from __future__ import annotations

import glob
import os
import shutil
import zipfile
from typing import Iterable

from .config import Config, ensure_default_config


def ensure_directories(cfg: Config) -> None:
    for path in _paths_from_config(cfg):
        os.makedirs(path, exist_ok=True)


def _paths_from_config(cfg: Config) -> Iterable[str]:
    return [
        cfg.raw.dgm1_dir,
        cfg.raw.dop20_dir,
        cfg.raw.citygml_lod1_dir,
        cfg.raw.citygml_lod2_dir,
        cfg.archives.dgm1_dir,
        cfg.archives.dop20_dir,
        cfg.archives.citygml_lod1_dir,
        cfg.archives.citygml_lod2_dir,
        cfg.work.work_dir,
        cfg.export.heightmap_dir,
        cfg.export.ortho_dir,
    ]


def materialize_archives(cfg: Config) -> None:
    """Best-effort expansion of archive zips into raw inputs."""
    ensure_directories(cfg)
    _unpack_all(cfg.archives.dgm1_dir, cfg.raw.dgm1_dir)
    _unpack_all(cfg.archives.citygml_lod1_dir, cfg.raw.citygml_lod1_dir)
    _unpack_all(cfg.archives.citygml_lod2_dir, cfg.raw.citygml_lod2_dir)
    _unpack_all(cfg.archives.dop20_dir, cfg.raw.dop20_dir)
    _copy_filelist(
        os.path.join(cfg.archives.dop20_dir, "filelist.txt"),
        os.path.join(os.path.dirname(cfg.raw.dop20_dir), "filelist.txt"),
    )


def _unpack_all(archive_dir: str, dest_dir: str) -> None:
    os.makedirs(dest_dir, exist_ok=True)
    for zpath in glob.glob(os.path.join(archive_dir, "*.zip")):
        print(f"Unpacking {zpath} -> {dest_dir}")
        with zipfile.ZipFile(zpath, "r") as zf:
            zf.extractall(dest_dir)


def _copy_filelist(src: str, dest: str) -> None:
    if not os.path.exists(src):
        return
    os.makedirs(os.path.dirname(dest), exist_ok=True)
    shutil.copy2(src, dest)
    print(f"Copied filelist: {src} -> {dest}")


__all__ = ["ensure_directories", "materialize_archives", "ensure_default_config"]