// A workflow_run event is privileged: accept only trusted pushes and the exact tested revision.
module.exports = async function knowledgeDeployGates({
  github,
  context,
  core,
  now = Date.now,
  sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms)),
}) {
  const source = context.payload.workflow_run
  const repository = `${context.repo.owner}/${context.repo.repo}`
  const branch = 'deploy/konwledge'
  if (
    source?.event !== 'push' ||
    source.conclusion !== 'success' ||
    source.head_branch !== branch ||
    source.head_repository?.full_name !== repository ||
    !/^[0-9a-f]{40}$/.test(source.head_sha)
  ) {
    throw new Error('Deployment requires a successful trusted branch push.')
  }
  const isCurrent = async () => {
    const { data } = await github.rest.repos.getBranch({ ...context.repo, branch })
    return data.commit.sha === source.head_sha
  }
  const skip = () => {
    core.info('Skipping a superseded deployment revision.')
    core.setOutput('current', 'false')
  }
  if (!(await isCurrent())) return skip()
  const deadline = now() + 30 * 60 * 1000
  while (now() < deadline) {
    const { data } = await github.rest.actions.listWorkflowRuns({
      ...context.repo,
      workflow_id: 'knowledge-fs-ci.yml',
      branch,
      event: 'push',
      head_sha: source.head_sha,
      per_page: 100,
    })
    const run = data.workflow_runs
      .filter(
        (candidate) =>
          candidate.head_sha === source.head_sha &&
          candidate.head_branch === branch &&
          candidate.event === 'push' &&
          candidate.head_repository?.full_name === repository,
      )
      .sort((a, b) => b.run_number - a.run_number || b.run_attempt - a.run_attempt)[0]
    if (run?.status === 'completed') {
      if (run.conclusion !== 'success')
        throw new Error(`KnowledgeFS CI did not succeed for ${source.head_sha}: ${run.conclusion}.`)
      if (!(await isCurrent())) return skip()
      core.info(`KnowledgeFS CI and image build succeeded for ${source.head_sha}.`)
      core.setOutput('current', 'true')
      return
    }
    if (!(await isCurrent())) return skip()
    core.info(`Waiting for KnowledgeFS CI at ${source.head_sha}.`)
    await sleep(15000)
  }
  throw new Error(`Timed out waiting for KnowledgeFS CI for ${source.head_sha}.`)
}