"""Download a Twitter/X thread's media via gallery-dl (handles auth, 403, and video/GIF -> mp4)."""
from __future__ import annotations
import argparse
import json
import subprocess
import sys
from pathlib import Path
try:
 from scripts.twitter_threads.error_types import ErrorInfo, make_error, Result, ThreadData, thread_from_dict
except ImportError:
 from error_types import ErrorInfo, make_error, Result, ThreadData, thread_from_dict



def download_media(thread: ThreadData, output_dir: Path, cookies_path: Path | None = None) -> Result[list[Path]]:
 try:
  output_dir.mkdir(parents=True, exist_ok=True)
 except OSError as e:
  return Result.err(make_error("WriteError", "download_media", str(e)))
 args = ["gallery-dl", "-o", "text-tweets=true", "-o", "conversations=true", "-D", str(output_dir)]
 if cookies_path is not None:
  args += ["--cookies", str(cookies_path)]
 args.append(thread.source_url)
 try:
  completed = subprocess.run(args, capture_output=True, text=True)
 except OSError as e:
  return Result.err(make_error("GalleryDlError", "download_media", str(e)))
 if completed.returncode != 0:
  return Result.err(make_error("GalleryDlError", "download_media", completed.stderr[:500]))
 post_ids = {p.post_id for p in thread.posts}
 files = [f for f in output_dir.rglob("*") if f.is_file() and f.name.split("_")[0] in post_ids]
 return Result.ok(sorted(files, key=lambda f: f.name))

def media_files_for_post(output_dir: Path, post_id: str) -> list[str]:
 return sorted(f.name for f in output_dir.glob(f"{post_id}_*") if f.is_file())

def main(argv: list[str] | None = None) -> int:
 parser = argparse.ArgumentParser(description="Download media for a Twitter/X thread_data.json via gallery-dl.")
 parser.add_argument("--input", type=Path, required=True, help="thread_data.json path")
 parser.add_argument("--output", type=Path, required=True, help="media output directory")
 parser.add_argument("--cookies", type=Path, default=None, help="cookies.txt for gallery-dl auth")
 args = parser.parse_args(argv)
 try:
  raw = args.input.read_text(encoding="utf-8")
 except OSError as e:
  sys.stderr.write(f"error: ReadError: {e}\n")
  return 1
 try:
  data = json.loads(raw)
 except json.JSONDecodeError as e:
  sys.stderr.write(f"error: JsonParseError: {e}\n")
  return 1
 thread = thread_from_dict(data)
 result = download_media(thread, args.output, args.cookies)
 if not result.is_ok:
  sys.stderr.write(f"error: {result.error.kind}: {result.error.detail}\n")
  return 1
 print(f"downloaded {len(result.data)} file(s) to {args.output}")
 return 0


if __name__ == "__main__":
 sys.exit(main())