module.exports = async ({ core, fetch }) => {
  const linuxReleasesUrl = 'https://storage.googleapis.com/flutter_infra_release/releases/releases_linux.json'
  const stableReleasePattern = /^\d+\.\d+\.\d+$/g
  const resultPath = 'config/flutter_version.json'
  
  /**
   * Downloads the flutter releases from URL
   * 
   * @param {*} fileUrl 
   * @returns object|boolean
   */
  async function downloadReleases(fileUrl) {
    try {
      const response = await fetch(fileUrl)

      return response.json()
    } catch (error) {
      console.error(
        `An error occurred while requesting the file URL: ${fileUrl}`,
        error
      )

      return false
    }
  }
  
  const linuxReleasesResponse = await downloadReleases(linuxReleasesUrl)
  
  if (linuxReleasesResponse === false) {
    core.setFailed(
      `Could not download Flutter version manifest from ${fileUrl}.`
    )

    return false
  }

  const {releases} = linuxReleasesResponse
  const latestRelease = releases.find((r) => r.version.match(stableReleasePattern))

  const fs = require('fs')
  const data = fs.readFileSync(resultPath, 'utf8')
  const oldJson = JSON.parse(data)

  const {version, channel, hash: commit} = latestRelease

  // Update result file, i.e. version.json
  const newJson = {
    ...oldJson,
    flutter: {
      channel,
      commit,
      version,
    },
  }

  // Write outputs
  fs.writeFileSync(resultPath, JSON.stringify(newJson, null, 4))
  core.exportVariable('FLUTTER_VERSION', version)
}