# Please ping @DilumAluthge when making any changes to this file.

# Here are some steps that we take in this workflow file for security reasons:
# 1. We do not checkout any code.
# 2. We only run actions that are defined in a repository in the `JuliaLang` GitHub organization.
# 3. We do not give the `GITHUB_TOKEN` any permissions.
# 4. We only give the Buildkite API token (`BUILDKITE_API_TOKEN_RETRY`) the minimum necessary
#    set of permissions.

# Important note to Buildkite maintainers:
# In order to make this work, you need to tell Buildkite that it should NOT create a brand-new
# build when someone closes and reopens a pull request. To do so:
# 1. Go to the relevant pipeline (e.g. https://buildkite.com/julialang/julia-master).
# 2. Click on the "Pipeline Settings" button.
# 3. In the left sidebar, under "Pipeline Settings", click on "GitHub".
# 4. In the "GitHub Settings", under "Build Pull Requests", make sure that the "Skip pull
#    request builds for existing commits" checkbox is checked. This is the setting that tells
#    Buildkite that it should NOT create a brand-new build when someone closes and reopens a
#    pull request.
# 5. At the bottom of the page, click the "Save GitHub Settings" button.

name: Rerun Failed Buildkite Jobs

# There are two ways that a user can rerun the failed Buildkite jobs:
# 1. Close and reopen the pull request.
#    In order to use this approach, the user must be in one of the following three categories:
#        (i)   Author of the pull request
#        (ii)  Commit permissions
#        (iii) Triage permissions
# 2. Post a comment on the pull request with exactly the following contents: /buildkite rerun failed
#    In order to use this approach, the user must be in the following category:
#        - A member of the JuliaLang GitHub organization (the membership must be publicized)

on:
  # When using the `pull_request_target` event, all PRs will get access to secret environment
  # variables (such as the `BUILDKITE_API_TOKEN_RETRY` secret environment variable), even if
  # the PR is from a fork. Therefore, for security reasons, we do not checkout any code in
  # this workflow.
  pull_request_target:
    types: [ reopened ]
  issue_comment:
    types: [ created ]

# We do not give the `GITHUB_TOKEN` any permissions.
# Therefore, the `GITHUB_TOKEN` only has the same access as any member of the public.
permissions:
  contents: none

jobs:
  rerun-failed-buildkite-jobs:
    name: Rerun Failed Buildkite Jobs
    runs-on: ubuntu-latest
    if: (github.repository == 'JuliaLang/julia') && ((github.event_name == 'pull_request_target' && github.event.action == 'reopened') || (github.event_name == 'issue_comment' && github.event.issue.pull_request && github.event.comment.body == '/buildkite rerun failed'))
    steps:
      # For security reasons, we do not checkout any code in this workflow.
      - name: Check organization membership
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          if [[ "${{ github.event_name }}" == "pull_request_target" ]]; then
            if [[ "${{ github.event.action }}" == "reopened" ]]; then
              echo "This is a \"reopened\" event, so we do not need to check the user's organization membership."
              echo "GOOD_TO_PROCEED=yes" >> ${GITHUB_ENV:?}
              echo "PULL_REQUEST_NUMBER=${{ github.event.number }}" >> ${GITHUB_ENV:?}
            else
              echo "ERROR: The github.event_name is \"pull_request_target\", but the github.event.action is not \"reopened\"."
              exit 1
            fi
          else
            curl -H "Authorization: token ${GITHUB_TOKEN:?}" "https://api.github.com/users/${{ github.event.sender.login }}"
            curl -H "Authorization: token ${GITHUB_TOKEN:?}" "https://api.github.com/users/${{ github.event.sender.login }}/orgs"
            export USER_IS_ORGANIZATION_MEMBER=`curl -H "Authorization: token ${GITHUB_TOKEN:?}" "https://api.github.com/users/${{ github.event.sender.login }}/orgs" | jq '[.[] | .login] | index("JuliaLang") != null' | tr -s ' '`
            if [[ "${USER_IS_ORGANIZATION_MEMBER:?}"   == "true" ]]; then
              echo "The \"${{ github.event.sender.login }}\" user is a public member of the JuliaLang organization."
              echo "GOOD_TO_PROCEED=yes" >> ${GITHUB_ENV:?}
              echo "PULL_REQUEST_NUMBER=${{ github.event.issue.number }}" >> ${GITHUB_ENV:?}
            else
              echo "ERROR: the \"${{ github.event.sender.login }}\" user is NOT a public member of the JuliaLang organization."
              echo "If you are a member, please make sure that you have publicized your membership."
              exit 1
            fi
          fi
      - run: |
          echo "GOOD_TO_PROCEED: ${{ env.GOOD_TO_PROCEED }}"
          echo "PULL_REQUEST_NUMBER: ${{ env.PULL_REQUEST_NUMBER }}"
      - uses: JuliaLang/buildkite-rerun-failed@057f6f2d37aa29a57b7679fd2af0df1d9f9188b4
        if: env.GOOD_TO_PROCEED == 'yes'
        with:
          buildkite_api_token: ${{ secrets.BUILDKITE_API_TOKEN_RETRY }}
          buildkite_organization_slug: 'julialang'
          buildkite_pipeline_slug: 'julia-master'
          pr_number: ${{ env.PULL_REQUEST_NUMBER }}