<?php
/**
 * Tom's Java Jive - MongoDB to MySQL Migration Script
 * 
 * This script migrates data from the existing MongoDB database to MySQL.
 * Run this script once after setting up the MySQL database with schema.sql
 * 
 * Usage: php migrate_from_mongodb.php [mongodb_url] [mongodb_dbname]
 * 
 * Prerequisites:
 * - PHP MongoDB extension installed
 * - MySQL database created and schema.sql executed
 * - database.php configured with MySQL credentials
 */

require_once __DIR__ . '/../config/database.php';
require_once __DIR__ . '/../includes/db.php';

// Configuration
$mongoUrl = $argv[1] ?? getenv('MONGO_URL') ?: 'mongodb://localhost:27017';
$mongoDbName = $argv[2] ?? getenv('MONGO_DB_NAME') ?: 'tomsjavajive';

echo "==============================================\n";
echo "Tom's Java Jive - MongoDB to MySQL Migration\n";
echo "==============================================\n\n";

// Check for MongoDB extension
if (!extension_loaded('mongodb')) {
    echo "ERROR: MongoDB PHP extension is not installed.\n";
    echo "Install it with: pecl install mongodb\n";
    echo "Or: apt-get install php-mongodb\n\n";
    echo "Alternatively, export data from MongoDB using mongodump/mongoexport\n";
    echo "and import it manually.\n";
    exit(1);
}

try {
    // Connect to MongoDB
    echo "Connecting to MongoDB at: $mongoUrl\n";
    $mongoClient = new MongoDB\Client($mongoUrl);
    $mongodb = $mongoClient->selectDatabase($mongoDbName);
    echo "Connected to MongoDB database: $mongoDbName\n\n";
    
    // Test MySQL connection
    $mysql = db();
    echo "Connected to MySQL database: " . DB_NAME . "\n\n";
    
} catch (Exception $e) {
    echo "ERROR: " . $e->getMessage() . "\n";
    exit(1);
}

/**
 * Helper function to convert MongoDB document to array
 */
function docToArray($doc) {
    if ($doc instanceof MongoDB\Model\BSONDocument || $doc instanceof MongoDB\Model\BSONArray) {
        return json_decode(json_encode($doc), true);
    }
    return $doc;
}

/**
 * Helper function to safely get nested value
 */
function safeGet($array, $key, $default = null) {
    return isset($array[$key]) ? $array[$key] : $default;
}

/**
 * Migrate Admin Users
 */
function migrateAdminUsers($mongodb, $mysql) {
    echo "Migrating admin users...\n";
    
    $cursor = $mongodb->admin_users->find();
    $count = 0;
    
    foreach ($cursor as $doc) {
        $doc = docToArray($doc);
        
        try {
            $mysql->insert('admin_users', [
                'user_id' => safeGet($doc, 'user_id') ?: safeGet($doc, 'admin_id'),
                'email' => safeGet($doc, 'email'),
                'password_hash' => safeGet($doc, 'password_hash'),
                'name' => safeGet($doc, 'name'),
                'picture' => safeGet($doc, 'picture'),
                'is_admin' => 1,
                'is_master' => safeGet($doc, 'is_master') ? 1 : 0,
                'permissions' => json_encode(safeGet($doc, 'permissions', [])),
                'created_at' => safeGet($doc, 'created_at') ?: date('Y-m-d H:i:s')
            ]);
            $count++;
        } catch (Exception $e) {
            echo "  Warning: Could not migrate admin {$doc['email']}: " . $e->getMessage() . "\n";
        }
    }
    
    echo "  Migrated $count admin users\n\n";
}

/**
 * Migrate Customers
 */
function migrateCustomers($mongodb, $mysql) {
    echo "Migrating customers...\n";
    
    $cursor = $mongodb->customers->find();
    $count = 0;
    
    foreach ($cursor as $doc) {
        $doc = docToArray($doc);
        
        try {
            $mysql->insert('customers', [
                'customer_id' => safeGet($doc, 'customer_id'),
                'email' => safeGet($doc, 'email'),
                'password_hash' => safeGet($doc, 'password_hash'),
                'name' => safeGet($doc, 'name'),
                'phone' => safeGet($doc, 'phone'),
                'shipping_address' => json_encode(safeGet($doc, 'shipping_address')),
                'billing_address' => json_encode(safeGet($doc, 'billing_address')),
                'wallet_balance' => safeGet($doc, 'account_balance', 0),
                'reward_points' => safeGet($doc, 'loyalty_points', 0),
                'is_guest' => safeGet($doc, 'is_guest') ? 1 : 0,
                'created_via' => safeGet($doc, 'created_via', 'web'),
                'created_at' => safeGet($doc, 'created_at') ?: date('Y-m-d H:i:s')
            ]);
            
            // Migrate wallet transactions
            $transactions = safeGet($doc, 'account_transactions', []);
            foreach ($transactions as $txn) {
                try {
                    $mysql->insert('wallet_transactions', [
                        'transaction_id' => safeGet($txn, 'transaction_id') ?: 'txn_' . bin2hex(random_bytes(6)),
                        'customer_id' => $doc['customer_id'],
                        'amount' => safeGet($txn, 'amount', 0),
                        'balance_after' => safeGet($txn, 'balance_after', 0),
                        'type' => mapTransactionType(safeGet($txn, 'type')),
                        'description' => safeGet($txn, 'description'),
                        'order_id' => safeGet($txn, 'order_id'),
                        'created_at' => safeGet($txn, 'date') ?: date('Y-m-d H:i:s')
                    ]);
                } catch (Exception $e) {
                    // Skip transaction errors
                }
            }
            
            $count++;
        } catch (Exception $e) {
            echo "  Warning: Could not migrate customer {$doc['email']}: " . $e->getMessage() . "\n";
        }
    }
    
    echo "  Migrated $count customers\n\n";
}

function mapTransactionType($type) {
    $map = [
        'deposit' => 'deposit',
        'payment' => 'withdrawal',
        'gift_card_purchase' => 'purchase',
        'admin_deposit' => 'deposit',
        'pos_payment' => 'withdrawal',
        'refund' => 'refund'
    ];
    return isset($map[$type]) ? $map[$type] : 'deposit';
}

/**
 * Migrate Products
 */
function migrateProducts($mongodb, $mysql) {
    echo "Migrating products...\n";
    
    $cursor = $mongodb->products->find();
    $count = 0;
    
    foreach ($cursor as $doc) {
        $doc = docToArray($doc);
        
        // Map blend_type to category
        $category = safeGet($doc, 'blend_type') ?: safeGet($doc, 'category') ?: 'coffee';
        
        try {
            $mysql->insert('products', [
                'product_id' => safeGet($doc, 'product_id'),
                'name' => safeGet($doc, 'name'),
                'description' => safeGet($doc, 'description'),
                'price' => safeGet($doc, 'price', 0),
                'sale_price' => safeGet($doc, 'sale_price'),
                'sku' => safeGet($doc, 'sku'),
                'barcode' => safeGet($doc, 'barcode'),
                'category' => $category,
                'tags' => json_encode([safeGet($doc, 'roast_level'), safeGet($doc, 'product_type')]),
                'images' => json_encode([safeGet($doc, 'image_url')]),
                'stock' => safeGet($doc, 'stock_quantity', 100),
                'low_stock_threshold' => safeGet($doc, 'low_stock_threshold', 10),
                'weight' => safeGet($doc, 'weight'),
                'is_active' => safeGet($doc, 'in_stock', true) ? 1 : 0,
                'is_featured' => safeGet($doc, 'on_sale', false) ? 1 : 0,
                'created_at' => safeGet($doc, 'created_at') ?: date('Y-m-d H:i:s')
            ]);
            $count++;
        } catch (Exception $e) {
            echo "  Warning: Could not migrate product {$doc['name']}: " . $e->getMessage() . "\n";
        }
    }
    
    echo "  Migrated $count products\n\n";
}

/**
 * Migrate Orders
 */
function migrateOrders($mongodb, $mysql) {
    echo "Migrating orders...\n";
    
    $cursor = $mongodb->orders->find();
    $count = 0;
    
    foreach ($cursor as $doc) {
        $doc = docToArray($doc);
        
        try {
            $mysql->insert('orders', [
                'order_id' => safeGet($doc, 'order_id'),
                'order_number' => safeGet($doc, 'order_number'),
                'customer_id' => safeGet($doc, 'customer_id'),
                'customer_email' => safeGet($doc, 'customer_email'),
                'customer_name' => safeGet($doc, 'customer_name'),
                'items' => json_encode(safeGet($doc, 'items', [])),
                'subtotal' => safeGet($doc, 'subtotal', 0),
                'shipping_cost' => safeGet($doc, 'shipping_cost', 0),
                'tax' => safeGet($doc, 'tax', 0),
                'discount' => safeGet($doc, 'discount_amount', 0),
                'total' => safeGet($doc, 'total', 0),
                'shipping_address' => json_encode(safeGet($doc, 'shipping_address')),
                'shipping_method' => safeGet($doc, 'shipping_method'),
                'payment_method' => safeGet($doc, 'payment_method'),
                'payment_status' => safeGet($doc, 'payment_status', 'pending'),
                'order_status' => safeGet($doc, 'order_status', 'pending'),
                'stripe_payment_intent' => safeGet($doc, 'checkout_session_id'),
                'tracking_number' => safeGet($doc, 'tracking_number'),
                'notes' => safeGet($doc, 'pos_notes'),
                'is_pos_order' => safeGet($doc, 'pos_order') ? 1 : 0,
                'created_at' => safeGet($doc, 'created_at') ?: date('Y-m-d H:i:s')
            ]);
            
            // Also insert into order_items for reporting
            $items = safeGet($doc, 'items', []);
            foreach ($items as $item) {
                try {
                    $mysql->insert('order_items', [
                        'order_id' => $doc['order_id'],
                        'product_id' => safeGet($item, 'product_id'),
                        'name' => safeGet($item, 'name'),
                        'price' => safeGet($item, 'price', 0),
                        'quantity' => safeGet($item, 'quantity', 1),
                        'total' => safeGet($item, 'total', 0)
                    ]);
                } catch (Exception $e) {
                    // Skip item errors
                }
            }
            
            $count++;
        } catch (Exception $e) {
            echo "  Warning: Could not migrate order {$doc['order_number']}: " . $e->getMessage() . "\n";
        }
    }
    
    echo "  Migrated $count orders\n\n";
}

/**
 * Migrate Gift Cards
 */
function migrateGiftCards($mongodb, $mysql) {
    echo "Migrating gift cards...\n";
    
    $cursor = $mongodb->gift_cards->find();
    $count = 0;
    
    foreach ($cursor as $doc) {
        $doc = docToArray($doc);
        
        try {
            $mysql->insert('gift_cards', [
                'gift_card_id' => safeGet($doc, 'gift_card_id'),
                'code' => safeGet($doc, 'code'),
                'initial_balance' => safeGet($doc, 'initial_balance', 0),
                'current_balance' => safeGet($doc, 'current_balance', 0),
                'purchaser_email' => safeGet($doc, 'purchased_by_email'),
                'recipient_email' => safeGet($doc, 'recipient_email'),
                'recipient_name' => safeGet($doc, 'recipient_name'),
                'message' => safeGet($doc, 'message'),
                'is_active' => safeGet($doc, 'status') !== 'disabled' ? 1 : 0,
                'created_at' => safeGet($doc, 'created_at') ?: date('Y-m-d H:i:s')
            ]);
            $count++;
        } catch (Exception $e) {
            echo "  Warning: Could not migrate gift card {$doc['code']}: " . $e->getMessage() . "\n";
        }
    }
    
    echo "  Migrated $count gift cards\n\n";
}

/**
 * Migrate Reviews
 */
function migrateReviews($mongodb, $mysql) {
    echo "Migrating reviews...\n";
    
    $cursor = $mongodb->product_reviews->find();
    $count = 0;
    
    foreach ($cursor as $doc) {
        $doc = docToArray($doc);
        
        try {
            $mysql->insert('reviews', [
                'review_id' => safeGet($doc, 'review_id'),
                'product_id' => safeGet($doc, 'product_id'),
                'customer_id' => safeGet($doc, 'customer_id'),
                'customer_name' => safeGet($doc, 'customer_name'),
                'customer_email' => safeGet($doc, 'customer_email'),
                'rating' => safeGet($doc, 'rating', 5),
                'title' => safeGet($doc, 'title'),
                'comment' => safeGet($doc, 'comment'),
                'is_verified_purchase' => safeGet($doc, 'verified_purchase') ? 1 : 0,
                'is_approved' => safeGet($doc, 'status') === 'approved' ? 1 : 0,
                'created_at' => safeGet($doc, 'created_at') ?: date('Y-m-d H:i:s')
            ]);
            $count++;
        } catch (Exception $e) {
            echo "  Warning: Could not migrate review: " . $e->getMessage() . "\n";
        }
    }
    
    echo "  Migrated $count reviews\n\n";
}

/**
 * Migrate Email Subscribers
 */
function migrateSubscribers($mongodb, $mysql) {
    echo "Migrating email subscribers...\n";
    
    $cursor = $mongodb->email_subscribers->find();
    $count = 0;
    
    foreach ($cursor as $doc) {
        $doc = docToArray($doc);
        
        try {
            $mysql->insert('email_subscribers', [
                'email' => safeGet($doc, 'email'),
                'name' => safeGet($doc, 'name'),
                'is_active' => safeGet($doc, 'status') === 'active' ? 1 : 0,
                'source' => safeGet($doc, 'source', 'website'),
                'created_at' => safeGet($doc, 'subscribed_at') ?: date('Y-m-d H:i:s')
            ]);
            $count++;
        } catch (Exception $e) {
            // Skip duplicate emails
        }
    }
    
    echo "  Migrated $count subscribers\n\n";
}

/**
 * Migrate Settings
 */
function migrateSettings($mongodb, $mysql) {
    echo "Migrating settings...\n";
    
    // Shipping settings
    $shipping = $mongodb->shipping_settings->findOne(['settings_id' => 'shipping_settings']);
    if ($shipping) {
        $shipping = docToArray($shipping);
        $mysql->query(
            "UPDATE settings SET setting_value = :val WHERE setting_key = 'shipping'",
            ['val' => json_encode([
                'flat_rate_enabled' => safeGet($shipping, 'flat_rate_enabled', true),
                'flat_rate_amount' => safeGet($shipping, 'flat_rate_amount', 5.99),
                'free_shipping_threshold' => safeGet($shipping, 'free_shipping_threshold', 50),
                'weight_based_enabled' => safeGet($shipping, 'weight_based_enabled', false)
            ])]
        );
        echo "  Migrated shipping settings\n";
    }
    
    // Payment settings
    $payment = $mongodb->payment_settings->findOne(['settings_id' => 'payment_settings']);
    if ($payment) {
        $payment = docToArray($payment);
        $mysql->query(
            "UPDATE settings SET setting_value = :val WHERE setting_key = 'payment'",
            ['val' => json_encode([
                'stripe_enabled' => safeGet($payment, 'stripe_enabled', true),
                'paypal_enabled' => safeGet($payment, 'paypal_enabled', false),
                'cod_enabled' => false
            ])]
        );
        echo "  Migrated payment settings\n";
    }
    
    echo "\n";
}

// Run migrations
echo "Starting migration...\n\n";

try {
    migrateAdminUsers($mongodb, $mysql);
    migrateCustomers($mongodb, $mysql);
    migrateProducts($mongodb, $mysql);
    migrateOrders($mongodb, $mysql);
    migrateGiftCards($mongodb, $mysql);
    migrateReviews($mongodb, $mysql);
    migrateSubscribers($mongodb, $mysql);
    migrateSettings($mongodb, $mysql);
    
    echo "==============================================\n";
    echo "Migration completed successfully!\n";
    echo "==============================================\n";
    
} catch (Exception $e) {
    echo "\nMIGRATION ERROR: " . $e->getMessage() . "\n";
    exit(1);
}