"""用户级 pouch 配置（~/.config/pouch/config.yaml）。"""

from __future__ import annotations

from dataclasses import dataclass
from pathlib import Path
from typing import Any

from pouch import yaml_io
from pouch.paths import CONFIG_FILE

DEFAULT_AUTO_UPDATE_INTERVAL = "24h"
_INTERVAL_UNITS = {
    "s": 1,
    "m": 60,
    "h": 3600,
    "d": 86400,
}


@dataclass(frozen=True)
class AutoUpdateSettings:
    enabled: bool = True
    interval_seconds: int = 24 * 3600


def load_user_config(path: Path | None = None) -> dict[str, Any]:
    path = path or CONFIG_FILE
    if not path.is_file():
        return {}
    data = yaml_io.safe_load(path.read_text(encoding="utf-8")) or {}
    if not isinstance(data, dict):
        raise SystemExit(f"pouch 配置格式错误: {path}")
    return data


def save_user_config(data: dict[str, Any], path: Path | None = None) -> None:
    path = path or CONFIG_FILE
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(
        yaml_io.safe_dump(data, allow_unicode=True, sort_keys=False),
        encoding="utf-8",
    )


def parse_interval(value: Any) -> int:
    if value is None or value is True:
        return AutoUpdateSettings().interval_seconds
    if isinstance(value, bool):
        raise ValueError(f"无效的自动更新间隔: {value!r}")
    if isinstance(value, int):
        if value < 0:
            raise ValueError(f"无效的自动更新间隔: {value!r}")
        return value
    text = str(value).strip().lower()
    if not text:
        return AutoUpdateSettings().interval_seconds
    if text.isdigit():
        return int(text)
    unit = text[-1]
    amount = text[:-1]
    if unit in _INTERVAL_UNITS and amount.isdigit():
        return int(amount) * _INTERVAL_UNITS[unit]
    raise ValueError(f"无效的自动更新间隔: {value!r}（例如 24h、1d、60m、3600）")


def load_auto_update_settings(
    config: dict[str, Any] | None = None,
    path: Path | None = None,
) -> AutoUpdateSettings:
    if config is None:
        config = load_user_config(path)
    raw = config.get("auto_update", True)
    if raw is False:
        return AutoUpdateSettings(enabled=False)
    if raw is True or raw is None:
        return AutoUpdateSettings()
    if not isinstance(raw, dict):
        return AutoUpdateSettings()
    enabled = raw.get("enabled", True)
    if enabled is False:
        return AutoUpdateSettings(enabled=False)
    try:
        interval = parse_interval(raw.get("interval", DEFAULT_AUTO_UPDATE_INTERVAL))
    except ValueError as exc:
        raise SystemExit(str(exc)) from exc
    return AutoUpdateSettings(enabled=bool(enabled), interval_seconds=interval)