openai.ts

import { readFileSync } from 'fs'

import OpenAI from 'openai';
import { ChatCompletionMessageParam } from 'openai/resources/chat';

import inquirer from 'inquirer';
import input from '@inquirer/input';

import {
  Product,
  LineItem,
  Card,
} from './types';

import {
  searchItem,
  addToCart,
  removeFromCart,
  updateItemInCart,
  listCart,
  checkout,
  payment,
  goodbye,
} from './functions';

import { tools } from './tools';

const menu: Product[] = JSON.parse(readFileSync("./menu.json", 'utf-8')).map((item: any) => ({ name: item.english, price: item.price }));

const cart: LineItem[] = [];

(async () => {
  const openai: OpenAI = new OpenAI({
    apiKey: process.apiKey,
  });

  const greeting = "What can I do for you today?";

  const messages: ChatCompletionMessageParam[] = [
    {
      role: "system",
      content: `You are a restaurant cashier taking order from customers. identify available items and place orders for customers. If the item is not avilable, tell customers. Available items are ${JSON.stringify(menu)}.`,
    },
    {
      role: 'assistant',
      content: greeting,
    },
    {
      role: 'user',
      content: await input({ message: greeting }),
    },
  ]

  while (true) {
    const completions = await openai.chat.completions.create({
      model: "gpt-3.5-turbo",
      messages: messages,
      tools: tools,
      tool_choice: "auto",
    });

    console.log(`completion: ${JSON.stringify(completions, null, 2)}`)

    const message = completions.choices[0].message

    messages.push(message)

    if (message.tool_calls) {
      // console.log(JSON.stringify(message, null, 2));
      let invoked: number = 0;
      message.tool_calls.map((tool_call: any) => {
        switch (tool_call.function.name) {
          case "addToCart": {
            console.log(JSON.stringify(tool_call));
            const item = JSON.parse(tool_call.function.arguments).item;
            const response = addToCart(item, cart, menu);
            messages.push({
              tool_call_id: tool_call.id,
              role: 'tool',
              content: JSON.stringify(response),
            });
            invoked += 1;
            break;
          }
          case "removeFromCart": {
            const item = JSON.parse(tool_call.function.arguments).item;
            const removed = removeFromCart(item, cart);
            messages.push({
              tool_call_id: tool_call.id,
              role: 'tool',
              content: JSON.stringify({ status: 200, body: { removed, description: "successfully removed" } }),
            });
            invoked += 1;
            break;
          }
          case "updateItemInCart": {
            const { item, quantity } = JSON.parse(tool_call.function.arguments);
            // console.log("udpate ", item, quantity);
            const updated = updateItemInCart(item, quantity, cart);
            messages.push({
              tool_call_id: tool_call.id,
              role: 'tool',
              content: JSON.stringify({ status: 200, body: { updated, description: "successfully updated" } }),
            })
            invoked += 1;
            break;
          }
          case "listCart": {
            // console.log(JSON.stringify(cart, null, 2));
            messages.push({
              tool_call_id: tool_call.id,
              role: 'tool',
              content: JSON.stringify({ status: 200, body: listCart(cart) }),
            })
            invoked += 1;
            break;
          }
          case "checkout": {
            // console.log(tool_call.function.arguments + " in checkout");
            // console.log(JSON.stringify(cart, null, 2));
            checkout(cart);
            const total = cart.map((lineItem: LineItem) => (lineItem.price * lineItem.quantity)).reduce((a: number, b: number) => (a + b), 0);
            messages.push({
              tool_call_id: tool_call.id,
              role: 'tool',
              content: JSON.stringify({ status: 200, body: { total: total, prompt: "cart has been sent to kitchen, ask customers card number to pay"} }),
            });
            invoked += 1;
            break;
          }
          case "payment": {
            // console.log(tool_call.function.arguments + " in payment");
            const { number, expiration, cvv } = JSON.parse(tool_call.function.arguments);
            const response = payment(number, expiration, cvv);
            messages.push({
              tool_call_id: tool_call.id,
              role: 'tool',
              content: JSON.stringify({ status: 200, body: response }),
            });
            invoked += 1;
            break;
          }
          case "searchItem": {
            // console.log(tool_call.function.arguments);
            const result = searchItem(JSON.parse(tool_call.function.arguments).item, menu);
            messages.push({
              tool_call_id: tool_call.id,
              role: 'tool',
              content: JSON.stringify({ status: 200, body: result}),
            });
            invoked += 1;
            break;
          }
          case "goodbye": {
            // console.log(tool_call.function.arguments + " in goodbye");
            input({ message: "thank you for dining with us. enjoy your meal!\n" }).then(() => { process.exit(0) });
            break;
          }
        }
        // console.log(JSON.stringify(messages, null, 2));
      })
      if (invoked == 0) {
        messages.push({
          tool_call_id: message.tool_calls[0].id,
          role: 'tool',
          content: JSON.stringify({ status: 400, body: "sorry, function is not available" }),
        })
      }
    } else {
      const assistantMessage: string = message.content as string;

      const userMessage = await input({ message: assistantMessage });
      messages.push({ role: 'user', content: userMessage });
    }
  }
})()