<?php

ini_set('display_errors', 1);

require_once '../../../resources/base_path_include.php';
require_once $base_path_to_learning_resources . "includes/connect.php";
require_once $base_path_to_learning_resources . "lib/function.php";
require_once $base_path_to_learning_resources . "lib/validate_api_signature.php";
require_once $base_path_to_learning_resources . "lib/validate_function.php";
require_once $base_path_to_learning . "user_management/authenticate.php";
require_once $base_path_to_learning . 'functions/common_functions.php';
require_once $base_path_to_learning_resources . "includes/specific_db_config.php";
require_once $base_path_to_learning_resources . 'lib/bucket_functions/bucket_functions.php';
require_once $base_path_to_learning . "vendor/autoload.php";
require_once $base_path_to_learning_resources . 'includes/aws_bucket_config.php';
require_once $base_path_to_learning . "user_management/functions/functions.php";
require_once $base_path_to_learning . "faculty_api/modules/library_management/library_function.php";
// require_once $base_path_to_learning . "admin_api/modules/library_management/fetch_specific_book.php";
require_once $base_path_to_learning . "faculty_api/faculty_function/common_faculty_function.php";
require_once $base_path_to_learning . "principal_api/principal_function/principal_function.php";

// Get and decode the JSON data from the request
$postdata = json_decode(file_get_contents("php://input"), true);



// Check if POST data is received
checkIfNoPhpContentsReceive();

// Validate required fields
$requiredFields = ['function_type', 'api_signature', 'jwt_token'];
foreach ($requiredFields as $field) {
    if (!isset($postdata[$field]) || !checkIfIssetAndNotEmpty($postdata[$field])) {
        errorreturn("All fields are required.");
    }
}

// Validate API signature
validateApiSignature($postdata['api_signature']);

// Authenticate JWT token
$jwttoken = $postdata['jwt_token'];
$jwt_validate = authenticate_jwt($jwttoken);

$userid = $jwt_validate->data->id;
$workspace_id = $jwt_validate->data->workspace_id;
$username = $jwt_validate->data->username;
$role = $jwt_validate->data->role;
$name = $jwt_validate->data->name;
$branch_id = $jwt_validate->data->branch_id;
$institution_id = $jwt_validate->data->institution_id;


$function_type = trim($postdata['function_type']);

$search_string = isset($postdata['search_string']) ? trim($postdata['search_string']) : '';
$limit = isset($postdata['limit']) ? trim($postdata['limit']) : 50;
$offset = isset($postdata['offset']) ? trim($postdata['offset']) : 0;

// Validate user access
$specific_db_name = validateUserAccess($conn_rjllearning, $userid, $role, $workspace_id, ["teacher"], $institution_id);
if (!$specific_db_name) {
    errorreturn('Access denied.');
} else {
    $conn_rjllearning_specific = dynamicDbConnection($specific_db_name);
}

require_once $base_path_to_learning . 'functions/get_branch_functions.php';
require_once $base_path_to_learning . 'user_management/user_versioning.php';

$version = isset($_POST['version']) ? $_POST['version'] : (isset($postdata['version']) ? $postdata['version'] : null);
$updated_time = isset($_POST['updated_time']) ? $_POST['updated_time'] : (isset($postdata['updated_time']) ? $postdata['updated_time'] : null);

$response = user_data_refresh($conn_rjllearning, $conn_rjllearning_specific,$version, $updated_time, $userid, $institution_id);

function getstudentbooks($conn_rjllearning_specific, $userid, $branch_id, $search_string, $conn_rjllearning,$function_type, $limit, $offset, $institution_id) {
    
    $Faculty_Codes = $conn_rjllearning_specific->prepare("SELECT id FROM faculty_info WHERE userid = ? AND institution_id = ? AND branch_id = ?");
    $Faculty_Codes->execute(array($userid, $institution_id, $branch_id));

    // Fetch a single row instead of all
    $result_faculty = $Faculty_Codes->fetch(PDO::FETCH_ASSOC);

    // Check if the faculty exists
    if ($result_faculty === false) {
        errorreturn("Faculty Not Found.");
    }

    // Retrieve the faculty_id from the result
    $faculty_id = $result_faculty['id'];
    $teacher_data = getClassSectionSubjectsAndInChargeRoles($conn_rjllearning, $conn_rjllearning_specific, $institution_id, $userid);
    $class_section_subjects  = $teacher_data['class_section_subjects'];
    $class_incharge_roles = $teacher_data['class_incharge_roles'];
    $staff_access_modules = $teacher_data['staff_access_modules'];

    $check_faculty_status=checkFacultyModuleGranted($function_type, $class_section_subjects, $class_incharge_roles, $staff_access_modules, null, null, null, $conn_rjllearning);
    if($check_faculty_status == false){
        errorreturn("Access denied: You do not have the required permissions.");
    }

    // SQL query to fetch student data along with currently issued books
    $sql = "
        SELECT 
            s.id AS student_id,
            CONCAT(s.name, ' (', s.admission_number, ')') AS student_name,
            COUNT(bi.book_id) AS books_currently_issued
        FROM 
            students s
        LEFT JOIN 
            book_issues bi ON s.id = bi.student_id AND bi.date_of_return IS NULL
        WHERE 
            s.institution_id = ? 
            AND s.branch_id = ?
            AND s.can_activate = 1
            AND (s.name LIKE ? OR s.admission_number LIKE ?)
        GROUP BY 
            s.id
        ORDER BY 
            s.id ASC
    ";
    if ($limit != 'all') {
        $sql .= " LIMIT " . $offset . ", " . $limit;
    }

    $stmt = $conn_rjllearning_specific->prepare($sql);
    $stmt->execute([$institution_id, $branch_id, '%' . $search_string . '%', '%' . $search_string . '%']);
    $result = $stmt->fetchAll(PDO::FETCH_ASSOC);


    $total_rows = count($result);
    $maxreach = $total_rows < $limit ? 1 : 0;

    return [
        'total_rows' => $total_rows,
        'student_info' => $result,
        'maxreach' => $maxreach
    ];
}




if ($postdata['function_type'] == "student_book_summary") {

    // if (!isset($postdata['student_id']) || empty(trim($postdata['student_id']))) {
    //     errorreturn("student_id is required.");
    // }

    // $student_id = trim($postdata['student_id']);

    $check_academic_confirmation = CheckAcademicSession($conn_rjllearning_specific, $institution_id);
    if (!$check_academic_confirmation) {
        errorreturn("Access denied. Academic session not active.");
    }

    $book_summary = getstudentbooks($conn_rjllearning_specific, $userid, $branch_id, $search_string, $conn_rjllearning,$function_type, $limit, $offset, $institution_id);

    successreturn ($book_summary);
}else{
    errorreturn ("Invalid function type");
}