"""Config and recorded routines on disk."""

from __future__ import annotations

import json
from pathlib import Path

ROOT = Path(__file__).resolve().parent.parent
CONFIG_DIR = ROOT / "config"
ROUTINE_DIR = CONFIG_DIR / "routines"


def _merge(defaults, saved):
    """Saved values win; keys only in defaults are filled in."""
    if not isinstance(defaults, dict) or not isinstance(saved, dict):
        return saved if saved is not None else defaults
    out = dict(defaults)
    for key, value in saved.items():
        out[key] = _merge(defaults.get(key), value) if key in defaults else value
    return out


def config_path(macro: str) -> Path:
    return CONFIG_DIR / f"{macro}.json"


def load(macro: str, defaults: dict) -> dict:
    path = config_path(macro)
    if not path.exists():
        return json.loads(json.dumps(defaults))
    with path.open(encoding="utf-8") as handle:
        return _merge(defaults, json.load(handle))


def save(macro: str, data: dict) -> Path:
    CONFIG_DIR.mkdir(parents=True, exist_ok=True)
    path = config_path(macro)
    with path.open("w", encoding="utf-8") as handle:
        json.dump(data, handle, indent=2)
        handle.write("\n")
    return path


def routine_path(name: str) -> Path:
    return ROUTINE_DIR / f"{name}.json"


def load_routine(name: str) -> list[dict]:
    path = routine_path(name)
    if not path.exists():
        raise FileNotFoundError(f"no routine called {name!r} — record one first")
    with path.open(encoding="utf-8") as handle:
        data = json.load(handle)
    return data.get("steps", []) if isinstance(data, dict) else data


def save_routine(name: str, steps: list[dict], note: str = "") -> Path:
    ROUTINE_DIR.mkdir(parents=True, exist_ok=True)
    path = routine_path(name)
    with path.open("w", encoding="utf-8") as handle:
        json.dump({"note": note, "steps": steps}, handle, indent=2)
        handle.write("\n")
    return path


def list_routines() -> list[str]:
    if not ROUTINE_DIR.exists():
        return []
    return sorted(path.stem for path in ROUTINE_DIR.glob("*.json"))