<?php
/**
 * Get User Quiz Attempts API
 * GET /api/custom-api/user-quiz-attempts.php
 * Requires: Authorization header with Bearer token
 */

header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, OPTIONS');
header("Access-Control-Allow-Headers: X-Requested-With, Content-Type, Authorization");
header('Content-Type: application/json');

if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    http_response_code(200);
    exit();
}

// Load WordPress
require_once('/mnt/blockstorage/ctms/wp-load.php');
require_once('auth-helper.php');

if ($_SERVER['REQUEST_METHOD'] !== 'GET') {
    send_error_response('Only GET requests are allowed', 405);
}

// Verify JWT token
$user_id = verify_jwt_token();

if (!$user_id) {
    send_error_response('User not authenticated', 401);
}

global $wpdb;

$quiz_attempts_table = $wpdb->prefix . 'quiz_attempts';
$quiz_attempt_data_table = $wpdb->prefix . 'quiz_attempt_data';
$users_table = $wpdb->prefix . 'users';
$quizzes_table = $wpdb->prefix . 'quizzes';
$questions_table = $wpdb->prefix . 'quiz_questions';

// Check if tables exist
$table_exists = $wpdb->get_var("SHOW TABLES LIKE '$quiz_attempts_table'");

if (!$table_exists) {
    send_error_response('Quiz attempts table not found', 404);
}

// Retrieve all quiz attempts for the user
$quiz_attempts = $wpdb->get_results($wpdb->prepare("
    SELECT
        ua.id AS attempt_id,
        u.display_name AS student_name,
        ua.score,
        ua.datetime,
        c.name AS class_name,
        q.title AS quiz_title
    FROM $quiz_attempts_table ua
    INNER JOIN $quizzes_table q ON ua.quiz_id = q.id
    INNER JOIN $users_table u ON ua.student_id = u.ID
    INNER JOIN {$wpdb->prefix}class_enrollment ce ON ua.student_id = ce.student_id
    INNER JOIN {$wpdb->prefix}classes c ON ce.class_id = c.id
    WHERE ua.student_id = %d
    ORDER BY ua.datetime DESC
", $user_id));

if (empty($quiz_attempts)) {
    send_json_response(array(
        'success' => true,
        'quiz_attempts' => array(),
        'total_count' => 0,
    ), 200);
}

// Format the results
$formatted_attempts = array();

foreach ($quiz_attempts as $attempt) {
    $attempt_id = $attempt->attempt_id;

    // Get detailed results for this attempt
    $details_results = $wpdb->get_results($wpdb->prepare("
        SELECT qq.title AS question_title, qad.answer, qad.is_correct
        FROM $quiz_attempt_data_table qad
        INNER JOIN $questions_table qq ON qad.question_id = qq.id
        WHERE qad.quiz_attempt_id = %d
    ", $attempt_id));

    $correct_answers = 0;
    $total_questions = count($details_results);
    $question_details = array();

    foreach ($details_results as $detail) {
        if ($detail->is_correct) {
            $correct_answers++;
        }

        $question_details[] = array(
            'question' => $detail->question_title,
            'answer' => $detail->answer,
            'is_correct' => (bool) $detail->is_correct,
        );
    }

    $percentage = $total_questions > 0 ? round(($correct_answers / $total_questions) * 100, 2) : 0;

    $formatted_attempts[] = array(
        'attempt_id' => (int) $attempt->attempt_id,
        'name' => $attempt->student_name,
        'class' => $attempt->class_name,
        'quiz_title' => $attempt->quiz_title,
        'score' => $attempt->score,
        'date' => $attempt->datetime,
        'percentage' => $percentage,
        'correct_answers' => $correct_answers,
        'total_questions' => $total_questions,
        'details' => $question_details,
    );
}

send_json_response(array(
    'success' => true,
    'quiz_attempts' => $formatted_attempts,
    'total_count' => count($formatted_attempts),
), 200);
?>