<?php
header('Content-Type: application/json');
session_start();
require_once 'db/config.php';

// Ensure admin is logged in
if (!isset($_SESSION['user_id']) || !in_array('Admin', $_SESSION['user_roles'])) {
    echo json_encode(['error' => 'Unauthorized']);
    exit;
}

$action = $_GET['action'] ?? '';

switch ($action) {
    case 'submissions_per_survey':
        $stmt = db()->query("SELECT s.title, COUNT(fs.id) as submission_count FROM surveys s LEFT JOIN feedback_submissions fs ON s.id = fs.survey_id GROUP BY s.id");
        $results = $stmt->fetchAll(PDO::FETCH_ASSOC);
        $labels = array_column($results, 'title');
        $values = array_column($results, 'submission_count');
        echo json_encode(['labels' => $labels, 'values' => $values]);
        break;

    case 'survey_question_analytics':
        $surveys_stmt = db()->query("SELECT * FROM surveys");
        $surveys = $surveys_stmt->fetchAll(PDO::FETCH_ASSOC);
        $response = [];

        foreach ($surveys as $survey) {
            $questions_stmt = db()->prepare("SELECT * FROM survey_questions WHERE survey_id = ? AND (question_type = 'rating' OR question_type = 'multiple-choice')");
            $questions_stmt->execute([$survey['id']]);
            $questions = $questions_stmt->fetchAll(PDO::FETCH_ASSOC);

            $survey_data = [
                'id' => $survey['id'],
                'title' => $survey['title'],
                'questions' => []
            ];

            foreach ($questions as $question) {
                $answers_stmt = db()->prepare("SELECT answer_text, COUNT(*) as count FROM survey_answers WHERE question_id = ? GROUP BY answer_text");
                $answers_stmt->execute([$question['id']]);
                $answers = $answers_stmt->fetchAll(PDO::FETCH_ASSOC);

                $question_data = [
                    'id' => $question['id'],
                    'question_text' => $question['question_text'],
                    'type' => $question['question_type'],
                    'answers' => [
                        'labels' => array_column($answers, 'answer_text'),
                        'values' => array_column($answers, 'count')
                    ]
                ];
                $survey_data['questions'][] = $question_data;
            }
            $response[] = $survey_data;
        }
        echo json_encode($response);
        break;

    default:
        echo json_encode(['error' => 'Invalid action']);
        break;
}