"""
Download Z-Anime Distill-8 FP8 artifacts from the Hugging Face Hub into ComfyUI model folders.
"""
from __future__ import annotations

import os
import shutil
import sys
import time

from huggingface_hub import hf_hub_download

from src import config
from src.errors import UserFacingError


def _ok_size(path: str) -> bool:
    name = os.path.basename(path)
    if not os.path.isfile(path):
        return False
    sz = os.path.getsize(path)
    return sz >= config.MIN_SIZES.get(name, 1_000_000)


def _download_one(repo_id: str, repo_file: str, dest: str) -> None:
    dest_dir = os.path.dirname(dest)
    os.makedirs(dest_dir, mode=0o755, exist_ok=True)
    if _ok_size(dest):
        print(f"[bootstrap] skip (exists): {dest}", flush=True)
        return
    for attempt in range(1, config.MAX_RETRIES + 1):
        try:
            if os.path.isfile(dest):
                os.remove(dest)
            print(
                f"[bootstrap] {repo_id} {repo_file} -> {dest} (attempt {attempt}/{config.MAX_RETRIES})",
                flush=True,
            )
            cached = hf_hub_download(
                repo_id=repo_id,
                filename=repo_file,
                repo_type="model",
            )
            shutil.copy2(cached, dest)
            if not _ok_size(dest):
                raise RuntimeError(f"file too small after copy: {dest}")
            print(f"[bootstrap] ok: {dest}", flush=True)
            return
        except Exception as e:
            print(f"[bootstrap] error: {e}", file=sys.stderr, flush=True)
            if attempt >= config.MAX_RETRIES:
                raise
            delay = min(config.BACKOFF_CAP_S, 2**attempt)
            print(f"[bootstrap] retry in {delay}s...", flush=True)
            time.sleep(delay)


def _mirror_text_encoder_to_clip(root: str) -> None:
    """
    ComfyUI's CLIPLoader resolves files under text_encoders/.
    The Z-Anime card also documents models/clip/; mirror the file for compatibility.
    """
    src = os.path.join(root, "text_encoders", config.CLIP_NAME)
    if not os.path.isfile(src) or not _ok_size(src):
        return
    dst = os.path.join(root, "clip", config.CLIP_NAME)
    os.makedirs(os.path.dirname(dst), exist_ok=True)
    if os.path.isfile(dst) and os.path.getsize(dst) == os.path.getsize(src):
        return
    try:
        if os.path.isfile(dst):
            os.remove(dst)
        os.link(src, dst)
        print(f"[bootstrap] hardlinked TE -> clip mirror: {dst}", flush=True)
    except OSError:
        shutil.copy2(src, dst)
        print(f"[bootstrap] copied TE -> clip mirror: {dst}", flush=True)


def bootstrap_model_artifacts() -> None:
    """Download config.ARTIFACTS into model_artifacts_root()."""
    root = config.model_artifacts_root()
    for repo_id, hub_path, rel in config.ARTIFACTS:
        dest = os.path.join(root, rel)
        _download_one(repo_id, hub_path, dest)
    _mirror_text_encoder_to_clip(root)
    print("[bootstrap] all model artifacts ready.", flush=True)