name: Checks / Changelog

on:
  pull_request_target:
    types: [opened, synchronize, reopened, ready_for_review, labeled, unlabeled]

permissions:
  contents: read
  pull-requests: write
  issues: write

jobs:
  check-changelog:
    name: Check changelog is added
    runs-on: ubuntu-latest
    steps:
      - name: Check for changelog entry
        id: check_files
        run: |
          AUTH=$(echo -n "x-access-token:${{ secrets.GITHUB_TOKEN }}" | base64 -w 0)
          git config --global http.${{ github.server_url }}/.extraheader "Authorization: basic $AUTH"
          git clone "${{ github.event.repository.clone_url }}" repo.git --bare

          git -C repo.git fetch origin pull/${{ github.event.pull_request.number }}/head

          # Check for Added (A) or Modified (M) files in changelog.d
          CHANGELOG_CHANGES=$(git -C repo.git diff --name-status ${{ github.event.pull_request.base.sha }}...${{ github.event.pull_request.head.sha }} -- changelog.d/)

          SRC_CHANGES=$(git -C repo.git diff --name-status ${{ github.event.pull_request.base.sha }}...${{ github.event.pull_request.head.sha }} -- src/)

          echo "Changes in changelog.d/:"
          echo "$CHANGELOG_CHANGES"
          echo "Changes in src/:"
          echo "$SRC_CHANGES"

          if echo "$CHANGELOG_CHANGES" | grep -q "^[AM]"; then
            echo "has_changelog=true" >> $GITHUB_OUTPUT
          else
            echo "has_changelog=false" >> $GITHUB_OUTPUT
          fi

          if [ -n "$SRC_CHANGES" ]; then
            echo "src_changed=true" >> $GITHUB_OUTPUT
          else
            echo "src_changed=false" >> $GITHUB_OUTPUT
          fi

      - name: Manage PR Labels
        uses: https://github.com/actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9
        env:
          HAS_CHANGELOG: ${{ steps.check_files.outputs.has_changelog }}
          SRC_CHANGED: ${{ steps.check_files.outputs.src_changed }}
        with:
          script: |
            const hasChangelog = process.env.HAS_CHANGELOG === 'true';
            const srcChanged = process.env.SRC_CHANGED === 'true';

            const { data: pullRequest } = await github.rest.pulls.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: context.issue.number,
            });

            const currentLabels = pullRequest.labels.map(l => l.name);

            if (hasChangelog) {
              console.log('PR has changelog');
              await github.rest.issues.addLabels({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: context.issue.number,
                labels: ['Changelog/Added'],
              });
            } else if (currentLabels.includes('Changelog/None')) {
              console.log('PR has Changelog/None label, skipping.');
            } else if (srcChanged) {
              console.log('PR is missing changelog');
              await github.rest.issues.addLabels({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: context.issue.number,
                labels: ['Changelog/Missing'],
              });
              core.setFailed("Missing changelog entry (detected)");
            } else if (currentLabels.includes('Changelog/Missing')) {
              core.setFailed("Missing changelog entry (label)");
            } else {
              console.log('Changelog not needed');
              // Changelog is probably not needed
            }