const Heroku = require('heroku-client')
const createStagingAppName = require('./create-staging-app-name')

module.exports = async function undeployFromStaging ({
  herokuToken,
  octokit,
  pullRequest,
  runId = null
}) {
  // Start a timer so we can report how long the deployment takes
  const startTime = Date.now()

  // Extract some important properties from the PR
  const {
    number: pullNumber,
    base: {
      repo: {
        name: repo,
        owner: { login: owner }
      }
    },
    head: {
      ref: branch
    }
  } = pullRequest

  const workflowRunLog = runId ? `https://github.com/${owner}/${repo}/actions/runs/${runId}` : null
  const logUrl = workflowRunLog

  const appName = createStagingAppName({ repo, pullNumber, branch })

  try {
    const title = `from the 'staging' environment as '${appName}'`

    console.log(`About to undeploy ${title}...`)

    // Time to talk to Heroku...
    const heroku = new Heroku({ token: herokuToken })

    // Is there already a Heroku App for this PR?
    let appExists = true
    try {
      await heroku.get(`/apps/${appName}`)
    } catch (error) {
      appExists = false
    }

    // If there is an existing app, delete it
    if (appExists) {
      try {
        await heroku.delete(`/apps/${appName}`)

        console.log(`Heroku app '${appName}' deleted`)
      } catch (error) {
        throw new Error(`Failed to delete Heroku app '${appName}'. Error: ${error}`)
      }
    }

    // Get the latest deployment environment to signal its deactivation
    const { data: deployments } = await octokit.repos.listDeployments({
      owner,
      repo,

      // In the GitHub API, there can only be one active deployment per environment.
      // For our many staging apps, we must use the unique appName as the environment.
      environment: appName
    })

    if (deployments.length === 0) {
      console.log('🚀 No deployments to deactivate!')
      console.log(`Finished undeploying after ${Math.round((Date.now() - startTime) / 1000)} seconds`)
      return
    }

    console.log(`Found ${deployments.length} GitHub Deployments`, deployments)

    // Deactivate ALL of the deployments
    for (const deployment of deployments) {
      const { data: deploymentStatus } = await octokit.repos.createDeploymentStatus({
        owner,
        repo,
        deployment_id: deployment.id,
        state: 'inactive',
        description: 'The app was undeployed',
        ...logUrl && { log_url: logUrl },
        // The 'ant-man' preview is required for `state` values of 'inactive', as well as
        // the use of the `log_url`, `environment_url`, and `auto_inactive` parameters.
        // The 'flash' preview is required for `state` values of 'in_progress' and 'queued'.
        mediaType: {
          previews: ['ant-man', 'flash']
        }
      })
      console.log(`🚀 Deployment status (ID: ${deployment.id}): ${deploymentStatus.state} - ${deploymentStatus.description}`)
    }

    console.log(`Finished undeploying after ${Math.round((Date.now() - startTime) / 1000)} seconds`)
  } catch (error) {
    // Report failure!
    const failureMessage = `Undeployment failed after ${Math.round((Date.now() - startTime) / 1000)} seconds. See logs for more information.`
    console.error(failureMessage)

    // Re-throw the error to bubble up
    throw error
  }
}