functions.php

<?php
// ===== functions.php =====
include 'config.php';

// Function to validate student data
function validateStudentData($data) {
    $errors = [];
    
    if (empty($data['first_name'])) {
        $errors[] = "First name is required";
    }
    
    if (empty($data['last_name'])) {
        $errors[] = "Last name is required";
    }
    
    if (empty($data['email'])) {
        $errors[] = "Email is required";
    } elseif (!filter_var($data['email'], FILTER_VALIDATE_EMAIL)) {
        $errors[] = "Invalid email format";
    }
    
    if (empty($data['phone'])) {
        $errors[] = "Phone number is required";
    } elseif (!preg_match('/^[0-9]{10,15}$/', $data['phone'])) {
        $errors[] = "Phone number must be 10-15 digits";
    }
    
    
    return $errors;
}



// Function to register student
function registerStudent($conn, $data) {
    $errors = validateStudentData($data);

    // print_r($data); exit(); // for debugging (1)

    $first_name = mysqli_real_escape_string($conn, $data['first_name']);
    $last_name = mysqli_real_escape_string($conn, $data['last_name']);
    $email = mysqli_real_escape_string($conn, $data['email']);
    $phone = mysqli_real_escape_string($conn, $data['phone']);
    

    if (!empty($errors)) {
        return ['success' => false, 'errors' => $errors];
    }
    
    $sql = "INSERT INTO students (first_name, last_name, email, phone) 
            VALUES ('$first_name', '$last_name', '$email', '$phone')";

    // echo($sql); exit();
    
    $exQuery = mysqli_query($conn, $sql);

    // print_r($exQuery);
    // exit(); //for debugging

    if ($exQuery) {
        $res = ['status' => true,'message' => 'Student registered successfully'];
          return $res;
        // echo json_encode($res); 
        exit();
    } else {
        $res = ['status' => false, 'errors' => ['Database error: ' . mysqli_error($conn)]];
         return $res;
        // echo json_encode($res); exit();
    }

}

// Function to get all students
function getAllStudents($conn) {
    $sql = "SELECT * FROM students ORDER BY last_name, first_name";
    $result = mysqli_query($conn, $sql);
    
    $students = [];
    
    if ($result) {
        while ($row = mysqli_fetch_assoc($result)) {
            $students[] = $row;
        }
    }
    
   // print_r($students); exit(); // for debugging (3)

    return $students;
}

?>