import type { SmartAi } from "./classes.smartai.js";
import { OpenAiProvider } from "./provider.openai.js";

type TProcessFunction = (input: string) => Promise<string>;

export interface IConversationOptions {
  processFunction: TProcessFunction;
}

/**
 * a conversation
 */
export class Conversation {
  // STATIC
  public static async createWithOpenAi(smartaiRefArg: SmartAi) {
    if (!smartaiRefArg.openaiProvider) {
      throw new Error('OpenAI provider not available');
    }
    const conversation = new Conversation(smartaiRefArg, {
      processFunction: async (input) => {
        return '' // TODO implement proper streaming
      }
    });
    return conversation;
  }

  public static async createWithAnthropic(smartaiRefArg: SmartAi) {
    if (!smartaiRefArg.anthropicProvider) {
      throw new Error('Anthropic provider not available');
    }
    const conversation = new Conversation(smartaiRefArg, {
      processFunction: async (input) => {
        return '' // TODO implement proper streaming
      }
    });
    return conversation;
  }

  public static async createWithPerplexity(smartaiRefArg: SmartAi) {
    if (!smartaiRefArg.perplexityProvider) {
      throw new Error('Perplexity provider not available');
    }
    const conversation = new Conversation(smartaiRefArg, {
      processFunction: async (input) => {
        return '' // TODO implement proper streaming
      }
    });
    return conversation;
  }

  public static async createWithOllama(smartaiRefArg: SmartAi) {
    if (!smartaiRefArg.ollamaProvider) {
      throw new Error('Ollama provider not available');
    }
    const conversation = new Conversation(smartaiRefArg, {
      processFunction: async (input) => {
        return '' // TODO implement proper streaming
      }
    });
    return conversation;
  }

  // INSTANCE
  smartaiRef: SmartAi
  private systemMessage: string;
  private processFunction: TProcessFunction;
  private inputStreamWriter: WritableStreamDefaultWriter<string> | null = null;
  private outputStreamController: ReadableStreamDefaultController<string> | null = null;

  constructor(smartairefArg: SmartAi, options: IConversationOptions) {
    this.processFunction = options.processFunction;
  }

  public async setSystemMessage(systemMessageArg: string) {
    this.systemMessage = systemMessageArg;
  }

  private setupOutputStream(): ReadableStream<string> {
    return new ReadableStream<string>({
      start: (controller) => {
        this.outputStreamController = controller;
      }
    });
  }

  private setupInputStream(): WritableStream<string> {
    const writableStream = new WritableStream<string>({
      write: async (chunk) => {
        const processedData = await this.processFunction(chunk);
        if (this.outputStreamController) {
          this.outputStreamController.enqueue(processedData);
        }
      },
      close: () => {
        this.outputStreamController?.close();
      },
      abort: (err) => {
        console.error('Stream aborted', err);
        this.outputStreamController?.error(err);
      }
    });
    return writableStream;
  }

  public getInputStreamWriter(): WritableStreamDefaultWriter<string> {
    if (!this.inputStreamWriter) {
      const inputStream = this.setupInputStream();
      this.inputStreamWriter = inputStream.getWriter();
    }
    return this.inputStreamWriter;
  }

  public getOutputStream(): ReadableStream<string> {
    return this.setupOutputStream();
  }
}