ctx.waitUntil(requestModel.call(chat));
return new CorsResponse(readable).finalize(request);

ctx.waitUntil(requestModel.call(chat));
return new CorsResponse(readable).finalize(request);

import {
  AICache,
  authorize,
  CorsResponse,
  OpenAIStreamHandler,
} from "@tm9657/backend-worker";
import GPT3Tokenizer from "gpt3-tokenizer";
import { Configuration, OpenAIApi } from "openai";

export interface Env {
  DATABASE_URL: string;
  OPENAI_KEY: string;
}

type AIRequestBody = {
  prompt: string;
  system?: string;
  top_p?: number;
  frequency_penalty?: number;
  max_tokens?: number;
};

let cache: AICache | null = null;

export default {
  async fetch(
    request: Request,
    env: Env,
    ctx: ExecutionContext
  ): Promise<Response> {
    const auth = await authorize(request);
    if (!auth) return new CorsResponse("Unauthorized", 401).finalize(request);

    const body: AIRequestBody = await request.json();
    if (!body || !body?.prompt)
      return new CorsResponse("Bad Request", 400).finalize(request);
    if (!cache) cache = new AICache();
    cache.init(env.DATABASE_URL);
    let openai: OpenAIApi = new OpenAIApi(
      new Configuration({
        apiKey: env.OPENAI_KEY,
      })
    );

    if (!openai)
      return new CorsResponse("Internal Server Error", 500).finalize(request);

    const usage = await cache.getUsage(auth.sub);
    if (!usage.getHardLimit())
      return new CorsResponse(
        "Monthly API limit hit, please upgrade your subscription!",
        429
      ).finalize(request);

    const tokenizer = new GPT3Tokenizer({ type: "gpt3" });
    const { readable, writable } = new TransformStream();

    const openAIRequest = await openai.createChatCompletion(
      {
        model: "gpt-3.5-turbo",
        messages: [
          { role: "system", content: body.system || "" },
          { role: "user", content: `${body.prompt}` },
        ],
        top_p: body.top_p || 0.05,
        max_tokens:
          4096 - tokenizer.encode(`${body.prompt} ${body.system}`).bpe.length,
        user: auth.sub,
        frequency_penalty: body.frequency_penalty || 1.0,
        stream: true,
      },
      { responseType: "stream" }
    );

    const writableStream = writable.getWriter();

    let total = "";
    const handler = new OpenAIStreamHandler(
      openAIRequest,
      async (message) => {
        total += message;
        await writableStream.write({ total, message });
      },
      async () => {
        await writableStream.close();
        await cache?.updateUsage(
          auth.sub,
          "chatGPT",
          tokenizer.encode(`${body.prompt} ${body.system} ${total}`).bpe.length
        );
      }
    ).promise();

    return new CorsResponse(readable).finalize(request);
  },
};

import {
  AICache,
  authorize,
  CorsResponse,
  OpenAIStreamHandler,
} from "@tm9657/backend-worker";
import GPT3Tokenizer from "gpt3-tokenizer";
import { Configuration, OpenAIApi } from "openai";

export interface Env {
  DATABASE_URL: string;
  OPENAI_KEY: string;
}

type AIRequestBody = {
  prompt: string;
  system?: string;
  top_p?: number;
  frequency_penalty?: number;
  max_tokens?: number;
};

let cache: AICache | null = null;

export default {
  async fetch(
    request: Request,
    env: Env,
    ctx: ExecutionContext
  ): Promise<Response> {
    const auth = await authorize(request);
    if (!auth) return new CorsResponse("Unauthorized", 401).finalize(request);

    const body: AIRequestBody = await request.json();
    if (!body || !body?.prompt)
      return new CorsResponse("Bad Request", 400).finalize(request);
    if (!cache) cache = new AICache();
    cache.init(env.DATABASE_URL);
    let openai: OpenAIApi = new OpenAIApi(
      new Configuration({
        apiKey: env.OPENAI_KEY,
      })
    );

    if (!openai)
      return new CorsResponse("Internal Server Error", 500).finalize(request);

    const usage = await cache.getUsage(auth.sub);
    if (!usage.getHardLimit())
      return new CorsResponse(
        "Monthly API limit hit, please upgrade your subscription!",
        429
      ).finalize(request);

    const tokenizer = new GPT3Tokenizer({ type: "gpt3" });
    const { readable, writable } = new TransformStream();

    const openAIRequest = await openai.createChatCompletion(
      {
        model: "gpt-3.5-turbo",
        messages: [
          { role: "system", content: body.system || "" },
          { role: "user", content: `${body.prompt}` },
        ],
        top_p: body.top_p || 0.05,
        max_tokens:
          4096 - tokenizer.encode(`${body.prompt} ${body.system}`).bpe.length,
        user: auth.sub,
        frequency_penalty: body.frequency_penalty || 1.0,
        stream: true,
      },
      { responseType: "stream" }
    );

    const writableStream = writable.getWriter();

    let total = "";
    const handler = new OpenAIStreamHandler(
      openAIRequest,
      async (message) => {
        total += message;
        await writableStream.write({ total, message });
      },
      async () => {
        await writableStream.close();
        await cache?.updateUsage(
          auth.sub,
          "chatGPT",
          tokenizer.encode(`${body.prompt} ${body.system} ${total}`).bpe.length
        );
      }
    ).promise();

    return new CorsResponse(readable).finalize(request);
  },
};