calculate_bounds(&self, shape: &Shape, apply_transform: bool) -> Bounds {
        let transform = &shape.transform;
        let center = &shape.center();
        let selrect = shape.selrect();
        let valign = shape.vertical_align();
        let sw = selrect.width();
        let sh = selrect.height();
        let sx = selrect.x();
        let sy = selrect.y();

        // Try the cache first: if dimensions and valign match, just apply position offset.
        let text_rect = if let Some(cached) = self.layout.cached_extrect.get() {
            if (cached.selrect_width - sw).abs() < 0.1
                && (cached.selrect_height - sh).abs() < 0.1
                && cached.valign == valign as u8
            {
                Rect::from_ltrb(
                    sx + cached.left,
                    sy + cached.top,
                    sx + cached.right,
                    sy + cached.bottom,
                )
            } else {
                self.compute_and_cache_extrect(shape, &selrect, valign)
            }
        } else {
            self.compute_and_cache_extrect(shape, &selrect, valign)
        };

        let mut bounds = Bounds::new(
            Point::new(text_rect.x(), text_rect.y()),
            Point::new(text_rect.x() + text_rect.width(), text_rect.y()),
            Point::new(
                text_rect.x() + text_rect.width(),
                text_rect.y() + text_rect.height(),
            ),
            Point::new(text_rect.x(), text_rect.y() + text_rect.height()),
        );

        if apply_transform && !transform.is_identity() {
            let mut matrix = *transform;
            matrix.post_translate(*center);
            matrix.pre_translate(-*center);
            bounds.transform_mut(&matrix);
        }

        bounds
    }

    pub fn content_rect(&self, selrect: &Rect, valign: VerticalAlign) -> Rect {
        let mut y = selrect.y();

        let width = if self.grow_type() == GrowType::AutoWidth {
            self.size.width
        } else {
            selrect.width()
        };

        let x = self.layout_origin_x(selrect, width);

        let height = if self.size.width.round() != width.round() {
            self.get_height(width)
        } else {
            self.size.height
        };

        let offset_y = vertical_align_offset(selrect.height(), height, valign);
        y += offset_y;

        Rect::from_xywh(x, y, width, height)
    }

    pub fn transform(&mut self, transform: &Matrix) {
        let left = self.bounds.left();
        let right = self.bounds.right();
        let top = self.bounds.top();
        let bottom = self.bounds.bottom();
        let p1 = transform.map_point(skia::Point::new(left, top));
        let p2 = transform.map_point(skia::Point::new(right, bottom));
        self.bounds = Rect::from_ltrb(p1.x, p1.y, p2.x, p2.y);
    }

    pub fn get_caret_position_from_shape_coords(
        &self,
        point: &Point,
    ) -> Option<TextPositionWithAffinity> {
        let mut offset_y = 0.0;
        let layout_paragraphs = self.layout.paragraphs.iter().flatten();

        for (paragraph_index, layout_paragraph) in layout_paragraphs.enumerate() {
            let start_y = offset_y;
            let end_y = offset_y + layout_paragraph.height();

            // We only test against paragraphs that can contain the current y
            // coordinate. Use >= for start and handle zero-height paragraphs.
            let paragraph_height = layout_paragraph.height();
            let matches = if paragraph_height > 0.0 {
                point.y >= start_y && point.y < end_y
            } else {
                // For zero-height paragraphs (empty lines), match if we're at the start position
                point.y >= start_y && point.y <= start_y + 1.0
            };

            if matches {
                // Skia's get_glyph_position_at_coordinate expects coordinates relative to
                // the paragraph's top-left. For multi-paragraph or wrapped text, each
                // paragraph has its own origin; subtract start_y so we pass paragraph-local coords.
                let para_pt = Point::new(point.x, point.y - start_y);
                let position_with_affinity =
                    layout_paragraph.get_glyph_position_at_coordinate((para_pt.x, para_pt.y));
                if let Some(paragraph) = self.paragraphs().get(paragraph_index) {
                    // Skia reports UTF-16 code units, the model counts characters.
                    let offset =
                        paragraph.utf16_offset_to_char(position_with_affinity.position as usize);

                    return Some(TextPositionWithAffinity::new(
                        position_with_affinity,
                        paragraph_index,
                        offset,
                    ));
                }
            }
            offset_y += layout_paragraph.height();
        }

        // Handle completely empty text shapes: if there are no paragraphs or all paragraphs
        // are empty, and the click is within the text shape bounds, return a default position
        if (self.paragraphs().is_empty() || self.layout.paragraphs.is_empty())
            && self.bounds.contains(*point)
        {
            // Create a default position at the start of the text
            use skia_safe::textlayout::Affinity;
            let default_position = PositionWithAffinity {
                position: 0,
                affinity: Affinity::Downstream,
            };
            return Some(TextPositionWithAffinity::new(
                default_position,
                0, // paragraph 0
                0, // offset 0
            ));
        }

        None
    }

    pub fn get_caret_position_from_screen_coords(
        &self,
        point: &Point,
        view_matrix: &Matrix,
        shape_matrix: &Matrix,
    ) -> Option<TextPositionWithAffinity> {
        let shape_rel_point = Shape::get_relative_point(point, view_matrix, shape_matrix)?;
        self.get_caret_position_from_shape_coords(&shape_rel_point)
    }

    /// Builds the ParagraphBuilders necessary to render
    /// this text.
    pub fn paragraph_builder_group_from_text(
        &self,
        use_shadow: Option<bool>,
    ) -> Vec<ParagraphBuilderGroup> {
        self.paragraph_builders(use_shadow, false, None, None, None, None)
    }

    /// Creates paragraph builders with always-opaque paint (BLACK @ alpha 255).
    /// Used as a clip mask for inner stroke rendering.
    pub fn paragraph_builder_group_opaque(&self) -> Vec<ParagraphBuilderGroup> {
        self.paragraph_builders(None, true, None, None, None, None)
    }

    /// Maximum number of stacked fills across every span in this text block.
    pub fn max_fill_layers(&self) -> usize {
        self.paragraphs()
            .iter()
            .flat_map(|p| p.children())
            .map(|s| s.fills.len())
            .max()
            .unwrap_or(0)
    }

    /// Builds paragraph builders that paint a single fill layer per span for SVG
    /// export. `layer_from_bottom` is 0 for the bottommost fill (fills[last]).
    pub fn paragraph_builder_group_for_fill_layer(
        &self,
        layer_from_bottom: usize,
    ) -> Vec<ParagraphBuilderGroup> {
        self.paragraph_builders(None, false, None, Some(layer_from_bottom), None, None)
    }

    /// Like [`paragraph_builder_group_for_fill_layer`], but spans whose fill at
    /// this layer is an image in `skip_image_ids` get transparent paint (those
    /// fills are re-emitted as linked SVG `<image>` elements).
    pub fn paragraph_builder_group_for_fill_layer_skipping_images(
        &self,
        layer_from_bottom: usize,
        skip_image_ids: &HashSet<Uuid>,
    ) -> Vec<ParagraphBuilderGroup> {
        self.paragraph_builders(
            None,
            false,
            None,
            Some(layer_from_bottom),
            None,
            Some(skip_image_ids),
        )
    }

    /// Opaque black glyphs only for spans whose fill at `layer_from_bottom` is
    /// the given image — used as an SVG `<clipPath>` for linked image fills.
    pub fn paragraph_builder_group_opaque_for_image_layer(
        &self,
        layer_from_bottom: usize,
        image_id: Uuid,
    ) -> Vec<ParagraphBuilderGroup> {
        self.paragraph_builders(
            None,
            false,
            None,
            None,
            Some((layer_from_bottom, image_id)),
            None,
        )
    }

    fn paragraph_builders(
        &self,
        use_shadow: Option<bool>,
        opaque: bool,
        align_override: Option<skia::textlayout::TextAlign>,
        fill_layer: Option<usize>,
        opaque_image_layer: Option<(usize, Uuid)>,
        skip_image_ids: Option<&HashSet<Uuid>>,
    ) -> Vec<ParagraphBuilderGroup> {
        let fonts = get_font_collection();
        let fallback_fonts = get_fallback_fonts();
        let mut paragraph_group = Vec::new();

        for paragraph in self.paragraphs() {
            let mut paragraph_style = paragraph.paragraph_to_style();
            if let Some(align) = align_override {
                paragraph_style.set_text_align(align);
            }
            let mut builder = ParagraphBuilder::new(&paragraph_style, fonts);
            let mut has_text = false;
            for span in paragraph.children() {
                let text_style = if let Some((layer, image_id)) = opaque_image_layer {
                    let mut style = span.to_style(
                        &self.bounds(),
                        fallback_fonts,
                        false,
                        paragraph.line_height(),
                    );
                    let mut paint = paint::Paint::default();
                    match span.fills_from_bottom(layer) {
                        Some(shapes::Fill::Image(img)) if img.id() == image_id => {
                            paint.set_color(skia::Color::BLACK);
                            paint.set_alpha(255);
                        }
                        _ => {
                            paint.set_color(skia::Color::TRANSPARENT);
                        }
                    }
                    style.set_foreground_paint(&paint);
                    style
                } else if let (Some(layer), Some(skip)) = (fill_layer, skip_image_ids) {
                    let skip_span = matches!(
                        span.fills_from_bottom(layer),
                        Some(shapes::Fill::Image(img)) if skip.contains(&img.id())
                    );
                    if skip_span {
                        let mut style = span.to_style(
                            &self.bounds(),
                            fallback_fonts,
                            false,
                            paragraph.line_height(),
                        );
                        let mut paint = paint::Paint::default();
                        paint.set_color(skia::Color::TRANSPARENT);
                        style.set_foreground_paint(&paint);
                        style
                    } else {
                        let remove_alpha =
                            opaque || (use_shadow.unwrap_or(false) && !span.is_transparent());
                        span.to_style_with_paint(
                            &self.bounds(),
                            fallback_fonts,
                            remove_alpha,
                            paragraph.line_height(),
                            fill_layer,
                        )
                    }
                } else {
                    let remove_alpha =
                        opaque || (use_shadow.unwrap_or(false) && !span.is_transparent());
                    span.to_style_with_paint(
                        &self.bounds(),
                        fallback_fonts,
                        remove_alpha,
                        paragraph.line_height(),
                        fill_layer,
                    )
                };
                let text: String = span.apply_text_transform();
                if !text.is_empty() {
                    has_text = true;
                }
                builder.push_style(&text_style);
                add_text_with_tabs(&mut builder, &text, span.font_size);
            }
            if !has_text {
                builder.add_text(" ");
            }
            paragraph_group.push(vec![builder]);
        }

        paragraph_group
    }

    /// Performs an Auto Width text layout.
    fn text_layout_auto_width(&self) -> TextContentLayoutResult {
        // Left-aligned MAX-width pass: longest_line() is glyph width, not the huge container.
        let mut measure_builders = self.paragraph_builders(
            None,
            false,
            Some(skia::textlayout::TextAlign::Left),
            None,
            None,
            None,
        );

        let normalized_line_height =
            calculate_normalized_line_height(&mut measure_builders, f32::MAX);

        let measure_paragraphs =
            build_paragraphs_from_paragraph_builders(&mut measure_builders, f32::MAX);

        let content_width = measure_paragraphs
            .iter()
            .flatten()
            .fold(0.0_f32, |auto_width, paragraph| {
                f32::max(paragraph.longest_line(), auto_width)
            })
            .ceil();

        // Re-layout at the intrinsic width (without the HTML margin slack).
        let mut paragraph_builders = self.paragraph_builder_group_from_text(None);
        let paragraphs =
            build_paragraphs_from_paragraph_builders(&mut paragraph_builders, content_width);
        let height = paragraphs
            .iter()
            .flatten()
            .fold(0.0_f32, |auto_height, paragraph| {
                auto_height + paragraph.height()
            });

        let reported_width = content_width + PARAGRAPH_SET_MARGIN_RIGHT;
        let size = TextContentSize::new_with_normalized_line_height(
            reported_width,
            height.ceil(),
            reported_width,
            normalized_line_height,
        );
        TextContentLayoutResult(paragraph_builders, paragraphs, size)
    }

    /// Private function that performs
    /// Performs an Auto Height text layout.
    fn text_layout_auto_height(&self) -> TextContentLayoutResult {
        let width = self.width();
        let mut paragraph_builders = self.paragraph_builder_group_from_text(None);

        let normalized_line_height =
            calculate_normalized_line_height(&mut paragraph_builders, width);

        let paragraphs = build_paragraphs_from_paragraph_builders(&mut paragraph_builders, width);
        let height = paragraphs
            .iter()
            .flatten()
            .fold(0.0, |auto_height, paragraph| {
                auto_height + paragraph.height()
            });
        let size = TextContentSize::new_with_normalized_line_height(
            width,
            height.ceil(),
            DEFAULT_TEXT_CONTENT_SIZE,
            normalized_line_height,
        );
        TextContentLayoutResult(paragraph_builders, paragraphs, size)
    }

    /// Performs a Fixed text layout.
    fn text_layout_fixed(&self) -> TextContentLayoutResult {
        let width = self.width();
        let mut paragraph_builders = self.paragraph_builder_group_from_text(None);

        let normalized_line_height =
            calculate_normalized_line_height(&mut paragraph_builders, width);

        let paragraphs = build_paragraphs_from_paragraph_builders(&mut paragraph_builders, width);
        let paragraph_height = paragraphs
            .iter()
            .flatten()
            .fold(0.0, |auto_height, paragraph| {
                auto_height + paragraph.height()
            });

        let size = TextContentSize::new_with_normalized_line_height(
            width.ceil(),
            paragraph_height.ceil(),
            DEFAULT_TEXT_CONTENT_SIZE,
            normalized_line_height,
        );
        TextContentLayoutResult(paragraph_builders, paragraphs, size)
    }

    pub fn get_width(&self, width: f32) -> f32 {
        if self.grow_type() == GrowType::AutoWidth {
            self.size.width
        } else {
            width
        }
    }

    pub fn get_height(&self, width: f32) -> f32 {
        let mut paragraph_builders = self.paragraph_builder_group_from_text(None);
        let paragraphs = build_paragraphs_from_paragraph_builders(&mut paragraph_builders, width);
        let paragraph_height = paragraphs
            .iter()
            .flatten()
            .fold(0.0, |auto_height, paragraph| {
                auto_height + paragraph.height()
            });
        paragraph_height
    }

    pub fn needs_update_layout(&self) -> bool {
        self.layout.needs_update()
    }

    /// True when cached Skia paragraphs can be painted as-is (no rebuild/layout).
    pub fn has_usable_paint_layout(&self, shape: &Shape) -> bool {
        if self.layout.needs_update() || self.layout_version != self.content_version {
            return false;
        }
        self.layout_matches_paint_container(shape)
    }

    pub(crate) fn layout_cache_versions_match(&self) -> bool {
        !self.layout.needs_update() && self.layout_version == self.content_version
    }

    pub(crate) fn layout_matches_paint_container(&self, shape: &Shape) -> bool {
        if self.grow_type() == GrowType::AutoWidth {
            return true;
        }
        let Some(layout_w) = self.layout_width else {
            return false;
        };
        let container_w = self.get_width(shape.selrect().width());
        (layout_w - container_w).abs() < f32::EPSILON
    }

    /// True when any span requests underline/overline/line-through (custom draw path).
    pub fn has_text_decorations(&self) -> bool {
        self.paragraphs().iter().any(|paragraph| {
            paragraph.children().iter().any(|span| {
                matches!(
                    span.text_decoration,
                    Some(d) if d != skia::textlayout::TextDecoration::NO_DECORATION
                )
            })
        })
    }

    pub fn set_layout_from_result(
        &mut self,
        result: TextContentLayoutResult,
        default_width: f32,
        default_height: f32,
    ) {
        self.layout.set(result.0, result.1);
        self.size
            .copy_finite_size(result.2, default_width, default_height);
        // Absolute image/gradient shaders are built against `self.bounds()`, so the
        // origin matches them and `cached_layout_paint_offset` carries any rtl shift.
        self.layout_paint_origin = Some(Point::new(self.bounds.x(), self.bounds.y()));
    }

    pub fn force_next_layout_update(&mut self) {
        self.layout_width = None;
        self.layout_paint_origin = None;
        self.layout.cached_extrect.set(None);
        // Bump the content version so update_layout can't early-return: auto-width
        // shapes always match their container and clearing the cache above doesn't
        // flip needs_update(), so a late font resolution would otherwise be skipped.
        self.content_version = self.content_version.wrapping_add(1);
    }

    pub fn update_layout(&mut self, selrect: Rect) -> TextContentSize {
        // Keep bounds in sync before building paints so absolute fill shaders
        // match the container we are laying out for.
        self.set_xywh(selrect.x(), selrect.y(), selrect.width(), selrect.height());

        // Auto-width ignores selrect width so get-text-dimensions can reuse the cached layout.
        let layout_matches_container = self.grow_type() == GrowType::AutoWidth
            || self
                .layout_width
                .is_some_and(|w| (w - selrect.width()).abs() < f32::EPSILON);

        if !self.layout.needs_update()
            && self.layout_version == self.content_version
            && layout_matches_container
        {
            return self.size;
        }

        self.size.set_size(selrect.width(), selrect.height());

        match self.grow_type() {
            GrowType::AutoHeight => {
                let result = self.text_layout_auto_height();
                self.layout_width = Some(result.2.width);
                self.set_layout_from_result(result, selrect.width(), selrect.height());
            }
            GrowType::AutoWidth => {
                let result = self.text_layout_auto_width();
                self.layout_width = Some(result.2.width);
                self.set_layout_from_result(result, selrect.width(), selrect.height());
            }
            GrowType::Fixed => {
                let result = self.text_layout_fixed();
                self.layout_width = Some(result.2.width);
                self.set_layout_from_result(result, selrect.width(), selrect.height());
            }
        }

        if self.is_empty() {
            let (placeholder_width, placeholder_height) = self.placeholder_dimensions(selrect);
            self.size.width = placeholder_width;
            self.size.height = placeholder_height;
            self.size.max_width = placeholder_width;
        }

        self.layout_version = self.content_version;
        self.size
    }

    /// Return true when the content represents a freshly created empty text.
    /// We consider it empty only if there is exactly one paragraph with a single
    /// span whose text buffer is empty. Any additional paragraphs or characters
    /// mean the user has already entered content.
    fn is_empty(&self) -> bool {
        if self.paragraphs.len() != 1 {
            return false;
        }

        let paragraph = match self.paragraphs.first() {
            Some(paragraph) => paragraph,
            None => return true,
        };
        if paragraph.children().len() != 1 {
            return false;
        }

        let span = match paragraph.children().first() {
            Some(span) => span,
            None => return true,
        };

        span.text.is_empty()
    }

    /// Compute the placeholder size used while the text is still empty. We ask
    /// Skia to measure a single glyph using the span's typography so the editor
    /// shows a caret-sized box that reflects the selected font, size and spacing.
    /// If that fails we fall back to the previous WASM size or the incoming
    /// selrect dimensions.
    fn placeholder_dimensions(&self, selrect: Rect) -> (f32, f32) {
        if let Some(paragraph) = self.paragraphs.first() {
            if let Some(span) = paragraph.children().first() {
                let fonts = get_font_collection();
                let fallback_fonts = get_fallback_fonts();
                let paragraph_style = paragraph.paragraph_to_style();
                let mut builder = ParagraphBuilder::new(&paragraph_style, fonts);

                let text_style = span.to_style(
                    &self.bounds(),
                    fallback_fonts,
                    false,
                    paragraph.line_height(),
                );

                builder.push_style(&text_style);
                builder.add_text("0");

                let mut paragraph_layout = builder.build();
                paragraph_layout.layout(f32::MAX);

                let width = paragraph_layout.max_intrinsic_width();
                let height = paragraph_layout.height();

                return (width, height);
            }
        }

        let fallback_width = selrect.width().max(self.size.width);
        let fallback_height = selrect.height().max(self.size.height);

        (fallback_width, fallback_height)
    }

    #[allow(dead_code)]
    pub fn intersect_position_in_shape(&self, shape: &Shape, x_pos: f32, y_pos: f32) -> bool {
        let rect = shape.selrect;
        let mut matrix = Matrix::new_identity();
        let center = shape.center();
        let Some(inv_transform) = &shape.transform.invert() else {
            return false;
        };
        matrix.pre_translate(center);
        matrix.pre_concat(inv_transform);
        matrix.pre_translate(-center);

        let result = matrix.map_point((x_pos, y_pos));

        let x_pos = result.x;
        let y_pos = result.y;

        x_pos >= rect.x() && x_pos <= rect.right() && y_pos >= rect.y() && y_pos <= rect.bottom()
    }

    pub fn intersect_position_in_text(&self, shape: &Shape, x_pos: f32, y_pos: f32) -> bool {
        let rect = self.content_rect(&shape.selrect, shape.vertical_align);
        let mut matrix = Matrix::new_identity();
        let center = shape.center();
        let Some(inv_transform) = &shape.transform.invert() else {
            return false;
        };
        matrix.pre_translate(center);
        matrix.pre_concat(inv_transform);
        matrix.pre_translate(-center);

        let result = matrix.map_point((x_pos, y_pos));

        // Change coords to content space
        let x_pos = result.x - rect.x();
        let y_pos = result.y - rect.y();

        if !self.layout.paragraphs.is_empty() {
            // Reuse stored laid-out paragraphs
            paragraph_intersects(
                self.layout
                    .paragraphs
                    .iter()
                    .flat_map(|group| group.first()),
                x_pos,
                y_pos,
            )
        } else {
            let width = self.width();
            let mut paragraph_builders = self.paragraph_builder_group_from_text(None);
            let paragraphs =
                build_paragraphs_from_paragraph_builders(&mut paragraph_builders, width);

            paragraph_intersects(paragraphs.iter().flatten(), x_pos, y_pos)
        }
    }
}

impl Default for TextContent {
    fn default() -> Self {
        Self {
            paragraphs: vec![],
            bounds: Rect::default(),
            grow_type: GrowType::Fixed,
            size: TextContentSize::default(),
            layout: TextContentLayout::new(),
            content_version: 0,
            layout_version: 0,
            layout_width: None,
            layout_paint_origin: None,
        }
    }
}

pub type TextAlign = skia::textlayout::TextAlign;
pub type TextDirection = skia::textlayout::TextDirection;
pub type TextDecoration = skia::textlayout::TextDecoration;

#[derive(Debug, PartialEq, Clone, Copy)]
pub enum TextTransform {
    Lowercase,
    Uppercase,
    Capitalize,
}

// FIXME: Rethink this type. We'll probably need to move the serialization to the
// wasm module and store here meaningful model values (and/or skia type aliases)
#[derive(Debug, PartialEq, Clone)]
pub struct Paragraph {
    text_align: TextAlign,
    text_direction: TextDirection,
    text_decoration: Option<TextDecoration>,
    text_transform: Option<TextTransform>,
    line_height: f32,
    letter_spacing: f32,
    children: Vec<TextSpan>,
}

impl Default for Paragraph {
    fn default() -> Self {
        Self {
            text_align: TextAlign::default(),
            text_direction: TextDirection::LTR,
            text_decoration: None,
            text_transform: None,
            line_height: 1.0,
            letter_spacing: 0.0,
            children: vec![],
        }
    }
}

impl Paragraph {
    #[allow(clippy::too_many_arguments)]
    pub fn new(
        text_align: TextAlign,
        text_direction: TextDirection,
        text_decoration: Option<TextDecoration>,
        text_transform: Option<TextTransform>,
        line_height: f32,
        letter_spacing: f32,
        children: Vec<TextSpan>,
    ) -> Self {
        Self {
            text_align,
            text_direction,
            text_decoration,
            text_transform,
            line_height,
            letter_spacing,
            children,
        }
    }

    pub fn children(&self) -> &[TextSpan] {
        &self.children
    }

    pub fn children_mut(&mut self) -> &mut Vec<TextSpan> {
        &mut self.children
    }

    fn set_span_positions(&mut self, index: u32) {
        for (span_index, span) in self.children.iter_mut().enumerate() {
            span.set_position(index, span_index as u32);
        }
    }

    fn char_count(&self) -> usize {
        self.children
            .iter()
            .map(|span| span.text.chars().count())
            .sum()
    }

    /// Translate a character offset into the UTF-16 offset Skia indexes by.
    /// Both differ on astral-plane characters (emoji) and whenever a text
    /// transform changes the length of the laid out text (`ß` -> `SS`).
    pub fn char_offset_to_utf16(&self, char_offset: usize) -> usize {
        let mut remaining = char_offset;
        let mut utf16 = 0;
        for span in &self.children {
            if remaining == 0 {
                break;
            }
            let span_len = span.text.chars().count();
            let take = remaining.min(span_len);
            let prefix: String = span.text.chars().take(take).collect();
            utf16 += span.transform_text(&prefix).encode_utf16().count();
            remaining -= take;
        }
        utf16
    }

    /// Translate a UTF-16 offset coming from Skia into a character offset.
    /// An offset inside a character rounds up, so it never splits a glyph.
    pub fn utf16_offset_to_char(&self, utf16_offset: usize) -> usize {
        let (mut low, mut high) = (0, self.char_count());
        while low < high {
            let middle = (low + high) / 2;
            if self.char_offset_to_utf16(middle) < utf16_offset {
                low = middle + 1;
            } else {
                high = middle;
            }
        }
        low
    }

    /// UTF-16 length of the character at `char_offset`, so a caret range covers
    /// the whole glyph.
    pub fn char_utf16_len_at(&self, char_offset: usize) -> usize {
        self.char_offset_to_utf16(char_offset + 1) - self.char_offset_to_utf16(char_offset)
    }

    pub fn line_height(&self) -> f32 {
        self.line_height
    }

    pub fn letter_spacing(&self) -> f32 {
        self.letter_spacing
    }

    pub fn text_align(&self) -> TextAlign {
        self.text_align
    }

    pub fn text_direction(&self) -> TextDirection {
        self.text_direction
    }

    pub fn text_decoration(&self) -> Option<TextDecoration> {
        self.text_decoration
    }

    pub fn text_transform(&self) -> Option<TextTransform> {
        self.text_transform
    }

    pub fn paragraph_to_style(&self) -> ParagraphStyle {
        let mut style = ParagraphStyle::default();

        style.set_height(self.line_height);
        style.set_text_align(self.text_align);
        style.set_text_direction(self.text_direction);
        style.set_replace_tab_characters(false);
        style.set_apply_rounding_hack(true);
        style.set_text_height_behavior(skia::textlayout::TextHeightBehavior::All);
        style
    }

    pub fn scale_content(&mut self, value: f32) {
        self.letter_spacing *= value;
        self.children
            .iter_mut()
            .for_each(|l| l.scale_content(value));
    }
}

/// Capitalize the first letter of each word, preserving all original whitespace.
/// Matches CSS `text-transform: capitalize` behavior: a "word" starts after
/// any non-letter character (whitespace, punctuation, digits, symbols).
fn capitalize_words(text: &str) -> String {
    let mut result = String::with_capacity(text.len());
    let mut capitalize_next = true;
    for c in text.chars() {
        if c.is_alphabetic() {
            if capitalize_next {
                result.extend(c.to_uppercase());
            } else {
                result.push(c);
            }
            capitalize_next = false;
        } else {
            result.push(c);
            capitalize_next = true;
        }
    }
    result
}

/// Add `text`, pushing every '\t' as a one em wide placeholder.
pub fn add_text_with_tabs(builder: &mut ParagraphBuilder, text: &str, font_size: f32) {
    let tab = PlaceholderStyle::new(
        font_size,
        0.0,
        PlaceholderAlignment::Baseline,
        TextBaseline::Alphabetic,
        0.0,
    );

    for (index, segment) in text.split('\t').enumerate() {
        if index > 0 {
            builder.add_placeholder(&tab);
        }
        builder.add_text(segment);
    }
}

/// Filter control characters below U+0020, preserving tabs and line breaks.
/// Browser-dependent: Firefox drops them, others replace with space.
fn process_ignored_chars(text: &str, browser: u8) -> String {
    text.chars()
        .filter_map(|c| {
            if c == '\t' || c == '\n' || c == '\r' || c == '\u{2028}' || c == '\u{2029}' {
                return Some(c);
            }
            if c < '\u{0020}' {
                if browser == Browser::Firefox as u8 {
                    None
                } else {
                    Some(' ')
                }
            } else {
                Some(c)
            }
        })
        .collect()
}

#[derive(Debug, PartialEq, Clone)]
pub struct TextSpan {
    pub text: String,
    pub font_family: FontFamily,
    pub font_size: f32,
    pub line_height: f32,
    pub letter_spacing: f32,
    pub font_weight: i32,
    pub font_variant_id: Uuid,
    pub text_decoration: Option<TextDecoration>,
    pub text_transform: Option<TextTransform>,
    pub text_direction: TextDirection,
    pub fills: Vec<shapes::Fill>,
    pub paragraph_position: u32,
    pub span_position: u32,
}

impl TextSpan {
    /// Fill at `layer` counting from the bottom (`0` = last / bottommost fill).
    pub fn fills_from_bottom(&self, layer: usize) -> Option<&shapes::Fill> {
        if layer < self.fills.len() {
            Some(&self.fills[self.fills.len() - 1 - layer])
        } else {
            None
        }
    }

    #[allow(clippy::too_many_arguments)]
    pub fn new(
        text: String,
        font_family: FontFamily,
        font_size: f32,
        line_height: f32,
        letter_spacing: f32,
        text_decoration: Option<TextDecoration>,
        text_transform: Option<TextTransform>,
        text_direction: TextDirection,
        font_weight: i32,
        font_variant_id: Uuid,
        fills: Vec<shapes::Fill>,
    ) -> Self {
        Self {
            text,
            font_family,
            font_size,
            line_height,
            letter_spacing,
            text_decoration,
            text_transform,
            text_direction,
            font_weight,
            font_variant_id,
            fills,
            paragraph_position: u32::MAX,
            span_position: u32::MAX,
        }
    }

    pub fn set_text(&mut self, text: String) {
        self.text = text;
    }

    pub fn set_position(&mut self, paragraph: u32, span: u32) {
        self.paragraph_position = paragraph;
        self.span_position = span;
    }

    pub fn to_style(
        &self,
        content_bounds: &Rect,
        fallback_fonts: &HashSet<String>,
        remove_alpha: bool,
        paragraph_line_height: f32,
    ) -> skia::textlayout::TextStyle {
        self.to_style_with_paint(
            content_bounds,
            fallback_fonts,
            remove_alpha,
            paragraph_line_height,
            None,
        )
    }

    fn to_style_with_paint(
        &self,
        content_bounds: &Rect,
        fallback_fonts: &HashSet<String>,
        remove_alpha: bool,
        paragraph_line_height: f32,
        fill_layer_from_bottom: Option<usize>,
    ) -> skia::textlayout::TextStyle {
        let mut style = skia::textlayout::TextStyle::default();
        let paint = if remove_alpha {
            let mut paint = paint::Paint::default();
            paint.set_color(skia::Color::BLACK);
            paint.set_alpha(255);
            paint
        } else if let Some(layer) = fill_layer_from_bottom {
            if layer < self.fills.len() {
                let fill_idx = self.fills.len() - 1 - layer;
                self.fills[fill_idx].to_paint(content_bounds, true)
            } else {
                let mut paint = paint::Paint::default();
                paint.set_color(skia::Color::TRANSPARENT);
                paint
            }
        } else {
            merge_fills(&self.fills, *content_bounds)
        };

        let max_line_height = f32::max(paragraph_line_height, self.line_height);
        style.set_height(max_line_height);
        style.set_height_override(true);
        style.set_foreground_paint(&paint);
        style.set_decoration_type(match self.text_decoration {
            Some(text_decoration) => text_decoration,
            None => skia::textlayout::TextDecoration::NO_DECORATION,
        });

        // Trick to avoid showing the text decoration
        style.set_decoration_thickness_multiplier(0.0);

        let mut font_families = vec![
            self.serialized_font_family(),
            default_font(),
            DEFAULT_EMOJI_FONT.to_string(),
        ];

        font_families.extend(fallback_fonts.iter().cloned());
        style.set_font_families(&font_families);
        style.set_font_size(self.font_size);
        style.set_letter_spacing(self.letter_spacing);
        style.set_half_leading(true);

        style
    }

    pub fn to_stroke_style(
        &self,
        stroke_paint: &Paint,
        fallback_fonts: &HashSet<String>,
        remove_alpha: bool,
        paragraph_line_height: f32,
    ) -> skia::textlayout::TextStyle {
        let mut style = self.to_style(
            &Rect::default(),
            fallback_fonts,
            remove_alpha,
            paragraph_line_height,
        );
        if remove_alpha {
            let mut paint = skia::Paint::default();
            paint.set_style(stroke_paint.style());
            paint.set_stroke_width(stroke_paint.stroke_width());
            paint.set_color(skia::Color::BLACK);
            paint.set_alpha(255);
            style.set_foreground_paint(&paint);
        } else {
            style.set_foreground_paint(stroke_paint);
        }

        style.set_font_size(self.font_size);
        style.set_letter_spacing(self.letter_spacing);
        style.set_decoration_type(match self.text_decoration {
            Some(text_decoration) => text_decoration,
            None => skia::textlayout::TextDecoration::NO_DECORATION,
        });
        style
    }

    fn serialized_font_family(&self) -> String {
        format!("{}", self.font_family)
    }

    pub fn transform_text(&self, text: &str) -> String {
        let text = process_ignored_chars(text, crate::globals::current_browser());
        match self.text_transform {
            Some(TextTransform::Uppercase) => text.to_uppercase(),
            Some(TextTransform::Lowercase) => text.to_lowercase(),
            Some(TextTransform::Capitalize) => capitalize_words(&text),
            None => text,
        }
    }

    pub fn apply_text_transform(&self) -> String {
        self.transform_text(&self.text)
    }

    pub fn scale_content(&mut self, value: f32) {
        self.font_size *= value;
    }

    pub fn is_transparent(&self) -> bool {
        self.fills.iter().all(|fill| match fill {
            shapes::Fill::Solid(shapes::SolidColor(color)) => color.a() == 0,
            _ => false,
        })
    }
}

#[derive(Debug, Copy, Clone)]
pub struct PositionData {
    pub paragraph: u32,
    pub span: u32,
    pub start_pos: u32,
    pub end_pos: u32,
    pub x: f32,
    pub y: f32,
    pub width: f32,
    pub height: f32,
    pub direction: u32,
}

#[derive(Debug)]
pub struct ParagraphLayout {
    pub paragraph: skia::textlayout::Paragraph,
    pub x: f32,
    pub y: f32,
    pub decorations: Vec<TextDecorationSegment>,
}

#[derive(Debug)]
pub struct TextLayoutData {
    pub position_data: Vec<PositionData>,
    pub paragraphs: Vec<ParagraphLayout>,
}

fn direction_to_int(direction: TextDirection) -> u32 {
    match direction {
        TextDirection::RTL => 0,
        TextDirection::LTR => 1,
    }
}

pub fn calculate_text_layout_data(
    shape: &Shape,
    text_content: &TextContent,
    paragraph_builder_groups: &mut [ParagraphBuilderGroup],
    skip_position_data: bool,
) -> TextLayoutData {
    let selrect_width = shape.selrect().width();
    let text_width = text_content.get_width(selrect_width);
    let selrect_height = shape.selrect().height();
    let x = text_content.layout_origin_x(&shape.selrect, text_width);
    let base_y = shape.selrect.y();
    let mut position_data: Vec<PositionData> = Vec::new();
    let mut previous_line_height = text_content.normalized_line_height();
    let text_paragraphs = text_content.paragraphs();

    // 1. Build + layout each paragraph once, recording heights as we go.
    let mut paragraph_heights: Vec<f32> = Vec::new();
    let mut built_groups: Vec<Vec<skia::textlayout::Paragraph>> =
        Vec::with_capacity(paragraph_builder_groups.len());
    for paragraph_builder_group in paragraph_builder_groups.iter_mut() {
        let group_len = paragraph_builder_group.len();
        let mut paragraph_offset_y = previous_line_height;
        let mut group_paragraphs: Vec<skia::textlayout::Paragraph> = Vec::with_capacity(group_len);
        for (builder_index, paragraph_builder) in paragraph_builder_group.iter_mut().enumerate() {
            let mut skia_paragraph = paragraph_builder.build();
            skia_paragraph.layout(text_width);
            if builder_index == group_len - 1 {
                if skia_paragraph.get_line_metrics().is_empty() {
                    paragraph_offset_y = skia_paragraph.ideographic_baseline();
                } else {
                    paragraph_offset_y = skia_paragraph.height();
                }
            }
            if builder_index == 0 {
                paragraph_heights.push(skia_paragraph.height());
            }
            group_paragraphs.push(skia_paragraph);
        }
        previous_line_height = paragraph_offset_y;
        built_groups.push(group_paragraphs);
    }

    // 2. Position each built paragraph using the heights from step 1.
    let total_text_height: f32 = paragraph_heights.iter().sum();
    let vertical_offset =
        vertical_align_offset(selrect_height, total_text_height, shape.vertical_align());
    let mut paragraph_layouts: Vec<ParagraphLayout> = Vec::new();
    let mut y_accum = base_y + vertical_offset;
    for (i, group_paragraphs) in built_groups.into_iter().enumerate() {
        // For each paragraph in the group (e.g., fill, stroke, etc.)
        for skia_paragraph in group_paragraphs.into_iter() {
            let decorations = text_paragraphs
                .get(i)
                .map(|text_paragraph| {
                    decoration_segments(&skia_paragraph, text_paragraph, x, y_accum)
                })
                .unwrap_or_default();
            paragraph_layouts.push(ParagraphLayout {
                paragraph: skia_paragraph,
                x,
                y: y_accum,
                decorations,
            });
        }
        y_accum += paragraph_heights[i];
    }

    // Calculate position data from paragraph_layouts
    if !skip_position_data {
        for (paragraph_index, para_layout) in paragraph_layouts.iter().enumerate() {
            let current_y = para_layout.y;
            let text_paragraph = text_paragraphs.get(paragraph_index);
            if let Some(text_para) = text_paragraph {
                let mut span_ranges: Vec<(usize, usize, usize)> = vec![];
                let mut cur = 0;
                for (span_index, span) in text_para.children().iter().enumerate() {
                    let text: String = span.apply_text_transform();
                    let text_len = text.encode_utf16().count();
                    span_ranges.push((cur, cur + text_len, span_index));
                    cur += text_len;
                }
                for (start, end, span_index) in span_ranges {
                    let rects = para_layout.paragraph.get_rects_for_range(
                        start..end,
                        RectHeightStyle::Tight,
                        RectWidthStyle::Tight,
                    );

                    for textbox in rects {
                        let direction = textbox.direct;
                        let mut rect = textbox.rect;
                        let cy = rect.top + rect.height() / 2.0;

                        // Get byte positions from Skia's transformed text layout
                        let start_pos = para_layout
                            .paragraph
                            .get_glyph_position_at_coordinate((rect.left + 0.1, cy))
                            .position as usize
                            - start;

                        let end_pos = para_layout
                            .paragraph
                            .get_glyph_position_at_coordinate((rect.right - 0.1, cy))
                            .position as usize
                            - start;

                        rect.offset((x, current_y));
                        position_data.push(PositionData {
                            paragraph: paragraph_index as u32,
                            span: span_index as u32,
                            start_pos: start_pos as u32,
                            end_pos: end_pos as u32,
                            x: rect.x(),
                            y: rect.y(),
                            width: rect.width(),
                            height: rect.height(),
                            direction: direction_to_int(direction),
                        });
                    }
                }
            }
        }
    }

    TextLayoutData {
        position_data,
        paragraphs: paragraph_layouts,
    }
}

pub fn calculate_position_data(
    shape: &Shape,
    text_content: &TextContent,
    skip_position_data: bool,
) -> Vec<PositionData> {
    let mut text_content = text_content.clone();
    text_content.update_layout(shape.selrect);

    let mut paragraph_builders = text_content.paragraph_builder_group_from_text(None);
    let layout_info = calculate_text_layout_data(
        shape,
        &text_content,
        &mut paragraph_builders,
        skip_position_data,
    );

    layout_info.position_data
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn vertical_align_top_keeps_the_content_at_the_origin() {
        assert_eq!(vertical_align_offset(200.0, 60.0, VerticalAlign::Top), 0.0);
    }

    #[test]
    fn vertical_align_center_takes_half_the_slack() {
        assert_eq!(
            vertical_align_offset(200.0, 60.0, VerticalAlign::Center),
            70.0
        );
    }

    #[test]
    fn vertical_align_bottom_takes_all_the_slack() {
        assert_eq!(
            vertical_align_offset(200.0, 60.0, VerticalAlign::Bottom),
            140.0
        );
    }

    #[test]
    fn vertical_align_offset_is_negative_when_content_overflows() {
        assert_eq!(
            vertical_align_offset(60.0, 200.0, VerticalAlign::Center),
            -70.0
        );
        assert_eq!(
            vertical_align_offset(60.0, 200.0, VerticalAlign::Bottom),
            -140.0
        );
    }

    #[test]
    fn capitalize_basic_words() {
        assert_eq!(capitalize_words("hello world"), "Hello World");
    }

    #[test]
    fn capitalize_preserves_leading_whitespace() {
        assert_eq!(capitalize_words(" hello"), " Hello");
    }

    #[test]
    fn capitalize_preserves_trailing_whitespace() {
        assert_eq!(capitalize_words("hello "), "Hello ");
    }

    #[test]
    fn capitalize_preserves_multiple_spaces() {
        assert_eq!(capitalize_words("hello  world"), "Hello  World");
    }

    #[test]
    fn capitalize_whitespace_only() {
        assert_eq!(capitalize_words(" "), " ");
        assert_eq!(capitalize_words("  "), "  ");
    }

    #[test]
    fn capitalize_empty_string() {
        assert_eq!(capitalize_words(""), "");
    }

    #[test]
    fn capitalize_single_char() {
        assert_eq!(capitalize_words("a"), "A");
    }

    #[test]
    fn capitalize_already_uppercase() {
        assert_eq!(capitalize_words("HELLO WORLD"), "HELLO WORLD");
    }

    #[test]
    fn capitalize_preserves_tabs_and_newlines() {
        assert_eq!(capitalize_words("hello\tworld"), "Hello\tWorld");
        assert_eq!(capitalize_words("hello\nworld"), "Hello\nWorld");
    }

    #[test]
    fn capitalize_after_punctuation() {
        assert_eq!(capitalize_words("(readonly)"), "(Readonly)");
        assert_eq!(capitalize_words("hello-world"), "Hello-World");
        assert_eq!(capitalize_words("one/two/three"), "One/Two/Three");
    }

    #[test]
    fn capitalize_after_digits() {
        assert_eq!(capitalize_words("item1name"), "Item1Name");
    }

    #[test]
    fn process_ignored_chars_preserves_spaces() {
        assert_eq!(process_ignored_chars("hello world", 0), "hello world");
    }

    #[test]
    fn process_ignored_chars_preserves_line_breaks() {
        assert_eq!(process_ignored_chars("hello\nworld", 0), "hello\nworld");
        assert_eq!(process_ignored_chars("hello\rworld", 0), "hello\rworld");
    }

    #[test]
    fn process_ignored_chars_preserves_tabs() {
        assert_eq!(process_ignored_chars("hello\tworld", 0), "hello\tworld");
        assert_eq!(
            process_ignored_chars("hello\tworld", Browser::Firefox as u8),
            "hello\tworld"
        );
    }

    #[test]
    fn process_ignored_chars_replaces_control_chars_chrome() {
        // U+0001 (SOH) should become space in non-Firefox
        assert_eq!(
            process_ignored_chars("a\x01b", Browser::Chrome as u8),
            "a b"
        );
    }

    #[test]
    fn process_ignored_chars_removes_control_chars_firefox() {
        assert_eq!(
            process_ignored_chars("a\x01b", Browser::Firefox as u8),
            "ab"
        );
    }

    fn test_paragraph(texts: &[&str]) -> Paragraph {
        let spans = texts
            .iter()
            .map(|text| {
                TextSpan::new(
                    text.to_string(),
                    FontFamily::new(Uuid::nil(), 400, crate::shapes::FontStyle::Normal),
                    14.0,
                    1.2,
                    0.0,
                    None,
                    None,
                    TextDirection::LTR,
                    400,
                    Uuid::nil(),
                    vec![],
                )
            })
            .collect();

        Paragraph::new(
            TextAlign::Left,
            TextDirection::LTR,
            None,
            None,
            1.2,
            0.0,
            spans,
        )
    }

    #[test]
    fn char_offsets_match_utf16_offsets_for_bmp_text() {
        let para = test_paragraph(&["Añadir"]);
        for offset in 0..=6 {
            assert_eq!(para.char_offset_to_utf16(offset), offset);
            assert_eq!(para.utf16_offset_to_char(offset), offset);
        }
    }

    #[test]
    fn char_offsets_account_for_astral_characters() {
        let para = test_paragraph(&["a", "😀b"]);

        assert_eq!(para.char_offset_to_utf16(0), 0);
        assert_eq!(para.char_offset_to_utf16(1), 1);
        assert_eq!(para.char_offset_to_utf16(2), 3);
        assert_eq!(para.char_offset_to_utf16(3), 4);

        assert_eq!(para.utf16_offset_to_char(0), 0);
        assert_eq!(para.utf16_offset_to_char(1), 1);
        assert_eq!(para.utf16_offset_to_char(3), 2);
        assert_eq!(para.utf16_offset_to_char(4), 3);
    }

    #[test]
    fn utf16_offset_inside_a_surrogate_pair_rounds_to_a_char_boundary() {
        let para = test_paragraph(&["a😀b"]);
        assert_eq!(para.utf16_offset_to_char(2), 2);
    }

    #[test]
    fn char_offsets_account_for_text_transforms() {
        // Skia lays out the transformed text, where "Straße" is "STRASSE".
        let mut para = test_paragraph(&["Straße"]);
        para.children_mut()[0].text_transform = Some(TextTransform::Uppercase);

        assert_eq!(para.char_offset_to_utf16(4), 4);
        assert_eq!(para.char_offset_to_utf16(6), 7);
        assert_eq!(para.char_utf16_len_at(4), 2);
        assert_eq!(para.utf16_offset_to_char(7), 6);
    }

    #[test]
    fn char_utf16_len_at_covers_the_whole_glyph() {
        let para = test_paragraph(&["a😀b"]);
        assert_eq!(para.char_utf16_len_at(0), 1);
        assert_eq!(para.char_utf16_len_at(1), 2);
        assert_eq!(para.char_utf16_len_at(2), 1);
    }

    fn sample_text_content() -> TextContent {
        let bounds = Rect::from_xywh(0.0, 0.0, 200.0, 100.0);
        let mut content = TextContent::new(bounds, GrowType::Fixed);
        content.add_paragraph(test_paragraph(&["hello"]));
        content
    }

    #[test]
    fn has_usable_paint_layout_false_when_paragraphs_empty() {
        let content = TextContent::new(Rect::from_xywh(0.0, 0.0, 100.0, 50.0), GrowType::Fixed);
        let shape = Shape::new(Uuid::nil());
        assert!(!content.has_usable_paint_layout(&shape));
    }

    #[test]
    fn has_usable_paint_layout_false_when_versions_mismatch() {
        let mut content = sample_text_content();
        content.layout.paragraphs = Rc::new(vec![vec![]]);
        content.layout_width = Some(200.0);
        content.layout_version = 1;
        content.content_version = 2;
        let mut shape = Shape::new(Uuid::nil());
        shape.set_selrect(0.0, 0.0, 200.0, 100.0);
        assert!(!content.has_usable_paint_layout(&shape));
    }

    #[test]
    fn has_usable_paint_layout_true_when_cached_and_versions_match() {
        let mut content = sample_text_content();
        content.layout.paragraphs = Rc::new(vec![vec![]]);
        content.layout_width = Some(200.0);
        content.layout_version = 3;
        content.content_version = 3;
        let mut shape = Shape::new(Uuid::nil());
        shape.set_selrect(0.0, 0.0, 200.0, 100.0);
        assert!(content.has_usable_paint_layout(&shape));
    }

    #[test]
    fn has_usable_paint_layout_false_when_selrect_width_changed() {
        let mut content = sample_text_content();
        content.layout.paragraphs = Rc::new(vec![vec![]]);
        content.layout_width = Some(200.0);
        content.layout_version = 3;
        content.content_version = 3;
        let mut shape = Shape::new(Uuid::nil());
        shape.set_selrect(0.0, 0.0, 300.0, 100.0);
        assert!(!content.has_usable_paint_layout(&shape));
    }

    fn text_shape_with_cached_layout(content: TextContent) -> Shape {
        let mut shape = Shape::new(Uuid::nil());
        shape.set_shape_type(shapes::Type::Text(content));
        shape.set_selrect(0.0, 0.0, 200.0, 100.0);
        shape
    }

    #[test]
    fn has_usable_paint_layout_false_when_rotated_and_resized() {
        let mut content = sample_text_content();
        content.layout.paragraphs = Rc::new(vec![vec![]]);
        content.layout_width = Some(200.0);
        content.layout_version = 3;
        content.content_version = 3;
        let base_shape = text_shape_with_cached_layout(content);
        let rotate = Matrix::rotate_deg(45.0);
        let resize = Matrix::scale((1.5, 1.0));
        let mut modifier = rotate;
        modifier.pre_concat(&resize);
        assert!(modifier_changes_text_layout(&base_shape, &modifier));
    }

    #[test]
    fn has_text_decorations_detects_underline() {
        let mut content = sample_text_content();
        content.paragraphs_mut()[0].children_mut()[0].text_decoration =
            Some(skia::textlayout::TextDecoration::UNDERLINE);
        assert!(content.has_text_decorations());
    }

    #[test]
    fn has_text_decorations_false_for_plain_text() {
        let content = sample_text_content();
        assert!(!content.has_text_decorations());
    }

    #[test]
    fn paint_content_for_selrect_borrows_when_bounds_match() {
        let content = sample_text_content();
        let selrect = Rect::from_xywh(10.0, 20.0, 200.0, 100.0);
        match content.paint_content_for_selrect(selrect) {
            Cow::Borrowed(_) => {}
            Cow::Owned(_) => panic!("expected borrowed content"),
        }
    }

    #[test]
    fn paint_content_for_selrect_rebounds_when_size_differs() {
        let content = sample_text_content();
        let selrect = Rect::from_xywh(0.0, 0.0, 300.0, 100.0);
        match content.paint_content_for_selrect(selrect) {
            Cow::Owned(rebound) => {
                assert_eq!(rebound.bounds().width(), 300.0);
                assert!(rebound.layout.needs_update());
            }
            Cow::Borrowed(_) => panic!("expected rebound content"),
        }
    }

    #[test]
    fn layout_paint_origin_set_when_layout_result_applied() {
        let mut content = sample_text_content();
        content.set_xywh(40.0, 60.0, 200.0, 100.0);
        let empty =
            TextContentLayoutResult(vec![], vec![], TextContentSize::new_with_size(200.0, 100.0));
        content.set_layout_from_result(empty, 200.0, 100.0);
        let selrect = Rect::from_xywh(40.0, 60.0, 200.0, 100.0);
        assert_eq!(
            content.cached_layout_paint_anchor(&selrect),
            Point::new(40.0, 60.0)
        );
        assert_eq!(
            content.cached_layout_paint_offset(&selrect),
            Point::new(0.0, 0.0)
        );
    }

    #[test]
    fn cached_layout_paint_offset_tracks_selrect_move() {
        let mut content = sample_text_content();
        content.layout_paint_origin = Some(Point::new(10.0, 20.0));
        // Simulate a move clone: bounds follow the new selrect, origin stays.
        content.set_xywh(110.0, 220.0, 200.0, 100.0);
        let selrect = Rect::from_xywh(110.0, 220.0, 200.0, 100.0);
        let offset = content.cached_layout_paint_offset(&selrect);
        assert_eq!(offset, Point::new(100.0, 200.0));
        assert_eq!(
            content.cached_layout_paint_anchor(&selrect),
            Point::new(10.0, 20.0)
        );
    }

    #[test]
    fn cached_layout_paint_offset_zero_without_origin() {
        let content = sample_text_content();
        let selrect = Rect::from_xywh(50.0, 75.0, 200.0, 100.0);
        assert_eq!(
            content.cached_layout_paint_offset(&selrect),
            Point::new(0.0, 0.0)
        );
        assert_eq!(
            content.cached_layout_paint_anchor(&selrect),
            Point::new(50.0, 75.0)
        );
    }

    #[test]
    fn layout_paint_origin_survives_bounds_transform_on_clone() {
        let mut content = sample_text_content();
        content.set_xywh(10.0, 20.0, 200.0, 100.0);
        content.layout_paint_origin = Some(Point::new(10.0, 20.0));
        content.layout.paragraphs = Rc::new(vec![vec![]]);
        content.layout_width = Some(200.0);
        content.layout_version = 1;
        content.content_version = 1;

        let mut moved = content.clone();
        let mut move_matrix = Matrix::new_identity();
        move_matrix.set_translate_x(50.0);
        move_matrix.set_translate_y(30.0);
        moved.transform(&move_matrix);

        assert_eq!(moved.bounds().x(), 60.0);
        assert_eq!(moved.bounds().y(), 50.0);
        assert!(Rc::ptr_eq(
            &content.layout.paragraphs,
            &moved.layout.paragraphs
        ));
        let selrect = Rect::from_xywh(60.0, 50.0, 200.0, 100.0);
        assert_eq!(
            moved.cached_layout_paint_anchor(&selrect),
            Point::new(10.0, 20.0)
        );
        assert_eq!(
            moved.cached_layout_paint_offset(&selrect),
            Point::new(50.0, 30.0)
        );
    }

    #[test]
    fn layout_clone_shares_skia_paragraphs() {
        let mut layout = TextContentLayout::new();
        layout.paragraphs = Rc::new(vec![vec![]]);
        let cloned = layout.clone();
        assert!(Rc::ptr_eq(&layout.paragraphs, &cloned.paragraphs));
        assert!(cloned.paragraph_builders.is_empty());
    }

    #[test]
    fn layout_clear_empties_paragraphs() {
        let mut layout = TextContentLayout::new();
        layout.paragraphs = Rc::new(vec![vec![]]);
        layout.clear();
        assert!(layout.needs_update());
    }

    // -----------------------------------------------------------------------
    // RTL auto-width growth anchor
    // -----------------------------------------------------------------------

    fn directed_paragraph(direction: TextDirection) -> Paragraph {
        let span = TextSpan::new(
            "hello".to_string(),
            FontFamily::new(Uuid::nil(), 400, crate::shapes::FontStyle::Normal),
            14.0,
            1.2,
            0.0,
            None,
            None,
            direction,
            400,
            Uuid::nil(),
            vec![],
        );
        Paragraph::new(TextAlign::Left, direction, None, None, 1.2, 0.0, vec![span])
    }

    /// Auto-width content measured wider than its stale selrect: mid-edit, where
    /// the anchor is observable.
    fn grown_content(directions: &[TextDirection], measured_width: f32) -> TextContent {
        let bounds = Rect::from_xywh(100.0, 50.0, 60.0, 20.0);
        let mut content = TextContent::new(bounds, GrowType::AutoWidth);
        for direction in directions {
            content.add_paragraph(directed_paragraph(*direction));
        }
        content.size.width = measured_width;
        content.size.height = 20.0;
        content
    }

    #[test]
    fn is_rtl_false_when_no_paragraphs() {
        let content = TextContent::new(Rect::from_xywh(0.0, 0.0, 10.0, 10.0), GrowType::AutoWidth);
        assert!(!content.is_rtl());
    }

    #[test]
    fn is_rtl_true_when_every_paragraph_is_rtl() {
        let content = grown_content(&[TextDirection::RTL, TextDirection::RTL], 120.0);
        assert!(content.is_rtl());
    }

    #[test]
    fn is_rtl_false_when_directions_are_mixed() {
        let content = grown_content(&[TextDirection::RTL, TextDirection::LTR], 120.0);
        assert!(!content.is_rtl());
    }

    #[test]
    fn is_rtl_false_when_every_paragraph_is_ltr() {
        let content = grown_content(&[TextDirection::LTR], 120.0);
        assert!(!content.is_rtl());
    }

    #[test]
    fn layout_origin_x_right_anchors_rtl_auto_width() {
        let content = grown_content(&[TextDirection::RTL], 120.0);
        let selrect = Rect::from_xywh(100.0, 50.0, 60.0, 20.0);
        // right edge (160) minus the measured width (120)
        assert_eq!(content.layout_origin_x(&selrect, 120.0), 40.0);
    }

    #[test]
    fn layout_origin_x_left_anchors_ltr_auto_width() {
        let content = grown_content(&[TextDirection::LTR], 120.0);
        let selrect = Rect::from_xywh(100.0, 50.0, 60.0, 20.0);
        assert_eq!(content.layout_origin_x(&selrect, 120.0), 100.0);
    }

    #[test]
    fn layout_origin_x_left_anchors_mixed_direction_auto_width() {
        let content = grown_content(&[TextDirection::RTL, TextDirection::LTR], 120.0);
        let selrect = Rect::from_xywh(100.0, 50.0, 60.0, 20.0);
        assert_eq!(content.layout_origin_x(&selrect, 120.0), 100.0);
    }

    #[test]
    fn layout_origin_x_ignores_direction_for_fixed_and_auto_height() {
        let selrect = Rect::from_xywh(100.0, 50.0, 60.0, 20.0);
        for grow_type in [GrowType::Fixed, GrowType::AutoHeight] {
            let mut content = grown_content(&[TextDirection::RTL], 120.0);
            content.set_grow_type(grow_type);
            assert_eq!(content.layout_origin_x(&selrect, 120.0), 100.0);
        }
    }

    #[test]
    fn layout_origin_x_is_selrect_x_once_the_selrect_is_committed() {
        let content = grown_content(&[TextDirection::RTL], 60.0);
        let selrect = Rect::from_xywh(100.0, 50.0, 60.0, 20.0);
        assert_eq!(content.layout_origin_x(&selrect, 60.0), selrect.x());
    }

    #[test]
    fn content_rect_right_anchors_grown_rtl_auto_width() {
        let content = grown_content(&[TextDirection::RTL], 120.0);
        let selrect = Rect::from_xywh(100.0, 50.0, 60.0, 20.0);
        let rect = content.content_rect(&selrect, VerticalAlign::Top);
        assert_eq!(rect.x(), 40.0);
        assert_eq!(rect.right(), selrect.right());
        assert_eq!(rect.width(), 120.0);
        assert_eq!(rect.y(), selrect.y());
    }

    #[test]
    fn content_rect_left_anchors_grown_ltr_auto_width() {
        let content = grown_content(&[TextDirection::LTR], 120.0);
        let selrect = Rect::from_xywh(100.0, 50.0, 60.0, 20.0);
        let rect = content.content_rect(&selrect, VerticalAlign::Top);
        assert_eq!(rect.x(), selrect.x());
        assert_eq!(rect.width(), 120.0);
    }

    #[test]
    fn content_rect_unchanged_for_fixed_rtl_content() {
        // A mismatch sends `content_rect` into `get_height`, which needs global
        // font state tests do not have.
        let mut content = grown_content(&[TextDirection::RTL], 60.0);
        content.set_grow_type(GrowType::Fixed);
        let selrect = Rect::from_xywh(100.0, 50.0, 60.0, 20.0);
        let rect = content.content_rect(&selrect, VerticalAlign::Top);
        assert_eq!(rect.x(), selrect.x());
        assert_eq!(rect.width(), selrect.width());
    }

    #[test]
    fn cached_paint_anchor_plus_offset_lands_on_the_layout_origin() {
        let mut content = grown_content(&[TextDirection::RTL], 120.0);
        content.layout_paint_origin = Some(Point::new(100.0, 50.0));
        let selrect = Rect::from_xywh(100.0, 50.0, 60.0, 20.0);
        let anchor = content.cached_layout_paint_anchor(&selrect);
        let offset = content.cached_layout_paint_offset(&selrect);
        assert_eq!(
            anchor.x + offset.x,
            content.layout_origin_x(&selrect, 120.0)
        );
    }

    #[test]
    fn cached_paint_offset_stays_a_pure_translation_when_the_shape_moves() {
        let mut content = grown_content(&[TextDirection::RTL], 120.0);
        content.layout_paint_origin = Some(Point::new(100.0, 50.0));
        let before = Rect::from_xywh(100.0, 50.0, 60.0, 20.0);
        let after = Rect::from_xywh(130.0, 70.0, 60.0, 20.0);
        let moved_by = Point::new(
            content.cached_layout_paint_offset(&after).x
                - content.cached_layout_paint_offset(&before).x,
            content.cached_layout_paint_offset(&after).y
                - content.cached_layout_paint_offset(&before).y,
        );
        assert_eq!(moved_by, Point::new(30.0, 20.0));
    }

    #[test]
    fn cached_paint_anchor_right_anchors_when_no_origin_was_baked() {
        let content = grown_content(&[TextDirection::RTL], 120.0);
        let selrect = Rect::from_xywh(100.0, 50.0, 60.0, 20.0);
        assert_eq!(content.layout_paint_origin, None);
        assert_eq!(content.cached_layout_paint_anchor(&selrect).x, 40.0);
        assert_eq!(content.cached_layout_paint_offset(&selrect).x, 0.0);
    }
}