Social-Network/includes/form_handlers/register_handler.php

<?php
// Variables declaration to prevent errors
$fname = "";
$lname = "";
$email = "";
$email_conf = "";
$pass = ""; 
$pass_conf = ""; 
$date = ""; // Registration Date
$errors = array(); // Used to hold any errors.

if(isset($_POST['register_but'])) {
    // Variable Assignments 

    //  *** strip_tags() is used to prevent html injection. *** //
    $fname = strip_tags($_POST['reg_fname']); //Sets the value from the forum.
    $fname = str_replace(' ', '', $fname); // Removes any spaces.
    $fname = ucfirst(strtolower($fname)); // Capitalizes first letter, lowercases the rest.
    $_SESSION['reg_fname'] = $fname; // Stores values into session variable.

    $lname = strip_tags($_POST['reg_lname']);
    $lname = str_replace(' ', '', $lname); 
    $lname = ucfirst(strtolower($lname));
    $_SESSION['reg_lname'] = $lname;

    $email = strip_tags($_POST['reg_email']); 
    $email = str_replace(' ', '', $email);
    $email = strtolower($email);
    $_SESSION['reg_email'] = $email;

    $email_conf = strip_tags($_POST['reg_email_conf']); 
    $email_conf = str_replace(' ', '', $email_conf); 
    $email_conf = strtolower($email_conf);
    $_SESSION['reg_email_conf'] = $email_conf;

    $pass = strip_tags($_POST['reg_pass']); 
    $pass = str_replace(' ', '', $pass); 

    $pass_conf = strip_tags($_POST['reg_pass_conf']); 
    $pass_conf = str_replace(' ', '', $pass_conf);

    $date = date("Y-m-d"); // Sets the registration date.

    if ($email == $email_conf) {
        if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
            $email = filter_var($email, FILTER_VALIDATE_EMAIL);
            $username_check = $con->prepare("SELECT COUNT(*) FROM users WHERE email = ?");
            $username_check->bind_param("s", $email);
            $username_check->bind_result($num_rows);
            $username_check->execute();
            $username_check->fetch();
            if ($num_rows > 0) {
                array_push($errors, "email_exists");
            }
        } else {
            array_push($errors, "email_invalid");
        }
    } else {
        array_push($errors, "email_mismatch");
    }

    if (strlen($fname) > 25 || strlen($fname) < 2) {
        array_push($errors, "fname_invalid");
    }
    
    if (strlen($lname) > 25 || strlen($lname) < 2) {
        array_push($errors, "lname_invalid");
    }

    if ($pass != $pass_conf) {
        array_push($errors, "pass_mismatch");
    } else {
        if(preg_match('/[^A-Za-z0-9]/', $pass)) {
            array_push($errors, "pass_invalid_char");
        } else {
            if (strlen($pass) > 30 || strlen($pass) < 5) {
                array_push($errors, "pass_invalid_length");
            }
        }
    }

    if (!file_exists('debug/logs')) {
        mkdir('debug/logs', 0755, true); // Create recursively with appropriate permissions
    }

    if (empty($errors)) {
        $pass = password_hash($pass, PASSWORD_BCRYPT); // Encrypts password
        $username = strtolower($fname . "." . $lname);

        $username_check = $con->prepare("SELECT COUNT(*) FROM users WHERE username = ?");
        $temp = $username;
        $username_check->bind_param("s", $temp);
        $username_check->bind_result($count);
        $username_check->execute();
        $username_check->fetch();
        $i = 0;
        while ($count == 1) {
            $i++;
            $temp = $username;
            if ($i > 0) {
                $temp .= $i; // Use string concatenation directly with .=
            }
            $username_check->bind_param("s", $temp);
            $username_check->bind_result($count);
            $username_check->execute();
            $username_check->fetch();
            error_log("\nCounter=$i\nTemp = $temp\nNum Of Names: $count", 3, 'debug/logs/register_error.log');
        }
        
        if ($i > 0) {
            $username = $username . $i;
        } 

        $username_check->close();

        $rand = rand(1,16);
        $profile_pic = random_profile_pic($rand);
        
        $create_user = $con->prepare("INSERT INTO users VALUES (NULL,?,?,?,?,?,?,?,'0','0','0',',')");
        $create_user->bind_param("sssssss", $fname,$lname,$username,$email,$pass,$date,$profile_pic);
        $create_user->execute();
        $create_user->close();

        array_push($errors, "<span style='color: #14C800;'>You're all set! Go ahead and login!</span><br>");

        $_SESSION['reg_fname'] = "";
        $_SESSION['reg_lname'] = "";
        $_SESSION['reg_email'] = "";
        $_SESSION['reg_email_conf'] = "";

    }
}

function random_profile_pic($rand) {
    $profile_pic = "assets/profile_pics/defaults/";
    switch ($rand) {
        case 1:
            $profile_pic = $profile_pic . "head_alizarin.png";
            break;
        case 2:
            $profile_pic = $profile_pic . "head_amethyst.png";
            break;
        case 3:
            $profile_pic = $profile_pic . "head_belize_hole.png";
            break;
        case 4:
            $profile_pic = $profile_pic . "head_carrot.png";
            break;
        case 5:
            $profile_pic = $profile_pic . "head_deep_blue.png";
            break;
        case 6:
            $profile_pic = $profile_pic . "head_emerald.png";
            break;
        case 7:
            $profile_pic = $profile_pic . "head_green_sea.png";
            break;
        case 8:
            $profile_pic = $profile_pic . "head_nephritis.png";
            break;
        case 9:
            $profile_pic = $profile_pic . "head_pete_river.png";
            break;
        case 10:
            $profile_pic = $profile_pic . "head_pomegranate.png";
            break;
        case 11:
            $profile_pic = $profile_pic . "head_pumpkin.png";
            break;
        case 12:
            $profile_pic = $profile_pic . "head_red.png";
            break;
        case 13:
            $profile_pic = $profile_pic . "head_sun_flower.png";
            break;
        case 14:
            $profile_pic = $profile_pic . "head_turqoise.png";
            break;
        case 15:
            $profile_pic = $profile_pic . "head_wet_asphalt.png";
            break;
        case 16:
            $profile_pic = $profile_pic . "head_wistera.png";
            break;
    }
    return $profile_pic;
}
?>