index.js

import { Linking } from 'react-native'
import qs from 'qs'

async function sendEmail (to, { cc, bcc, subject, body, checkCanOpen = true } = {}) {
  let url = 'mailto:'

  if (to) {
    const toStr = Array.isArray(to) ? to.join(',') : to
    url += encodeURIComponent(toStr)

    if (cc) {
      cc = Array.isArray(cc) ? cc.join(',') : cc
    }

    if (bcc) {
      bcc = Array.isArray(bcc) ? bcc.join(',') : bcc
    }

    const query = qs.stringify({ cc, bcc, subject, body })

    if (query.length) {
      url += `?${query}`
    }
  }

  if (checkCanOpen) {
    const supported = await Linking.canOpenURL(url)
    if (!supported) {
      return Promise.reject(new Error('Provided URL can not be handled'))
    }
  }

  return Linking.openURL(url)
}

export default sendEmail