/**
 * Message format for chat interactions
 */
export interface ChatMessage {
  role: 'assistant' | 'user' | 'system';
  content: string;
}

/**
 * Options for chat interactions
 */
export interface ChatOptions {
  systemMessage: string;
  userMessage: string;
  messageHistory: ChatMessage[];
}

/**
 * Response format for chat interactions
 */
export interface ChatResponse {
  role: 'assistant';
  message: string;
}

/**
 * Abstract base class for multi-modal AI models.
 * Provides a common interface for different AI providers (OpenAI, Anthropic, Perplexity, Ollama)
 */
export abstract class MultiModalModel {
  /**
   * Initializes the model and any necessary resources
   * Should be called before using any other methods
   */
  abstract start(): Promise<void>;
  
  /**
   * Cleans up any resources used by the model
   * Should be called when the model is no longer needed
   */
  abstract stop(): Promise<void>;

  /**
   * Synchronous chat interaction with the model
   * @param optionsArg Options containing system message, user message, and message history
   * @returns Promise resolving to the assistant's response
   */
  public abstract chat(optionsArg: ChatOptions): Promise<ChatResponse>;
  
  /**
   * Streaming interface for chat interactions
   * Allows for real-time responses from the model
   * @param input Stream of user messages
   * @returns Stream of model responses
   */
  public abstract chatStream(input: ReadableStream<Uint8Array>): Promise<ReadableStream<string>>;

  /**
   * Text-to-speech conversion
   * @param optionsArg Options containing the message to convert to speech
   * @returns Promise resolving to a readable stream of audio data
   * @throws Error if the provider doesn't support audio generation
   */
  public abstract audio(optionsArg: { message: string }): Promise<NodeJS.ReadableStream>;
}