"""非敏感应用设置的 SQLite Repository。"""

import json
from datetime import datetime, timezone
from pathlib import Path
from typing import Any, Mapping, Optional, Union

from .db import initialize_database, open_database
from .task_models import AppSettingRecord


PathValue = Union[str, Path]


def _utc_now_iso() -> str:
    return datetime.now(timezone.utc).isoformat(timespec="seconds").replace(
        "+00:00", "Z"
    )


class SettingsRepository:
    """用 JSON 保存非敏感设置；凭据不得传入本类。"""

    def __init__(self, db_path: Optional[PathValue] = None):
        self._db_path = initialize_database(db_path)

    def get(self, setting_key: str, default: Any = None) -> Any:
        """读取设置值；键不存在时返回 default。"""

        record = self.get_record(setting_key)
        return default if record is None else record.value

    def get_record(self, setting_key: str) -> Optional[AppSettingRecord]:
        """读取包含更新时间的完整设置记录。"""

        key = self._validate_key(setting_key)
        connection = open_database(self._db_path)
        try:
            row = connection.execute(
                "SELECT setting_key, value_json, updated_at"
                " FROM app_settings WHERE setting_key = ?",
                (key,),
            ).fetchone()
        finally:
            connection.close()
        if row is None:
            return None
        return AppSettingRecord(
            setting_key=row["setting_key"],
            value=json.loads(row["value_json"]),
            updated_at=row["updated_at"],
        )

    def set(
        self, setting_key: str, value: Any, updated_at: Optional[str] = None
    ) -> AppSettingRecord:
        """新增或更新一个非敏感设置并返回保存后的记录。"""

        key = self._validate_key(setting_key)
        now = updated_at or _utc_now_iso()
        value_json = json.dumps(value, ensure_ascii=False)
        connection = open_database(self._db_path)
        try:
            with connection:
                connection.execute(
                    "INSERT INTO app_settings (setting_key, value_json, updated_at)"
                    " VALUES (?, ?, ?)"
                    " ON CONFLICT(setting_key) DO UPDATE SET"
                    " value_json = excluded.value_json,"
                    " updated_at = excluded.updated_at",
                    (key, value_json, now),
                )
        finally:
            connection.close()
        return AppSettingRecord(key, value, now)

    def set_many(
        self, values: Mapping[str, Any], updated_at: Optional[str] = None
    ) -> list[AppSettingRecord]:
        """在同一事务中保存多个非敏感设置。"""

        if not values:
            return []

        normalized = [
            (self._validate_key(key), value) for key, value in values.items()
        ]
        now = updated_at or _utc_now_iso()
        connection = open_database(self._db_path)
        try:
            with connection:
                for key, value in normalized:
                    connection.execute(
                        "INSERT INTO app_settings"
                        " (setting_key, value_json, updated_at)"
                        " VALUES (?, ?, ?)"
                        " ON CONFLICT(setting_key) DO UPDATE SET"
                        " value_json = excluded.value_json,"
                        " updated_at = excluded.updated_at",
                        (key, json.dumps(value, ensure_ascii=False), now),
                    )
        finally:
            connection.close()
        return [AppSettingRecord(key, value, now) for key, value in normalized]

    def delete(self, setting_key: str) -> bool:
        """删除设置；确实删除了一条记录时返回 True。"""

        key = self._validate_key(setting_key)
        connection = open_database(self._db_path)
        try:
            with connection:
                cursor = connection.execute(
                    "DELETE FROM app_settings WHERE setting_key = ?", (key,)
                )
            return cursor.rowcount > 0
        finally:
            connection.close()

    @staticmethod
    def _validate_key(setting_key: str) -> str:
        key = setting_key.strip()
        if not key:
            raise ValueError("setting_key 不能为空")
        return key