const mysql = require('mysql2/promise');
require('dotenv').config();
const fs = require('fs');
const path = require('path');

const NODE_ENV = process.env.NODE_ENV || 'development';

const getSSLConfig = () => {
    const useSSL = String(process.env.DB_SSL || '').toLowerCase() === 'true';
    const caPath = process.env.DB_SSL_CA_PATH;
    if (!useSSL) return undefined;

    try {
        if (caPath) {
            const resolved = path.resolve(caPath);
            if (fs.existsSync(resolved)) {
                console.log('🔐 (createDb) Loading DB CA certificate from:', resolved);
                return {
                    ca: fs.readFileSync(resolved),
                    rejectUnauthorized: false
                };
            } else {
                console.warn('⚠️  (createDb) CA file not found at:', resolved, '- proceeding with rejectUnauthorized:false');
            }
        } else {
            console.warn('⚠️  (createDb) DB_SSL_CA_PATH not set - proceeding with rejectUnauthorized:false');
        }
    } catch (e) {
        console.warn('⚠️  (createDb) Failed to load CA file:', e.message, '- proceeding with rejectUnauthorized:false');
    }
    return { rejectUnauthorized: false };
};

let dbConfig;
if (NODE_ENV === 'development') {
    dbConfig = {
        host: process.env.DEV_DB_HOST || 'localhost',
        port: Number(process.env.DEV_DB_PORT) || 3306,
        user: process.env.DEV_DB_USER || 'root',
        password: process.env.DEV_DB_PASSWORD || '', // XAMPP default: no password
        database: process.env.DEV_DB_NAME || 'profitplanet_centralserver',
        ssl: undefined
    };
} else {
    dbConfig = {
        host: process.env.DB_HOST,
        port: Number(process.env.DB_PORT) || 3306,
        user: process.env.DB_USER,
        password: process.env.DB_PASSWORD,
        database: process.env.DB_NAME,
        ssl: getSSLConfig()
    };
}

const allowCreateDb = String(process.env.DB_ALLOW_CREATE_DB || 'false').toLowerCase() === 'true';

// --- Performance Helpers (added) ---
async function ensureIndex(conn, table, indexName, indexDDL) {
    const [rows] = await conn.query(`SHOW INDEX FROM \`${table}\` WHERE Key_name = ?`, [indexName]);
    if (!rows.length) {
        await conn.query(`CREATE INDEX \`${indexName}\` ON \`${table}\` (${indexDDL})`);
        console.log(`🆕 Created index ${indexName} ON ${table}`);
    } else {
        console.log(`ℹ️  Index ${indexName} already exists on ${table}`);
    }
}

async function createDatabase() {
    console.log('🚀 Starting MySQL database initialization...');
    console.log('📍 Database host:', process.env.DB_HOST);
    console.log('📍 Database name:', process.env.DB_NAME);
    
    let connection;
    try {
        if (allowCreateDb) {
            // Connect without specifying a database to create it if it doesn't exist
            connection = await mysql.createConnection({
                host: dbConfig.host,
                port: dbConfig.port,
                user: dbConfig.user,
                password: dbConfig.password,
                ssl: dbConfig.ssl
            });

            await connection.query(`CREATE DATABASE IF NOT EXISTS \`${dbConfig.database}\`;`);
            console.log(`✅ Database "${dbConfig.database}" created/verified`);
            await connection.end();
        } else {
            console.log('ℹ️  Skipping database creation (DB_ALLOW_CREATE_DB=false)');
        }

        // Reconnect with the database specified
        connection = await mysql.createConnection(dbConfig);
        console.log('✅ Connected to MySQL database');

        // --- Core Tables ---

        // 1. users table: Central user authentication and common attributes
        await connection.query(`
            CREATE TABLE IF NOT EXISTS users (
                id INT AUTO_INCREMENT PRIMARY KEY,
                email VARCHAR(255) UNIQUE NOT NULL,
                password VARCHAR(255) NOT NULL,
                user_type ENUM('personal', 'company') NOT NULL,
                role ENUM('user', 'admin', 'super_admin') DEFAULT 'user',
                iban VARCHAR(34),
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                last_login_at TIMESTAMP NULL,
                INDEX idx_email (email),
                INDEX idx_user_type (user_type),
                INDEX idx_role (role)
            );
        `);
        console.log('✅ Users table created/verified');

        // 2. personal_profiles table: Details specific to personal users
        await connection.query(`
            CREATE TABLE IF NOT EXISTS personal_profiles (
                id INT AUTO_INCREMENT PRIMARY KEY,
                user_id INT NOT NULL,
                first_name VARCHAR(255) NOT NULL,
                last_name VARCHAR(255) NOT NULL,
                phone VARCHAR(255) NULL,
                date_of_birth DATE,
                nationality VARCHAR(255),
                address TEXT,
                zip_code VARCHAR(20),
                city VARCHAR(100),
                country VARCHAR(100),
                phone_secondary VARCHAR(255),
                emergency_contact_name VARCHAR(255),
                emergency_contact_phone VARCHAR(255),
                account_holder_name VARCHAR(255),
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
                UNIQUE KEY unique_user_profile (user_id)
            );
        `);
        console.log('✅ Personal profiles table created/verified');

        // 3. company_profiles table: Details specific to company users
        await connection.query(`
            CREATE TABLE IF NOT EXISTS company_profiles (
                id INT AUTO_INCREMENT PRIMARY KEY,
                user_id INT NOT NULL,
                company_name VARCHAR(255) NOT NULL,
                registration_number VARCHAR(255) UNIQUE,
                phone VARCHAR(255) NULL,
                address TEXT,
                zip_code VARCHAR(20),
                city VARCHAR(100),
                country VARCHAR(100),
                branch VARCHAR(255),
                number_of_employees INT,
                business_type VARCHAR(255),
                contact_person_name VARCHAR(255),
                contact_person_phone VARCHAR(255),
                account_holder_name VARCHAR(255),
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
                UNIQUE KEY unique_user_profile (user_id),
                UNIQUE KEY unique_registration_number (registration_number)
            );
        `);
        console.log('✅ Company profiles table created/verified');

        // 4. user_status table: Comprehensive tracking of user verification and completion steps
        await connection.query(`
            CREATE TABLE IF NOT EXISTS user_status (
                user_id INT PRIMARY KEY,
                status ENUM('inactive', 'pending', 'active', 'suspended', 'archived') DEFAULT 'pending',
                previous_status ENUM('inactive', 'pending', 'active', 'suspended', 'archived') NULL,
                email_verified BOOLEAN DEFAULT FALSE,
                email_verified_at TIMESTAMP NULL,
                profile_completed BOOLEAN DEFAULT FALSE,
                profile_completed_at TIMESTAMP NULL,
                documents_uploaded BOOLEAN DEFAULT FALSE,
                documents_uploaded_at TIMESTAMP NULL,
                contract_signed BOOLEAN DEFAULT FALSE,
                contract_signed_at TIMESTAMP NULL,
                is_admin_verified BOOLEAN DEFAULT FALSE,
                admin_verified_at TIMESTAMP NULL,
                registration_completed BOOLEAN DEFAULT FALSE,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
            );
        `);
        console.log('✅ User status table created/verified');
        
        // Modify existing ENUM columns to add 'archived' status (for existing databases)
        try {
            await connection.query(`
                ALTER TABLE user_status 
                MODIFY COLUMN status ENUM('inactive', 'pending', 'active', 'suspended', 'archived') DEFAULT 'pending'
            `);
            console.log('✅ Updated status column to include archived');
        } catch (err) {
            console.warn('⚠️  Could not modify status column:', err.message);
        }
        
        try {
            await connection.query(`
                ALTER TABLE user_status 
                MODIFY COLUMN previous_status ENUM('inactive', 'pending', 'active', 'suspended', 'archived') NULL
            `);
            console.log('✅ Updated previous_status column to include archived');
        } catch (err) {
            console.warn('⚠️  Could not modify previous_status column:', err.message);
        }

        // --- Authentication & Verification Tables ---

        // 5. refresh_tokens table: For refresh token authentication
        await connection.query(`
            CREATE TABLE IF NOT EXISTS refresh_tokens (
                id INT AUTO_INCREMENT PRIMARY KEY,
                user_id INT NOT NULL,
                token VARCHAR(255) UNIQUE NOT NULL,
                expires_at DATETIME NOT NULL,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                revoked_at TIMESTAMP NULL,
                FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
                INDEX idx_user_id (user_id),
                INDEX idx_expires_at (expires_at)
            );
        `);
        console.log('✅ Refresh tokens table created/verified');

        // 6. email_verifications table: For email verification codes
        await connection.query(`
            CREATE TABLE IF NOT EXISTS email_verifications (
                id INT AUTO_INCREMENT PRIMARY KEY,
                user_id INT NOT NULL,
                verification_code VARCHAR(6) NOT NULL,
                expires_at DATETIME NOT NULL,
                verified_at TIMESTAMP NULL,
                attempts INT DEFAULT 0,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
                INDEX idx_user_code (user_id, verification_code),
                INDEX idx_expires_at (expires_at)
            );
        `);
        console.log('✅ Email verifications table created/verified');

        // 7. password_resets table: For password reset tokens
        await connection.query(`
            CREATE TABLE IF NOT EXISTS password_resets (
                id INT AUTO_INCREMENT PRIMARY KEY,
                user_id INT NOT NULL,
                token VARCHAR(255) UNIQUE NOT NULL,
                expires_at DATETIME NOT NULL,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                used_at TIMESTAMP NULL,
                FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
                INDEX idx_user_token (user_id, token),
                INDEX idx_expires_at (expires_at)
            );
        `);
        console.log('✅ Password resets table created/verified');

        // --- Document & Logging Tables ---

        // 8. user_documents table: Stores object storage IDs
        await connection.query(`
            CREATE TABLE IF NOT EXISTS user_documents (
                id INT AUTO_INCREMENT PRIMARY KEY,
                user_id INT NOT NULL,
                document_type ENUM('personal_id', 'company_id', 'signature', 'contract', 'other') NOT NULL,
                object_storage_id VARCHAR(255) UNIQUE NOT NULL,
                original_filename VARCHAR(255),
                file_size INT,
                mime_type VARCHAR(100),
                upload_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                verified_by_admin BOOLEAN DEFAULT FALSE,
                admin_verified_at TIMESTAMP NULL,
                FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
                INDEX idx_user_document_type (user_id, document_type),
                INDEX idx_object_storage_id (object_storage_id)
            );
        `);
        console.log('✅ User documents table created/verified');

        // 8c. document_templates table: Stores template metadata and object storage keys
        await connection.query(`
            CREATE TABLE IF NOT EXISTS document_templates (
                id INT AUTO_INCREMENT PRIMARY KEY,
                name VARCHAR(255) NOT NULL,
                type VARCHAR(100) NOT NULL,
                storageKey VARCHAR(255) NOT NULL,
                description TEXT,
                lang VARCHAR(10) NOT NULL,
                user_type ENUM('personal','company','both') DEFAULT 'both',
                version INT DEFAULT 1,
                state ENUM('active','inactive') DEFAULT 'inactive',
                createdAt TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updatedAt TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
            );
        `);
        console.log('✅ Document templates table created/verified');

        // 8b. user_id_documents table: Stores ID-specific metadata (front/back object storage IDs)
        await connection.query(`
            CREATE TABLE IF NOT EXISTS user_id_documents (
                id INT AUTO_INCREMENT PRIMARY KEY,
                user_id INT NOT NULL,
                document_type ENUM('personal_id', 'company_id') NOT NULL,
                front_object_storage_id VARCHAR(255) NOT NULL,
                back_object_storage_id VARCHAR(255) NULL,
                original_filename_front VARCHAR(255),
                original_filename_back VARCHAR(255),
                id_type VARCHAR(50),
                id_number VARCHAR(100),
                expiry_date DATE,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE
            );
        `);
        console.log('✅ User ID documents table created/verified');

        // 9. user_action_logs table: For detailed user activity logging
        await connection.query(`
            CREATE TABLE IF NOT EXISTS user_action_logs (
                id INT AUTO_INCREMENT PRIMARY KEY,
                user_id INT NULL,
                affected_user_id INT NULL,
                action VARCHAR(100) NOT NULL,
                performed_by_user_id INT NULL,
                details JSON,
                ip_address VARCHAR(45),
                user_agent TEXT,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE,               -- NEW FK
                FOREIGN KEY (affected_user_id) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE,
                FOREIGN KEY (performed_by_user_id) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE,
                INDEX idx_user_id (user_id),                                                                 -- NEW index
                INDEX idx_affected_user (affected_user_id),
                INDEX idx_performed_by (performed_by_user_id),
                INDEX idx_action (action),
                INDEX idx_created_at (created_at)
            );
        `);
        console.log('✅ User action logs table created/verified');

        // --- Add missing user_id column for existing databases + backfill ---
        try {
          // Add column if missing
          await connection.query(`ALTER TABLE user_action_logs ADD COLUMN user_id INT NULL`);
          console.log('🆕 Added user_action_logs.user_id column');

          // Add FK if just added
          try {
            await connection.query(`
              ALTER TABLE user_action_logs
              ADD CONSTRAINT fk_user_action_logs_user
              FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE
            `);
            console.log('🆕 Added FK fk_user_action_logs_user');
          } catch (e) {
            console.log('ℹ️  FK fk_user_action_logs_user already exists or cannot add:', e.message);
          }

          // Add index if missing
          try {
            await connection.query(`CREATE INDEX idx_user_id ON user_action_logs (user_id)`);
            console.log('🆕 Added index idx_user_id on user_action_logs.user_id');
          } catch (e) {
            console.log('ℹ️  idx_user_id already exists or cannot add:', e.message);
          }

          // Backfill: prefer performed_by_user_id, else affected_user_id
          try {
            const [res1] = await connection.query(`
              UPDATE user_action_logs
              SET user_id = performed_by_user_id
              WHERE user_id IS NULL AND performed_by_user_id IS NOT NULL
            `);
            const [res2] = await connection.query(`
              UPDATE user_action_logs
              SET user_id = affected_user_id
              WHERE user_id IS NULL AND affected_user_id IS NOT NULL
            `);
            console.log('🧹 Backfilled user_action_logs.user_id from performed_by_user_id/affected_user_id');
          } catch (e) {
            console.warn('⚠️  Could not backfill user_action_logs.user_id:', e.message);
          }
        } catch (e) {
          // Column may already exist; ignore
          if (!/Duplicate column name|exists/i.test(e.message)) {
            console.log('ℹ️  user_action_logs.user_id add skipped or not required:', e.message);
          } else {
            console.log('ℹ️  user_action_logs.user_id already exists');
          }
        }

        // --- Email & Registration Flow Tables ---

        // 10. email_attempts table: For tracking email sending attempts
        await connection.query(`
            CREATE TABLE IF NOT EXISTS email_attempts (
                id INT AUTO_INCREMENT PRIMARY KEY,
                user_id INT NOT NULL,
                attempt_type ENUM('verification', 'password_reset', 'registration_completion', 'notification', 'other') NOT NULL,
                email_address VARCHAR(255) NOT NULL,
                success BOOLEAN DEFAULT FALSE,
                error_message TEXT,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
                INDEX idx_user_attempts (user_id, attempt_type),
                INDEX idx_created_at (created_at)
            );
        `);
        console.log('✅ Email attempts table created/verified');

        // --- Referral Tables ---

        // 12. referral_tokens table: Manages referral codes
        await connection.query(`
            CREATE TABLE IF NOT EXISTS referral_tokens (
                id INT AUTO_INCREMENT PRIMARY KEY,
                token VARCHAR(64) UNIQUE NOT NULL,
                created_by_user_id INT NOT NULL,
                expires_at DATETIME NOT NULL,
                max_uses INT DEFAULT -1,
                uses_remaining INT DEFAULT -1,
                status ENUM('active', 'inactive', 'expired', 'exhausted') DEFAULT 'active',
                deactivation_reason VARCHAR(50),
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                FOREIGN KEY (created_by_user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
                INDEX idx_token (token),
                INDEX idx_status_expires (status, expires_at),
                INDEX idx_created_by (created_by_user_id)
            );
        `);
        
          // News table for News Manager
          await connection.query(`
            CREATE TABLE IF NOT EXISTS news (
              id INT AUTO_INCREMENT PRIMARY KEY,
              title VARCHAR(255) NOT NULL,
              summary TEXT NULL,
              content MEDIUMTEXT NULL,
              slug VARCHAR(255) UNIQUE NOT NULL,
              category VARCHAR(128) NULL,
              object_storage_id VARCHAR(255) NULL,
              original_filename VARCHAR(255) NULL,
              is_active TINYINT(1) NOT NULL DEFAULT 1,
              published_at DATETIME NULL,
              created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
              updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
            );
          `);
          console.log('✅ News table created/verified');
        console.log('✅ Referral tokens table created/verified');

        // 13. referral_token_usage table: Tracks each use of a referral token
        await connection.query(`
            CREATE TABLE IF NOT EXISTS referral_token_usage (
                id INT AUTO_INCREMENT PRIMARY KEY,
                referral_token_id INT NOT NULL,
                used_by_user_id INT NOT NULL,
                used_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                FOREIGN KEY (referral_token_id) REFERENCES referral_tokens(id) ON DELETE CASCADE ON UPDATE CASCADE,
                FOREIGN KEY (used_by_user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
                UNIQUE KEY unique_token_user_usage (referral_token_id, used_by_user_id),
                INDEX idx_token_usage (referral_token_id),
                INDEX idx_user_usage (used_by_user_id)
            );
        `);
        console.log('✅ Referral token usage table created/verified');

        // --- Authorization Tables ---

        // 14. permissions table: Defines granular permissions
        await connection.query(`
            CREATE TABLE IF NOT EXISTS permissions (
                id INT AUTO_INCREMENT PRIMARY KEY,
                name VARCHAR(100) UNIQUE NOT NULL,
                description VARCHAR(255),
                is_active BOOLEAN DEFAULT TRUE,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP, -- Added
                created_by INT NULL, -- Added
                FOREIGN KEY (created_by) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE
            );
        `);
        console.log('✅ Permissions table created/verified');

        // 15. user_permissions join table: Assigns specific permissions to users
        await connection.query(`
            CREATE TABLE IF NOT EXISTS user_permissions (
                id INT AUTO_INCREMENT PRIMARY KEY,
                user_id INT NOT NULL,
                permission_id INT NOT NULL,
                granted_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                granted_by INT NULL, -- Added column
                FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
                FOREIGN KEY (permission_id) REFERENCES permissions(id) ON DELETE CASCADE ON UPDATE CASCADE,
                FOREIGN KEY (granted_by) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE, -- FK constraint
                UNIQUE KEY unique_user_permission (user_id, permission_id)
            );
        `);
        console.log('✅ User permissions table created/verified');

        // --- User Settings Table ---
        await connection.query(`
            CREATE TABLE IF NOT EXISTS user_settings (
                user_id INT PRIMARY KEY,
                theme ENUM('light', 'dark') DEFAULT 'light',
                font_size ENUM('normal', 'large') DEFAULT 'normal',
                high_contrast_mode BOOLEAN DEFAULT FALSE,
                two_factor_auth_enabled BOOLEAN DEFAULT FALSE,
                account_visibility ENUM('public', 'private') DEFAULT 'public',
                show_email BOOLEAN DEFAULT TRUE,
                show_phone BOOLEAN DEFAULT TRUE,
                data_export_requested BOOLEAN DEFAULT FALSE,
                last_data_export_at TIMESTAMP NULL,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE
            );
        `);
        console.log('✅ User settings table created/verified');

        // --- Rate Limiting Table ---
        await connection.query(`
            CREATE TABLE IF NOT EXISTS rate_limit (
                id INT AUTO_INCREMENT PRIMARY KEY,
                rate_key VARCHAR(255) NOT NULL,
                window_start DATETIME NOT NULL,
                count INT DEFAULT 0,
                window_seconds INT NOT NULL,
                max INT NOT NULL,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                UNIQUE KEY unique_key_window (rate_key, window_start)
            );
        `);
        console.log('✅ Rate limit table created/verified');

        // --- Tax: countries and VAT rates ---
        await connection.query(`
            CREATE TABLE IF NOT EXISTS countries (
                id INT AUTO_INCREMENT PRIMARY KEY,
                country_code VARCHAR(3) NOT NULL,
                country_name VARCHAR(255) NOT NULL,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                created_by INT NULL,
                updated_by INT NULL,
                CONSTRAINT uq_country_code UNIQUE (country_code),
                INDEX idx_country_name (country_name),
                FOREIGN KEY (created_by) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE,
                FOREIGN KEY (updated_by) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE
            );
        `);
        console.log('✅ Countries table created/verified');

        await connection.query(`
            CREATE TABLE IF NOT EXISTS vat_rates (
                id BIGINT AUTO_INCREMENT PRIMARY KEY,
                country_id INT NOT NULL,
                standard_rate DECIMAL(6,3) NULL,
                reduced_rate DECIMAL(6,3) NULL,
                super_reduced_rate DECIMAL(6,3) NULL,
                parking_rate DECIMAL(6,3) NULL,
                effective_from DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
                effective_to DATETIME NULL,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                created_by INT NULL,
                updated_by INT NULL,
                FOREIGN KEY (country_id) REFERENCES countries(id) ON DELETE CASCADE ON UPDATE CASCADE,
                FOREIGN KEY (created_by) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE,
                FOREIGN KEY (updated_by) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE,
                INDEX idx_vat_country_eff_to (country_id, effective_to),
                INDEX idx_vat_standard (standard_rate)
            );
        `);
        console.log('✅ VAT rates table created/verified');

        await connection.query(`
            CREATE TABLE IF NOT EXISTS vat_rate_history (
                id BIGINT AUTO_INCREMENT PRIMARY KEY,
                country_id INT NOT NULL,
                standard_rate DECIMAL(6,3) NULL,
                reduced_rate DECIMAL(6,3) NULL,
                super_reduced_rate DECIMAL(6,3) NULL,
                parking_rate DECIMAL(6,3) NULL,
                effective_from DATETIME NOT NULL,
                effective_to DATETIME NULL,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                created_by INT NULL,
                updated_by INT NULL,
                FOREIGN KEY (country_id) REFERENCES countries(id) ON DELETE CASCADE ON UPDATE CASCADE,
                FOREIGN KEY (created_by) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE,
                FOREIGN KEY (updated_by) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE,
                INDEX idx_vat_hist_country_from (country_id, effective_from),
                INDEX idx_vat_hist_country_to (country_id, effective_to)
            );
        `);
        console.log('✅ VAT rate history table created/verified');

        // --- NEW: company_stamps table (for company/admin managed stamps) ---
        await connection.query(`
            CREATE TABLE IF NOT EXISTS company_stamps (
                id INT AUTO_INCREMENT PRIMARY KEY,
                company_id INT NOT NULL,
                label VARCHAR(100) NULL,
                mime_type VARCHAR(50) NOT NULL,
                image_base64 LONGTEXT NOT NULL,
                is_active BOOLEAN DEFAULT FALSE,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                FOREIGN KEY (company_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
                UNIQUE KEY unique_company_label (company_id, label),
                INDEX idx_company_active (company_id, is_active)
            );
        `);
        console.log('✅ Company stamps table created/verified');

        // --- Coffee / Subscriptions Table (simplified) ---
        await connection.query(`
            CREATE TABLE IF NOT EXISTS coffee_table (
                id BIGINT AUTO_INCREMENT PRIMARY KEY,
                title VARCHAR(200) NOT NULL,
                description TEXT NOT NULL,
                price DECIMAL(10,2) NOT NULL DEFAULT 0.00,
                currency CHAR(3) NOT NULL DEFAULT 'EUR',
                is_featured BOOLEAN NOT NULL DEFAULT FALSE,
                billing_interval ENUM('day','week','month','year') NULL,
                interval_count INT UNSIGNED NULL,
                object_storage_id VARCHAR(255) NULL,
                original_filename VARCHAR(255) NULL,
                state BOOLEAN NOT NULL DEFAULT TRUE,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
            );
        `);
        console.log('✅ Coffee table (simplified) created/verified');

        // --- Pools Table ---
        await connection.query(`
            CREATE TABLE IF NOT EXISTS pools (
                id INT AUTO_INCREMENT PRIMARY KEY,
                pool_name VARCHAR(255) NOT NULL,
                description TEXT,
                price DECIMAL(10,2) NOT NULL DEFAULT 0.00,
                pool_type ENUM('coffee', 'other') NOT NULL DEFAULT 'other',
                is_active BOOLEAN DEFAULT TRUE,
                created_by INT NULL,
                updated_by INT NULL,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                FOREIGN KEY (created_by) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE,
                FOREIGN KEY (updated_by) REFERENCES users(id) ON DELETE SET NULL ON UPDATE CASCADE,
                INDEX idx_pool_type (pool_type),
                INDEX idx_is_active (is_active)
            );
        `);
        console.log('✅ Pools table created/verified');

        // --- Affiliates Table ---
        await connection.query(`
            CREATE TABLE IF NOT EXISTS affiliates (
                id INT AUTO_INCREMENT PRIMARY KEY,
                name VARCHAR(255) NOT NULL,
                description TEXT,
                url VARCHAR(512) NOT NULL,
                object_storage_id VARCHAR(255) NULL,
                original_filename VARCHAR(255) NULL,
                category VARCHAR(100) NOT NULL,
                is_active BOOLEAN DEFAULT TRUE,
                commission_rate VARCHAR(50),
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                INDEX idx_category (category),
                INDEX idx_is_active (is_active)
            );
        `);
        console.log('✅ Affiliates table created/verified');

        // --- Matrix: Global 5-ary tree config and relations ---
        await connection.query(`
            CREATE TABLE IF NOT EXISTS matrix_config (
                id TINYINT PRIMARY KEY DEFAULT 1,
                master_top_user_id INT NOT NULL,
                name VARCHAR(255) NULL,                -- ADDED (was missing, caused Unknown column 'name')
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                CONSTRAINT fk_matrix_config_master FOREIGN KEY (master_top_user_id) REFERENCES users(id) ON DELETE RESTRICT ON UPDATE CASCADE,
                CONSTRAINT chk_matrix_singleton CHECK (id = 1)
            );
        `);
        // Safeguard: if table pre-existed without name column, add it
        try {
          await connection.query(`ALTER TABLE matrix_config ADD COLUMN name VARCHAR(255) NULL`);
          console.log('🆕 Added missing matrix_config.name column');
        } catch (e) {
          if (!/Duplicate column/i.test(e.message)) {
            console.log('ℹ️  matrix_config.name alter skipped:', e.message);
          }
        }
        console.log('✅ Matrix config table created/verified');

        await connection.query(`
            CREATE TABLE IF NOT EXISTS user_tree_edges (
                id BIGINT AUTO_INCREMENT PRIMARY KEY,
                parent_user_id INT NOT NULL,
                child_user_id INT NOT NULL,
                position INT NOT NULL,                                -- CHANGED: allow unlimited positions
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                CONSTRAINT fk_edges_parent FOREIGN KEY (parent_user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
                CONSTRAINT fk_edges_child FOREIGN KEY (child_user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
                CONSTRAINT uq_child UNIQUE (child_user_id),
                CONSTRAINT uq_parent_position UNIQUE (parent_user_id, position)
                -- REMOVED: chk_position CHECK (position BETWEEN 1 AND 5)
            );
        `);
        console.log('✅ User tree edges table created/verified');

        // --- Migration: relax position constraints on existing schemas ---
        try {
          await connection.query(`ALTER TABLE user_tree_edges MODIFY COLUMN position INT NOT NULL`);
          console.log('🛠️  user_tree_edges.position changed to INT');
        } catch (e) {
          console.log('ℹ️  position type change skipped:', e.message);
        }
        try {
          await connection.query(`ALTER TABLE user_tree_edges DROP CHECK chk_position`);
          console.log('🧹 Dropped CHECK constraint chk_position on user_tree_edges');
        } catch (e) {
          // MySQL versions or engines may report different messages if CHECK is not enforced or named differently
          console.log('ℹ️  DROP CHECK chk_position skipped:', e.message);
        }

        await connection.query(`
            CREATE TABLE IF NOT EXISTS matrix_instances (
              id INT AUTO_INCREMENT PRIMARY KEY,
              root_user_id INT NOT NULL,
              name VARCHAR(255) NULL,
              is_active BOOLEAN DEFAULT TRUE,
              max_depth INT NULL,
              ego_activated_at TIMESTAMP NULL,
              immediate_children_count INT DEFAULT 0,
              first_free_position TINYINT NULL,
              created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
              updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
              CONSTRAINT fk_matrix_instances_root FOREIGN KEY (root_user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
              CONSTRAINT chk_first_free_pos CHECK (first_free_position IS NULL OR (first_free_position BETWEEN 1 AND 5))
            );
        `);
        console.log('✅ matrix_instances table created/verified');

        // Legacy: ensure legacy matrix_config exists (still needed short-term for migration)
        await connection.query(`
          CREATE TABLE IF NOT EXISTS matrix_config (
            id TINYINT PRIMARY KEY DEFAULT 1,
            master_top_user_id INT NOT NULL,
            name VARCHAR(255) NULL,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
            updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
            CONSTRAINT fk_matrix_config_master FOREIGN KEY (master_top_user_id) REFERENCES users(id) ON DELETE RESTRICT ON UPDATE CASCADE
          );
        `);
        console.log('ℹ️  matrix_config (legacy) verified');

        // --- user_matrix_metadata: add matrix_instance_id + alter PK ---
        await connection.query(`
          CREATE TABLE IF NOT EXISTS user_matrix_metadata (
            matrix_instance_id INT PRIMARY KEY,
            root_user_id INT NOT NULL,
            ego_activated_at TIMESTAMP NULL,
            last_bfs_fill_at TIMESTAMP NULL,
            immediate_children_count INT DEFAULT 0,
            first_free_position TINYINT NULL,
            name VARCHAR(255) NULL,
            is_active BOOLEAN DEFAULT TRUE,
            max_depth INT NULL,
            updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
            CONSTRAINT fk_meta_instance FOREIGN KEY (matrix_instance_id) REFERENCES matrix_instances(id) ON DELETE CASCADE ON UPDATE CASCADE,
            CONSTRAINT fk_meta_root FOREIGN KEY (root_user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
            CONSTRAINT chk_meta_first_free CHECK (first_free_position IS NULL OR (first_free_position BETWEEN 1 AND 5)),
            INDEX idx_meta_root (root_user_id)
          );
        `);
        console.log('✅ user_matrix_metadata (multi) created/verified');

        // Migration: if legacy data without matrix_instances rows
        const [instCheck] = await connection.query(`SELECT COUNT(*) AS cnt FROM matrix_instances`);
        if (Number(instCheck[0].cnt) === 0) {
          const [legacyCfg] = await connection.query(`SELECT master_top_user_id, name FROM matrix_config WHERE id=1`);
            if (legacyCfg.length) {
              const legacyRoot = legacyCfg[0].master_top_user_id;
              const legacyName = legacyCfg[0].name || null;
              // Determine existing root children stats
              const [legacyEdges] = await connection.query(`SELECT position FROM user_tree_edges WHERE parent_user_id = ?`, [legacyRoot]);
              const usedRootPos = new Set(legacyEdges.map(r => Number(r.position)));
              let firstFree = null;
              for (let i = 1; i <= 5; i++) { if (!usedRootPos.has(i)) { firstFree = i; break; } }
              // Create initial instance
              const [instRes] = await connection.query(`
                INSERT INTO matrix_instances
                  (root_user_id, name, is_active, max_depth, ego_activated_at, immediate_children_count, first_free_position)
                VALUES (?, ?, TRUE, NULL, NOW(), ?, NULL)         -- CHANGED: first_free_position NULL for root
              `, [legacyRoot, legacyName, legacyEdges.length, /* firstFree removed */ null]);
              const firstInstanceId = instRes.insertId;
              // Backfill metadata
              await connection.query(`
                INSERT INTO user_matrix_metadata
                  (matrix_instance_id, root_user_id, ego_activated_at, immediate_children_count, first_free_position, name, is_active, max_depth)
                VALUES (?, ?, NOW(), ?, ?, ?, TRUE, NULL)
              `, [firstInstanceId, legacyRoot, legacyEdges.length, firstFree, legacyName]);
              console.log('🧩 Migration: created first matrix_instance id=', firstInstanceId);
            }
        }

        // --- Legacy cleanup: remove old matrix_id / fk_edges_matrix referencing obsolete `matrices` table ---
        try {
          const [legacyCols] = await connection.query(`SHOW COLUMNS FROM user_tree_edges LIKE 'matrix_id'`);
          if (legacyCols.length) {
            console.log('🧹 Found legacy user_tree_edges.matrix_id; dropping old FK & column');
            try { await connection.query(`ALTER TABLE user_tree_edges DROP FOREIGN KEY fk_edges_matrix`); } catch (e) {
              console.log('ℹ️  fk_edges_matrix drop skipped:', e.message);
            }
            try { await connection.query(`ALTER TABLE user_tree_edges DROP COLUMN matrix_id`); } catch (e) {
              console.log('ℹ️  matrix_id column drop skipped:', e.message);
            }
          }
        } catch (e) {
          console.log('ℹ️  Legacy matrix_id cleanup check failed:', e.message);
        }

        // --- Ensure multi-instance columns (idempotent) ---
        try { await connection.query(`ALTER TABLE user_tree_edges ADD COLUMN matrix_instance_id INT NULL`); } catch (_) {}
        try { await connection.query(`ALTER TABLE user_tree_edges ADD COLUMN rogue_user BOOLEAN DEFAULT FALSE`); } catch (_) {}
        try {
          await connection.query(`
            ALTER TABLE user_tree_edges
            ADD CONSTRAINT fk_edges_instance FOREIGN KEY (matrix_instance_id)
            REFERENCES matrix_instances(id) ON DELETE CASCADE ON UPDATE CASCADE
          `);
          console.log('🆕 FK fk_edges_instance added');
        } catch (e) {
          console.log('ℹ️  fk_edges_instance already exists or failed:', e.message);
        }

        // Backfill matrix_instance_id for existing edges
        const [firstInstRow] = await connection.query(`SELECT id FROM matrix_instances ORDER BY id ASC LIMIT 1`);
        const firstInstanceId = firstInstRow[0]?.id;
        if (firstInstanceId) {
          await connection.query(`UPDATE user_tree_edges SET matrix_instance_id = ? WHERE matrix_instance_id IS NULL`, [firstInstanceId]);
        }

        // Indexes (idempotent)
        try { await connection.query(`CREATE INDEX idx_edges_instance_parent ON user_tree_edges (matrix_instance_id, parent_user_id)`); } catch (_) {}
        try { await connection.query(`CREATE INDEX idx_edges_instance_child ON user_tree_edges (matrix_instance_id, child_user_id)`); } catch (_) {}
        try { await connection.query(`CREATE INDEX idx_edges_rogue ON user_tree_edges (matrix_instance_id, rogue_user)`); } catch (_) {}

        // --- Alter user_tree_closure: add matrix_instance_id ---
        await connection.query(`
          CREATE TABLE IF NOT EXISTS user_tree_closure (
            matrix_instance_id INT NOT NULL,
            ancestor_user_id INT NOT NULL,
            descendant_user_id INT NOT NULL,
            depth INT NOT NULL,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
            CONSTRAINT pk_closure PRIMARY KEY (matrix_instance_id, ancestor_user_id, descendant_user_id),
            CONSTRAINT fk_closure_instance FOREIGN KEY (matrix_instance_id) REFERENCES matrix_instances(id) ON DELETE CASCADE ON UPDATE CASCADE,
            CONSTRAINT fk_closure_ancestor FOREIGN KEY (ancestor_user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
            CONSTRAINT fk_closure_descendant FOREIGN KEY (descendant_user_id) REFERENCES users(id) ON DELETE CASCADE ON UPDATE CASCADE,
            CONSTRAINT chk_depth_nonneg CHECK (depth >= 0)
          );
        `);
        console.log('✅ user_tree_closure (multi) created/verified');

        // If legacy closure rows without matrix_instance_id (older separate table definition), attempt add column & backfill
        try {
          await connection.query(`ALTER TABLE user_tree_closure ADD COLUMN matrix_instance_id INT NOT NULL`);
          console.log('🆕 Added matrix_instance_id column to existing user_tree_closure');
        } catch (e) {
          // already integrated new definition
        }
        if (firstInstanceId) {
          try {
            await connection.query(`UPDATE user_tree_closure SET matrix_instance_id = ? WHERE matrix_instance_id IS NULL`, [firstInstanceId]);
            console.log('🧩 Backfilled closure matrix_instance_id');
          } catch (e) {
            console.log('ℹ️  Closure backfill skipped:', e.message);
          }
        }
        try { await connection.query(`CREATE INDEX idx_closure_instance_depth ON user_tree_closure (matrix_instance_id, depth)`); } catch (_) {}
        try { await connection.query(`CREATE INDEX idx_closure_instance_ancestor ON user_tree_closure (matrix_instance_id, ancestor_user_id)`); } catch (_) {}

        // Remove singleton constraint if present (best effort)
        try {
          await connection.query(`ALTER TABLE matrix_config DROP CHECK chk_matrix_singleton`);
          console.log('🧹 Dropped chk_matrix_singleton');
        } catch (e) {
          console.log('ℹ️  chk_matrix_singleton drop skipped:', e.message);
        }

        console.log('🎉 Normalized database schema created/updated successfully!');
        
        await connection.end();
        return true;
        
    } catch (error) {
        console.error('💥 Error during database initialization:', error.message);
        if (connection) {
            await connection.end();
        }
        throw error;
    }
}

module.exports = { createDatabase };