/**
 * =============================================================================
 * Texas Hold'em - Модуль базы данных (SQLite)
 * =============================================================================
 */

const initSqlJs = require('sql.js');
const fs = require('fs');
const path = require('path');
const bcrypt = require('bcryptjs');
const jwt = require('jsonwebtoken');
const { v4: uuidv4 } = require('uuid');

// Путь к файлу БД
const DB_PATH = path.join(__dirname, 'poker.db');
const JWT_SECRET = process.env.JWT_SECRET || 'poker-secret-key-change-in-production';
const JWT_EXPIRES = '7d';

let db = null;

/**
 * Инициализация базы данных
 */
async function initDatabase() {
    const SQL = await initSqlJs();
    
    // Загружаем существующую БД или создаём новую
    if (fs.existsSync(DB_PATH)) {
        const buffer = fs.readFileSync(DB_PATH);
        db = new SQL.Database(buffer);
        console.log('📦 База данных загружена');
    } else {
        db = new SQL.Database();
        console.log('📦 Создана новая база данных');
    }
    
    // Создаём таблицы
    createTables();
    
    // Создаём админа по умолчанию
    await createDefaultAdmin();
    
    return db;
}

/**
 * Создание таблиц
 */
function createTables() {
    // Пользователи
    db.run(`
        CREATE TABLE IF NOT EXISTS users (
            id TEXT PRIMARY KEY,
            username TEXT UNIQUE NOT NULL,
            password_hash TEXT NOT NULL,
            role TEXT DEFAULT 'user',
            created_at TEXT DEFAULT CURRENT_TIMESTAMP,
            last_login TEXT,
            total_games INTEGER DEFAULT 0,
            total_wins INTEGER DEFAULT 0,
            total_chips_won INTEGER DEFAULT 0
        )
    `);
    
    // Настройки пользователей
    db.run(`
        CREATE TABLE IF NOT EXISTS user_settings (
            user_id TEXT PRIMARY KEY,
            sound INTEGER DEFAULT 1,
            animations INTEGER DEFAULT 1,
            show_hand_strength INTEGER DEFAULT 1,
            autofold INTEGER DEFAULT 1,
            card_back_style TEXT DEFAULT 'default',
            card_back_custom TEXT,
            FOREIGN KEY (user_id) REFERENCES users(id)
        )
    `);
    
    // Админские настройки (глобальные)
    db.run(`
        CREATE TABLE IF NOT EXISTS admin_settings (
            key TEXT PRIMARY KEY,
            value TEXT,
            updated_at TEXT DEFAULT CURRENT_TIMESTAMP,
            updated_by TEXT
        )
    `);
    
    // Логи действий
    db.run(`
        CREATE TABLE IF NOT EXISTS action_logs (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            timestamp TEXT DEFAULT CURRENT_TIMESTAMP,
            user_id TEXT,
            username TEXT,
            action_type TEXT NOT NULL,
            action_data TEXT,
            room_id TEXT,
            ip_address TEXT
        )
    `);
    
    // Чат сообщения
    db.run(`
        CREATE TABLE IF NOT EXISTS chat_messages (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            timestamp TEXT DEFAULT CURRENT_TIMESTAMP,
            room_id TEXT,
            room_type TEXT,
            user_id TEXT,
            username TEXT NOT NULL,
            message TEXT NOT NULL,
            is_system INTEGER DEFAULT 0
        )
    `);
    
    // Сессии игр
    db.run(`
        CREATE TABLE IF NOT EXISTS game_sessions (
            id TEXT PRIMARY KEY,
            room_id TEXT,
            started_at TEXT DEFAULT CURRENT_TIMESTAMP,
            ended_at TEXT,
            players TEXT,
            winner_id TEXT,
            pot_size INTEGER,
            game_data TEXT
        )
    `);
    
    saveDatabase();
    console.log('📋 Таблицы созданы');
}

/**
 * Создать админа по умолчанию
 */
async function createDefaultAdmin() {
    const adminExists = db.exec("SELECT id FROM users WHERE role = 'admin' LIMIT 1");
    
    if (adminExists.length === 0 || adminExists[0].values.length === 0) {
        const adminId = uuidv4();
        const passwordHash = bcrypt.hashSync('admin123', 10);
        
        db.run(`
            INSERT INTO users (id, username, password_hash, role)
            VALUES (?, ?, ?, 'admin')
        `, [adminId, 'admin', passwordHash]);
        
        saveDatabase();
        console.log('👑 Создан администратор по умолчанию: admin / admin123');
    }
}

/**
 * Сохранить БД на диск
 */
function saveDatabase() {
    if (db) {
        const data = db.export();
        const buffer = Buffer.from(data);
        fs.writeFileSync(DB_PATH, buffer);
    }
}

// =============================================================================
// ПОЛЬЗОВАТЕЛИ И АВТОРИЗАЦИЯ
// =============================================================================

/**
 * Регистрация пользователя
 */
function registerUser(username, password) {
    try {
        // Проверяем, существует ли пользователь
        const existing = db.exec("SELECT id FROM users WHERE username = ?", [username]);
        if (existing.length > 0 && existing[0].values.length > 0) {
            return { success: false, error: 'Пользователь уже существует' };
        }
        
        const userId = uuidv4();
        const passwordHash = bcrypt.hashSync(password, 10);
        
        db.run(`
            INSERT INTO users (id, username, password_hash)
            VALUES (?, ?, ?)
        `, [userId, username, passwordHash]);
        
        // Создаём настройки по умолчанию
        db.run(`
            INSERT INTO user_settings (user_id)
            VALUES (?)
        `, [userId]);
        
        saveDatabase();
        
        // Логируем
        logAction(userId, username, 'register', { username });
        
        // Генерируем токен
        const token = generateToken(userId, username, 'user');
        
        return { 
            success: true, 
            user: { id: userId, username, role: 'user' },
            token 
        };
    } catch (error) {
        console.error('Ошибка регистрации:', error);
        return { success: false, error: 'Ошибка регистрации' };
    }
}

/**
 * Авторизация пользователя
 */
function loginUser(username, password) {
    try {
        const result = db.exec(`
            SELECT id, username, password_hash, role 
            FROM users 
            WHERE username = ?
        `, [username]);
        
        if (result.length === 0 || result[0].values.length === 0) {
            return { success: false, error: 'Неверный логин или пароль' };
        }
        
        const [userId, storedUsername, passwordHash, role] = result[0].values[0];
        
        if (!bcrypt.compareSync(password, passwordHash)) {
            return { success: false, error: 'Неверный логин или пароль' };
        }
        
        // Обновляем last_login
        db.run(`
            UPDATE users SET last_login = datetime('now') WHERE id = ?
        `, [userId]);
        saveDatabase();
        
        // Логируем
        logAction(userId, storedUsername, 'login', { username: storedUsername });
        
        // Генерируем токен
        const token = generateToken(userId, storedUsername, role);
        
        return { 
            success: true, 
            user: { id: userId, username: storedUsername, role },
            token 
        };
    } catch (error) {
        console.error('Ошибка авторизации:', error);
        return { success: false, error: 'Ошибка авторизации' };
    }
}

/**
 * Генерировать JWT токен
 */
function generateToken(userId, username, role) {
    return jwt.sign(
        { userId, username, role },
        JWT_SECRET,
        { expiresIn: JWT_EXPIRES }
    );
}

/**
 * Проверить JWT токен
 */
function verifyToken(token) {
    try {
        return jwt.verify(token, JWT_SECRET);
    } catch (error) {
        return null;
    }
}

/**
 * Получить пользователя по ID
 */
function getUserById(userId) {
    const result = db.exec(`
        SELECT id, username, role, created_at, last_login, total_games, total_wins, total_chips_won
        FROM users 
        WHERE id = ?
    `, [userId]);
    
    if (result.length === 0 || result[0].values.length === 0) {
        return null;
    }
    
    const [id, username, role, created_at, last_login, total_games, total_wins, total_chips_won] = result[0].values[0];
    return { id, username, role, created_at, last_login, total_games, total_wins, total_chips_won };
}

// =============================================================================
// НАСТРОЙКИ
// =============================================================================

/**
 * Получить настройки пользователя
 */
function getUserSettings(userId) {
    const result = db.exec(`
        SELECT sound, animations, show_hand_strength, autofold, card_back_style, card_back_custom
        FROM user_settings
        WHERE user_id = ?
    `, [userId]);
    
    if (result.length === 0 || result[0].values.length === 0) {
        return {
            sound: true,
            animations: true,
            showHandStrength: true,
            autofold: true,
            cardBackStyle: 'default',
            cardBackCustom: null
        };
    }
    
    const [sound, animations, showHandStrength, autofold, cardBackStyle, cardBackCustom] = result[0].values[0];
    return {
        sound: !!sound,
        animations: !!animations,
        showHandStrength: !!showHandStrength,
        autofold: !!autofold,
        cardBackStyle: cardBackStyle || 'default',
        cardBackCustom
    };
}

/**
 * Сохранить настройки пользователя
 */
function saveUserSettings(userId, settings) {
    db.run(`
        INSERT OR REPLACE INTO user_settings 
        (user_id, sound, animations, show_hand_strength, autofold, card_back_style, card_back_custom)
        VALUES (?, ?, ?, ?, ?, ?, ?)
    `, [
        userId,
        settings.sound ? 1 : 0,
        settings.animations ? 1 : 0,
        settings.showHandStrength ? 1 : 0,
        settings.autofold ? 1 : 0,
        settings.cardBackStyle || 'default',
        settings.cardBackCustom || null
    ]);
    saveDatabase();
    return true;
}

/**
 * Получить админские настройки
 */
function getAdminSettings() {
    const result = db.exec(`SELECT key, value FROM admin_settings`);
    
    const settings = {
        llmEnabled: false,
        llmProvider: 'ollama',
        llmApiUrl: 'http://localhost:11434',
        llmModel: 'llama3.2',
        llmApiKey: '',
        serverUrl: 'ws://localhost:3000'
    };
    
    if (result.length > 0) {
        result[0].values.forEach(([key, value]) => {
            if (key === 'llmEnabled') {
                settings.llmEnabled = value === 'true';
            } else {
                settings[key] = value;
            }
        });
    }
    
    return settings;
}

/**
 * Сохранить админские настройки
 */
function saveAdminSettings(settings, adminId) {
    const keys = ['llmEnabled', 'llmProvider', 'llmApiUrl', 'llmModel', 'llmApiKey', 'serverUrl'];
    
    keys.forEach(key => {
        if (settings[key] !== undefined) {
            const value = typeof settings[key] === 'boolean' ? settings[key].toString() : settings[key];
            db.run(`
                INSERT OR REPLACE INTO admin_settings (key, value, updated_at, updated_by)
                VALUES (?, ?, datetime('now'), ?)
            `, [key, value, adminId]);
        }
    });
    
    saveDatabase();
    return true;
}

// =============================================================================
// ЛОГИРОВАНИЕ
// =============================================================================

/**
 * Логировать действие
 */
function logAction(userId, username, actionType, actionData = {}, roomId = null, ipAddress = null) {
    db.run(`
        INSERT INTO action_logs (user_id, username, action_type, action_data, room_id, ip_address)
        VALUES (?, ?, ?, ?, ?, ?)
    `, [userId, username, actionType, JSON.stringify(actionData), roomId, ipAddress]);
    saveDatabase();
}

/**
 * Получить логи (для админа)
 */
function getLogs(options = {}) {
    const { limit = 100, offset = 0, actionType = null, userId = null, startDate = null, endDate = null } = options;
    
    let sql = `SELECT * FROM action_logs WHERE 1=1`;
    const params = [];
    
    if (actionType) {
        sql += ` AND action_type = ?`;
        params.push(actionType);
    }
    
    if (userId) {
        sql += ` AND user_id = ?`;
        params.push(userId);
    }
    
    if (startDate) {
        sql += ` AND timestamp >= ?`;
        params.push(startDate);
    }
    
    if (endDate) {
        sql += ` AND timestamp <= ?`;
        params.push(endDate);
    }
    
    sql += ` ORDER BY timestamp DESC LIMIT ? OFFSET ?`;
    params.push(limit, offset);
    
    const result = db.exec(sql, params);
    
    if (result.length === 0) return [];
    
    return result[0].values.map(row => ({
        id: row[0],
        timestamp: row[1],
        userId: row[2],
        username: row[3],
        actionType: row[4],
        actionData: JSON.parse(row[5] || '{}'),
        roomId: row[6],
        ipAddress: row[7]
    }));
}

/**
 * Получить статистику логов
 */
function getLogStats() {
    const totalResult = db.exec(`SELECT COUNT(*) FROM action_logs`);
    const total = totalResult[0]?.values[0]?.[0] || 0;
    
    const byTypeResult = db.exec(`
        SELECT action_type, COUNT(*) as count 
        FROM action_logs 
        GROUP BY action_type 
        ORDER BY count DESC
    `);
    
    const byType = byTypeResult.length > 0 
        ? byTypeResult[0].values.map(([type, count]) => ({ type, count }))
        : [];
    
    const todayResult = db.exec(`
        SELECT COUNT(*) FROM action_logs 
        WHERE date(timestamp) = date('now')
    `);
    const today = todayResult[0]?.values[0]?.[0] || 0;
    
    return { total, byType, today };
}

// =============================================================================
// ЧАТ
// =============================================================================

/**
 * Сохранить сообщение чата
 */
function saveChatMessage(roomId, roomType, userId, username, message, isSystem = false) {
    db.run(`
        INSERT INTO chat_messages (room_id, room_type, user_id, username, message, is_system)
        VALUES (?, ?, ?, ?, ?, ?)
    `, [roomId, roomType, userId, username, message, isSystem ? 1 : 0]);
    saveDatabase();
}

/**
 * Получить историю чата комнаты
 */
function getChatHistory(roomId, limit = 50) {
    const result = db.exec(`
        SELECT timestamp, username, message, is_system
        FROM chat_messages
        WHERE room_id = ?
        ORDER BY timestamp DESC
        LIMIT ?
    `, [roomId, limit]);
    
    if (result.length === 0) return [];
    
    return result[0].values.map(row => ({
        timestamp: row[0],
        username: row[1],
        message: row[2],
        isSystem: !!row[3]
    })).reverse();
}

/**
 * Очистить чат комнаты
 */
function clearRoomChat(roomId) {
    db.run(`DELETE FROM chat_messages WHERE room_id = ?`, [roomId]);
    saveDatabase();
}

// =============================================================================
// ЭКСПОРТ
// =============================================================================

module.exports = {
    initDatabase,
    saveDatabase,
    
    // Пользователи
    registerUser,
    loginUser,
    verifyToken,
    getUserById,
    
    // Настройки
    getUserSettings,
    saveUserSettings,
    getAdminSettings,
    saveAdminSettings,
    
    // Логирование
    logAction,
    getLogs,
    getLogStats,
    
    // Чат
    saveChatMessage,
    getChatHistory,
    clearRoomChat
};