Jellyfin and Subsync Fixes (#13)

src/core/services/jimaku-download-path.ts

@@ -0,0 +1,51 @@
+import * as path from 'node:path';
+
+const DEFAULT_JIMAKU_LANGUAGE_SUFFIX = 'ja';
+const DEFAULT_SUBTITLE_EXTENSION = '.srt';
+
+function stripFileExtension(name: string): string {
+  const ext = path.extname(name);
+  return ext ? name.slice(0, -ext.length) : name;
+}
+
+function sanitizeFilenameSegment(value: string, fallback: string): string {
+  const sanitized = value
+    .replace(/[\\/:*?"<>|]/g, ' ')
+    .replace(/\s+/g, ' ')
+    .trim();
+  return sanitized || fallback;
+}
+
+function resolveMediaFilename(mediaPath: string): string {
+  if (!/^[a-z][a-z0-9+.-]*:\/\//i.test(mediaPath)) {
+    return path.basename(path.resolve(mediaPath));
+  }
+
+  try {
+    const parsedUrl = new URL(mediaPath);
+    const decodedPath = decodeURIComponent(parsedUrl.pathname);
+    const fromPath = path.basename(decodedPath);
+    if (fromPath) {
+      return fromPath;
+    }
+    return parsedUrl.hostname.replace(/^www\./, '') || 'subtitle';
+  } catch {
+    return path.basename(mediaPath);
+  }
+}
+
+export function buildJimakuSubtitleFilenameFromMediaPath(
+  mediaPath: string,
+  downloadedSubtitleName: string,
+  languageSuffix = DEFAULT_JIMAKU_LANGUAGE_SUFFIX,
+): string {
+  const mediaFilename = resolveMediaFilename(mediaPath);
+  const mediaBasename = sanitizeFilenameSegment(stripFileExtension(mediaFilename), 'subtitle');
+  const subtitleName = path.basename(downloadedSubtitleName);
+  const subtitleExt = path.extname(subtitleName) || DEFAULT_SUBTITLE_EXTENSION;
+  const normalizedLanguageSuffix = sanitizeFilenameSegment(languageSuffix, 'ja').replace(
+    /\s+/g,
+    '-',
+  );
+  return `${mediaBasename}.${normalizedLanguageSuffix}${subtitleExt}`;
+}