Refactor search fallback and preview flows

worker/downloader.py

@@ -36,12 +36,6 @@ def parse_duration(value):
     return f"{hours:02d}:{minutes:02d}:{seconds:02d}"
 
 
-def format_label(height, ext):
-    if height:
-        return f"{height}p ({ext})"
-    return f"Best ({ext})"
-
-
 def build_quality_options(formats: List[dict]):
     heights = []
     for item in formats:
@@ -99,6 +93,45 @@ def probe(url):
     print(json.dumps(preview), flush=True)
 
 
+def parse_timestamp(value: str) -> int:
+    text = (value or "").strip()
+    if not text:
+        return 0
+    parts = text.split(":")
+    try:
+        if len(parts) == 3:
+            hours, minutes, seconds = parts
+            return int(hours) * 3600 + int(minutes) * 60 + int(float(seconds))
+        if len(parts) == 2:
+            minutes, seconds = parts
+            return int(minutes) * 60 + int(float(seconds))
+        return int(float(text))
+    except ValueError:
+        return 0
+
+
+def resolve_source_file(tmpdir: str) -> str:
+    files = [os.path.join(tmpdir, name) for name in os.listdir(tmpdir)]
+    media_files = [path for path in files if os.path.isfile(path)]
+    if not media_files:
+        raise RuntimeError("yt-dlp did not produce an output file")
+    return sorted(media_files)[0]
+
+
+def should_trim(start: str, end: str) -> bool:
+    start_seconds = parse_timestamp(start)
+    end_seconds = parse_timestamp(end)
+    return end_seconds > start_seconds
+
+
+def build_ffmpeg_cmd(source_file: str, output_path: str, start: str, end: str) -> List[str]:
+    cmd = ["ffmpeg", "-y"]
+    if should_trim(start, end):
+        cmd.extend(["-ss", start, "-to", end])
+    cmd.extend(["-i", source_file, "-c", "copy", output_path])
+    return cmd
+
+
 def main():
     parser = argparse.ArgumentParser()
     parser.add_argument("--mode", choices=["probe", "download"], default="download")
@@ -132,25 +165,10 @@ def main():
         run(download_cmd)
         emit("downloaded", 55, "Source downloaded")
 
-        files = [os.path.join(tmpdir, name) for name in os.listdir(tmpdir)]
-        if not files:
-            raise RuntimeError("yt-dlp did not produce an output file")
-        source_file = sorted(files)[0]
-
-        ffmpeg_cmd = [
-            "ffmpeg",
-            "-y",
-            "-ss",
-            args.start,
-            "-to",
-            args.end,
-            "-i",
-            source_file,
-            "-c",
-            "copy",
-            args.output,
-        ]
-        emit("cropping", 75, "Cropping requested segment")
+        source_file = resolve_source_file(tmpdir)
+        ffmpeg_cmd = build_ffmpeg_cmd(source_file, args.output, args.start, args.end)
+        message = "Cropping requested segment" if should_trim(args.start, args.end) else "Saving downloaded media"
+        emit("cropping", 75, message)
         run(ffmpeg_cmd)
 
     emit("completed", 100, "Download complete", args.output)