index.php

<?php
$title = "Shorty | URL shortner";
$css_path = "public/css/style.css";
include "templates/header.php";
require "db_helper.php";

$shortened_url = "";
date_default_timezone_set("Asia/Calcutta");   //India time (GMT+5:30)
if (isset($_GET["id"])) {
  $id = $_GET["id"];
  $select_sql = "SELECT * FROM url WHERE id='$id'";
  $result = mysqli_query($conn, $select_sql);

  if (!$result) {
    header("location: ./error.php?error=500");
    mysqli_close($conn);
    exit();
  }

  $shortened_url = mysqli_fetch_assoc($result);

  if (!$shortened_url) {
    header("location: ./error.php?error=404");
    mysqli_close($conn);
    exit();
  }

  $now = new DateTime("now");
  $expiry_date = new DateTime($shortened_url["expiryDate"]);

  if ($expiry_date == NULL || $now < $expiry_date) {
    header("Location: {$shortened_url['url']}");
  } else {
    header("location: ./error.php?error=404");
  }

  mysqli_close($conn);
}

if (isset($_POST["submit"])) {
  $url = mysqli_real_escape_string($conn, htmlspecialchars($_POST["url"]));
  $expiry_date = mysqli_real_escape_string($conn, htmlspecialchars($_POST["expiryDate"] == "custom" ? $_POST["customDate"] : NULL));
  $userId = isset($_SESSION["userid"]) ? $_SESSION["userid"] : NULL;
  $expiry_date_set = mysqli_real_escape_string($conn, htmlspecialchars($_POST["expiryDate"]));

  $bytes = random_bytes(5);
  $generated_id = bin2hex($bytes);

  if ($expiry_date == NULL && $userId == NULL) {
    $insert_sql = "INSERT INTO url(id, url, expiryDate, userId) VALUES('$generated_id', '$url', NULL, NULL);";
  } else if ($expiry_date && $userId == NULL) {
    $insert_sql = "INSERT INTO url(id, url, expiryDate, userId) VALUES('$generated_id', '$url', '$expiry_date', NULL);";
  } else if ($expiry_date == NULL && $userId) {
    $insert_sql = "INSERT INTO url(id, url, expiryDate, userId) VALUES('$generated_id', '$url', NULL, '$userId');";
  } else if ($expiry_date && $userId) {
    $insert_sql = "INSERT INTO url(id, url, expiryDate, userId) VALUES('$generated_id', '$url', '$expiry_date', '$userId');";
  }

  if (!mysqli_query($conn, $insert_sql)) {
    header("location: ./error.php?error=500");
    mysqli_close($conn);
    exit();
  }

  $select_sql = "SELECT * FROM url WHERE id='$generated_id'";

  $result = mysqli_query($conn, $select_sql);
  if (!$result) {
    header("location: ./error.php?error=500");
    mysqli_close($conn);
    exit();
  }

  $shortened_url = mysqli_fetch_assoc($result);
  mysqli_close($conn);
}
?>

<main>


  <?php if ($shortened_url) { ?>
    <p class="flash success">Success! Shortened URL: <a target="_blank" href="<?php echo "https://shorty.ml?id={$shortened_url['id']}" ?>"><?php echo "shorty.ml?id={$shortened_url['id']}" ?></a></p>
  <?php } ?>
  <?php if (isset($_GET["success"]) && $_GET["success"] == "loginsuccess") { ?>
    <p class="flash success">Welcome back! You have been logged in.</p>
  <?php } ?>
  <?php if (isset($_GET["success"]) && $_GET["success"] == "logoutsuccess") { ?>
    <p class="flash success">Logged out, please come again!</p>
  <?php } ?>

  <div class="form-container">
    <h2>Shorten your lengthy URL</h2>
    <form class="url-form" action="index.php" method="post">
      <label for="url">Enter URL (Include protocol before the URL)</label>
      <input type="text" name="url" id="url">
      <span class="enter-url">Enter your URL</span>
      <span class="invalid-url">Enter valid URL</span>

      <p>Set expiry date for the shortened link</p>
      <div class="radio-button-container">
        <div class="radio-control">
          <input type="radio" name="expiryDate" id="permanent" value="permanent" checked>
          <label for="permanent">Permanent</label>
        </div>
        <div class="radio-control">
          <input type="radio" name="expiryDate" id="custom" value="custom">
          <label for="custom">Custom</label>
          <input type="datetime-local" name="customDate">
        </div>
        <span class="choose-date">Choose expiry date</span>
        <span class="set-date">Set custom expiry date</span>
      </div>
      <input class="btn shorten-btn" type="submit" name="submit" value="Shorten">
    </form>
  </div>


</main>

<?php
$js_route = "./public/js/urlValidation.js";
include "./templates/footer.php";
?>