"""Unzip service — extract files from ZIP archive (no DB, no parse)."""
import zipfile, io, base64


def handle_unzip(rfile, content_length):
    """Parse ZIP upload, return list of extracted files as base64."""
    body = rfile.read(content_length)

    # Find file data in raw multipart
    idx = body.find(b"\r\n\r\n")
    if idx < 0:
        return {"ok": False, "error": "invalid multipart"}

    raw = body[idx + 4:]
    zip_start = raw.find(b"PK\x03\x04")
    if zip_start < 0:
        return {"ok": False, "error": "not a ZIP file"}

    zip_data = raw[zip_start:]

    files = []
    with zipfile.ZipFile(io.BytesIO(zip_data)) as zf:
        for name in zf.namelist():
            if name.endswith("/"):
                continue
            data = zf.read(name)
            ext = name.rsplit(".", 1)[-1].lower() if "." in name else ""
            files.append({
                "filename": name,
                "data_b64": base64.b64encode(data).decode(),
                "ext": ext,
                "size": len(data),
            })

    return {"ok": True, "files": files}