import os
from pathlib import Path
from urllib.parse import urlparse
import requests
import yaml
from tqdm import tqdm

CONFIG_PATH = "config.yaml"
BASE_DOWNLOAD_DIR = Path("downloads")  # semua file masuk ke sini


def load_config(path: str):
    with open(path, "r") as f:
        data = yaml.safe_load(f)

    if isinstance(data, list):
        return data
    elif isinstance(data, dict) and "items" in data:
        return data["items"]
    else:
        raise ValueError("Format config.yaml tidak dikenali")


def get_filename_from_url(url: str) -> str:
    parsed = urlparse(url)
    name = os.path.basename(parsed.path)
    if not name:
        name = "downloaded_file"
    return name


def build_filename(url: str, name_from_config: str | None) -> str:
    """
    Tentukan nama file final:
    - kalau name di config kosong -> pakai nama dari URL
    - kalau name TIDAK punya ekstensi -> pakai name + ekstensi dari URL
    - kalau name sudah ada ekstensi -> pakai name apa adanya
    """
    url_name = get_filename_from_url(url)
    url_root, url_ext = os.path.splitext(url_name)

    if not name_from_config:
        return url_name

    cfg_root, cfg_ext = os.path.splitext(name_from_config)

    # kalau nggak ada ekstensi di name config → pakai ekstensi dari URL
    if not cfg_ext and url_ext:
        return cfg_root + url_ext

    # kalau sudah ada ekstensi → pakai apa adanya
    return name_from_config


def maybe_get_filename_from_headers(response: requests.Response, fallback: str) -> str:
    cd = response.headers.get("content-disposition")
    if not cd:
        return fallback

    parts = cd.split(";")
    for part in parts:
        part = part.strip()
        if part.lower().startswith("filename="):
            filename = part.split("=", 1)[1].strip().strip('"')
            if filename:
                return filename
    return fallback


def download_file(url: str, target_dir: Path, name_from_config: str | None = None):
    target_dir.mkdir(parents=True, exist_ok=True)

    # Tentukan nama file awal (dari URL + name di config)
    planned_name = build_filename(url, name_from_config)
    dest_path = target_dir / planned_name

    # Cek apakah file sudah ada
    if dest_path.exists():
        print(f"[SKIP] File already exists: {dest_path}")
        return

    print(f"[INFO] Downloading: {url}")
    resp = requests.get(url, stream=True)
    resp.raise_for_status()

    # Kalau server kasih nama file di header, kita override,
    # tapi hanya kalau user TIDAK set 'name' di config.
    if name_from_config:
        filename = planned_name
    else:
        filename = maybe_get_filename_from_headers(resp, planned_name)

    dest_path = target_dir / filename

    total_size = int(resp.headers.get("content-length", 0))
    chunk_size = 8192

    progress = tqdm(
        total=total_size if total_size > 0 else None,
        unit="B",
        unit_scale=True,
        desc=str(filename),
    )

    with open(dest_path, "wb") as f:
        for chunk in resp.iter_content(chunk_size=chunk_size):
            if chunk:
                f.write(chunk)
                progress.update(len(chunk))

    progress.close()
    print(f"[OK] Saved to: {dest_path}")


def main():
    print(f"[INFO] Loading config from {CONFIG_PATH}")
    entries = load_config(CONFIG_PATH)

    for entry in entries:
        url = entry.get("url")
        folder = entry.get("folder", "")
        name = entry.get("name")  # boleh None

        if not url:
            print("[WARN] Entry tanpa URL, di-skip:", entry)
            continue

        target_dir = BASE_DOWNLOAD_DIR / folder
        download_file(url, target_dir, name_from_config=name)

    print("[DONE] Semua download selesai.")


if __name__ == "__main__":
    main()