"""
Table of Contents overlay sub-application.

Simple TOC overlay (deprecated in favor of NavigationOverlay).
Kept for backward compatibility.
"""

from __future__ import annotations
from typing import TYPE_CHECKING, List, Tuple
from PIL import Image

from .base import OverlaySubApplication
from ..gesture import GestureResponse, ActionType
from ..state import OverlayState
from ..html_generator import generate_toc_overlay

if TYPE_CHECKING:
    from ..application import EbookReader


class TOCOverlay(OverlaySubApplication):
    """
    Simple Table of Contents overlay.

    NOTE: This is deprecated in favor of NavigationOverlay which provides
    a unified interface for both TOC and bookmarks. Kept for backward compatibility.

    Features:
    - List of chapters with clickable links
    - Chapter navigation
    """

    def __init__(self, reader: 'EbookReader'):
        """Initialize TOC overlay."""
        super().__init__(reader)
        self._cached_chapters: List[Tuple[str, int]] = []

    def get_overlay_type(self) -> OverlayState:
        """Return TOC overlay type."""
        return OverlayState.TOC

    def open(self, base_page: Image.Image, **kwargs) -> Image.Image:
        """
        Open the TOC overlay.

        Args:
            base_page: Current reading page to show underneath
            chapters: List of (chapter_title, chapter_index) tuples

        Returns:
            Composited image with TOC overlay
        """
        chapters = kwargs.get('chapters', [])

        # Store for later use
        self._cached_chapters = chapters

        # Calculate panel size (60% width, 70% height)
        panel_size = self._calculate_panel_size(0.6, 0.7)

        # Convert chapters to format expected by HTML generator
        chapter_data = [
            {"index": idx, "title": title}
            for title, idx in chapters
        ]

        # Generate TOC HTML with clickable links
        html = generate_toc_overlay(chapter_data, page_size=panel_size)

        # Render HTML to image
        overlay_panel = self.render_html_to_image(html, panel_size)

        # Cache for later use
        self._cached_base_page = base_page.copy()
        self._cached_overlay_image = overlay_panel

        # Composite and return
        return self.composite_overlay(base_page, overlay_panel)

    def handle_tap(self, x: int, y: int) -> GestureResponse:
        """
        Handle tap within TOC overlay.

        Detects:
        - Chapter selection (chapter:N)
        - Tap outside overlay (closes)

        Args:
            x, y: Screen coordinates of tap

        Returns:
            GestureResponse with appropriate action
        """
        # Query the overlay to see what was tapped
        query_result = self.query_overlay_pixel(x, y)

        # If query failed (tap outside overlay), close it
        if not query_result:
            return GestureResponse(ActionType.OVERLAY_CLOSED, {})

        # Check if tapped on a link (chapter)
        if query_result.get("is_interactive") and query_result.get("link_target"):
            link_target = query_result["link_target"]

            # Parse "chapter:N" format
            if link_target.startswith("chapter:"):
                try:
                    chapter_idx = int(link_target.split(":")[1])

                    # Get chapter title for response
                    chapter_title = None
                    for title, idx in self._cached_chapters:
                        if idx == chapter_idx:
                            chapter_title = title
                            break

                    # Jump to selected chapter
                    self.reader.jump_to_chapter(chapter_idx)

                    return GestureResponse(ActionType.CHAPTER_SELECTED, {
                        "chapter_index": chapter_idx,
                        "chapter_title": chapter_title or f"Chapter {chapter_idx}"
                    })
                except (ValueError, IndexError):
                    pass

        # Not a chapter link, close overlay
        return GestureResponse(ActionType.OVERLAY_CLOSED, {})