import { ChatCompletionFunctions, ChatCompletionRequestMessageFunctionCall } from "openai";
import config from "./config";

type parameterMap = {
  string: string,
  number: number,
};

type nameTypeMap = {[name: string]: keyof parameterMap} | Record<string, never>;

type OpenAIFunctionRequestData<T extends nameTypeMap> = {
  [name in keyof T]: T[name];
};

/**
 * Represents the function that can be ran by the OpenAI model
 */
export interface OpenAIFunction<T extends nameTypeMap = nameTypeMap> {
  name: string,
  description?: string,
  parameters: {
    type: "object",
    properties: T extends Record<string, never> ? Record<string, never> : {
      [name in T[string]]: {
        type: T[name],
        description?: string,
      }
    },
    required?: Array<keyof T>,
  },
}

export abstract class OpenAIFunction<T extends nameTypeMap = nameTypeMap> {
  getSettings(): ChatCompletionFunctions {
    return {
      name: this.name,
      description: this.description,
      parameters: this.parameters,
    };
  }

  abstract execute(data: OpenAIFunctionRequestData<T>): string;
}

/*
 * Manages functions for the OpenAI
 **/
export default class FunctionManager {
  store = new Map<string, OpenAIFunction>();

  constructor() {
    this.store.set("getTime", new GetTime());
  }

  public getFunctions(): ChatCompletionFunctions[] {
    const rvalue: ChatCompletionFunctions[] = [];
    for (const [, value] of this.store) {
      rvalue.push(value.getSettings());
    }
    return rvalue;
  }

  public handleFunction(request: ChatCompletionRequestMessageFunctionCall) {
    try {
      const parsedArguments = JSON.parse(request.arguments ?? "");
      return this.store.get(request.name ?? "")?.execute(parsedArguments);
    }
    catch (e) {
      console.error("Function arguments raw: " + request.arguments);
      throw new Error(`Failed to parse the function JSON arguments when running function [${request.name}]`, {cause: e});
    }
  }
}

// buildins

class GetTime extends OpenAIFunction<Record<string, never>> {
  name = "getTime";
  description = "Gets current date and time with a timezone attached";
  parameters = {
    type: "object" as const,
    properties: {} as Record<string, never>,
  };

  execute(): string {
    return `${Intl.DateTimeFormat().resolvedOptions().timeZone}): ${new Date().toLocaleString("en-US", config.calendarConfig)}`;
  }
}