from __future__ import annotations

import hashlib
import json
import time
from pathlib import Path

from pydantic import BaseModel, Field


class BundleCacheEntry(BaseModel):
    content: str
    headers: dict[str, str] = Field(default_factory=dict)


def build_bundle_cache_key(*, client_type: str, source_names: list[str]) -> str:
    raw = f"{client_type}|{','.join(source_names)}"
    return hashlib.sha256(raw.encode("utf-8")).hexdigest()


def load_bundle_cache(*, cache_dir: Path, cache_key: str, ttl_seconds: int) -> BundleCacheEntry | None:
    yaml_path = cache_dir / f"{cache_key}.yaml"
    meta_path = cache_dir / f"{cache_key}.json"
    if not yaml_path.is_file() or not meta_path.is_file():
        return None

    expires_at = meta_path.stat().st_mtime + ttl_seconds
    if expires_at < time.time():
        return None

    try:
        metadata = json.loads(meta_path.read_text(encoding="utf-8"))
    except json.JSONDecodeError:
        return None
    content = yaml_path.read_text(encoding="utf-8")
    headers = metadata.get("headers")
    if not isinstance(headers, dict):
        headers = {}
    return BundleCacheEntry(content=content, headers={str(k): str(v) for k, v in headers.items()})


def save_bundle_cache(
    *,
    cache_dir: Path,
    cache_key: str,
    content: str,
    headers: dict[str, str],
) -> Path:
    cache_dir.mkdir(parents=True, exist_ok=True)
    yaml_path = cache_dir / f"{cache_key}.yaml"
    meta_path = cache_dir / f"{cache_key}.json"
    yaml_path.write_text(content, encoding="utf-8")
    meta_path.write_text(json.dumps({"headers": headers}, ensure_ascii=False, indent=2), encoding="utf-8")
    return yaml_path