;; This Source Code Form is subject to the terms of the Mozilla Public
;; License, v. 2.0. If a copy of the MPL was not distributed with this
;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
;;
;; Copyright (c) KALEIDOS INC

(ns app.main.data.workspace.wasm-text
  "Helpers/events to resize wasm text shapes without depending on workspace.texts.

  This exists to avoid circular deps:
  workspace.texts -> workspace.libraries -> workspace.texts"
  (:require
   [app.common.data.macros :as dm]
   [app.common.files.helpers :as cfh]
   [app.common.geom.matrix :as gmt]
   [app.common.geom.point :as gpt]
   [app.common.types.modifiers :as ctm]
   [app.main.data.helpers :as dsh]
   [app.main.data.workspace.modifiers :as dwm]
   [app.render-wasm.api :as wasm.api]
   [app.render-wasm.api.fonts :as wasm.fonts]
   [beicon.v2.core :as rx]
   [potok.v2.core :as ptk]))

(defn resize-wasm-text-modifiers
  ([shape]
   (resize-wasm-text-modifiers shape (:content shape)))

  ([{:keys [id points selrect grow-type] :as shape} content]
   (wasm.api/use-shape id)
   (wasm.api/set-shape-text-content id content)
   (wasm.api/set-shape-text-images id content)

   (let [dimension (wasm.api/get-text-dimensions)
         width-scale (if (#{:fixed :auto-height} grow-type)
                       1.0
                       (/ (:width dimension) (:width selrect)))
         height-scale (if (= :fixed grow-type)
                        1.0
                        (/ (:height dimension) (:height selrect)))
         resize-v  (gpt/point width-scale height-scale)
         origin    (first points)]

     {id
      {:modifiers
       (ctm/resize-modifiers
        resize-v
        origin
        (:transform shape (gmt/matrix))
        (:transform-inverse shape (gmt/matrix)))}})))

(defn resize-wasm-text
  "Resize a single text shape (auto-width/auto-height) by id.
  No-op if the id is not a text shape or is :fixed."
  [id]
  (ptk/reify ::resize-wasm-text
    ptk/WatchEvent
    (watch [_ state _]
      (let [objects (dsh/lookup-page-objects state)
            shape   (get objects id)]
        (if (and (some? shape)
                 (cfh/text-shape? shape)
                 (not= :fixed (:grow-type shape)))
          (rx/of (dwm/apply-wasm-modifiers (resize-wasm-text-modifiers shape)))
          (rx/empty))))))

(defn resize-wasm-text-debounce-commit
  []
  (ptk/reify ::resize-wasm-text-debounce-commit
    ptk/WatchEvent
    (watch [_ state _]
      (let [ids (get state ::resize-wasm-text-debounce-ids)
            objects (dsh/lookup-page-objects state)

            modifiers
            (reduce
             (fn [modifiers id]
               (let [shape (get objects id)]
                 (cond-> modifiers
                   (and (some? shape)
                        (cfh/text-shape? shape)
                        (not= :fixed (:grow-type shape)))
                   (merge (resize-wasm-text-modifiers shape)))))
             {}
             ids)]
        (if (not (empty? modifiers))
          (rx/of (dwm/apply-wasm-modifiers modifiers))
          (rx/empty))))))

;; This event will debounce the resize events so, if there are many, they
;; are processed at the same time and not one-by-one. This will improve
;; performance because it's better to make only one layout calculation instead
;; of (potentialy) hundreds.
(defn resize-wasm-text-debounce-inner
  [id]
  (let [cur-event (js/Symbol)]
    (ptk/reify ::resize-wasm-text-debounce-inner
      ptk/UpdateEvent
      (update [_ state]
        (-> state
            (update ::resize-wasm-text-debounce-ids (fnil conj []) id)
            (cond-> (nil? (::resize-wasm-text-debounce-event state))
              (assoc ::resize-wasm-text-debounce-event cur-event))))

      ptk/WatchEvent
      (watch [_ state stream]
        (if (= (::resize-wasm-text-debounce-event state) cur-event)
          (let [stopper (->> stream (rx/filter (ptk/type? :app.main.data.workspace/finalize)))]
            (rx/concat
             (rx/merge
              (->> stream
                   (rx/filter (ptk/type? ::resize-wasm-text-debounce-inner))
                   (rx/debounce 40)
                   (rx/take 1)
                   (rx/map #(resize-wasm-text-debounce-commit))
                   (rx/take-until stopper))
              (rx/of (resize-wasm-text-debounce-inner id)))
             (rx/of #(dissoc %
                             ::resize-wasm-text-debounce-ids
                             ::resize-wasm-text-debounce-event))))
          (rx/empty))))))

(defn resize-wasm-text-debounce
  [id]
  (ptk/reify ::resize-wasm-text-debounce
    ptk/WatchEvent
    (watch [_ state _]
      (let [page-id (:current-page-id state)
            objects (dsh/lookup-page-objects state page-id)
            content (dm/get-in objects [id :content])
            fonts   (wasm.fonts/get-content-fonts content)

            fonts-loaded?
            (->> fonts
                 (every?
                  (fn [font]
                    (let [font-data (wasm.fonts/make-font-data font)]
                      (wasm.fonts/font-stored? font-data (:emoji? font-data))))))]

        (if (not fonts-loaded?)
          (->> (rx/of (resize-wasm-text-debounce id))
               (rx/delay 20))
          (rx/of (resize-wasm-text-debounce-inner id)))))))

(defn resize-wasm-text-all
  "Resize all text shapes (auto-width/auto-height) from a collection of ids."
  [ids]
  (ptk/reify ::resize-wasm-text-all
    ptk/WatchEvent
    (watch [_ _ _]
      (->> (rx/from ids)
           (rx/map resize-wasm-text)))))