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

if (!isset($_SESSION['user_id'])) {
    header("location: login.php");
    exit;
}

if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['competition_id']) && isset($_FILES['submission_file'])) {
    $user_id = $_SESSION['user_id'];
    $competition_id = $_POST['competition_id'];
    $file = $_FILES['submission_file'];

    // File upload error handling
    if ($file['error'] !== UPLOAD_ERR_OK) {
        // Handle upload error
        header("location: user_dashboard.php?upload_error=1");
        exit;
    }

    // Create uploads directory if it doesn't exist
    $upload_dir = 'uploads/';
    if (!is_dir($upload_dir)) {
        mkdir($upload_dir, 0775, true);
    }

    // Generate a unique filename
    $file_extension = pathinfo($file['name'], PATHINFO_EXTENSION);
    $unique_filename = uniqid('submission_', true) . '.' . $file_extension;
    $file_path = $upload_dir . $unique_filename;

    // Move the file to the uploads directory
    if (move_uploaded_file($file['tmp_name'], $file_path)) {
        try {
            $pdo = db();
            $stmt = $pdo->prepare("INSERT INTO competition_submissions (user_id, competition_id, file_path) VALUES (?, ?, ?)");
            $stmt->execute([$user_id, $competition_id, $file_path]);
        } catch (PDOException $e) {
            // Handle DB error
            // You might want to log this error
            // If DB insert fails, you might want to delete the uploaded file
            unlink($file_path);
            header("location: user_dashboard.php?upload_error=2");
            exit;
        }
    }

    header("location: user_dashboard.php");
    exit;
}

header("location: user_dashboard.php");
exit;