"""Local per-book metadata pulled from the server — currently just "read"
status (EBook.is_read from the /api/sync/ snapshot). Kept separate from
progress.py (reading position): different concern, different cadence — this
is only ever set by `diora-tui sync`, never by the reader itself.
"""

from __future__ import annotations

import json
from pathlib import Path

from platformdirs import user_data_dir

_DATA_DIR = Path(user_data_dir("diora-tui", "diora"))
_META_FILE = _DATA_DIR / "library.json"


def _load_all() -> dict[str, dict]:
    if not _META_FILE.exists():
        return {}
    try:
        return json.loads(_META_FILE.read_text())
    except (json.JSONDecodeError, OSError):
        return {}


def _save_all(data: dict[str, dict]) -> None:
    _DATA_DIR.mkdir(parents=True, exist_ok=True)
    _META_FILE.write_text(json.dumps(data, indent=2))


def is_read(book_id: str) -> bool:
    entry = _load_all().get(book_id)
    return bool(entry and entry.get("is_read"))


def set_many(read_status: dict[str, bool]) -> None:
    if not read_status:
        return
    data = _load_all()
    for book_id, read in read_status.items():
        data.setdefault(book_id, {})["is_read"] = read
    _save_all(data)