Mainline/engine/display/backends/pygame.py

"""
Pygame display backend - renders to a native application window.
"""

import time

from engine.display.renderer import parse_ansi


class PygameDisplay:
    """Pygame display backend - renders to native window.

    Supports reuse mode - when reuse=True, skips SDL initialization
    and reuses the existing pygame window from a previous instance.
    """

    width: int = 80
    window_width: int = 800
    window_height: int = 600

    def __init__(
        self,
        cell_width: int = 10,
        cell_height: int = 18,
        window_width: int = 800,
        window_height: int = 600,
        target_fps: float = 30.0,
    ):
        self.width = 80
        self.height = 24
        self.cell_width = cell_width
        self.cell_height = cell_height
        self.window_width = window_width
        self.window_height = window_height
        self.target_fps = target_fps
        self._initialized = False
        self._pygame = None
        self._screen = None
        self._font = None
        self._resized = False
        self._quit_requested = False
        self._last_frame_time = 0.0
        self._frame_period = 1.0 / target_fps if target_fps > 0 else 0

    def _get_font_path(self) -> str | None:
        """Get font path for rendering."""
        import os
        import sys
        from pathlib import Path

        env_font = os.environ.get("MAINLINE_PYGAME_FONT")
        if env_font and os.path.exists(env_font):
            return env_font

        def search_dir(base_path: str) -> str | None:
            if not os.path.exists(base_path):
                return None
            if os.path.isfile(base_path):
                return base_path
            for font_file in Path(base_path).rglob("*"):
                if font_file.suffix.lower() in (".ttf", ".otf", ".ttc"):
                    name = font_file.stem.lower()
                    if "geist" in name and ("nerd" in name or "mono" in name):
                        return str(font_file)
            return None

        search_dirs = []
        if sys.platform == "darwin":
            search_dirs.append(os.path.expanduser("~/Library/Fonts/"))
        elif sys.platform == "win32":
            search_dirs.append(
                os.path.expanduser("~\\AppData\\Local\\Microsoft\\Windows\\Fonts\\")
            )
        else:
            search_dirs.extend(
                [
                    os.path.expanduser("~/.local/share/fonts/"),
                    os.path.expanduser("~/.fonts/"),
                    "/usr/share/fonts/",
                ]
            )

        for search_dir_path in search_dirs:
            found = search_dir(search_dir_path)
            if found:
                return found

        return None

    def init(self, width: int, height: int, reuse: bool = False) -> None:
        """Initialize display with dimensions.

        Args:
            width: Terminal width in characters
            height: Terminal height in rows
            reuse: If True, attach to existing pygame window instead of creating new
        """
        self.width = width
        self.height = height

        import os

        os.environ["SDL_VIDEODRIVER"] = "x11"

        try:
            import pygame
        except ImportError:
            return

        if reuse and PygameDisplay._pygame_initialized:
            self._pygame = pygame
            self._initialized = True
            return

        pygame.init()
        pygame.display.set_caption("Mainline")

        self._screen = pygame.display.set_mode(
            (self.window_width, self.window_height),
            pygame.RESIZABLE,
        )
        self._pygame = pygame
        PygameDisplay._pygame_initialized = True

        font_path = self._get_font_path()
        if font_path:
            try:
                self._font = pygame.font.Font(font_path, self.cell_height - 2)
            except Exception:
                self._font = pygame.font.SysFont("monospace", self.cell_height - 2)
        else:
            self._font = pygame.font.SysFont("monospace", self.cell_height - 2)

        self._initialized = True

    def show(self, buffer: list[str], border: bool = False) -> None:
        if not self._initialized or not self._pygame:
            return

        t0 = time.perf_counter()

        for event in self._pygame.event.get():
            if event.type == self._pygame.QUIT:
                self._quit_requested = True
            elif event.type == self._pygame.KEYDOWN:
                if event.key in (self._pygame.K_ESCAPE, self._pygame.K_c):
                    if event.key == self._pygame.K_c and not (
                        event.mod & self._pygame.KMOD_LCTRL
                        or event.mod & self._pygame.KMOD_RCTRL
                    ):
                        continue
                    self._quit_requested = True
            elif event.type == self._pygame.VIDEORESIZE:
                self.window_width = event.w
                self.window_height = event.h
                self.width = max(1, self.window_width // self.cell_width)
                self.height = max(1, self.window_height // self.cell_height)
                self._resized = True

        # FPS limiting - skip frame if we're going too fast
        if self._frame_period > 0:
            now = time.perf_counter()
            elapsed = now - self._last_frame_time
            if elapsed < self._frame_period:
                return  # Skip this frame
            self._last_frame_time = now

        # Get metrics for border display
        fps = 0.0
        frame_time = 0.0
        from engine.display import get_monitor

        monitor = get_monitor()
        if monitor:
            stats = monitor.get_stats()
            avg_ms = stats.get("avg_ms", 0) if stats else 0
            frame_count = stats.get("frame_count", 0) if stats else 0
            if avg_ms and frame_count > 0:
                fps = 1000.0 / avg_ms
                frame_time = avg_ms

        # Apply border if requested
        if border:
            from engine.display import render_border

            buffer = render_border(buffer, self.width, self.height, fps, frame_time)

        self._screen.fill((0, 0, 0))

        for row_idx, line in enumerate(buffer[: self.height]):
            if row_idx >= self.height:
                break

            tokens = parse_ansi(line)
            x_pos = 0

            for text, fg, bg, _bold in tokens:
                if not text:
                    continue

                if bg != (0, 0, 0):
                    bg_surface = self._font.render(text, True, fg, bg)
                    self._screen.blit(bg_surface, (x_pos, row_idx * self.cell_height))
                else:
                    text_surface = self._font.render(text, True, fg)
                    self._screen.blit(text_surface, (x_pos, row_idx * self.cell_height))

                x_pos += self._font.size(text)[0]

        self._pygame.display.flip()

        elapsed_ms = (time.perf_counter() - t0) * 1000

        if monitor:
            chars_in = sum(len(line) for line in buffer)
            monitor.record_effect("pygame_display", elapsed_ms, chars_in, chars_in)

    def clear(self) -> None:
        if self._screen and self._pygame:
            self._screen.fill((0, 0, 0))
            self._pygame.display.flip()

    def get_dimensions(self) -> tuple[int, int]:
        """Get current terminal dimensions based on window size.

        Returns:
            (width, height) in character cells
        """
        # Query actual window size and recalculate character cells
        if self._screen and self._pygame:
            try:
                w, h = self._screen.get_size()
                if w != self.window_width or h != self.window_height:
                    self.window_width = w
                    self.window_height = h
                    self.width = max(1, w // self.cell_width)
                    self.height = max(1, h // self.cell_height)
            except Exception:
                pass
        return self.width, self.height

    def cleanup(self, quit_pygame: bool = True) -> None:
        """Cleanup display resources.

        Args:
            quit_pygame: If True, quit pygame entirely. Set to False when
                        reusing the display to avoid closing shared window.
        """
        if quit_pygame and self._pygame:
            self._pygame.quit()
            PygameDisplay._pygame_initialized = False

    @classmethod
    def reset_state(cls) -> None:
        """Reset pygame state - useful for testing."""
        cls._pygame_initialized = False

    def is_quit_requested(self) -> bool:
        """Check if user requested quit (Ctrl+C, Ctrl+Q, or Escape).

        Returns True if the user pressed Ctrl+C, Ctrl+Q, or Escape.
        The main loop should check this and raise KeyboardInterrupt.
        """
        return self._quit_requested

    def clear_quit_request(self) -> bool:
        """Clear the quit request flag after handling.

        Returns the previous quit request state.
        """
        was_requested = self._quit_requested
        self._quit_requested = False
        return was_requested