<?php
/**
 * Tom's Java Jive - POS Order API
 * Creates orders from the POS system
 */

header('Content-Type: application/json');

require_once __DIR__ . '/../includes/functions.php';
require_once __DIR__ . '/../includes/auth.php';

// Only accept POST
if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    jsonResponse(['error' => 'Method not allowed'], 405);
}

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

if (empty($input['items']) || !is_array($input['items'])) {
    jsonResponse(['error' => 'No items provided'], 400);
}

$items = $input['items'];
$paymentMethod = $input['payment_method'] ?? 'cash';
$notes = $input['notes'] ?? '';
$customerId = $input['customer_id'] ?? null;
$customerEmail = $input['customer_email'] ?? null;
$discountAmount = floatval($input['discount'] ?? 0);
$couponCode = $input['coupon_code'] ?? null;

// Calculate totals
$subtotal = 0;
$orderItems = [];

foreach ($items as $item) {
    // Verify product exists and has stock
    $product = db()->fetch(
        "SELECT product_id, name, price, sale_price, stock FROM products WHERE product_id = :id AND is_active = 1",
        ['id' => $item['product_id']]
    );
    
    if (!$product) {
        jsonResponse(['error' => 'Product not found: ' . $item['name']], 400);
    }
    
    if ($product['stock'] < $item['quantity']) {
        jsonResponse(['error' => 'Insufficient stock for: ' . $product['name']], 400);
    }
    
    $price = $product['sale_price'] ?? $product['price'];
    $lineTotal = $price * $item['quantity'];
    $subtotal += $lineTotal;
    
    $orderItems[] = [
        'product_id' => $product['product_id'],
        'name' => $product['name'],
        'price' => $price,
        'quantity' => $item['quantity'],
        'total' => $lineTotal
    ];
}

// Apply coupon if provided
$couponDiscount = 0;
if ($couponCode) {
    $coupon = db()->fetch(
        "SELECT * FROM coupons WHERE code = :code AND is_active = 1 
         AND (starts_at IS NULL OR starts_at <= NOW()) 
         AND (expires_at IS NULL OR expires_at > NOW())
         AND (max_uses IS NULL OR times_used < max_uses)",
        ['code' => strtoupper($couponCode)]
    );
    
    if ($coupon) {
        if ($coupon['min_order_amount'] && $subtotal < $coupon['min_order_amount']) {
            // Coupon minimum not met, ignore
        } else {
            if ($coupon['discount_type'] === 'percentage') {
                $couponDiscount = $subtotal * ($coupon['discount_value'] / 100);
            } else {
                $couponDiscount = min($coupon['discount_value'], $subtotal);
            }
            
            // Update coupon usage
            db()->query("UPDATE coupons SET times_used = times_used + 1 WHERE coupon_id = :id", 
                ['id' => $coupon['coupon_id']]);
        }
    }
}

// Calculate final total
$discount = $discountAmount + $couponDiscount;
$taxRate = 0; // Adjust based on settings
$tax = ($subtotal - $discount) * $taxRate;
$total = $subtotal - $discount + $tax;

// Handle wallet payment
$walletUsed = 0;
if ($paymentMethod === 'wallet' && $customerId) {
    $customer = db()->fetch(
        "SELECT wallet_balance FROM customers WHERE customer_id = :id",
        ['id' => $customerId]
    );
    
    if (!$customer || $customer['wallet_balance'] < $total) {
        jsonResponse(['error' => 'Insufficient wallet balance'], 400);
    }
    
    $walletUsed = $total;
    
    // Deduct from wallet
    db()->query(
        "UPDATE customers SET wallet_balance = wallet_balance - :amount WHERE customer_id = :id",
        ['amount' => $walletUsed, 'id' => $customerId]
    );
    
    // Log wallet transaction
    $newBalance = $customer['wallet_balance'] - $walletUsed;
    db()->insert('wallet_transactions', [
        'transaction_id' => generateId('wt_'),
        'customer_id' => $customerId,
        'amount' => -$walletUsed,
        'balance_after' => $newBalance,
        'type' => 'purchase',
        'description' => 'POS Purchase'
    ]);
}

// Generate order
$orderId = generateId('ord_');
$orderNumber = generateOrderNumber();

try {
    // Create order
    db()->insert('orders', [
        'order_id' => $orderId,
        'order_number' => $orderNumber,
        'customer_id' => $customerId,
        'customer_email' => $customerEmail ?? 'pos@store.local',
        'customer_name' => $input['customer_name'] ?? 'POS Customer',
        'items' => json_encode($orderItems),
        'subtotal' => $subtotal,
        'tax' => $tax,
        'discount' => $discount,
        'wallet_amount_used' => $walletUsed,
        'total' => $total,
        'payment_method' => $paymentMethod,
        'payment_status' => 'paid',
        'order_status' => 'confirmed',
        'notes' => $notes,
        'is_pos_order' => 1
    ]);
    
    // Insert order items
    foreach ($orderItems as $item) {
        db()->insert('order_items', [
            'order_id' => $orderId,
            'product_id' => $item['product_id'],
            'name' => $item['name'],
            'price' => $item['price'],
            'quantity' => $item['quantity'],
            'total' => $item['total']
        ]);
        
        // Update stock
        db()->query(
            "UPDATE products SET stock = stock - :qty WHERE product_id = :id",
            ['qty' => $item['quantity'], 'id' => $item['product_id']]
        );
    }
    
    // Award reward points if customer
    if ($customerId) {
        $pointsEarned = floor($total); // 1 point per dollar
        db()->query(
            "UPDATE customers SET reward_points = reward_points + :points WHERE customer_id = :id",
            ['points' => $pointsEarned, 'id' => $customerId]
        );
    }
    
    jsonResponse([
        'success' => true,
        'order_id' => $orderId,
        'order_number' => $orderNumber,
        'total' => $total,
        'items' => $orderItems
    ]);
    
} catch (Exception $e) {
    jsonResponse(['error' => 'Failed to create order: ' . $e->getMessage()], 500);
}