<?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 . "admin_api/modules/library_management/library_function.php";

$postdata = json_decode(file_get_contents("php://input"), true);

checkIfNoPhpContentsReceive();

if (
    // !isset($postdata['institution_id']) or !checkIfIssetAndNotEmpty($postdata['institution_id']) or
    // !isset($postdata['branch_id']) || !checkIfIssetAndNotEmpty($postdata['branch_id']) or
    !isset($postdata['function_type']) or !checkIfIssetAndNotEmpty($postdata['function_type']) or
    !isset($postdata['api_signature']) or !checkIfIssetAndNotEmpty($postdata['api_signature']) or
    !isset($postdata['jwt_token']) or !checkIfIssetAndNotEmpty($postdata['jwt_token'])
) {
    errorreturn("all fields are required.");
}

validateApiSignature($postdata['api_signature']);

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

$specific_db_name = validateUserAccess($conn_rjllearning, $userid, $role, $workspace_id,["principal"], null);
if (!$specific_db_name) {
    errorreturn('Access denied.');
} else {
    $conn_rjllearning_specific = dynamicDbConnection($specific_db_name);
}

require_once $base_path_to_learning . 'functions/common_functions.php';
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);

$academicSessionId = CheckAcademicSession($conn_rjllearning_specific, $institution_id);
if (!$academicSessionId) {
    errorreturn("Invalid institution_id");
}

$isBranchClassSubjectValid = checkBranchClassSubject($conn_rjllearning_specific, $branch_id, null, null, $institution_id);
if (!$isBranchClassSubjectValid) {
    errorreturn("Invalid branch_id.");
}


function getStudent_issued_details($conn_rjllearning_specific, $student_id, $institution_id, $branch_id)
{
    // Fetch student details
    $sql = "SELECT id, name FROM students WHERE id = ? AND institution_id = ? AND branch_id = ? AND can_activate = 1";
    $stmt = $conn_rjllearning_specific->prepare($sql);
    $stmt->execute([$student_id, $institution_id, $branch_id]);
    $student_detail = $stmt->fetch();

    if (!$student_detail) {
        errorreturn("No student exists for the given institution and branch.");
    }

    // Assign the student's name
    $std_id = $student_detail['id'];
    $student_name = $student_detail['name'];

    // Fetch issued book details
    $sql = "SELECT book_id, date_of_issue, due_date, date_of_return FROM book_issues WHERE student_id = ? AND institution_id = ? AND branch_id = ? AND date_of_issue IS NOT NULL";
    $stmt = $conn_rjllearning_specific->prepare($sql);
    $stmt->execute([$std_id, $institution_id, $branch_id]);
    $issued_books = $stmt->fetchAll();

    if (!$issued_books) {
        errorreturn("No books have been issued to this student.");
    }

    $book_detail = [];

    foreach ($issued_books as $books) {
        $sql = "SELECT book_name, author FROM library_management WHERE id = ?  AND institution_id = ? AND branch_id = ?";
        $stmt = $conn_rjllearning_specific->prepare($sql);
        $stmt->execute([$books['book_id'],$institution_id, $branch_id]);
        $book_info = $stmt->fetch();

        if ($book_info) {
            $book_detail[] = array(
                "book_id" => $books['book_id'],
                "book_name" => $book_info['book_name'],
                "author" => $book_info['author'],
                "date_of_issue" => $books['date_of_issue'],
                "due_date" => $books['due_date'],
                "date_of_return" => $books['date_of_return'] ? $books['date_of_return'] : "Not Returned"
            );
        }
    }
    return array(
        // "student_id" => $student_id,
        "student_name" => $student_name, 
        "total_books_issued" => count($book_detail),
        "issued_books" => $book_detail
    );
}

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

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

    $fetch_student_books = getStudent_issued_details($conn_rjllearning_specific, $student_id, $institution_id, $branch_id);

    if ($fetch_student_books) {
        successreturn($fetch_student_books);
    } else {
        errorreturn("No book issue details available for this student.");
    }
}else{
    errorreturn("Invalid function");
}

