name: Clippy changelog check

on:
  merge_group:
  pull_request:
    types: [opened, reopened, synchronize, edited]

concurrency:
  # For a given workflow, if we push to the same PR, cancel all previous builds on that PR.
  # If the push is not attached to a PR, we will cancel all builds on the same branch.
  group: "${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}"
  cancel-in-progress: true

jobs:
  changelog:
    runs-on: ubuntu-latest

    defaults:
      run:
        shell: bash

    steps:
    # Run
    - name: Check Changelog
      if: ${{ github.event_name == 'pull_request' }}
      run: |
        body=$(curl -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" -s "https://api.github.com/repos/rust-lang/rust-clippy/pulls/$PR_NUMBER" | \
          python -c "import sys, json; print(json.load(sys.stdin)['body'])")
        output=$(awk '/^changelog:\s*\S/ && !/changelog: \[.*\]: your change/' <<< "$body" | sed "s/changelog:\s*//g")
        if [ -z "$output" ]; then
          echo "ERROR: pull request message must contain 'changelog: ...' with your changelog. Please add it."
          exit 1
        else
          echo "changelog: $output"
        fi
      env:
        PYTHONIOENCODING: 'utf-8'
        PR_NUMBER: '${{ github.event.number }}'

  # We need to have the "conclusion" job also on PR CI, to make it possible
  # to add PRs to a merge queue.
  conclusion_changelog:
    needs: [ changelog ]
    # We need to ensure this job does *not* get skipped if its dependencies fail,
    # because a skipped job is considered a success by GitHub. So we have to
    # overwrite `if:`. We use `!cancelled()` to ensure the job does still not get run
    # when the workflow is canceled manually.
    #
    # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
    if: ${{ !cancelled() }}
    runs-on: ubuntu-latest
    steps:
      # Manually check the status of all dependencies. `if: failure()` does not work.
      - name: Conclusion
        run: |
          # Print the dependent jobs to see them in the CI log
          jq -C <<< '${{ toJson(needs) }}'
          # Check if all jobs that we depend on (in the needs array) were successful.
          jq --exit-status 'all(.result == "success")' <<< '${{ toJson(needs) }}'