const express = require('express');
const cors = require('cors');
const helmet = require('helmet');
const rateLimit = require('express-rate-limit');
const path = require('path');
const http = require('http');
const WebSocket = require('ws');
const { v4: uuidv4 } = require('uuid');

// ==========================================
// 🛡️ TURSO DATABASE (PASSIVE CONNECTION)
// ==========================================
let db = null;
try {
    const { createClient } = require('@libsql/client');
    db = createClient({
        url: process.env.TURSO_URL || 'libsql://skydata-admin3388-6.turso.io',
        authToken: process.env.TURSO_AUTH_TOKEN || ''
    });
    console.log('[DB] Turso client initialized (passive mode).');
} catch (e) {
    console.warn('[DB] Turso client failed to load, continuing without DB:', e.message);
}

async function initDB() {
    try {
        if (!db) {
            console.log('[DB] No DB client available, skipping connection test.');
            return;
        }
        await db.execute("SELECT 1");
        console.log('[DB] Turso connection verified (SELECT 1 OK).');
    } catch (e) {
        console.warn('[DB] Turso connection test failed, server will continue in RAM-only mode:', e.message);
    }
}
initDB();

const app = express();
const server = http.createServer(app);
const wss = new WebSocket.Server({ server });
const PORT = 7860;

app.set('trust proxy', 1);
app.use(helmet({ crossOriginResourcePolicy: { policy: "cross-origin" } }));

const allowedOrigins = ['http://localhost:3000', 'https://agenuclear.gamer.gd', 'https://skydata001-space.hf.space'];

app.use(cors({
    origin: function(origin, callback) {
        if (!origin || allowedOrigins.includes(origin)) callback(null, true);
        else callback(new Error('Unauthorized'));
    },
    exposedHeaders: ['Content-Length', 'ETag', 'Last-Modified']
}));

const limiter = rateLimit({ windowMs: 15 * 60 * 1000, max: 1000, standardHeaders: true, legacyHeaders: false });
app.use(limiter);
app.use('/', express.static(path.join(__dirname, 'public'), { setHeaders: (res) => res.set('Cache-Control', 'public, max-age=86400') }));

// ==========================================
// 🎮 MULTIPLAYER GAME STATE (RAM ONLY)
// ==========================================
const rooms = new Map();
const pvpQueue = [];

function createRoom(mode, maxPlayers) {
    const roomId = uuidv4();
    rooms.set(roomId, {
        id: roomId,
        mode: mode,
        maxPlayers: maxPlayers,
        players: new Map(),     // ws -> { joinedAt, token }
        claims: new Map(),      // iso -> { name, color }
        status: 'waiting'
    });
    return roomId;
}

// ==========================================
// 🚀 WEBSOCKET HANDLER
// ==========================================
wss.on('connection', (ws, req) => {
    // Security: Check Origin
    const origin = req.headers.origin;
    if (origin && !allowedOrigins.includes(origin)) {
        ws.close(1008, 'Unauthorized Protocol');
        return;
    }

    let currentRoomId = null;
    let isClaimed = false;
    let claimTimer = null;

    ws.on('message', (message) => {
        try {
            const data = JSON.parse(message);

            // 1. JOIN MATCHMAKING (LOBBY) — فقط يحجز غرفة ويرسل معلوماتها
            if (data.type === 'join_matchmaking') {
                if (data.mode === 'ww') {
                    let targetRoom = [...rooms.values()].find(r => r.mode === 'ww' && r.players.size < r.maxPlayers);
                    if (!targetRoom) {
                        const newRoomId = createRoom('ww', 50);
                        targetRoom = rooms.get(newRoomId);
                    }
                    const matchToken = uuidv4();
                    ws.send(JSON.stringify({ type: 'match_found', roomId: targetRoom.id, token: matchToken }));
                } 
                else if (data.mode === 'pvp') {
                    pvpQueue.push(ws);
                    updatePvPQueue();

                    if (pvpQueue.length >= 2) {
                        const p1 = pvpQueue.shift();
                        const p2 = pvpQueue.shift();
                        const roomId = createRoom('pvp', 2);
                        const room = rooms.get(roomId);

                        const token1 = uuidv4();
                        const token2 = uuidv4();
                        if (p1.readyState === WebSocket.OPEN) p1.send(JSON.stringify({ type: 'match_found', roomId: room.id, token: token1 }));
                        if (p2.readyState === WebSocket.OPEN) p2.send(JSON.stringify({ type: 'match_found', roomId: room.id, token: token2 }));
                    }
                }
            }

            // 2. JOIN ROOM — اللاعب يدخل الجولة الفعلية من game.html
            if (data.type === 'join_room') {
                const room = rooms.get(data.roomId);
                if (room && room.players.size < room.maxPlayers) {
                    currentRoomId = data.roomId;
                    room.players.set(ws, { joinedAt: Date.now(), token: data.token });

                    ws.send(JSON.stringify({ type: 'joined_room', roomId: room.id }));

                    // إرسال الدول المحتلة الحالية
                    const existingClaims = Array.from(room.claims.entries()).map(([iso, info]) => ({ iso, name: info.name, color: info.color }));
                    ws.send(JSON.stringify({ type: 'room_state', claims: existingClaims }));

                    // مؤقت 120 ثانية
                    claimTimer = setTimeout(() => {
                        if (!isClaimed) {
                            ws.send(JSON.stringify({ type: 'kick', msg: 'انتهى الوقت (120 ثانية) ولم تختر دولة.' }));
                            ws.close(1000, 'Time Out');
                        }
                    }, 120000);
                } else {
                    ws.send(JSON.stringify({ type: 'error', msg: 'الغرفة ممتلئة أو غير موجودة!' }));
                }
            }

            // 3. CLAIM COUNTRY
            if (data.type === 'claim_country') {
                if (!currentRoomId) {
                    ws.send(JSON.stringify({ type: 'error', msg: 'أنت لست في جولة! أعد الدخول من اللوبي.' }));
                    return;
                }
                const room = rooms.get(currentRoomId);
                if (!room) {
                    ws.send(JSON.stringify({ type: 'error', msg: 'الغرفة غير موجودة!' }));
                    return;
                }

                const { iso, name, color } = data;

                if (isClaimed) return ws.send(JSON.stringify({ type: 'error', msg: 'أنت تملك دولة بالفعل!' }));
                if (room.claims.has(iso)) return ws.send(JSON.stringify({ type: 'error', msg: 'هذه الدولة محتلة بالفعل!' }));

                const nameTaken = Array.from(room.claims.values()).some(c => c.name === name);
                if (nameTaken) return ws.send(JSON.stringify({ type: 'error', msg: 'هذا الاسم مستخدم في هذه الجولة!' }));

                if (!/^[A-Za-z]{3,10}$/.test(name)) return ws.send(JSON.stringify({ type: 'error', msg: 'الاسم غير صالح!' }));

                room.claims.set(iso, { name, color });
                isClaimed = true;
                clearTimeout(claimTimer);

                const claimData = { type: 'player_claimed', iso, name, color };
                room.players.forEach((playerData, playerWs) => {
                    if (playerWs.readyState === WebSocket.OPEN) {
                        playerWs.send(JSON.stringify(claimData));
                    }
                });

                ws.send(JSON.stringify({ type: 'claim_success', iso, name, color }));
            }

        } catch (e) {
            console.warn('[WS] Malformed Message Detected');
        }
    });

    function updatePvPQueue() {
        pvpQueue.forEach((qWs, index) => {
            if (qWs.readyState === WebSocket.OPEN) {
                qWs.send(JSON.stringify({ type: 'queue_update', pos: index + 1, total: pvpQueue.length }));
            }
        });
    }

    ws.on('close', () => {
        const qIndex = pvpQueue.indexOf(ws);
        if (qIndex > -1) {
            pvpQueue.splice(qIndex, 1);
            updatePvPQueue();
        }

        if (currentRoomId) {
            const room = rooms.get(currentRoomId);
            if (room) {
                room.players.delete(ws);
                if (room.players.size === 0) {
                    console.log(`[RAM] Room ${room.id} ended. Claims: ${room.claims.size}. Data discarded from RAM.`);
                    rooms.delete(currentRoomId);
                }
            }
        }
    });
});

server.listen(PORT, '0.0.0.0', () => {
    console.log(`[Multiplayer] Server running on port ${PORT}`);
});