import json
import os
import uuid
from json import JSONEncoder

import socketio

from bridzik import Bridzik, BridzikException, Card
from db.db import init_db
from api import auth as auth_module, history
from api.auth import AuthError


def _env_bool(name: str, default: bool) -> bool:
    val = os.environ.get(name)
    if val is None:
        return default
    return val.lower() in ("1", "true", "yes", "on")


# --- configuration (env-driven, dev-friendly defaults) --------------------
_cors = os.environ.get("CORS_ALLOWED_ORIGINS", "*")
CORS_ALLOWED_ORIGINS = "*" if _cors == "*" else [o.strip() for o in _cors.split(",")]
SIO_LOGGER = _env_bool("SOCKETIO_LOGGER", False)

LOBBY = "lobby"  # room every connection joins to receive the public game list

sio = socketio.AsyncServer(
    async_mode="asgi",
    cors_allowed_origins=CORS_ALLOWED_ORIGINS,
    logger=SIO_LOGGER,
    engineio_logger=SIO_LOGGER,
)


async def _health_app(scope, receive, send):
    """Minimal ASGI handler for non-socket.io HTTP routes (liveness checks)."""
    if scope["type"] == "lifespan":
        while True:
            message = await receive()
            if message["type"] == "lifespan.startup":
                await init_db()
                await _restore_unfinished_games()
                await send({"type": "lifespan.startup.complete"})
            elif message["type"] == "lifespan.shutdown":
                await send({"type": "lifespan.shutdown.complete"})
                return
    if scope["type"] == "http":
        ok = scope.get("path", "") in ("/health", "/healthz")
        status = 200 if ok else 404
        body = b"ok" if ok else b"not found"
        await send({"type": "http.response.start", "status": status,
                    "headers": [(b"content-type", b"text/plain")]})
        await send({"type": "http.response.body", "body": body})


# Run with: uvicorn api:app --host 0.0.0.0 --port 5000
app = socketio.ASGIApp(sio, other_asgi_app=_health_app)

# --- in-memory state ------------------------------------------------------
# Single-process only. For multi-worker deployments this moves to Redis
# (socketio.AsyncRedisManager) plus a shared game store.
games: dict[str, "Game"] = {}
# Maps a live connection (sid) to the seat it controls: {"gid": str, "order": int}.
# This is the source of truth for "who is acting" — never trust a client-supplied
# player number.
sessions: dict[str, dict] = {}
# Maps a live connection (sid) to its authenticated account: {"player_id": int,
# "username": str}. Set on login/confirm or on connect via the auth token.
# Required before a connection may create or join a game.
accounts: dict[str, dict] = {}


class Game:
    def __init__(self, gid: str, name: str):
        self.gid = gid
        self.name = name
        self.players: list["Player"] = []
        self.started = False
        self.bridzik_core: Bridzik | None = None

    def start(self):
        self.bridzik_core = Bridzik()
        self.started = True

    def player_by_token(self, token: str) -> "Player | None":
        return next((p for p in self.players if p.token == token), None)

    def player_by_sid(self, sid: str) -> "Player | None":
        return next((p for p in self.players if p.sid == sid), None)

    def player_by_order(self, order: int) -> "Player | None":
        return next((p for p in self.players if p.order == order), None)


class Player:
    def __init__(self, sid: str, name: str, order: int, player_id: int):
        self.sid = sid
        self.name = name  # display name == account username
        self.order = order
        self.player_id = player_id  # persistent account id (db.models.Player.id)
        self.token = str(uuid.uuid4())  # secret token used for secure reconnect
        self.connected = True


class CardStatusEncoder(JSONEncoder):
    """Serializes the engine status, which may contain Card objects."""

    def default(self, obj):
        if isinstance(obj, Card):
            return {"color": obj.color.name, "value": obj.value.name}
        return JSONEncoder.default(self, obj)


def public_games() -> list:
    """Public lobby view — no sids, no reconnect tokens."""
    return [
        {
            "gid": g.gid,
            "name": g.name,
            "started": g.started,
            "players": [
                {
                    "order": p.order,
                    "name": p.name,
                    "connected": p.connected,
                    "player_id": p.player_id,
                }
                for p in g.players
            ],
        }
        for g in games.values()
    ]


# --- emit helpers ---------------------------------------------------------

async def broadcast_lobby():
    await sio.emit("get_games", {"games": public_games()}, room=LOBBY)


async def send_game_status(gid: str):
    game = games[gid]
    core = game.bridzik_core
    last_round = core.series[-1].get_last_round()
    status = json.loads(json.dumps(core.get_status(), cls=CardStatusEncoder))
    # Use DB-backed standings so the score is correct even after a server restart
    # (the engine only knows rounds completed since restart).
    status["standings"] = await history.get_standings(gid)
    await sio.emit(
        "game_status",
        {
            "gid": gid,
            "completed": core.is_completed(),
            # Self-contained roster so the game view doesn't depend on the lobby snapshot.
            "players": [
                {"order": p.order, "name": p.name, "connected": p.connected}
                for p in sorted(game.players, key=lambda p: p.order)
            ],
            "series_number": core.series[-1].series_number,
            "round_number": last_round.round_number,
            "cards_in_round": 8 - last_round.round_number,  # tricks == max bid
            "status": status,
        },
        room=gid,
    )


async def send_player_cards(gid: str, order: int, to: str):
    core = games[gid].bridzik_core
    await sio.emit(
        "player_cards",
        {"cards": json.loads(json.dumps(core.get_player_cards(int(order)), cls=Card.JSONEncoder))},
        to=to,
    )


async def send_error(sid: str, message: str):
    await sio.emit("error", {"error": message}, to=sid)


async def _mark_player_offline(game: "Game", player: "Player"):
    """Mark player disconnected, delete the game if everyone left, else notify the room."""
    player.connected = False
    if not any(p.connected for p in game.players):
        del games[game.gid]
    else:
        await sio.emit(
            "player_connection",
            {"order": player.order, "connected": False},
            room=game.gid,
        )


def _active_game(sid: str) -> "tuple[Game, dict] | None":
    """Resolve the started game and seat for a connection, or None."""
    sess = sessions.get(sid)
    if sess is None:
        return None
    game = games.get(sess["gid"])
    if game is None or not game.started:
        return None
    return game, sess


async def _restore_unfinished_games():
    """Po starte servera obnov rozohrate hry z DB do pamate (hraci offline).

    Karty su rozdane nanovo (pozicia z `series`/`round`); hraci sa vratia cez
    `rejoin_game` podla svojej trvalej identity (per-hra tokeny restart neprezili).
    """
    for info in await history.get_unfinished_games():
        if info["gid"] in games:
            continue
        game = Game(info["gid"], info["name"])
        game.bridzik_core = info["core"]
        game.started = True
        for seat, (pid, uname) in enumerate(info["seats"]):
            player = Player(None, uname, seat, pid)
            player.connected = False
            game.players.append(player)
        games[info["gid"]] = game


# --- connection lifecycle -------------------------------------------------

@sio.event
async def connect(sid, environ, auth=None):
    await sio.enter_room(sid, LOBBY)
    # Auto-login via the session token the client stored after a previous login.
    token = auth.get("token") if isinstance(auth, dict) else None
    identity = await auth_module.player_by_token(token)
    if identity is not None:
        accounts[sid] = identity
        await sio.emit("login", {"player": identity}, to=sid)
    await sio.emit("get_games", {"games": public_games()}, to=sid)


@sio.event
async def disconnect(sid):
    accounts.pop(sid, None)
    sess = sessions.pop(sid, None)
    game = games.get(sess["gid"]) if sess else None
    if game is not None:
        player = game.player_by_sid(sid)
        if player is not None:
            await _mark_player_offline(game, player)
    await broadcast_lobby()


# --- authentication (TOTP) ------------------------------------------------

@sio.on("register_account")
async def register_account(sid, username):
    try:
        data = await auth_module.register_account(username)
    except AuthError as exc:
        return await send_error(sid, str(exc))
    # otpauth_uri -> the client renders it as a QR code to scan into the app.
    await sio.emit("register_account", data, to=sid)


@sio.on("confirm_account")
async def confirm_account(sid, username, code):
    try:
        identity = await auth_module.confirm_account(username, code)
    except AuthError as exc:
        return await send_error(sid, str(exc))
    accounts[sid] = {"player_id": identity["player_id"], "username": identity["username"]}
    await sio.emit("login", {"player": accounts[sid], "token": identity["token"]}, to=sid)


@sio.on("login")
async def login(sid, username, code):
    try:
        identity = await auth_module.login(username, code)
    except AuthError as exc:
        return await send_error(sid, str(exc))
    accounts[sid] = {"player_id": identity["player_id"], "username": identity["username"]}
    await sio.emit("login", {"player": accounts[sid], "token": identity["token"]}, to=sid)


# --- lobby ----------------------------------------------------------------

@sio.on("create_game")
async def create_game(sid, name):
    if sid not in accounts:
        return await send_error(sid, "Musíte byť prihlásený.")
    gid = str(uuid.uuid4())
    games[gid] = Game(gid, name)
    await sio.emit("create_game", {"gid": gid}, to=sid)
    await broadcast_lobby()


@sio.on("get_games")
async def get_games(sid, *args):
    await sio.emit("get_games", {"games": public_games()}, to=sid)


@sio.on("register_player")
async def register_player(sid, gid):
    account = accounts.get(sid)
    if account is None:
        return await send_error(sid, "Musíte byť prihlásený.")
    if sid in sessions:
        return await send_error(sid, "Uz ste v hre.")
    game = games.get(gid)
    if game is None:
        return await send_error(sid, "Hra neexistuje.")
    if game.started:
        return await send_error(sid, "Hra uz zacala.")
    if len(game.players) >= 4:
        return await send_error(sid, "Prekroceny pocet hracov.")
    if any(p.player_id == account["player_id"] for p in game.players):
        return await send_error(sid, "Uz ste v tejto hre.")

    # Lowest free seat (robust if someone left the lobby before start).
    used = {p.order for p in game.players}
    order = next(o for o in range(4) if o not in used)
    player = Player(sid, account["username"], order, account["player_id"])
    game.players.append(player)
    sessions[sid] = {"gid": gid, "order": order}
    await sio.enter_room(sid, gid)
    # The token is private to this player and required for a secure reconnect.
    await sio.emit(
        "register_player",
        {"player": {"order": order, "name": player.name}, "token": player.token},
        to=sid,
    )
    await broadcast_lobby()


@sio.on("leave_game")
async def leave_game(sid):
    """Explicit exit (e.g. a 'Back to lobby' button). The socket stays
    connected and remains in the lobby room."""
    sess = sessions.pop(sid, None)
    if sess is None:
        return  # not in a game; nothing to do
    game = games.get(sess["gid"])
    if game is not None:
        await sio.leave_room(sid, game.gid)
        player = game.player_by_sid(sid)
        if game.started:
            # Game in progress: keep the seat (reconnect via token still works),
            # just mark the player offline.
            if player is not None:
                await _mark_player_offline(game, player)
        else:
            # Not started yet: free the seat entirely.
            if player is not None:
                game.players.remove(player)
            if not game.players:
                del games[game.gid]
    await broadcast_lobby()


@sio.on("start_game")
async def start_game(sid, gid):
    sess = sessions.get(sid)
    if sess is None or sess["gid"] != gid:
        return await send_error(sid, "Nie ste v tejto hre.")
    if sess["order"] != 0:
        return await send_error(sid, "Iba hostitel moze spustit hru.")
    game = games.get(gid)
    if game is None:
        return await send_error(sid, "Hra neexistuje.")
    if game.started:
        return await send_error(sid, "Hra uz zacala.")
    if len(game.players) != 4:
        return await send_error(sid, "Nedostatocny pocet hracov.")

    game.start()
    # Persist the game with its 4 seats (ordered 0..3) so history can attribute guesses.
    seated = sorted(game.players, key=lambda p: p.order)
    await history.record_game_started(gid, game.name, [p.player_id for p in seated])
    await broadcast_lobby()
    await send_game_status(gid)
    for player in game.players:
        await send_player_cards(gid, player.order, player.sid)


@sio.on("end_game")
async def end_game(sid, gid):
    """Host (seat 0) permanently ends a game that won't be finished. Marks it
    ended in the DB (so it won't be restored) and sends everyone back to the lobby."""
    sess = sessions.get(sid)
    if sess is None or sess["gid"] != gid:
        return await send_error(sid, "Nie ste v tejto hre.")
    if sess["order"] != 0:
        return await send_error(sid, "Iba hostitel moze ukoncit hru.")
    game = games.get(gid)
    if game is None:
        return await send_error(sid, "Hra neexistuje.")

    await history.mark_game_ended(gid)
    # Notify the room first (while players are still in it), then tear it down.
    await sio.emit("game_ended", {"gid": gid}, room=gid)
    for player in game.players:
        if player.sid:
            sessions.pop(player.sid, None)
            await sio.leave_room(player.sid, gid)
    del games[gid]
    await broadcast_lobby()


@sio.on("reconnect_to_game")
async def reconnect_to_game(sid, gid, token):
    # Best-effort background reconnect: fail silently (no error toast). After a
    # server restart the old token is gone -> the user rejoins from the lobby.
    game = games.get(gid)
    if game is None:
        return
    player = game.player_by_token(token)
    if player is None:
        return

    old_sid = player.sid
    if old_sid != sid:
        sessions.pop(old_sid, None)
    player.sid = sid
    player.connected = True
    sessions[sid] = {"gid": gid, "order": player.order}
    await sio.enter_room(sid, gid)
    await sio.emit(
        "register_player",
        {"player": {"order": player.order, "name": player.name}, "token": player.token},
        to=sid,
    )
    if game.started:
        await send_game_status(gid)
        await send_player_cards(gid, player.order, sid)
    await sio.emit("player_connection", {"order": player.order, "connected": True}, room=gid)
    await broadcast_lobby()


@sio.on("rejoin_game")
async def rejoin_game(sid, gid):
    """Re-seat into a game via the logged-in account (used after a server restart,
    when per-game reconnect tokens are gone). Identity comes from the session."""
    account = accounts.get(sid)
    if account is None:
        return await send_error(sid, "Musíte byť prihlásený.")
    if sid in sessions:
        return await send_error(sid, "Uz ste v hre.")
    game = games.get(gid)
    if game is None:
        return await send_error(sid, "Hra neexistuje.")
    player = next(
        (p for p in game.players if p.player_id == account["player_id"]), None
    )
    if player is None:
        return await send_error(sid, "Nie ste hracom tejto hry.")

    old_sid = player.sid
    if old_sid and old_sid != sid:
        sessions.pop(old_sid, None)
    player.sid = sid
    player.connected = True
    sessions[sid] = {"gid": gid, "order": player.order}
    await sio.enter_room(sid, gid)
    await sio.emit(
        "register_player",
        {"player": {"order": player.order, "name": player.name}, "token": player.token},
        to=sid,
    )
    if game.started:
        await send_game_status(gid)
        await send_player_cards(gid, player.order, sid)
    await sio.emit("player_connection", {"order": player.order, "connected": True}, room=gid)
    await broadcast_lobby()


# --- in-game actions (seat derived from the connection, never the client) -

@sio.on("game_status")
async def game_status(sid, *args):
    resolved = _active_game(sid)
    if resolved is None:
        return await send_error(sid, "Nie ste v rozohratej hre.")
    game, _ = resolved
    await send_game_status(game.gid)


@sio.on("player_cards")
async def player_cards(sid, *args):
    resolved = _active_game(sid)
    if resolved is None:
        return await send_error(sid, "Nie ste v rozohratej hre.")
    game, sess = resolved
    await send_player_cards(game.gid, sess["order"], sid)


@sio.on("add_guess")
async def add_guess(sid, guess):
    resolved = _active_game(sid)
    if resolved is None:
        return await send_error(sid, "Nie ste v rozohratej hre.")
    game, sess = resolved
    try:
        value = int(guess)
    except (TypeError, ValueError):
        return await send_error(sid, "Neplatny tip.")
    try:
        game.bridzik_core.add_player_guess(sess["order"], value)
    except BridzikException as exc:
        return await send_error(sid, str(exc))
    await send_game_status(game.gid)


@sio.on("play_card")
async def play_card(sid, card_key):
    resolved = _active_game(sid)
    if resolved is None:
        return await send_error(sid, "Nie ste v rozohratej hre.")
    game, sess = resolved
    core = game.bridzik_core
    hand = core.get_player_cards(sess["order"])
    try:
        key = int(card_key)
    except (TypeError, ValueError):
        return await send_error(sid, "Neplatna karta.")
    if key not in hand:
        return await send_error(sid, "Neplatna karta.")
    try:
        core.play_card(sess["order"], hand[key])
    except BridzikException as exc:
        return await send_error(sid, str(exc))
    # Persist completed rounds first so the DB-backed standings in game_status are
    # up to date (idempotent; also marks the game ended).
    await history.record_completed_rounds(game.gid, core)
    await send_game_status(game.gid)
    for player in game.players:
        await send_player_cards(game.gid, player.order, player.sid)


# --- history (read-only) --------------------------------------------------

@sio.on("get_player_history")
async def get_player_history(sid, *args):
    account = accounts.get(sid)
    if account is None:
        return await send_error(sid, "Musíte byť prihlásený.")
    rows = await history.get_player_history(account["player_id"])
    await sio.emit("get_player_history", {"games": rows}, to=sid)


@sio.on("get_game_detail")
async def get_game_detail(sid, gid):
    account = accounts.get(sid)
    if account is None:
        return await send_error(sid, "Musíte byť prihlásený.")
    detail = await history.get_game_detail(gid)
    if detail is None:
        return await send_error(sid, "Hra neexistuje.")
    await sio.emit("get_game_detail", detail, to=sid)