import { isAllowedOrigin } from '../utils'

import { MessageType } from '../types'

type MessageOptions = {
  value?: string | number | boolean | object
}

export default class CommunicationHandler {
  send(type: MessageType, options: MessageOptions = {}) {
    if (!isAllowedOrigin(document.referrer)) {
      console.warn(
        'Unable to send message. Please run your app from within Help Scout.'
      )
      return
    }

    window.parent.postMessage(
      // stringify then parse to remove anything that could cause postMessage errors
      JSON.parse(
        JSON.stringify({
          ...options,
          type,
          appId: window.name?.replace(/app-side-panel-|app-/, ''),
          iframeId: window.name,
        })
      ),
      document.referrer
    )
  }

  async receive<T>(type: MessageType) {
    return await new Promise<T>(resolve => {
      window.addEventListener('message', function onMessage(event) {
        if (!isAllowedOrigin(event.origin)) {
          // ignore messages from other origins
          return
        }

        try {
          const { data } = event
          const { type: receivingType, ...rest } = data
          if (receivingType === type) {
            resolve(rest)
          }
        } catch (error) {
          console.error('Unable to read postMessage data.')
        }
      })
    })
  }

  listen(type: MessageType, callback: (data: unknown) => void) {
    window.addEventListener('message', function onMessage(event) {
      if (!isAllowedOrigin(event.origin)) {
        // ignore messages from other origins
        return
      }

      try {
        const { data } = event
        const { type: receivingType, ...rest } = data
        if (receivingType === type) {
          callback(rest)
        }
      } catch (error) {
        console.error('Unable to read postMessage data.')
      }
    })
  }
}