stack/apps/gateway/src/plugin/plugin.module.ts

import {
  Global,
  Inject,
  Logger,
  Module,
  type OnModuleDestroy,
  type OnModuleInit,
} from '@nestjs/common';
import { DiscordPlugin } from '@mosaic/discord-plugin';
import { TelegramPlugin } from '@mosaic/telegram-plugin';
import { PluginService } from './plugin.service.js';
import type { IChannelPlugin } from './plugin.interface.js';

export const PLUGIN_REGISTRY = Symbol('PLUGIN_REGISTRY');

class DiscordChannelPluginAdapter implements IChannelPlugin {
  readonly name = 'discord';

  constructor(private readonly plugin: DiscordPlugin) {}

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

  async stop(): Promise<void> {
    await this.plugin.stop();
  }
}

class TelegramChannelPluginAdapter implements IChannelPlugin {
  readonly name = 'telegram';

  constructor(private readonly plugin: TelegramPlugin) {}

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

  async stop(): Promise<void> {
    await this.plugin.stop();
  }
}

const DEFAULT_GATEWAY_URL = 'http://localhost:4000';

function createPluginRegistry(): IChannelPlugin[] {
  const plugins: IChannelPlugin[] = [];
  const discordToken = process.env['DISCORD_BOT_TOKEN'];
  const discordGuildId = process.env['DISCORD_GUILD_ID'];
  const discordGatewayUrl = process.env['DISCORD_GATEWAY_URL'] ?? DEFAULT_GATEWAY_URL;

  if (discordToken) {
    plugins.push(
      new DiscordChannelPluginAdapter(
        new DiscordPlugin({
          token: discordToken,
          guildId: discordGuildId,
          gatewayUrl: discordGatewayUrl,
        }),
      ),
    );
  }

  const telegramToken = process.env['TELEGRAM_BOT_TOKEN'];
  const telegramGatewayUrl = process.env['TELEGRAM_GATEWAY_URL'] ?? DEFAULT_GATEWAY_URL;

  if (telegramToken) {
    plugins.push(
      new TelegramChannelPluginAdapter(
        new TelegramPlugin({
          token: telegramToken,
          gatewayUrl: telegramGatewayUrl,
        }),
      ),
    );
  }

  return plugins;
}

@Global()
@Module({
  providers: [
    {
      provide: PLUGIN_REGISTRY,
      useFactory: (): IChannelPlugin[] => createPluginRegistry(),
    },
    PluginService,
  ],
  exports: [PluginService, PLUGIN_REGISTRY],
})
export class PluginModule implements OnModuleInit, OnModuleDestroy {
  private readonly logger = new Logger(PluginModule.name);

  constructor(@Inject(PLUGIN_REGISTRY) private readonly plugins: IChannelPlugin[]) {}

  async onModuleInit(): Promise<void> {
    for (const plugin of this.plugins) {
      this.logger.log(`Starting plugin: ${plugin.name}`);
      await plugin.start();
    }
  }

  async onModuleDestroy(): Promise<void> {
    for (const plugin of [...this.plugins].reverse()) {
      this.logger.log(`Stopping plugin: ${plugin.name}`);
      await plugin.stop();
    }
  }
}