<?php
declare(strict_types=1);

function init_store(): void {
  ensure_schema();
  seed_data();
}

function ensure_schema(): void {
  $pdo = db();
  $pdo->exec(
    'CREATE TABLE IF NOT EXISTS categories (
      id INT AUTO_INCREMENT PRIMARY KEY,
      name VARCHAR(120) NOT NULL,
      created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4'
  );

  $pdo->exec(
    'CREATE TABLE IF NOT EXISTS products (
      id INT AUTO_INCREMENT PRIMARY KEY,
      name VARCHAR(160) NOT NULL,
      description TEXT NOT NULL,
      price DECIMAL(10,2) NOT NULL,
      stock INT NOT NULL DEFAULT 0,
      rating DECIMAL(3,2) NOT NULL DEFAULT 0.00,
      category_id INT NULL,
      image_url VARCHAR(255) NULL,
      created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
      INDEX (category_id)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4'
  );

  $pdo->exec(
    'CREATE TABLE IF NOT EXISTS orders (
      id INT AUTO_INCREMENT PRIMARY KEY,
      order_number VARCHAR(20) NOT NULL,
      customer_name VARCHAR(120) NOT NULL,
      customer_email VARCHAR(160) NOT NULL,
      customer_address VARCHAR(255) NOT NULL,
      status VARCHAR(30) NOT NULL,
      total_price DECIMAL(10,2) NOT NULL,
      created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
      UNIQUE KEY (order_number)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4'
  );

  $pdo->exec(
    'CREATE TABLE IF NOT EXISTS order_items (
      id INT AUTO_INCREMENT PRIMARY KEY,
      order_id INT NOT NULL,
      product_id INT NOT NULL,
      quantity INT NOT NULL,
      price DECIMAL(10,2) NOT NULL,
      created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
      INDEX (order_id),
      INDEX (product_id)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4'
  );
}

function seed_data(): void {
  $pdo = db();
  $count = (int) $pdo->query('SELECT COUNT(*) FROM products')->fetchColumn();
  if ($count > 0) {
    return;
  }

  $categories = [
    'Apparel',
    'Electronics',
    'Moroccan Goods'
  ];

  $categoryStmt = $pdo->prepare('INSERT INTO categories (name) VALUES (:name)');
  $categoryIds = [];
  foreach ($categories as $name) {
    $categoryStmt->execute([':name' => $name]);
    $categoryIds[$name] = (int) $pdo->lastInsertId();
  }

  $products = [
    [
      'name' => 'Atlas Hoodie',
      'description' => 'Midweight cotton hoodie with brushed interior and clean stitch detailing.',
      'price' => 79.00,
      'stock' => 24,
      'rating' => 4.6,
      'category' => 'Apparel'
    ],
    [
      'name' => 'Casablanca Sneakers',
      'description' => 'Everyday sneaker with cushioned sole and minimalist profile.',
      'price' => 98.00,
      'stock' => 18,
      'rating' => 4.4,
      'category' => 'Apparel'
    ],
    [
      'name' => 'Rabat Smartwatch',
      'description' => 'Slim fitness watch with sleep tracking and a 7-day battery.',
      'price' => 149.00,
      'stock' => 12,
      'rating' => 4.2,
      'category' => 'Electronics'
    ],
    [
      'name' => 'Sahara Bluetooth Speaker',
      'description' => 'Portable speaker with clean bass and long-lasting battery.',
      'price' => 129.00,
      'stock' => 10,
      'rating' => 4.3,
      'category' => 'Electronics'
    ],
    [
      'name' => 'Fez Copper Lamp',
      'description' => 'Hand-finished lamp with soft perforated light pattern.',
      'price' => 119.00,
      'stock' => 7,
      'rating' => 4.8,
      'category' => 'Moroccan Goods'
    ],
    [
      'name' => 'Agadir Ceramic Tagine',
      'description' => 'Glazed ceramic tagine for slow cooking and elegant serving.',
      'price' => 84.00,
      'stock' => 9,
      'rating' => 4.7,
      'category' => 'Moroccan Goods'
    ]
  ];

  $productStmt = $pdo->prepare(
    'INSERT INTO products (name, description, price, stock, rating, category_id) VALUES (:name, :description, :price, :stock, :rating, :category_id)'
  );

  foreach ($products as $product) {
    $productStmt->execute([
      ':name' => $product['name'],
      ':description' => $product['description'],
      ':price' => $product['price'],
      ':stock' => $product['stock'],
      ':rating' => $product['rating'],
      ':category_id' => $categoryIds[$product['category']] ?? null
    ]);
  }
}

function get_categories(): array {
  $stmt = db()->query('SELECT id, name FROM categories ORDER BY name ASC');
  return $stmt->fetchAll();
}

function get_products(?string $search = null, ?int $categoryId = null, ?string $sort = null): array {
  $sql = 'SELECT p.*, c.name AS category_name FROM products p LEFT JOIN categories c ON c.id = p.category_id WHERE 1=1';
  $params = [];

  if ($search) {
    $sql .= ' AND (p.name LIKE :search OR p.description LIKE :search)';
    $params[':search'] = '%' . $search . '%';
  }

  if ($categoryId) {
    $sql .= ' AND p.category_id = :category_id';
    $params[':category_id'] = $categoryId;
  }

  switch ($sort) {
    case 'price_asc':
      $sql .= ' ORDER BY p.price ASC';
      break;
    case 'price_desc':
      $sql .= ' ORDER BY p.price DESC';
      break;
    default:
      $sql .= ' ORDER BY p.created_at DESC';
      break;
  }

  $stmt = db()->prepare($sql);
  $stmt->execute($params);
  return $stmt->fetchAll();
}

function get_product(int $id): ?array {
  $stmt = db()->prepare('SELECT p.*, c.name AS category_name FROM products p LEFT JOIN categories c ON c.id = p.category_id WHERE p.id = :id');
  $stmt->execute([':id' => $id]);
  $product = $stmt->fetch();
  return $product ?: null;
}

function format_price(float $price): string {
  return '$' . number_format($price, 2);
}

function product_image_data(string $label): string {
  $clean = preg_replace('/[^A-Za-z0-9]/', '', $label);
  $text = strtoupper(substr($clean, 0, 2));
  if ($text === '') {
    $text = 'ES';
  }
  $svg = "<svg xmlns='http://www.w3.org/2000/svg' width='600' height='400' viewBox='0 0 600 400'><rect width='600' height='400' fill='#f1f3f6'/><text x='50%' y='50%' dominant-baseline='middle' text-anchor='middle' font-family='Inter, Arial, sans-serif' font-size='96' fill='#111827'>" . $text . "</text></svg>";
  return 'data:image/svg+xml;utf8,' . rawurlencode($svg);
}

function cart_count(): int {
  $cart = $_SESSION['cart'] ?? [];
  return array_sum($cart);
}

function cart_items(): array {
  $cart = $_SESSION['cart'] ?? [];
  if (!$cart) {
    return [];
  }

  $ids = array_keys($cart);
  $placeholders = implode(',', array_fill(0, count($ids), '?'));
  $stmt = db()->prepare(
    "SELECT p.*, c.name AS category_name FROM products p LEFT JOIN categories c ON c.id = p.category_id WHERE p.id IN ($placeholders)"
  );
  $stmt->execute($ids);
  $products = $stmt->fetchAll();
  $indexed = [];
  foreach ($products as $product) {
    $indexed[(int) $product['id']] = $product;
  }

  $items = [];
  foreach ($cart as $productId => $qty) {
    $product = $indexed[(int) $productId] ?? null;
    if (!$product) {
      continue;
    }
    $lineTotal = ((float) $product['price']) * $qty;
    $items[] = [
      'product' => $product,
      'quantity' => $qty,
      'line_total' => $lineTotal
    ];
  }
  return $items;
}

function cart_total(): float {
  $total = 0.0;
  foreach (cart_items() as $item) {
    $total += $item['line_total'];
  }
  return $total;
}

function cart_add(int $productId, int $quantity): void {
  if ($quantity < 1) {
    return;
  }
  $cart = $_SESSION['cart'] ?? [];
  $cart[$productId] = ($cart[$productId] ?? 0) + $quantity;
  $_SESSION['cart'] = $cart;
}

function cart_update(int $productId, int $quantity): void {
  $cart = $_SESSION['cart'] ?? [];
  if ($quantity < 1) {
    unset($cart[$productId]);
  } else {
    $cart[$productId] = $quantity;
  }
  $_SESSION['cart'] = $cart;
}

function cart_clear(): void {
  unset($_SESSION['cart']);
}

function create_order(array $customer, array $items): ?string {
  if (!$items) {
    return null;
  }

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

  try {
    $orderNumber = 'ES9-' . strtoupper(bin2hex(random_bytes(3)));
    $total = 0.0;
    foreach ($items as $item) {
      $total += $item['line_total'];
    }

    $orderStmt = $pdo->prepare(
      'INSERT INTO orders (order_number, customer_name, customer_email, customer_address, status, total_price) VALUES (:order_number, :customer_name, :customer_email, :customer_address, :status, :total_price)'
    );
    $orderStmt->execute([
      ':order_number' => $orderNumber,
      ':customer_name' => $customer['name'],
      ':customer_email' => $customer['email'],
      ':customer_address' => $customer['address'],
      ':status' => 'Processing',
      ':total_price' => $total
    ]);

    $orderId = (int) $pdo->lastInsertId();

    $itemStmt = $pdo->prepare(
      'INSERT INTO order_items (order_id, product_id, quantity, price) VALUES (:order_id, :product_id, :quantity, :price)'
    );

    foreach ($items as $item) {
      $itemStmt->execute([
        ':order_id' => $orderId,
        ':product_id' => $item['product']['id'],
        ':quantity' => $item['quantity'],
        ':price' => $item['product']['price']
      ]);
    }

    $pdo->commit();
    return $orderNumber;
  } catch (Throwable $e) {
    $pdo->rollBack();
    return null;
  }
}

function get_order_by_number(string $orderNumber): ?array {
  $stmt = db()->prepare('SELECT * FROM orders WHERE order_number = :order_number');
  $stmt->execute([':order_number' => $orderNumber]);
  $order = $stmt->fetch();
  return $order ?: null;
}

function get_order_items(int $orderId): array {
  $stmt = db()->prepare(
    'SELECT oi.*, p.name, p.description FROM order_items oi LEFT JOIN products p ON p.id = oi.product_id WHERE oi.order_id = :order_id'
  );
  $stmt->execute([':order_id' => $orderId]);
  return $stmt->fetchAll();
}

function get_orders(): array {
  $stmt = db()->query('SELECT * FROM orders ORDER BY created_at DESC');
  return $stmt->fetchAll();
}

function update_order_status(int $orderId, string $status): void {
  $stmt = db()->prepare('UPDATE orders SET status = :status WHERE id = :id');
  $stmt->execute([':status' => $status, ':id' => $orderId]);
}