<?php
header('Content-type:application/json;charset=utf-8'); // Set the response content type to JSON

$target_dir = "/home/beatsaber-wip-uploader/maps/";

/**
 * Generates a random map id
 */
function generateMapId()
{
  $mapId = "";
  $characters = "0123456789abcdefghijklmnopqrstuvwxyz";
  for ($i = 0; $i < 4; $i++) {
    $mapId .= $characters[rand(0, strlen($characters) - 1)];
  }
  return $mapId;
}

/**
 * Checks if the file is a valid beatsaber map
 */
function isValidBeatSaberMap($file)
{
  $zip = new ZipArchive();
  if ($zip->open($file) === true) {
    if ($zip->locateName("info.dat", ZipArchive::FL_NOCASE) === false) {
      return false;
    }
    $zip->close();
    return true;
  }
  return false;
}

try {
  $map = $_FILES["map"]; // the file to upload

  if (!isset($map)) { // if the file is not set
    header("Location: /?map=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
    header("Location: /?map=File is too large");
    die();
  }

  if (!isValidBeatSaberMap($file)) {
    header("Location: /?map=This 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");
    header("Location: /?map=Failed to upload file");
    die();
  }

  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();
}