<?php
session_start();
require_once 'db/config.php';

// Protect this page - redirect to login if user is not logged in
if (!isset($_SESSION['user'])) {
    header('Location: login.php');
    exit;
}

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $user_id = $_SESSION['user']['id'];
    $fuel_type = $_POST['fuel_type'];
    $quantity = $_POST['quantity'];

    // Validate input
    if (empty($fuel_type) || empty($quantity) || !is_numeric($quantity) || $quantity <= 0) {
        $_SESSION['order_error'] = "Invalid input.";
        header('Location: dashboard.php');
        exit;
    }

    try {
        $pdoconn = db();

        // Fetch the latest price
        $stmt = $pdoconn->query("SELECT * FROM prices ORDER BY updated_at DESC LIMIT 1");
        $latest_prices = $stmt->fetch();

        if (!$latest_prices) {
            $_SESSION['order_error'] = "Could not retrieve latest prices. Please try again later.";
            header('Location: dashboard.php');
            exit;
        }

        $price = ($fuel_type === 'petrol') ? $latest_prices['petrol_price'] : $latest_prices['diesel_price'];
        $total_price = $quantity * $price;

        // Insert the order
        $sql = "INSERT INTO orders (user_id, fuel_type, quantity, total_price) VALUES (:user_id, :fuel_type, :quantity, :total_price)";
        $stmt = $pdoconn->prepare($sql);
        $stmt->execute([
            ':user_id' => $user_id,
            ':fuel_type' => $fuel_type,
            ':quantity' => $quantity,
            ':total_price' => $total_price
        ]);

        $_SESSION['order_success'] = "Your order has been placed successfully!";
        header('Location: dashboard.php');
        exit;

    } catch (PDOException $e) {
        error_log("Order submission failed: " . $e->getMessage());
        $_SESSION['order_error'] = "There was an error placing your order. Please try again.";
        header('Location: dashboard.php');
        exit;
    }
} else {
    // Redirect if accessed directly
    header('Location: dashboard.php');
    exit;
}
?>