"""Upload router for handling file uploads."""

import logging
import os
from pathlib import Path

from fastapi import APIRouter, File, HTTPException, UploadFile
from pydantic import BaseModel

from src.agents.middlewares.thread_data_middleware import THREAD_DATA_BASE_DIR

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api/threads/{thread_id}/uploads", tags=["uploads"])

# File extensions that should be converted to markdown
CONVERTIBLE_EXTENSIONS = {
    ".pdf",
    ".ppt",
    ".pptx",
    ".xls",
    ".xlsx",
    ".doc",
    ".docx",
}


class UploadResponse(BaseModel):
    """Response model for file upload."""

    success: bool
    files: list[dict[str, str]]
    message: str


def get_uploads_dir(thread_id: str) -> Path:
    """Get the uploads directory for a thread.

    Args:
        thread_id: The thread ID.

    Returns:
        Path to the uploads directory.
    """
    base_dir = Path(os.getcwd()) / THREAD_DATA_BASE_DIR / thread_id / "user-data" / "uploads"
    base_dir.mkdir(parents=True, exist_ok=True)
    return base_dir


async def convert_file_to_markdown(file_path: Path) -> Path | None:
    """Convert a file to markdown using markitdown.

    Args:
        file_path: Path to the file to convert.

    Returns:
        Path to the markdown file if conversion was successful, None otherwise.
    """
    try:
        from markitdown import MarkItDown

        md = MarkItDown()
        result = md.convert(str(file_path))

        # Save as .md file with same name
        md_path = file_path.with_suffix(".md")
        md_path.write_text(result.text_content, encoding="utf-8")

        logger.info(f"Converted {file_path.name} to markdown: {md_path.name}")
        return md_path
    except Exception as e:
        logger.error(f"Failed to convert {file_path.name} to markdown: {e}")
        return None


@router.post("", response_model=UploadResponse)
async def upload_files(
    thread_id: str,
    files: list[UploadFile] = File(...),
) -> UploadResponse:
    """Upload multiple files to a thread's uploads directory.

    For PDF, PPT, Excel, and Word files, they will be converted to markdown using markitdown.
    All files (original and converted) are saved to /mnt/user-data/uploads.

    Args:
        thread_id: The thread ID to upload files to.
        files: List of files to upload.

    Returns:
        Upload response with success status and file information.
    """
    if not files:
        raise HTTPException(status_code=400, detail="No files provided")

    uploads_dir = get_uploads_dir(thread_id)
    uploaded_files = []

    for file in files:
        if not file.filename:
            continue

        try:
            # Save the original file
            file_path = uploads_dir / file.filename
            content = await file.read()
            file_path.write_bytes(content)

            # Build relative path from backend root
            relative_path = f".deer-flow/threads/{thread_id}/user-data/uploads/{file.filename}"

            file_info = {
                "filename": file.filename,
                "size": str(len(content)),
                "path": relative_path,  # Actual filesystem path (relative to backend/)
                "virtual_path": f"/mnt/user-data/uploads/{file.filename}",  # Path for Agent in sandbox
                "artifact_url": f"/api/threads/{thread_id}/artifacts/mnt/user-data/uploads/{file.filename}",  # HTTP URL
            }

            logger.info(f"Saved file: {file.filename} ({len(content)} bytes) to {relative_path}")

            # Check if file should be converted to markdown
            file_ext = file_path.suffix.lower()
            if file_ext in CONVERTIBLE_EXTENSIONS:
                md_path = await convert_file_to_markdown(file_path)
                if md_path:
                    md_relative_path = f".deer-flow/threads/{thread_id}/user-data/uploads/{md_path.name}"
                    file_info["markdown_file"] = md_path.name
                    file_info["markdown_path"] = md_relative_path
                    file_info["markdown_virtual_path"] = f"/mnt/user-data/uploads/{md_path.name}"
                    file_info["markdown_artifact_url"] = f"/api/threads/{thread_id}/artifacts/mnt/user-data/uploads/{md_path.name}"

            uploaded_files.append(file_info)

        except Exception as e:
            logger.error(f"Failed to upload {file.filename}: {e}")
            raise HTTPException(status_code=500, detail=f"Failed to upload {file.filename}: {str(e)}")

    return UploadResponse(
        success=True,
        files=uploaded_files,
        message=f"Successfully uploaded {len(uploaded_files)} file(s)",
    )


@router.get("/list", response_model=dict)
async def list_uploaded_files(thread_id: str) -> dict:
    """List all files in a thread's uploads directory.

    Args:
        thread_id: The thread ID to list files for.

    Returns:
        Dictionary containing list of files with their metadata.
    """
    uploads_dir = get_uploads_dir(thread_id)

    if not uploads_dir.exists():
        return {"files": [], "count": 0}

    files = []
    for file_path in sorted(uploads_dir.iterdir()):
        if file_path.is_file():
            stat = file_path.stat()
            relative_path = f".deer-flow/threads/{thread_id}/user-data/uploads/{file_path.name}"
            files.append(
                {
                    "filename": file_path.name,
                    "size": stat.st_size,
                    "path": relative_path,  # Actual filesystem path (relative to backend/)
                    "virtual_path": f"/mnt/user-data/uploads/{file_path.name}",  # Path for Agent in sandbox
                    "artifact_url": f"/api/threads/{thread_id}/artifacts/mnt/user-data/uploads/{file_path.name}",  # HTTP URL
                    "extension": file_path.suffix,
                    "modified": stat.st_mtime,
                }
            )

    return {"files": files, "count": len(files)}


@router.delete("/{filename}")
async def delete_uploaded_file(thread_id: str, filename: str) -> dict:
    """Delete a file from a thread's uploads directory.

    Args:
        thread_id: The thread ID.
        filename: The filename to delete.

    Returns:
        Success message.
    """
    uploads_dir = get_uploads_dir(thread_id)
    file_path = uploads_dir / filename

    if not file_path.exists():
        raise HTTPException(status_code=404, detail=f"File not found: {filename}")

    # Security check: ensure the path is within the uploads directory
    try:
        file_path.resolve().relative_to(uploads_dir.resolve())
    except ValueError:
        raise HTTPException(status_code=403, detail="Access denied")

    try:
        file_path.unlink()
        logger.info(f"Deleted file: {filename}")
        return {"success": True, "message": f"Deleted {filename}"}
    except Exception as e:
        logger.error(f"Failed to delete {filename}: {e}")
        raise HTTPException(status_code=500, detail=f"Failed to delete {filename}: {str(e)}")
