#!/usr/bin/env python3
from __future__ import annotations

import argparse
import glob
import json
from pathlib import Path
import tarfile
import re

from scan_gmail_payloads import MultiFileReader


def load_episode_ids(path: Path) -> set[str]:
    ids: set[str] = set()
    with path.open() as f:
        for line in f:
            if not line.strip():
                continue
            ids.add(str(json.loads(line)["episode_id"]))
    return ids


def episode_from_member(name: str) -> str | None:
    parts = name.split("/")
    if len(parts) < 3 or parts[0] != "processed":
        return None
    ep = parts[2]
    if not ep.startswith("episode_"):
        return None
    return ep.removeprefix("episode_")


def main() -> None:
    p = argparse.ArgumentParser()
    p.add_argument("--parts-glob", default="/data/gmail_aitw/raw/aitw_parts/a.tar.part-*")
    p.add_argument("--episodes", default="/data/gmail_aitw/manifests/gmail_payloads_episodes.jsonl")
    p.add_argument("--out-dir", default="/data/gmail_aitw/extracted/gmail")
    p.add_argument("--domain", default="google_apps")
    args = p.parse_args()

    episode_ids = load_episode_ids(Path(args.episodes))
    part_re = re.compile(r"a\.tar\.part-\d{3}$")
    parts = [Path(p) for p in sorted(glob.glob(args.parts_glob)) if part_re.search(Path(p).name)]
    out_dir = Path(args.out_dir)
    out_dir.mkdir(parents=True, exist_ok=True)
    reader = MultiFileReader(parts)
    extracted = 0
    try:
        with tarfile.open(fileobj=reader, mode="r|") as tf:
            for member in tf:
                ep = episode_from_member(member.name)
                if ep not in episode_ids:
                    continue
                if args.domain and not member.name.startswith(f"processed/{args.domain}/"):
                    continue
                target = out_dir / "/".join(member.name.split("/")[1:])
                if member.isdir():
                    target.mkdir(parents=True, exist_ok=True)
                    continue
                if not member.isfile():
                    continue
                target.parent.mkdir(parents=True, exist_ok=True)
                src = tf.extractfile(member)
                if src is None:
                    continue
                with target.open("wb") as fout:
                    while True:
                        chunk = src.read(1024 * 1024)
                        if not chunk:
                            break
                        fout.write(chunk)
                extracted += 1
                if extracted % 1000 == 0:
                    print(json.dumps({"extracted_files": extracted, "last": str(target)}), flush=True)
    finally:
        reader.close()
    print(json.dumps({"extracted_files": extracted, "out_dir": str(out_dir)}, indent=2))


if __name__ == "__main__":
    main()