from __future__ import annotations

import json
import os
from pathlib import Path
from typing import Any

from huggingface_hub import HfApi, hf_hub_download


def load_remote_file(
    api: HfApi,
    repo_id: str,
    path_in_repo: str,
    local_dir: Path,
    *,
    revision: str | None = None,
) -> Path | None:
    del api
    try:
        downloaded = hf_hub_download(
            repo_id=repo_id,
            filename=path_in_repo,
            repo_type="dataset",
            revision=revision,
            local_dir=str(local_dir),
            token=os.getenv("HF_TOKEN"),
        )
    except Exception:
        return None
    return Path(downloaded)


def load_remote_json_file(
    api: HfApi,
    repo_id: str,
    path_in_repo: str,
    local_dir: Path,
    *,
    revision: str | None = None,
) -> dict[str, Any] | None:
    downloaded = load_remote_file(
        api,
        repo_id,
        path_in_repo,
        local_dir,
        revision=revision,
    )
    if downloaded is None:
        return None
    return json.loads(downloaded.read_text(encoding="utf-8"))


def list_remote_paths(api: HfApi, repo_id: str, *, revision: str | None = None) -> set[str]:
    try:
        info = api.dataset_info(repo_id=repo_id, revision=revision, files_metadata=True)
    except TypeError:
        info = api.dataset_info(repo_id=repo_id, revision=revision)
    except Exception:
        return set()
    return {sibling.rfilename for sibling in getattr(info, "siblings", [])}


def stable_snapshot_candidates(latest_payload: dict[str, Any] | None, filename: str) -> list[str]:
    if latest_payload is None:
        return [filename]
    candidates: list[str] = []
    manifest_path = str(latest_payload.get("manifest_path") or "").strip("/")
    snapshot_dir = str(latest_payload.get("snapshot_dir") or "").strip("/")
    latest_snapshot_id = str(latest_payload.get("latest_snapshot_id") or "").strip()

    if filename == "manifest.json" and manifest_path:
        candidates.append(manifest_path)
    if snapshot_dir and snapshot_dir not in {".", "/"}:
        candidates.append(f"{snapshot_dir}/{filename}")
    archived_manifest_path = str(latest_payload.get("archived_manifest_path") or "").strip("/")
    if filename == "manifest.json" and archived_manifest_path:
        candidates.append(archived_manifest_path)
    if manifest_path and "/" in manifest_path:
        manifest_dir = manifest_path.rsplit("/", 1)[0]
        candidates.append(f"{manifest_dir}/{filename}")
    if latest_snapshot_id:
        candidates.append(f"snapshots/{latest_snapshot_id}/{filename}")
    candidates.append(filename)

    deduped: list[str] = []
    seen: set[str] = set()
    for candidate in candidates:
        normalized = candidate.lstrip("./")
        if not normalized or normalized in seen:
            continue
        seen.add(normalized)
        deduped.append(normalized)
    return deduped