import { randomUUID } from "crypto";

import Logs from "./logs.js";

class ProcessData {
  #process;
  #name;
  #request = {
    callbacks: {},
    functions: {}
  };
  #response = {
    functions: {}
  };

  constructor(processInstance = process, name = 'process', showStdout = false) {
    this.#process = processInstance;
    this.#name = name;
    this.#process.on('message', (message) => {
      this.#handleMessage(message);
    });
    this.#process.stdout?.on('data', data => {
      if (showStdout) {
        Logs.out('%s stdout: ↩︎', name);
        console.log(data.toString());
      }
    });
    this.#process.stderr?.on('data', data => {
      Logs.out('%s stderr', name, data.toString());
    });
  }

  get(type, params) {
    const id = randomUUID();
    this.#process.send({ method: 'get', type, id, params });
    return new Promise(resolve => {
      this.#request.callbacks[id] = resolve;
    });
  }

  registerResponse(type, func) {
    this.#response.functions[type] = func;
  }

  #responseData(type, params, id) {
    const func = this.#response.functions[type];
    func?.(params).then(data => {
      this.#process.send({ type: 'response', data, id });
    });
  }

  post(type, data) {
    this.#process.send({ method: 'post', type, data });
  }

  registerRequest(type, func) {
    this.#request.functions[type] = func;
  }

  #requestData(type, data) {
    const func = this.#request.functions[type];
    func?.(data);
  }

  #handleMessage(message) {
    const { callbacks } = this.#request;
    const { method, type, data, error, id, params } = message;
    if (error) {
      console.error(error);
    }
    if (method == 'get' && id) {
      this.#responseData(type, params, id);
    }
    else if (type == 'response' && id && callbacks[id]) {
      callbacks[id](data);
      delete callbacks[id];
    }
    else if (method == 'post' && type) {
      this.#requestData(type, data);
    }
  }
}

export default ProcessData;