codeowners-approved-slack.yml

name: CODEOWNERS Approved - Slack Notification

on:
  workflow_call:
    inputs:
      skip-draft:
        description: "Skip notification for draft PRs"
        required: false
        type: boolean
        default: true
      require-full-approval:
        description: "If true, only notify when reviewDecision is APPROVED. If false, notify on first approval."
        required: false
        type: boolean
        default: true
      slack-message-prefix:
        description: "Custom prefix for Slack message (emoji + text)"
        required: false
        type: string
        default: ":white_check_mark: CODEOWNERS gate satisfied"
    secrets:
      SLACK_RELEASE_CHANGELOG_WEBHOOK:
        description: "Slack incoming webhook URL"
        required: true
      GH_TOKEN:
        description: "GitHub token with PR read access (uses GITHUB_TOKEN if not provided)"
        required: false

jobs:
  notify:
    name: Notify Slack on CODEOWNERS Approval
    # Only run when the submitted review is an approval
    if: github.event.review.state == 'approved'
    runs-on: ubuntu-latest

    steps:
      - name: Fetch PR decision and check for duplicate notification
        id: pr
        uses: actions/github-script@v7
        with:
          github-token: ${{ secrets.GH_TOKEN || github.token }}
          script: |
            const { owner, repo } = context.repo;
            const prNumber = context.payload.pull_request.number;

            const query = `query($owner:String!, $repo:String!, $number:Int!) {
              repository(owner:$owner, name:$repo) {
                pullRequest(number:$number) {
                  number
                  title
                  url
                  isDraft
                  headRefOid
                  baseRefName
                  reviewDecision
                }
              }
            }`;

            const data = await github.graphql(query, { owner, repo, number: prNumber });
            const pr = data.repository.pullRequest;

            core.setOutput("number", String(pr.number));
            core.setOutput("title", pr.title);
            core.setOutput("url", pr.url);
            core.setOutput("is_draft", pr.isDraft ? "true" : "false");
            core.setOutput("head_sha", pr.headRefOid);
            core.setOutput("base", pr.baseRefName);
            core.setOutput("review_decision", pr.reviewDecision ?? "");

            // Dedupe marker per head SHA (so new commits can re-trigger notification)
            const marker = `<!-- codeowners-approved:${pr.headRefOid} -->`;
            core.setOutput("marker", marker);

            // Check if we've already notified for this SHA
            const comments = await github.paginate(github.rest.issues.listComments, {
              owner,
              repo,
              issue_number: prNumber,
              per_page: 100,
            });

            const alreadyNotified = comments.some(c => (c.body || "").includes(marker));
            core.setOutput("already_notified", alreadyNotified ? "true" : "false");

            // Log for debugging
            console.log(`PR #${pr.number}: draft=${pr.isDraft}, decision=${pr.reviewDecision}, notified=${alreadyNotified}`);

      - name: Skip notification (conditions not met)
        if: |
          (inputs.skip-draft && steps.pr.outputs.is_draft == 'true') ||
          (inputs.require-full-approval && steps.pr.outputs.review_decision != 'APPROVED') ||
          steps.pr.outputs.already_notified == 'true'
        run: |
          echo "### Notification Skipped" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "| Condition | Value |" >> $GITHUB_STEP_SUMMARY
          echo "|-----------|-------|" >> $GITHUB_STEP_SUMMARY
          echo "| Is Draft | ${{ steps.pr.outputs.is_draft }} |" >> $GITHUB_STEP_SUMMARY
          echo "| Review Decision | ${{ steps.pr.outputs.review_decision }} |" >> $GITHUB_STEP_SUMMARY
          echo "| Already Notified | ${{ steps.pr.outputs.already_notified }} |" >> $GITHUB_STEP_SUMMARY

      - name: Build Slack message
        id: slack_msg
        if: |
          (inputs.skip-draft == false || steps.pr.outputs.is_draft != 'true') &&
          (inputs.require-full-approval == false || steps.pr.outputs.review_decision == 'APPROVED') &&
          steps.pr.outputs.already_notified != 'true'
        run: |
          {
            echo "message<<EOF"
            echo "${{ inputs.slack-message-prefix }}"
            echo "<${{ steps.pr.outputs.url }}|PR #${{ steps.pr.outputs.number }} — ${{ steps.pr.outputs.title }}>"
            echo "Base: \`${{ steps.pr.outputs.base }}\`  Head: \`${{ steps.pr.outputs.head_sha }}\`"
            echo "Approved by: \`${{ github.event.review.user.login }}\`"
            echo "EOF"
          } >> $GITHUB_OUTPUT

      - name: Post to Slack
        if: |
          (inputs.skip-draft == false || steps.pr.outputs.is_draft != 'true') &&
          (inputs.require-full-approval == false || steps.pr.outputs.review_decision == 'APPROVED') &&
          steps.pr.outputs.already_notified != 'true'
        uses: slackapi/slack-github-action@v2
        with:
          webhook-type: incoming-webhook
          webhook: ${{ secrets.SLACK_RELEASE_CHANGELOG_WEBHOOK }}
          payload: |
            {
              "text": ${{ toJSON(steps.slack_msg.outputs.message) }}
            }

      - name: Summary (notification sent)
        if: |
          (inputs.skip-draft == false || steps.pr.outputs.is_draft != 'true') &&
          (inputs.require-full-approval == false || steps.pr.outputs.review_decision == 'APPROVED') &&
          steps.pr.outputs.already_notified != 'true'
        run: |
          echo "### Slack Notification Sent" >> $GITHUB_STEP_SUMMARY
          echo "" >> $GITHUB_STEP_SUMMARY
          echo "| Field | Value |" >> $GITHUB_STEP_SUMMARY
          echo "|-------|-------|" >> $GITHUB_STEP_SUMMARY
          echo "| PR | [#${{ steps.pr.outputs.number }}](${{ steps.pr.outputs.url }}) |" >> $GITHUB_STEP_SUMMARY
          echo "| Title | ${{ steps.pr.outputs.title }} |" >> $GITHUB_STEP_SUMMARY
          echo "| Base | \`${{ steps.pr.outputs.base }}\` |" >> $GITHUB_STEP_SUMMARY
          echo "| Head SHA | \`${{ steps.pr.outputs.head_sha }}\` |" >> $GITHUB_STEP_SUMMARY
          echo "| Approved By | @${{ github.event.review.user.login }} |" >> $GITHUB_STEP_SUMMARY