diff --git a/upload.php b/upload.php
index c406e76..e26abd5 100644
--- a/upload.php
+++ b/upload.php
@@ -1,7 +1,7 @@
 <?php
 header('Content-type:application/json;charset=utf-8'); // Set the response content type to JSON
 
-$target_dir = "./maps/";
+$target_dir = "/home/beatsaber-wip-uploader/maps/";
 
 /**
  * Generates a random map id
@@ -9,7 +9,7 @@ $target_dir = "./maps/";
 function generateMapId()
 {
   $mapId = "";
-  $characters = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
+  $characters = "0123456789abcdefghijklmnopqrstuvwxyz";
   for ($i = 0; $i < 4; $i++) {
     $mapId .= $characters[rand(0, strlen($characters) - 1)];
   }
@@ -17,60 +17,73 @@ function generateMapId()
 }
 
 /**
- * Checks if the file is a zip file
+ * Checks if the file is a valid beatsaber map
  */
-function isZipFile($file)
+function isValidBeatSaberMap($file)
 {
-  $fileType = strtolower(pathinfo($file, PATHINFO_EXTENSION));
-  return $fileType == "zip";
-}
-
-$mapId = generateMapId(); // the id of the map
-
-$map = $_FILES["map"]; // the file to upload
-
-if (!isset($map)) { // if the file is not set
-  echo "No file was uploaded";
-  die();
-}
-
-$file = $map["tmp_name"]; // the temporary file path
-$size = $map["size"]; // the size of the file
-
-if ($size > 100000000) { // if the file is larger than 100MB
-  echo "The file is too large";
-  die();
-}
-
-if (!isZipFile($map["name"])) {
-  echo "The file is not a zip file";
-  die();
-}
-
-$fileHash = hash_file("sha256", $file); // the hash of the file
-
-$exists = false;
-foreach (scandir($target_dir) as $file) { // scan the maps directory for a file with the same hash
-  if ($file == "." || $file == "..") { // ignore the . and .. files
-    continue;
-  }
-  if (hash_file("sha256", $target_dir . $file) == $fileHash) {
-    $mapId = pathinfo($file, PATHINFO_FILENAME);
-    $exists = true;
-    break;
+  $zip = new ZipArchive();
+  if ($zip->open($file) === true) {
+    if ($zip->locateName("info.dat", ZipArchive::FL_NOCASE) === false) {
+      return false;
+    }
+    $zip->close();
+    return true;
   }
+  return false;
 }
 
-if ($exists) { // if the file already exists, redirect to the existing file
+try {
+  $map = $_FILES["map"]; // the file to upload
+
+  if (!isset($map)) { // if the file is not set
+    echo "No file was uploaded";
+    die();
+  }
+
+  $mapId = generateMapId(); // the id of the map
+  $file = $map["tmp_name"]; // the temporary file path
+  $size = $map["size"]; // the size of the file
+
+  if ($size > 100000000) { // if the file is larger than 100MB
+    echo "The file is too large";
+    die();
+  }
+
+  if (!isValidBeatSaberMap($file)) {
+    echo "The file is not a valid BeatSaber map";
+    die();
+  }
+
+  $fileHash = hash_file("sha256", $file); // the hash of the file
+
+  $exists = false;
+  foreach (scandir($target_dir) as $scannedFile) { // scan the maps directory for a file with the same hash
+    if ($scannedFile == "." || $scannedFile == "..") { // ignore the . and .. files
+      continue;
+    }
+    if (hash_file("sha256", $target_dir . $scannedFile) == $fileHash) {
+      $mapId = pathinfo($scannedFile, PATHINFO_FILENAME);
+      $exists = true;
+      break;
+    }
+  }
+
+  if ($exists) { // if the file already exists, redirect to the existing file
+    header("Location: /?map=https://wip.fascinated.cc/maps/" . $mapId . ".zip");
+    die();
+  }
+
+  $target_file = $target_dir . $mapId . ".zip"; // the output file path
+  if (!move_uploaded_file($file, $target_file)) {
+    error_log("Error: Failed to move uploaded file from $file to $target_file");
+    echo "There was an error uploading the file";
+    die();
+  }
+
+  error_log("Uploaded file moved from $file to $target_file");
+
   header("Location: /?map=https://wip.fascinated.cc/maps/" . $mapId . ".zip");
+} catch (Exception $e) {
+  echo "There was an error uploading the file. Error: " . $e->getMessage();
   die();
 }
-
-$target_file = $target_dir . $mapId . ".zip";
-if (!move_uploaded_file($file, $target_file)) {
-  echo "There was an error uploading the file";
-  die();
-}
-
-// redirect to /?map=https://wip.fascinated.cc/maps/" . $mapId . ".zip
-header("Location: /?map=https://wip.fascinated.cc/maps/" . $mapId . ".zip");