import { BrowserWindow } from 'electron';
import { windowManager } from '@electron/service/window-service';
import logManager from '@electron/service/logger';
import type { GatewayEvent, RuntimeRefreshTopic } from './types';
import * as chatHandlers from './handlers/chat';
import * as providerHandlers from './handlers/provider';
import * as skillHandlers from './handlers/skills';

type RuntimeChangeBroadcast = {
  topics: RuntimeRefreshTopic[];
  reason?: string;
  warnings?: string[];
  channelType?: string;
  accountId?: string;
};

class GatewayManager {
  private initialized = false;
  private status: 'connected' | 'disconnected' | 'reconnecting' = 'disconnected';

  private setStatus(status: 'connected' | 'disconnected' | 'reconnecting'): void {
    this.status = status;
    this.broadcast({ type: 'gateway:status', status });
  }

  async init(): Promise<void> {
    if (this.initialized) return;
    this.initialized = true;
    this.status = 'connected';
    logManager.info('GatewayManager initialized');
    this.broadcast({ type: 'gateway:status', status: 'connected' });
  }

  async start(): Promise<void> {
    await this.init();
  }

  async stop(): Promise<void> {
    this.initialized = false;
    this.setStatus('disconnected');
  }

  async restart(options?: RuntimeChangeBroadcast): Promise<void> {
    this.initialized = false;
    this.setStatus('reconnecting');
    await this.init();
    if (options) {
      this.notifyRuntimeChanged(options);
    }
  }

  getStatus(): {
    status: 'connected' | 'disconnected' | 'reconnecting';
    initialized: boolean;
    mode: 'in-process';
  } {
    return {
      status: this.status,
      initialized: this.initialized,
      mode: 'in-process',
    };
  }

  async checkHealth(): Promise<{
    ok: boolean;
    status: 'connected' | 'disconnected' | 'reconnecting';
    initialized: boolean;
    mode: 'in-process';
  }> {
    return {
      ok: this.initialized && this.status === 'connected',
      ...this.getStatus(),
    };
  }

  async rpc(method: string, params: any): Promise<any> {
    if (!this.initialized) {
      await this.init();
    }

    logManager.info(`Gateway RPC: ${method}`, params);

    switch (method) {
      case 'chat.send':
        return chatHandlers.handleChatSend(params, (event) => this.broadcast(event));
      case 'chat.history':
        return chatHandlers.handleChatHistory(params);
      case 'chat.abort':
        return chatHandlers.handleChatAbort(params, (event) => this.broadcast(event));
      case 'session.list':
        return chatHandlers.handleSessionList();
      case 'session.delete':
        return chatHandlers.handleSessionDelete(params);
      case 'provider.list':
        return providerHandlers.handleProviderList();
      case 'provider.getDefault':
        return providerHandlers.handleProviderGetDefault();
      case 'skills.status':
        return skillHandlers.handleSkillsStatus();
      case 'skills.update':
        return skillHandlers.handleSkillsUpdate(params);
      default:
        throw new Error(`Unknown gateway RPC method: ${method}`);
    }
  }

  broadcast(event: GatewayEvent): void {
    const mainWindow = BrowserWindow.getAllWindows().find(
      (win) => windowManager.getName(win) === 'main'
    );
    if (mainWindow && !mainWindow.isDestroyed()) {
      mainWindow.webContents.send('gateway:event', event);
    }
  }

  notifyRuntimeChanged(options: RuntimeChangeBroadcast): void {
    const topics = Array.from(new Set(options.topics.filter(Boolean)));
    if (topics.length === 0) {
      return;
    }

    this.broadcast({
      type: 'runtime:changed',
      topics,
      reason: options.reason,
      warnings: options.warnings && options.warnings.length > 0 ? options.warnings : undefined,
      channelType: options.channelType,
      accountId: options.accountId,
      syncedAt: new Date().toISOString(),
    });
  }

  reloadProviders(options?: RuntimeChangeBroadcast): void {
    logManager.info('GatewayManager reloading providers');
    // For now, providers are resolved on each chat.send call,
    // so no in-memory cache to invalidate. Future: notify active sessions.
    this.notifyRuntimeChanged({
      topics: options?.topics ?? ['providers', 'models'],
      reason: options?.reason ?? 'providers:reload',
      warnings: options?.warnings,
      channelType: options?.channelType,
      accountId: options?.accountId,
    });
  }
}

export const gatewayManager = new GatewayManager();