"""API client for communicating with the Media Server."""

from __future__ import annotations

import asyncio
import hashlib
import logging
import uuid
from collections.abc import Callable
from typing import Any

import aiohttp
from aiohttp import ClientError, ClientResponseError

from .const import (
    API_HEALTH,
    API_STATUS,
    API_PLAY,
    API_PAUSE,
    API_STOP,
    API_NEXT,
    API_PREVIOUS,
    API_VOLUME,
    API_MUTE,
    API_SEEK,
    API_TURN_ON,
    API_TURN_OFF,
    API_TOGGLE,
    API_SCRIPTS_LIST,
    API_SCRIPTS_EXECUTE,
    API_BROWSER_FOLDERS,
    API_BROWSER_BROWSE,
    API_BROWSER_PLAY,
    API_DISPLAY_MONITORS,
    API_FOREGROUND,
    API_DISPLAY_BRIGHTNESS,
    API_DISPLAY_POWER,
    API_DISPLAY_CONTRAST,
    API_DISPLAY_INPUT_SOURCE,
    API_DISPLAY_COLOR_PRESET,
    API_DISPLAY_PICTURE_MODE,
)

_LOGGER = logging.getLogger(__name__)


class MediaServerError(Exception):
    """Base exception for Media Server errors."""


class MediaServerConnectionError(MediaServerError):
    """Exception for connection errors."""


class MediaServerAuthError(MediaServerError):
    """Exception for authentication errors."""


class MediaServerRateLimitError(MediaServerError):
    """Raised when the server replies with HTTP 429.

    The media server's in-process token-bucket limiter (v0.3.0+) returns 429
    with a ``Retry-After`` header — capture it so callers can back off.
    """

    def __init__(self, message: str, retry_after: float | None = None) -> None:
        super().__init__(message)
        self.retry_after = retry_after


class MediaServerClient:
    """Client for the Media Server REST API."""

    def __init__(
        self,
        host: str,
        port: int,
        token: str,
        session: aiohttp.ClientSession | None = None,
        use_ssl: bool = False,
        verify_ssl: bool = True,
    ) -> None:
        """Initialize the client.

        Args:
            host: Server hostname or IP address
            port: Server port
            token: API authentication token
            session: Optional aiohttp session (will create one if not provided)
            use_ssl: If True, talk HTTPS instead of HTTP. The media server v0.3.0+
                supports ``ssl_certfile`` / ``ssl_keyfile`` in ``config.yaml``.
            verify_ssl: If False, skip TLS certificate verification (only needed
                for self-signed certs on a trusted LAN).
        """
        self._host = host
        self._port = int(port)  # Ensure port is an integer
        self._token = token
        self._session = session
        self._own_session = session is None
        self._use_ssl = use_ssl
        # aiohttp accepts ``ssl=False`` to disable verification; ``None`` keeps
        # the default verifying SSLContext.
        self._ssl: bool | None = False if (use_ssl and not verify_ssl) else None
        scheme = "https" if use_ssl else "http"
        self._base_url = f"{scheme}://{host}:{self._port}"

    async def _ensure_session(self) -> aiohttp.ClientSession:
        """Ensure we have an aiohttp session."""
        if self._session is None or self._session.closed:
            self._session = aiohttp.ClientSession()
            self._own_session = True
        return self._session

    async def close(self) -> None:
        """Close the client session."""
        if self._own_session and self._session and not self._session.closed:
            await self._session.close()

    def _get_headers(self) -> dict[str, str]:
        """Get headers for API requests.

        When no token is configured the media server runs in anonymous mode
        (``auth.auth_enabled()`` returns False), so we omit the Authorization
        header entirely rather than sending ``Bearer `` with an empty value.

        Every request carries a per-call ``X-Request-ID`` that the media server
        echoes back into its log lines (audit log + access log) so a problem
        in HA can be correlated to the matching server-side entry. The id is
        a UUID4 hex (32 chars) which fits the server's ``[A-Za-z0-9._-]{1,128}``
        allow-list and is therefore preserved verbatim instead of being
        replaced by a fresh server-side id.
        """
        headers = {
            "Content-Type": "application/json",
            "X-Request-ID": uuid.uuid4().hex,
        }
        if self._token:
            headers["Authorization"] = f"Bearer {self._token}"
        return headers

    async def _request(
        self,
        method: str,
        endpoint: str,
        json_data: dict | None = None,
        auth_required: bool = True,
    ) -> dict[str, Any]:
        """Make an API request.

        Args:
            method: HTTP method (GET, POST, etc.)
            endpoint: API endpoint path
            json_data: Optional JSON body data
            auth_required: Whether to include authentication header

        Returns:
            Response data as dictionary

        Raises:
            MediaServerConnectionError: On connection errors
            MediaServerAuthError: On authentication errors
            MediaServerError: On other errors
        """
        session = await self._ensure_session()
        url = f"{self._base_url}{endpoint}"
        # Always send X-Request-ID, even on unauthenticated calls — it's the
        # observability hook, not an auth token, and the health endpoint
        # benefits from being log-correlated just like every other.
        headers = self._get_headers() if auth_required else {
            "Content-Type": "application/json",
            "X-Request-ID": uuid.uuid4().hex,
        }

        try:
            timeout = aiohttp.ClientTimeout(total=10)
            async with session.request(
                method,
                url,
                headers=headers,
                json=json_data,
                timeout=timeout,
                ssl=self._ssl,
            ) as response:
                if response.status == 401:
                    raise MediaServerAuthError("Invalid API token")
                if response.status == 403:
                    raise MediaServerAuthError("Access forbidden")
                if response.status == 429:
                    retry_after_raw = response.headers.get("Retry-After", "")
                    try:
                        retry_after = float(retry_after_raw) if retry_after_raw else None
                    except ValueError:
                        retry_after = None
                    raise MediaServerRateLimitError(
                        f"Rate limited by server (retry after {retry_after}s)",
                        retry_after=retry_after,
                    )

                response.raise_for_status()
                return await response.json()

        except aiohttp.ClientConnectorError as err:
            raise MediaServerConnectionError(
                f"Cannot connect to server at {self._base_url}: {err}"
            ) from err
        except ClientResponseError as err:
            raise MediaServerError(f"API error: {err.status} {err.message}") from err
        except ClientError as err:
            raise MediaServerConnectionError(f"Connection error: {err}") from err

    async def check_connection(self) -> bool:
        """Check if the server is reachable and token is valid.

        Returns:
            True if connection is successful
        """
        try:
            # First check health (no auth)
            await self._request("GET", API_HEALTH, auth_required=False)
            # Then check auth by getting status
            await self._request("GET", API_STATUS)
            return True
        except MediaServerError:
            return False

    async def get_health(self) -> dict[str, Any]:
        """Get server health status (no authentication required).

        Returns:
            Health status data
        """
        return await self._request("GET", API_HEALTH, auth_required=False)

    async def get_status(self) -> dict[str, Any]:
        """Get current media playback status.

        Returns:
            Media status data including state, title, artist, volume, etc.
        """
        data = await self._request("GET", API_STATUS)

        # Convert relative album_art_url to absolute URL with cache-buster
        # (and token only when auth is enabled on the server side).
        if data.get("album_art_url") and data["album_art_url"].startswith("/"):
            # Add track info hash to force HA to re-fetch when track changes
            import hashlib
            track_id = f"{data.get('title', '')}-{data.get('artist', '')}"
            track_hash = hashlib.md5(track_id.encode()).hexdigest()[:8]
            token_param = f"token={self._token}&" if self._token else ""
            data["album_art_url"] = (
                f"{self._base_url}{data['album_art_url']}?{token_param}t={track_hash}"
            )

        return data

    async def play(self) -> dict[str, Any]:
        """Resume or start playback.

        Returns:
            Response data
        """
        return await self._request("POST", API_PLAY)

    async def pause(self) -> dict[str, Any]:
        """Pause playback.

        Returns:
            Response data
        """
        return await self._request("POST", API_PAUSE)

    async def stop(self) -> dict[str, Any]:
        """Stop playback.

        Returns:
            Response data
        """
        return await self._request("POST", API_STOP)

    async def next_track(self) -> dict[str, Any]:
        """Skip to next track.

        Returns:
            Response data
        """
        return await self._request("POST", API_NEXT)

    async def previous_track(self) -> dict[str, Any]:
        """Go to previous track.

        Returns:
            Response data
        """
        return await self._request("POST", API_PREVIOUS)

    async def set_volume(self, volume: int) -> dict[str, Any]:
        """Set the volume level.

        Args:
            volume: Volume level (0-100)

        Returns:
            Response data
        """
        return await self._request("POST", API_VOLUME, {"volume": volume})

    async def toggle_mute(self) -> dict[str, Any]:
        """Toggle mute state.

        Returns:
            Response data with new mute state
        """
        return await self._request("POST", API_MUTE)

    async def seek(self, position: float) -> dict[str, Any]:
        """Seek to a position in the current track.

        Args:
            position: Position in seconds

        Returns:
            Response data
        """
        return await self._request("POST", API_SEEK, {"position": position})

    async def turn_on(self) -> dict[str, Any]:
        """Send turn on command.

        Returns:
            Response data
        """
        return await self._request("POST", API_TURN_ON)

    async def turn_off(self) -> dict[str, Any]:
        """Send turn off command.

        Returns:
            Response data
        """
        return await self._request("POST", API_TURN_OFF)

    async def toggle(self) -> dict[str, Any]:
        """Send toggle command.

        Returns:
            Response data
        """
        return await self._request("POST", API_TOGGLE)

    async def list_scripts(self) -> list[dict[str, Any]]:
        """List available scripts on the server.

        Returns:
            List of scripts with name, description, and timeout
        """
        return await self._request("GET", API_SCRIPTS_LIST)

    async def execute_script(
        self,
        script_name: str,
        params: dict[str, str | int | float | bool] | None = None,
    ) -> dict[str, Any]:
        """Execute a script on the server.

        The server (v0.3.0+) rate-limits ``/api/scripts/execute`` at 10/min per
        peer. If we hit 429 we wait for ``Retry-After`` (capped at 30 s) and
        retry once — enough for a brief HA-side burst without masking a real
        sustained overload, which falls through as ``MediaServerRateLimitError``.

        Args:
            script_name: Name of the script to execute
            params: Optional named parameters (validated against script schema)

        Returns:
            Execution result with success, exit_code, stdout, stderr
        """
        endpoint = f"{API_SCRIPTS_EXECUTE}/{script_name}"
        json_data = {"params": params or {}}
        try:
            return await self._request("POST", endpoint, json_data)
        except MediaServerRateLimitError as err:
            wait = min(err.retry_after or 5.0, 30.0)
            _LOGGER.warning(
                "execute_script(%s) rate-limited, retrying after %.1fs",
                script_name,
                wait,
            )
            await asyncio.sleep(wait)
            return await self._request("POST", endpoint, json_data)

    async def get_media_folders(self) -> dict[str, dict[str, Any]]:
        """Get configured media folders.

        Returns:
            Dictionary of folders with folder_id as key and folder config as value
        """
        response = await self._request("GET", API_BROWSER_FOLDERS)
        # Server >= c9ee41a wraps the result as {"folders": {...}, "management_enabled": bool}.
        # Older servers returned the flat folder dict directly.
        if isinstance(response, dict) and "folders" in response and isinstance(response["folders"], dict):
            return response["folders"]
        return response

    async def browse_folder(
        self, folder_id: str, path: str = "", offset: int = 0, limit: int = 100
    ) -> dict[str, Any]:
        """Browse a media folder.

        Args:
            folder_id: ID of the folder to browse
            path: Path within the folder (empty for root)
            offset: Pagination offset
            limit: Number of items to return

        Returns:
            Dictionary with current_path, parent_path, items, total, offset, limit
        """
        params = {
            "folder_id": folder_id,
            "path": path,
            "offset": offset,
            "limit": limit,
        }
        query_string = "&".join(f"{k}={v}" for k, v in params.items())
        endpoint = f"{API_BROWSER_BROWSE}?{query_string}"
        return await self._request("GET", endpoint)

    async def play_media_file(self, file_path: str) -> dict[str, Any]:
        """Play a media file by absolute path.

        Args:
            file_path: Absolute path to the media file

        Returns:
            Response data with success status
        """
        return await self._request("POST", API_BROWSER_PLAY, {"path": file_path})

    async def get_display_monitors(self) -> list[dict[str, Any]]:
        """Get list of connected monitors with brightness, power, DDC/CI state.

        Uses the server's short TTL cache so per-entity polling does not pay
        the full DDC/CI probe cost on every call.
        """
        return await self._request("GET", API_DISPLAY_MONITORS)

    async def set_display_brightness(self, monitor_id: int, brightness: int) -> dict[str, Any]:
        """Set brightness for a specific monitor.

        Args:
            monitor_id: Monitor index
            brightness: Brightness level (0-100)

        Returns:
            Response data with success status
        """
        return await self._request(
            "POST", f"{API_DISPLAY_BRIGHTNESS}/{monitor_id}", {"brightness": brightness}
        )

    async def set_display_power(self, monitor_id: int, on: bool) -> dict[str, Any]:
        """Set power state for a specific monitor.

        Args:
            monitor_id: Monitor index
            on: True to turn on, False to turn off

        Returns:
            Response data with success status
        """
        return await self._request(
            "POST", f"{API_DISPLAY_POWER}/{monitor_id}", {"on": on}
        )

    async def set_display_contrast(self, monitor_id: int, contrast: int) -> dict[str, Any]:
        """Set DDC/CI contrast for a specific monitor (0-100)."""
        return await self._request(
            "POST", f"{API_DISPLAY_CONTRAST}/{monitor_id}", {"contrast": contrast}
        )

    async def set_display_input_source(self, monitor_id: int, source: str) -> dict[str, Any]:
        """Switch a monitor's DDC/CI input source by enum name (e.g. 'HDMI1')."""
        return await self._request(
            "POST", f"{API_DISPLAY_INPUT_SOURCE}/{monitor_id}", {"source": source}
        )

    async def set_display_color_preset(self, monitor_id: int, preset: str) -> dict[str, Any]:
        """Apply a DDC/CI color preset by enum name (e.g. 'COLOR_TEMP_6500K')."""
        return await self._request(
            "POST", f"{API_DISPLAY_COLOR_PRESET}/{monitor_id}", {"preset": preset}
        )

    async def set_display_picture_mode(self, monitor_id: int, code: int) -> dict[str, Any]:
        """Apply a DDC/CI picture/scene mode (VCP 0xDC) by raw code."""
        return await self._request(
            "POST", f"{API_DISPLAY_PICTURE_MODE}/{monitor_id}", {"code": code}
        )

    async def get_foreground(self) -> dict[str, Any]:
        """Get the foreground window/process snapshot.

        Returns the structured payload described in the media server's
        ``ForegroundInfo`` dataclass: process name, window title, fullscreen
        flag, owning monitor, geometry, and process start time.
        """
        return await self._request("GET", API_FOREGROUND)


class MediaServerWebSocket:
    """WebSocket client for real-time media status updates."""

    def __init__(
        self,
        host: str,
        port: int,
        token: str,
        on_status_update: Callable[[dict[str, Any]], None],
        on_disconnect: Callable[[], None] | None = None,
        on_scripts_changed: Callable[[], None] | None = None,
        on_foreground_update: Callable[[dict[str, Any]], None] | None = None,
        use_ssl: bool = False,
        verify_ssl: bool = True,
    ) -> None:
        """Initialize the WebSocket client.

        Args:
            host: Server hostname or IP
            port: Server port
            token: API authentication token
            on_status_update: Callback when status update received
            on_disconnect: Callback when connection lost
            on_scripts_changed: Callback when scripts have changed
            on_foreground_update: Callback when foreground process changes
            use_ssl: If True, talk WSS instead of WS.
            verify_ssl: If False, skip TLS certificate verification.
        """
        self._host = host
        self._port = int(port)
        self._token = token
        self._on_status_update = on_status_update
        self._on_disconnect = on_disconnect
        self._on_scripts_changed = on_scripts_changed
        self._on_foreground_update = on_foreground_update
        self._use_ssl = use_ssl
        self._ssl: bool | None = False if (use_ssl and not verify_ssl) else None
        # The server's WS endpoint accepts an unauthenticated connection when
        # api_tokens is empty (see media.py:websocket_endpoint), so we only
        # append ?token=... when one was configured. Pre-0.3.0 servers only
        # know the query path; 0.3.0+ servers prefer the ``Sec-WebSocket-Protocol``
        # subprotocol (which keeps the token out of URLs / Referer / logs) but
        # still accept the query as a documented back-compat fallback. We send
        # both so the integration works against either server version.
        token_query = f"?token={token}" if token else ""
        scheme = "wss" if use_ssl else "ws"
        self._ws_url = f"{scheme}://{host}:{self._port}/api/media/ws{token_query}"
        self._session: aiohttp.ClientSession | None = None
        self._ws: aiohttp.ClientWebSocketResponse | None = None
        self._receive_task: asyncio.Task | None = None
        self._running = False

    async def connect(self) -> bool:
        """Establish WebSocket connection.

        Returns:
            True if connection successful
        """
        try:
            if self._session is None or self._session.closed:
                self._session = aiohttp.ClientSession()

            ws_kwargs: dict[str, Any] = {
                "heartbeat": 30,
                "timeout": aiohttp.ClientTimeout(total=10),
            }
            if self._token:
                # Subprotocol-based auth (preferred by media server v0.3.0+).
                # aiohttp negotiates this header; if the server doesn't echo
                # it back (older versions), aiohttp still completes the
                # handshake — at which point the ?token= query in the URL
                # takes over. Safe across both server generations.
                ws_kwargs["protocols"] = [f"media-server.token.{self._token}"]
            if self._ssl is not None:
                ws_kwargs["ssl"] = self._ssl

            self._ws = await self._session.ws_connect(self._ws_url, **ws_kwargs)
            self._running = True

            # Start receive loop
            self._receive_task = asyncio.create_task(self._receive_loop())

            _LOGGER.info("WebSocket connected to %s:%s", self._host, self._port)
            return True

        except Exception as err:
            _LOGGER.warning("WebSocket connection failed: %s", err)
            return False

    async def disconnect(self) -> None:
        """Close WebSocket connection."""
        self._running = False

        if self._receive_task:
            self._receive_task.cancel()
            try:
                await self._receive_task
            except asyncio.CancelledError:
                pass
            self._receive_task = None

        if self._ws and not self._ws.closed:
            await self._ws.close()
            self._ws = None

        if self._session and not self._session.closed:
            await self._session.close()
            self._session = None

        _LOGGER.debug("WebSocket disconnected")

    async def _receive_loop(self) -> None:
        """Background loop to receive WebSocket messages."""
        while self._running and self._ws and not self._ws.closed:
            try:
                msg = await self._ws.receive(timeout=60)

                if msg.type == aiohttp.WSMsgType.TEXT:
                    data = msg.json()
                    msg_type = data.get("type")

                    if msg_type in ("status", "status_update"):
                        status_data = data.get("data", {})
                        # Convert album art URL to absolute
                        if (
                            status_data.get("album_art_url")
                            and status_data["album_art_url"].startswith("/")
                        ):
                            track_id = f"{status_data.get('title', '')}-{status_data.get('artist', '')}"
                            track_hash = hashlib.md5(track_id.encode()).hexdigest()[:8]
                            token_param = f"token={self._token}&" if self._token else ""
                            http_scheme = "https" if self._use_ssl else "http"
                            status_data["album_art_url"] = (
                                f"{http_scheme}://{self._host}:{self._port}"
                                f"{status_data['album_art_url']}?{token_param}t={track_hash}"
                            )
                        self._on_status_update(status_data)
                    elif msg_type == "scripts_changed":
                        _LOGGER.info("Scripts changed notification received")
                        if self._on_scripts_changed:
                            self._on_scripts_changed()
                    elif msg_type in ("foreground", "foreground_update"):
                        if self._on_foreground_update:
                            self._on_foreground_update(data.get("data", {}))
                    elif msg_type == "pong":
                        _LOGGER.debug("Received pong")

                elif msg.type == aiohttp.WSMsgType.CLOSED:
                    _LOGGER.warning("WebSocket closed by server")
                    break
                elif msg.type == aiohttp.WSMsgType.ERROR:
                    _LOGGER.error("WebSocket error: %s", self._ws.exception())
                    break

            except asyncio.TimeoutError:
                # Send ping to keep connection alive
                if self._ws and not self._ws.closed:
                    try:
                        await self._ws.send_json({"type": "ping"})
                    except Exception:
                        break
            except asyncio.CancelledError:
                break
            except Exception as err:
                _LOGGER.error("WebSocket receive error: %s", err)
                break

        # Connection lost, notify callback
        if self._on_disconnect:
            self._on_disconnect()

    @property
    def is_connected(self) -> bool:
        """Return True if WebSocket is connected."""
        return self._ws is not None and not self._ws.closed