const express = require('express');
const path = require('path');
const session = require('express-session');
const bcrypt = require('bcrypt');
const helmet = require('helmet');
const cors = require('cors');
require('dotenv').config();

// Инициализация базы данных
const { db, initDatabase } = require('./database/init');

const app = express();
const port = process.env.PORT || 3000;

// Middleware
app.use(helmet({
    contentSecurityPolicy: false, // Отключаем для удобства разработки
}));
app.use(cors());
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

// Сессии
app.use(session({
    secret: process.env.SESSION_SECRET || 'your-secret-key-change-in-production',
    resave: false,
    saveUninitialized: false,
    cookie: {
        secure: process.env.NODE_ENV === 'production',
        maxAge: 24 * 60 * 60 * 1000 // 24 часа
    }
}));

// Middleware для проверки аутентификации
function requireAuth(req, res, next) {
    if (req.session.userId) {
        next();
    } else {
        res.status(401).json({ error: 'Authentication required' });
    }
}

// Основная страница - перенаправление на SaaS платформу
app.get('/', (req, res) => {
    res.sendFile(path.join(__dirname, 'public', 'dashboard.html'));
});

// Старая функциональность счетчика кликов (доступна по /counter)
app.get('/counter', (req, res) => {
    res.sendFile(path.join(__dirname, 'public', 'index.html'));
});

// SaaS платформа
app.get('/dashboard', (req, res) => {
    res.sendFile(path.join(__dirname, 'public', 'dashboard.html'));
});

// Health check
app.get('/health', (req, res) => {
    res.json({ status: 'ok', timestamp: new Date().toISOString() });
});

// API Routes
app.post('/api/auth/login', (req, res) => {
    const { email, password } = req.body;

    if (!email || !password) {
        return res.status(400).json({ error: 'Email and password are required' });
    }

    db.get('SELECT * FROM users WHERE email = ?', [email], (err, user) => {
        if (err) {
            return res.status(500).json({ error: 'Database error' });
        }

        if (!user) {
            return res.status(401).json({ error: 'Invalid credentials' });
        }

        bcrypt.compare(password, user.password_hash, (err, isValid) => {
            if (err || !isValid) {
                return res.status(401).json({ error: 'Invalid credentials' });
            }

            req.session.userId = user.id;
            req.session.username = user.username;

            res.json({
                user: {
                    id: user.id,
                    username: user.username,
                    email: user.email,
                    subscription_type: user.subscription_type
                }
            });
        });
    });
});

app.post('/api/auth/register', (req, res) => {
    const { username, email, password } = req.body;

    if (!username || !email || !password) {
        return res.status(400).json({ error: 'Username, email and password are required' });
    }

    if (password.length < 6) {
        return res.status(400).json({ error: 'Password must be at least 6 characters' });
    }

    bcrypt.hash(password, 10, (err, hash) => {
        if (err) {
            return res.status(500).json({ error: 'Error hashing password' });
        }

        db.run('INSERT INTO users (username, email, password_hash) VALUES (?, ?, ?)',
            [username, email, hash], function(err) {
            if (err) {
                if (err.code === 'SQLITE_CONSTRAINT') {
                    return res.status(400).json({ error: 'Username or email already exists' });
                }
                return res.status(500).json({ error: 'Database error' });
            }

            req.session.userId = this.lastID;
            req.session.username = username;

            res.status(201).json({
                user: {
                    id: this.lastID,
                    username,
                    email,
                    subscription_type: 'free'
                }
            });
        });
    });
});

app.post('/api/auth/logout', (req, res) => {
    req.session.destroy((err) => {
        if (err) {
            return res.status(500).json({ error: 'Error logging out' });
        }
        res.json({ message: 'Logged out successfully' });
    });
});

// Получение информации о пользователе
app.get('/api/user/profile', requireAuth, (req, res) => {
    db.get('SELECT id, username, email, subscription_type, created_at FROM users WHERE id = ?',
        [req.session.userId], (err, user) => {
        if (err) {
            return res.status(500).json({ error: 'Database error' });
        }
        res.json({ user });
    });
});

// Управление credentials
app.get('/api/user/credentials', requireAuth, (req, res) => {
    db.all(`SELECT id, service_name, credential_type, description, created_at
            FROM user_credentials WHERE user_id = ? AND is_active = 1`,
        [req.session.userId], (err, credentials) => {
        if (err) {
            return res.status(500).json({ error: 'Database error' });
        }
        res.json({ credentials });
    });
});

app.post('/api/user/credentials', requireAuth, (req, res) => {
    const { service_name, credential_type, value, description } = req.body;

    if (!service_name || !credential_type || !value) {
        return res.status(400).json({ error: 'Missing required fields' });
    }

    // Простое "шифрование" - в продакшене используйте настоящее шифрование
    const encrypted_value = Buffer.from(value).toString('base64');

    db.run(`INSERT OR REPLACE INTO user_credentials
            (user_id, service_name, credential_type, encrypted_value, description)
            VALUES (?, ?, ?, ?, ?)`,
        [req.session.userId, service_name, credential_type, encrypted_value, description],
        function(err) {
            if (err) {
                return res.status(500).json({ error: 'Database error' });
            }
            res.status(201).json({
                id: this.lastID,
                message: 'Credential saved successfully'
            });
        });
});

app.delete('/api/user/credentials/:id', requireAuth, (req, res) => {
    const credentialId = req.params.id;

    db.run('DELETE FROM user_credentials WHERE id = ? AND user_id = ?',
        [credentialId, req.session.userId], function(err) {
        if (err) {
            return res.status(500).json({ error: 'Database error' });
        }
        if (this.changes === 0) {
            return res.status(404).json({ error: 'Credential not found' });
        }
        res.json({ message: 'Credential deleted successfully' });
    });
});

// Шаблоны рабочих процессов
app.get('/api/templates', (req, res) => {
    const { category, featured } = req.query;
    let query = 'SELECT * FROM workflow_templates WHERE is_active = 1';
    const params = [];

    if (category) {
        query += ' AND category = ?';
        params.push(category);
    }

    if (featured === 'true') {
        query += ' AND is_featured = 1';
    }

    query += ' ORDER BY is_featured DESC, created_at DESC';

    db.all(query, params, (err, templates) => {
        if (err) {
            return res.status(500).json({ error: 'Database error' });
        }

        // Парсим JSON поля
        const processedTemplates = templates.map(template => ({
            ...template,
            template_data: JSON.parse(template.template_data),
            required_credentials: JSON.parse(template.required_credentials)
        }));

        res.json({ templates: processedTemplates });
    });
});

app.get('/api/templates/:id', (req, res) => {
    const templateId = req.params.id;

    db.get('SELECT * FROM workflow_templates WHERE id = ? AND is_active = 1',
        [templateId], (err, template) => {
        if (err) {
            return res.status(500).json({ error: 'Database error' });
        }
        if (!template) {
            return res.status(404).json({ error: 'Template not found' });
        }

        // Парсим JSON поля
        template.template_data = JSON.parse(template.template_data);
        template.required_credentials = JSON.parse(template.required_credentials);

        res.json({ template });
    });
});

// Пользовательские рабочие процессы
app.get('/api/user/workflows', requireAuth, (req, res) => {
    db.all(`SELECT uw.*, wt.name as template_name
            FROM user_workflows uw
            LEFT JOIN workflow_templates wt ON uw.template_id = wt.id
            WHERE uw.user_id = ?
            ORDER BY uw.created_at DESC`,
        [req.session.userId], (err, workflows) => {
        if (err) {
            return res.status(500).json({ error: 'Database error' });
        }
        res.json({ workflows });
    });
});

app.post('/api/user/workflows', requireAuth, (req, res) => {
    const { template_id, workflow_name, configuration } = req.body;

    if (!workflow_name) {
        return res.status(400).json({ error: 'Workflow name is required' });
    }

    db.run(`INSERT INTO user_workflows (user_id, template_id, workflow_name, configuration)
            VALUES (?, ?, ?, ?)`,
        [req.session.userId, template_id || null, workflow_name, JSON.stringify(configuration || {})],
        function(err) {
            if (err) {
                return res.status(500).json({ error: 'Database error' });
            }
            res.status(201).json({
                id: this.lastID,
                message: 'Workflow created successfully'
            });
        });
});

// Статистика использования
app.get('/api/user/stats', requireAuth, (req, res) => {
    const queries = [
        'SELECT COUNT(*) as total_workflows FROM user_workflows WHERE user_id = ?',
        'SELECT COUNT(*) as total_credentials FROM user_credentials WHERE user_id = ? AND is_active = 1',
        'SELECT COUNT(*) as total_executions FROM usage_stats WHERE user_id = ?'
    ];

    Promise.all(queries.map(query => new Promise((resolve, reject) => {
        db.get(query, [req.session.userId], (err, result) => {
            if (err) reject(err);
            else resolve(result);
        });
    }))).then(results => {
        res.json({
            stats: {
                total_workflows: results[0].total_workflows,
                total_credentials: results[1].total_credentials,
                total_executions: results[2].total_executions
            }
        });
    }).catch(() => {
        res.status(500).json({ error: 'Database error' });
    });
});

// Static файлы (после пользовательских маршрутов)
app.use(express.static(path.join(__dirname, 'public')));

// Инициализация приложения
async function startApp() {
    try {
        await initDatabase();

        app.listen(port, () => {
            console.log(`🚀 SaaS Automation Platform running on http://localhost:${port}`);
            console.log(`📊 Health check available at: http://localhost:${port}/health`);
            console.log(`🔑 Demo credentials: demo@example.com / demo123`);
        });
    } catch (error) {
        console.error('❌ Failed to initialize application:', error);
        process.exit(1);
    }
}

startApp();