<?php
header('Content-Type: application/json');
require_once __DIR__ . '/../db/config.php';
require_once __DIR__ . '/../includes/WablasService.php';

$input = file_get_contents('php://input');
$data = json_decode($input, true);

if (!$data) {
    echo json_encode(['success' => false, 'error' => 'No data provided']);
    exit;
}

try {
    $pdo = db();
    $pdo->beginTransaction();

    // Validate order_type against allowed ENUM values
    $allowed_types = ['dine-in', 'takeaway', 'delivery', 'drive-thru'];
    $order_type = isset($data['order_type']) && in_array($data['order_type'], $allowed_types) 
        ? $data['order_type'] 
        : 'dine-in';

    // Get outlet_id from input, default to 1 if missing
    $outlet_id = isset($data['outlet_id']) ? intval($data['outlet_id']) : 1;

    $table_id = null;
    $table_number = null;

    if ($order_type === 'dine-in') {
        $tid = $data['table_number'] ?? null; // Front-end sends ID as table_number
        if ($tid) {
            // Validate table exists AND belongs to the correct outlet
            $stmt = $pdo->prepare(
                "SELECT t.id, t.name 
                FROM tables t
                JOIN areas a ON t.area_id = a.id
                WHERE t.id = ? AND a.outlet_id = ?"
            );
            $stmt->execute([$tid, $outlet_id]);
            $table = $stmt->fetch(PDO::FETCH_ASSOC);
            if ($table) {
                $table_id = $table['id'];
                $table_number = $table['name'];
            }
        }
        
        // If not found or not provided, leave null (Walk-in/Counter) or try to find a default table for this outlet
        if (!$table_id) {
             // Optional: try to find the first available table for this outlet
             $stmt = $pdo->prepare(
                "SELECT t.id, t.name 
                FROM tables t 
                JOIN areas a ON t.area_id = a.id
                WHERE a.outlet_id = ?
                LIMIT 1"
             );
             $stmt->execute([$outlet_id]);
             $table = $stmt->fetch(PDO::FETCH_ASSOC);
             if ($table) {
                 $table_id = $table['id'];
                 $table_number = $table['name'];
             }
        }
    }

    // Customer Handling
    $customer_id = $data['customer_id'] ?? null;
    $customer_name = $data['customer_name'] ?? null;
    $customer_phone = $data['customer_phone'] ?? null;
    
    // Fetch Loyalty Settings
    $settingsStmt = $pdo->query("SELECT points_per_order, points_for_free_meal FROM loyalty_settings WHERE id = 1");
    $settings = $settingsStmt->fetch(PDO::FETCH_ASSOC);
    $points_per_order = $settings ? intval($settings['points_per_order']) : 10;
    $points_threshold = $settings ? intval($settings['points_for_free_meal']) : 70;

    $current_points = 0;
    $points_deducted = 0;
    $points_awarded = 0;

    if ($customer_id) {
        $stmt = $pdo->prepare("SELECT name, phone, points FROM customers WHERE id = ?");
        $stmt->execute([$customer_id]);
        $cust = $stmt->fetch(PDO::FETCH_ASSOC);
        if ($cust) {
            $customer_name = $cust['name'];
            $customer_phone = $cust['phone'];
            $current_points = intval($cust['points']);
        } else {
            $customer_id = null;
        }
    }
    
    // Loyalty Redemption Logic
    $redeem_loyalty = !empty($data['redeem_loyalty']);
    if ($redeem_loyalty && $customer_id) {
        if ($current_points < $points_threshold) {
             throw new Exception("Insufficient loyalty points for redemption.");
        }
        // Deduct points
        $deductStmt = $pdo->prepare("UPDATE customers SET points = points - ? WHERE id = ?");
        $deductStmt->execute([$points_threshold, $customer_id]);
        $points_deducted = $points_threshold;
        
        // --- OVERRIDE PAYMENT TYPE ---
        $ptStmt = $pdo->prepare("SELECT id FROM payment_types WHERE name = 'Loyalty Redeem' LIMIT 1");
        $ptStmt->execute();
        $loyaltyPt = $ptStmt->fetchColumn();
        if ($loyaltyPt) {
            $data['payment_type_id'] = $loyaltyPt;
        }
    }
    
    // Award Points
    if ($customer_id) {
        $awardStmt = $pdo->prepare("UPDATE customers SET points = points + ? WHERE id = ?");
        $awardStmt->execute([$points_per_order, $customer_id]);
        $points_awarded = $points_per_order;
    }

    // Payment Type
    $payment_type_id = isset($data['payment_type_id']) ? intval($data['payment_type_id']) : null;

    $discount = isset($data['discount']) ? floatval($data['discount']) : 0.00;
    $total_amount = isset($data['total_amount']) ? floatval($data['total_amount']) : 0.00;

    // Check for Existing Order ID (Update Mode)
    $order_id = isset($data['order_id']) ? intval($data['order_id']) : null;
    $is_update = false;

    if ($order_id) {
        // Verify existence and status (optional: only update pending orders?)
        $checkStmt = $pdo->prepare("SELECT id FROM orders WHERE id = ?");
        $checkStmt->execute([$order_id]);
        if ($checkStmt->fetch()) {
            $is_update = true;
        } else {
            // If ID sent but not found, create new? Or error?
            // Let's treat as new if not found to avoid errors, or maybe user meant to update.
            // Safe bet: error if explicit update requested but failed.
            // But for now, let's just create new if ID is invalid, or better, stick to the plan: Update if ID present.
            $order_id = null; // Reset to create new
        }
    }

    if ($is_update) {
        // UPDATE Existing Order
        $stmt = $pdo->prepare("UPDATE orders SET 
            outlet_id = ?, table_id = ?, table_number = ?, order_type = ?, 
            customer_id = ?, customer_name = ?, customer_phone = ?, 
            payment_type_id = ?, total_amount = ?, discount = ?, status = 'pending' 
            WHERE id = ?");
        $stmt->execute([
            $outlet_id, $table_id, $table_number, $order_type, 
            $customer_id, $customer_name, $customer_phone, 
            $payment_type_id, $total_amount, $discount, 
            $order_id
        ]);

        // Clear existing items to replace them
        $delStmt = $pdo->prepare("DELETE FROM order_items WHERE order_id = ?");
        $delStmt->execute([$order_id]);

    } else {
        // INSERT New Order
        $stmt = $pdo->prepare("INSERT INTO orders (outlet_id, table_id, table_number, order_type, customer_id, customer_name, customer_phone, payment_type_id, total_amount, discount, status) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 'pending')");
        $stmt->execute([$outlet_id, $table_id, $table_number, $order_type, $customer_id, $customer_name, $customer_phone, $payment_type_id, $total_amount, $discount]);
        $order_id = $pdo->lastInsertId();
    }

    // Insert Items (Common for both Insert and Update)
    $item_stmt = $pdo->prepare("INSERT INTO order_items (order_id, product_id, variant_id, quantity, unit_price) VALUES (?, ?, ?, ?, ?)");
    
    // Pre-prepare statements for name fetching
    $prodNameStmt = $pdo->prepare("SELECT name FROM products WHERE id = ?");
    $varNameStmt = $pdo->prepare("SELECT name FROM product_variants WHERE id = ?");
    
    $order_items_list = []; // To store item details for notification

    if (!empty($data['items']) && is_array($data['items'])) {
        foreach ($data['items'] as $item) {
            $pid = $item['product_id'] ?? ($item['id'] ?? null);
            $qty = $item['quantity'] ?? 1;
            $price = $item['unit_price'] ?? ($item['price'] ?? 0);
            $vid = $item['variant_id'] ?? null;

            if ($pid) {
                $item_stmt->execute([$order_id, $pid, $vid, $qty, $price]);

                // Fetch names for notification
                $prodNameStmt->execute([$pid]);
                $pRow = $prodNameStmt->fetch(PDO::FETCH_ASSOC);
                $pName = $pRow ? $pRow['name'] : 'Item';

                if ($vid) {
                    $varNameStmt->execute([$vid]);
                    $vRow = $varNameStmt->fetch(PDO::FETCH_ASSOC);
                    if ($vRow) {
                        $pName .= " (" . $vRow['name'] . ")";
                    }
                }
                $order_items_list[] = "$qty x $pName";
            }
        }
    }

    $pdo->commit();
    
    // --- Post-Transaction Actions ---

    // Send WhatsApp Notification if Customer exists
    if ($customer_id && $customer_phone) {
        try {
            // Calculate final points
            $final_points = $current_points - $points_deducted + $points_awarded;
            
            // Determine message content
            $wablas = new WablasService($pdo);

            // Fetch Company Name
            require_once __DIR__ . '/../includes/functions.php';
            $companySettings = get_company_settings();
            $company_name = $companySettings['company_name'] ?? 'Flatlogic POS';
            
            // Fetch Template
            $stmt = $pdo->prepare("SELECT setting_value FROM integration_settings WHERE provider = 'wablas' AND setting_key = 'order_template'");
            $stmt->execute();
            $template = $stmt->fetchColumn();
            
            // Default Template if not set
            if (!$template) {
                $template = "Dear *{customer_name}*,

Thank you for dining with *{company_name}*! 🍽️

*Order Details:*
{order_details}

Total: *{total_amount}* OMR

You've earned *{points_earned} points* with this order.
💰 *Current Balance: {new_balance} points*

{loyalty_status}";
            }

            // Calculate Loyalty Status String
            $loyalty_status = "";
            if ($final_points >= $points_threshold) {
                $loyalty_status = "🎉 Congratulations! You have enough points for a *FREE MEAL* on your next visit!";
            } else {
                $needed = $points_threshold - $final_points;
                $loyalty_status = "You need *$needed more points* to unlock a free meal.";
            }

            // Prepare replacements
            $replacements = [
                '{customer_name}' => $customer_name,
                '{company_name}' => $company_name,
                '{order_id}' => $order_id,
                '{order_details}' => !empty($order_items_list) ? implode("\n", $order_items_list) : 'N/A',
                '{total_amount}' => number_format($total_amount, 3),
                '{points_earned}' => $points_awarded,
                '{points_redeemed}' => $points_deducted,
                '{new_balance}' => $final_points,
                '{loyalty_status}' => $loyalty_status
            ];
            
            $msg = str_replace(array_keys($replacements), array_values($replacements), $template);
            
            // Send (fire and forget, don't block response on failure, just log)
            $res = $wablas->sendMessage($customer_phone, $msg);
            if (!$res['success']) {
                error_log("Wablas Notification Failed: " . $res['message']);
            }
            
        } catch (Exception $w) {
            error_log("Wablas Exception: " . $w->getMessage());
        }
    }

    echo json_encode(['success' => true, 'order_id' => $order_id]);

} catch (Exception $e) {
    if ($pdo->inTransaction()) {
        $pdo->rollBack();
    }
    error_log("Order Error: " . $e->getMessage());
    echo json_encode(['success' => false, 'error' => $e->getMessage()]);
}