import { BrowserWindow, ipcMain } from 'electron'
import type { ConfigKeys, IConfig } from '@lib/types'
import { CONFIG_KEYS, IPC_EVENTS } from '@lib/constants'
import { debounce } from '@lib/utils'

import logManager from '@electron/service/logger'

const DEFAULT_CONFIG: IConfig = {
  [CONFIG_KEYS.THEME_MODE]: 'system',
  [CONFIG_KEYS.PRIMARY_COLOR]: '#BB5BE7',
  [CONFIG_KEYS.LANGUAGE]: 'zh',
  [CONFIG_KEYS.FONT_SIZE]: 14,
  [CONFIG_KEYS.MINIMIZE_TO_TRAY]: false,
  [CONFIG_KEYS.PROVIDER]: '',
  [CONFIG_KEYS.DEFAULT_MODEL]: null,
  [CONFIG_KEYS.SELECTED_CHANNELS]: [],
  [CONFIG_KEYS.IMAGE_CACHE]: [],
}

export class ConfigService {
  private static _instance: ConfigService;
  private _store: any;
  private _defaultConfig: IConfig = DEFAULT_CONFIG;

  private _listeners: Array<(config: IConfig) => void> = [];


  private constructor() {
    // store 通过 init() 异步初始化，避免 ESM 模块在 CJS 打包环境中同步导入的问题
  }

  public async init() {
    if (this._store) return;
    const { default: Store } = await import('electron-store');
    this._store = new Store<IConfig>({
      name: 'config',
      defaults: DEFAULT_CONFIG,
    });
    this._setupIpcEvents();
    logManager.info('ConfigService initialized successfully.')
  }

  private _ensureStore() {
    if (!this._store) {
      throw new Error('ConfigService has not been initialized. Call init() first.');
    }
  }

  private _setupIpcEvents() {
    const duration = 200;
    const handelUpdate = debounce((val) => this.update(val), duration);

    ipcMain.handle(IPC_EVENTS.GET_CONFIG, (_, key) => this.get(key));
    ipcMain.handle(IPC_EVENTS.SET_CONFIG, (_, key, val) => {
      this.set(key, val);
      return { success: true };
    });
    ipcMain.on(IPC_EVENTS.UPDATE_CONFIG, (_, updates) => handelUpdate(updates));
  }

  public static getInstance(): ConfigService {
    if (!this._instance) {
      this._instance = new ConfigService();
    }
    return this._instance;
  }

  private _notifyListeners(): void {
    this._ensureStore();
    BrowserWindow.getAllWindows().forEach(win => win.webContents.send(IPC_EVENTS.CONFIG_UPDATED, this._store.store));
    this._listeners.forEach(listener => listener({ ...this._store.store }));
  }

  public getConfig(): IConfig {
    if (!this._store) {
      return { ...this._defaultConfig };
    }
    return this._store.store;
  }

  public get<T = any>(key: ConfigKeys): T {
    if (!this._store) {
      return this._defaultConfig[key] as T;
    }
    return this._store.get(key) as T
  }

  public set(key: ConfigKeys, value: unknown, autoSave: boolean = true): void {
    this._ensureStore();
    const oldValue = this._store.get(key);
    if (oldValue === value) return;
    this._store.set(key, value);
    logManager.info(`Config set: ${key} = ${JSON.stringify(value)}`);
    logManager.info(`Config file path: ${this._store.path}`);
    autoSave && this._notifyListeners();
  }

  public update(updates: Partial<IConfig>, autoSave: boolean = true): void {
    this._ensureStore();
    (Object.keys(updates) as ConfigKeys[]).forEach((key) => {
      this._store.set(key, updates[key]);
    });
    autoSave && this._notifyListeners();
  }

  public resetToDefault(): void {
    this._ensureStore();
    (Object.keys(this._defaultConfig) as ConfigKeys[]).forEach((key) => {
      this._store.set(key, this._defaultConfig[key]);
    });
    logManager.info('Config reset to default.');
    this._notifyListeners();
  }

  public onConfigChange(listener: ((config: IConfig) => void)): () => void {
    this._listeners.push(listener);

    return () => this._listeners = this._listeners.filter(l => l !== listener);
  }

}

export const configManager = ConfigService.getInstance();
export default configManager;