import curses
import threading
from pathlib import Path
from mpvremote import config
from mpvremote.mpv_client import MpvClient
from mpvremote.views import AboutView, MainView, PlaylistView, QueueView, SettingsView


class App:
    def __init__(self, stdscr):
        self.stdscr = stdscr
        self.client = MpvClient(config.SOCKET)
        self.running = True

        curses.curs_set(0)
        stdscr.keypad(True)
        stdscr.nodelay(False)
        try:
            curses.set_escdelay(50)
        except (AttributeError, curses.error):
            pass

        self._init_colors()

        self.height, self.width = stdscr.getmaxyx()

        self.views = {
            'main': MainView(self),
            'playlist': PlaylistView(self),
            'queue': QueueView(self),
            'settings': SettingsView(self),
            'about': AboutView(self),
        }
        self.current_view = self.views['main']
        self.messages = []

        # Video cache + background rescan
        self._video_cache = ()
        self._video_cache_version = 0
        self._video_cache_lock = threading.Lock()
        self._initial_scan_complete = threading.Event()
        self._rescan_stop = threading.Event()
        self._rescan_thread = threading.Thread(target=self._rescan_loop, daemon=True)
        self._rescan_thread.start()

    def _init_colors(self):
        curses.start_color()
        curses.use_default_colors()

        navy_bg = curses.COLOR_BLUE
        if curses.can_change_color() and curses.COLORS >= 256:
            try:
                curses.init_color(16, 0, 0, 500)
                navy_bg = 16
            except curses.error:
                pass

        curses.init_pair(1, curses.COLOR_WHITE, navy_bg)
        curses.init_pair(2, curses.COLOR_GREEN, -1)
        curses.init_pair(3, curses.COLOR_YELLOW, -1)
        curses.init_pair(4, curses.COLOR_WHITE, navy_bg)

    def _scan_videos(self):
        """Scan MEDIA_DIR for video files. Thread-safe."""
        try:
            media_path = Path(config.MEDIA_DIR)
            if not media_path.exists():
                self._commit_video_cache([])
                return

            videos = []
            for ext in config.VIDEO_EXTS:
                for file_path in media_path.rglob(f"*.{ext}"):
                    rel = str(file_path.relative_to(media_path))
                    videos.append((rel, str(file_path)))

            self._commit_video_cache(videos)
        except Exception:
            pass
        finally:
            self._initial_scan_complete.set()

    def _commit_video_cache(self, videos):
        """Publish an immutable, pre-normalized snapshot of scanned videos."""
        sorted_videos = sorted(videos, key=lambda item: item[0].casefold())
        cache = tuple((name, path, name.casefold()) for name, path in sorted_videos)
        with self._video_cache_lock:
            self._video_cache = cache
            self._video_cache_version += 1

    def _rescan_loop(self):
        """Scan immediately, then rescan every 2 minutes in the background."""
        while not self._rescan_stop.is_set():
            self._scan_videos()
            if self._rescan_stop.wait(120):
                break

    def get_videos(self):
        """Return cached video list. Thread-safe."""
        with self._video_cache_lock:
            return [(name, path) for name, path, _ in self._video_cache]

    def get_videos_with_version(self):
        """Return an immutable normalized snapshot and its cache version."""
        with self._video_cache_lock:
            return self._video_cache, self._video_cache_version

    def video_scan_complete(self):
        """Return whether at least one media-directory scan has finished."""
        return self._initial_scan_complete.is_set()

    def refresh_videos(self):
        """Rescan the configured media directory immediately."""
        self._scan_videos()

    def run(self):
        while self.running:
            queue_active = self.current_view is self.views['queue']
            self.stdscr.timeout(100 if queue_active else -1)
            update = getattr(self.current_view, "update", None)
            if update is not None:
                update()
            self.draw()
            key = self.stdscr.getch()
            if key == -1:
                continue
            if not self.current_view.handle_key(key):
                self.running = False
        self._rescan_stop.set()
        self._rescan_thread.join(timeout=5)

    def draw(self):
        self.stdscr.erase()
        self.current_view.draw()
        self.stdscr.noutrefresh()
        curses.doupdate()

    def switch_view(self, name):
        self.current_view = self.views[name]
        self.stdscr.clear()
        self.stdscr.refresh()

    def add_message(self, msg):
        self.messages.append(msg)
        max_msgs = max(1, self.height - 4)
        while len(self.messages) > max_msgs:
            self.messages.pop(0)

    def draw_status_bar(self, text):
        text = text[:self.width - 1].ljust(self.width - 1)
        try:
            self.stdscr.addstr(0, 0, text, curses.color_pair(1) | curses.A_BOLD)
        except curses.error:
            pass

    def draw_help_bar(self, text):
        row = self.height - 1
        text = text[:self.width - 1].ljust(self.width - 1)
        try:
            self.stdscr.addstr(row, 0, text, curses.color_pair(4))
        except curses.error:
            pass

    def draw_messages(self, start_row=2):
        max_rows = max(0, self.height - start_row - 1)
        visible = self.messages[-max_rows:] if max_rows > 0 else []
        for i, msg in enumerate(visible):
            row = start_row + i
            if row >= self.height - 1:
                break
            text = msg[:self.width - 1]
            try:
                self.stdscr.addstr(row, 0, text, curses.color_pair(3))
            except curses.error:
                pass