"""Download a release archive and extract it. A complete local file is extracted without downloading again."""
import tarfile
import urllib.error
import urllib.request
import zipfile
from pathlib import Path

UA = "LLLL-tools"


def _archive_name(path: Path) -> str:
    name = path.name.lower()
    if name.endswith(".part"):
        name = name[: -len(".part")]
    return name


def archive_complete(path: Path) -> bool:
    if not path.is_file() or path.stat().st_size == 0:
        return False
    name = _archive_name(path)
    try:
        if name.endswith(".zip") or name.endswith(".ipa"):
            with zipfile.ZipFile(path) as archive:
                return bool(archive.infolist())
        if ".tar." in name or name.endswith(".tgz"):
            mode = "r:xz" if name.endswith(".tar.xz") else "r:gz"
            with tarfile.open(path, mode) as archive:
                for _ in archive:
                    pass
            return True
    except (OSError, tarfile.TarError, zipfile.BadZipFile):
        return False
    return False


def _total_size(resp, have: int, code: int) -> int | None:
    if code == 206:
        content_range = resp.headers.get("Content-Range")
        if content_range and "/" in content_range:
            total = content_range.rsplit("/", 1)[-1]
            if total.isdigit():
                return int(total)
        length = resp.headers.get("Content-Length")
        if length and length.isdigit():
            return have + int(length)
        return None
    length = resp.headers.get("Content-Length")
    if length and length.isdigit():
        return int(length)
    return None


def ensure_archive(url: str, dest: Path) -> None:
    dest.parent.mkdir(parents=True, exist_ok=True)
    part = dest.with_name(dest.name + ".part")
    if archive_complete(dest):
        return
    if archive_complete(part):
        part.replace(dest)
        return
    if dest.exists() and not part.exists():
        dest.replace(part)
    elif dest.exists():
        dest.unlink()

    have = part.stat().st_size if part.exists() else 0
    headers = {"User-Agent": UA}
    if have:
        headers["Range"] = f"bytes={have}-"
    request = urllib.request.Request(url, headers=headers)
    try:
        response = urllib.request.urlopen(request, timeout=120)
    except urllib.error.HTTPError as exc:
        if exc.code == 416 and archive_complete(part):
            part.replace(dest)
            return
        print(f"下载失败：{exc.code}")
        raise SystemExit(2)
    except (urllib.error.URLError, TimeoutError, OSError):
        print("下载未完成")
        raise SystemExit(2)

    try:
        with response:
            code = getattr(response, "status", 200)
            if code == 200:
                have = 0
            elif code != 206:
                print(f"下载失败：{code}")
                raise SystemExit(2)
            total = _total_size(response, have, code)
            shown = -1
            with part.open("wb" if code == 200 else "ab") as output:
                done = have if code == 206 else 0
                while True:
                    chunk = response.read(1024 * 1024)
                    if not chunk:
                        break
                    output.write(chunk)
                    done += len(chunk)
                    if not total:
                        continue
                    pct = min(100, done * 100 // total)
                    if pct // 10 != shown:
                        shown = pct // 10
                        print(f"\r{pct}%", end="", flush=True)
            if shown >= 0:
                print()
    except (urllib.error.URLError, TimeoutError, OSError):
        print("下载未完成")
        raise SystemExit(2)

    if archive_complete(part):
        part.replace(dest)
        return
    if total and part.exists() and part.stat().st_size == total:
        part.unlink(missing_ok=True)
        print("下载内容无法解压")
        raise SystemExit(2)
    print("下载未完成")
    raise SystemExit(2)


def extract_archive(archive: Path, dest: Path) -> None:
    dest.mkdir(parents=True, exist_ok=True)
    root = dest.resolve()
    name = archive.name.lower()
    if name.endswith(".zip"):
        with zipfile.ZipFile(archive) as zipped:
            for info in zipped.infolist():
                target = (dest / info.filename).resolve()
                if not target.is_relative_to(root):
                    raise SystemExit("压缩包路径不安全")
            zipped.extractall(dest)
        return
    with tarfile.open(archive) as packed:
        packed.extractall(dest, filter="data")