Service System

abstract class Service {
  static serviceType: ServiceType;
  
  constructor(runtime?: IAgentRuntime) {}
  
  abstract capabilityDescription: string;
  config?: ServiceConfig;
  
  static async start(runtime: IAgentRuntime): Promise<Service> {
    // Return new instance of service
  }
  
  abstract stop(): Promise<void>;
}

// Core service types (from @elizaos/core)
const ServiceType = {
  // Define core service types
} as const;

// Plugins extend service types through module augmentation
declare module '@elizaos/core' {
  interface ServiceTypeRegistry {
    DISCORD: 'discord';
    TELEGRAM: 'telegram';
    TWITTER: 'twitter';
    // ... other plugin-specific types
  }
}

class DiscordService extends Service {
  static serviceType = 'discord' as const;
  capabilityDescription = 'Discord bot integration';
  
  private client: Discord.Client;
  
  constructor(private runtime: IAgentRuntime) {
    super(runtime);
  }
  
  static async start(runtime: IAgentRuntime): Promise<Service> {
    const service = new DiscordService(runtime);
    await service.initialize();
    return service;
  }
  
  private async initialize() {
    this.client = new Discord.Client();
    
    this.client.on('messageCreate', async (message) => {
      // Convert to Memory format
      const memory = await this.convertMessage(message);
      
      // Process through runtime
      await this.runtime.processActions(memory, []);
    });
    
    await this.client.login(process.env.DISCORD_TOKEN);
  }
  
  async stop() {
    await this.client.destroy();
  }
}

class TaskService extends Service {
  name = ServiceType.TASK;
  private interval: NodeJS.Timer;
  
  async start(runtime: IAgentRuntime) {
    // Check for scheduled tasks every minute
    this.interval = setInterval(async () => {
      const tasks = await runtime.databaseAdapter.getTasks({
        status: 'pending',
        scheduledFor: { $lte: new Date() }
      });
      
      for (const task of tasks) {
        await this.executeTask(task, runtime);
      }
    }, 60000);
  }
  
  async stop() {
    clearInterval(this.interval);
  }
}

// Model services typically implement model providers instead
class OpenAIModelProvider implements ModelProvider {
  async generateText(params: GenerateTextParams) {
    const client = new OpenAI({
      apiKey: process.env.OPENAI_API_KEY
    });
    
    const response = await client.chat.completions.create({
      model: params.model || "gpt-4",
      messages: params.messages
    });
    
    return response.choices[0].message;
  }
  
  async embed(params: EmbedParams) {
    // Implementation for embeddings
  }
}

// In a plugin
export const discordPlugin: Plugin = {
  name: 'discord',
  services: [DiscordService],
  
  init: async (config, runtime) => {
    // Services auto-registered and started
  }
};

class NotificationService extends Service {
  static serviceType = 'notification' as const;
  capabilityDescription = 'Cross-platform notifications';
  
  async notify(message: string) {
    // Get service by type
    const discord = this.runtime.getService('discord');
    if (discord) {
      await discord.sendMessage(channelId, message);
    }
    
    // Check all registered services
    const services = this.runtime.getAllServices();
    // Coordinate across services
  }
}