import { Operations, getSequenceID } from '../models/Commons';

const isDev = false;

export function setPostListener() {
  window.addEventListener('message', postMessageListener, false);
}

export function getUrlParameterByName(name: string, url?: string) {
  if (!url) {
    url = window.location.href;
  }
  name = name.replace(/[\[\]]/g, '\\$&');
  const regex = new RegExp('[?&]' + name + '(=([^&#]*))'),
    results = regex.exec(url);
  if (!results) {
    return null;
  }
  if (!results[2]) {
    return null;
  }
  return decodeURIComponent(results[2].replace(/\+/g, ' '));
}

const callbacks: { [id: string]: Function } = {};
const registeredEvents: { [operation: number]: () => Promise<any[]> } = {};
export function sendRequestToFramework(operation: Operations, data?: any[]): Promise<any> {
  const result = new Promise((resolve, reject) => {
    const requestId = getSequenceID();
    callbacks[requestId] = (data: any, errors?: any) => {
      if (errors !== undefined) {
        reject(errors);
      } else {
        resolve(data);
      }
    };
    const message = {
      id: requestId,
      operation: operation,
      data: data
    };
    window.parent.postMessage(JSON.stringify(message), '*');
  });
  return result;
}
export function sendRegisterRequestToFramework(eventHandler: (...params: any[]) => Promise<any>, operation: Operations): Promise<void> {
  const result = new Promise<void>((resolve, reject) => {
    const requestId = getSequenceID();
    registeredEvents[operation] = eventHandler;
    callbacks[requestId] = (data: any, errors?: any) => {
      if (errors !== undefined) {
        delete registeredEvents[operation];
        reject(errors);
      } else {
        resolve();
      }
    };
    const message = {
      id: requestId,
      registerOperation: operation
    };
    window.parent.postMessage(JSON.stringify(message), '*');
  });
  return result;
}
function postMessageListener(event: MessageEvent) {
  if (!isJSON(event.data)) {
    return;
  }
  try {
    const message = JSON.parse(event.data);
    if ('isResponse' in message) {
      if (message.request && message.request.id && callbacks[message.request.id]) {
        callbacks[message.request.id](message.resolve, message.reject);
        delete callbacks[message.request.id];
      }
    } else {
      if ('operation' in message && registeredEvents[message.operation]) {
        registeredEvents[message.operation](...message.data).then(
          (value: any) => sendResponse(message, true, value),
          (value: any) => sendResponse(message, false, value)
        );
      }
    }
  } catch (e) {}
}
function isJSON(input: any) {
  try {
    JSON.parse(input);
  } catch (e) {
    return false;
  }
  return true;
}
function sendResponse(request: IRequest, resolves: boolean, data: any) {
  const response: IResponse = {
    request: request,
    isResponse: true,
    reject: resolves ? undefined : data,
    resolve: resolves ? data : undefined
  };
  window.parent.postMessage(JSON.stringify(response), '*');
}

export interface IResponse {
  request: IRequest;
  isResponse: boolean;
  reject: any;
  resolve: any;
}
export interface IRequest {
  operation: Operations;
  data: any[];
}