chore: Modernize version check script

Author: GermanCoding

server/.htaccess

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+RewriteEngine On
+RewriteRule ^version-check/?$ /version-check.php [L]

server/Dockerfile

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+FROM php:8.4-apache
+RUN a2enmod rewrite
+RUN rm -f /var/www/html/index.html
+COPY version-check.php /var/www/html/version-check.php
+COPY .htaccess /var/www/html/.htaccess
+RUN chown -R www-data:www-data /var/www/html/
+EXPOSE 80

server/survey.php

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+<?php
+
+/**
+ * Version upgrade path manager for SyncTrayzor
+ * 
+ * Clients request this with their current version, arch, and variant (portable, etc)
+ * and this gives them a version to upgrade to (if any), along with the method of
+ * upgrading to it (manual navigation to Github release page, automatic silent upgrade,
+ * etc). 
+ * 
+ * $versions is a record of all of the current releases, which we might want to upgrade
+ * people to. It has the structure:
+ * [
+ *    version => [
+ *       variant => [
+ *          'url' => [
+ *             arch => 'url',
+ *             ...
+ *          ],
+ *       ],
+ *       ...
+ *       'release_notes' => release_notes,
+ *    ],
+ *    ...
+ * ]
+ *
+ * version: version string e.g. '1.2.3'
+ * variant: e.g. 'portable', 'installed'. Matched against the variant provided by the
+ *          client, or '*' can be used to specify a default.
+ * arch:    e.g. 'x86', 'x64'. Matched against the arch provided by the client, or '*'
+ *          can used to specify a default.
+ * release_notes: Release notes to display to the user.
+ * 
+ * $upgrades is a map of old_version => new_version, and specifies the formatter to
+ * use to communicate with old_version. It also allows various overrides to be
+ * specified (e.g. release notes)
+ * It has the structure:
+ * [
+ *    old_version => ['to' => new_version, 'formatter' => formatter_version, 'overrides' => [overrides]],
+ *    ...
+ * ]
+ *
+ * old_version: version being upgraded from
+ * new_version: version to upgrade to
+ * formatter_version: formatter version to use (in $response_formatters)
+ * overrides: optional overrides, used by the formatter
+ */
+
+set_error_handler('error_handler');
+date_default_timezone_set('UTC');
+header('Content-Type: application/json');
+
+// Allowed values for arch and variant
+$allowed_arches = ['x64', 'arm64'];
+$allowed_variants = ['installed', 'portable'];
+
+function error_handler($severity, $message, $filename, $lineno)
+{
+   throw new ErrorException($message, 0, $severity, $filename, $lineno);
+}
+
+function get_with_wildcard($src, $value, $default = null)
+{
+   if (isset($src[$value]))
+      return $src[$value];
+   if (isset($src['*']))
+      return $src['*'];
+   return $default;
+}
+
+$versions = [
+   '2.0.0' => [
+      'base_url' => 'https://github.com/GermanCoding/SyncTrayzor/releases/download',
+      'installed' => [
+         'direct_download_url' => [
+            'x64' => "{base_url}/v{version}/SyncTrayzorSetup-x64.exe",
+            'arm64' => "{base_url}/v{version}/SyncTrayzorSetup-arm64.exe",
+         ],
+      ],
+      'portable' => [
+         'direct_download_url' => [
+            'x64' => "{base_url}/v{version}/SyncTrayzorPortable-x64.zip",
+            'arm' => "{base_url}/v{version}/SyncTrayzorPortable-arm64.zip",
+         ],
+      ],     
+      'sha512sum_download_url' => "{base_url}/v{version}/sha512sum.txt.asc",
+      'release_page_url' => 'https://github.com/GermanCoding/SyncTrayzor/releases/tag/v{version}',
+      'release_notes' => "N/A",
+   ]
+];
+
+$upgrades = [
+   '1.1.29' => ['to' => 'latest', 'formatter' => '5']
+];
+
+$response_formatters = [
+   // Base for 2.0.0 releases (same as the last 1.x releases)
+   '5' => function($arch, $variant, $to_version, $to_version_info, $overrides)
+   {
+      $variant_info = isset($overrides[$variant]) ? get_with_wildcard($overrides, $variant) : get_with_wildcard($to_version_info, $variant);
+
+      $data = [
+         'version' => $to_version,
+         'direct_download_url' => get_with_wildcard($variant_info['direct_download_url'], $arch),
+         'sha512sum_download_url' => $to_version_info['sha512sum_download_url'],
+         'release_page_url' => $to_version_info['release_page_url'],
+         'release_notes' => isset($overrides['release_notes']) ? $overrides['release_notes'] : $to_version_info['release_notes'],
+      ];
+
+      return $data;
+   },
+];
+
+$error = null;
+$loggable_error = null;
+$data = null;
+
+try
+{
+   // Use filter_input for better input handling
+   $version = isset($_GET['version']) ? trim(strip_tags($_GET['version'])) : null;
+   $arch = isset($_GET['arch']) ? trim(strip_tags($_GET['arch'])) : null;
+   $variant = isset($_GET['variant']) ? trim(strip_tags($_GET['variant'])) : null;
+
+   // Validate inputs
+   if (empty($version) || empty($arch) || empty($variant))
+   {
+      $error = ['code' => 1, 'message' => 'version, arch, or variant not specified'];
+   }
+   // Only allow known arches and variants
+   else if (!in_array($arch, $allowed_arches, true) || !in_array($variant, $allowed_variants, true))
+   {
+      $error = ['code' => 3, 'message' => 'Invalid arch or variant'];
+   }
+   else if (isset($upgrades[$version]))
+   {
+      $to_version = $upgrades[$version]['to'];
+      if ($to_version === 'latest')
+         $to_version = array_keys($versions)[0];
+
+      $formatter = $response_formatters[$upgrades[$version]['formatter']];
+      $overrides = $upgrades[$version]['overrides'] ?? [];
+
+      $base_url = $overrides['base_url'] ?? $versions[$to_version]['base_url'];
+
+      array_walk_recursive($versions[$to_version], function(&$value, $key) use ($to_version, $base_url) {
+         $value = str_replace('{version}', $to_version, $value);
+         $value = str_replace('{base_url}', $base_url, $value);
+      });
+      $to_version_info = $versions[$to_version];
+
+      $data = $formatter($arch, $variant, $to_version, $to_version_info, $overrides);
+   }
+}
+catch (Exception $e)
+{
+   $error = ['code' => 2, 'message' => 'Unhandled error. Please try again later'];
+   error_log($e->getMessage() . "\n" . $e->getTraceAsString());
+}
+
+$rsp = [];
+if ($data != null)
+   $rsp['data'] = $data;
+if ($error != null)
+   $rsp['error'] = $error;
+
+$output = json_encode($rsp, JSON_UNESCAPED_SLASHES | JSON_FORCE_OBJECT | JSON_PRETTY_PRINT);
+
+$date = date('c');
+
+echo $output;