process-pr-merge.yml

name: process-pr-merge

# This workflow processes commits pushed to the main branch to:
# 1. Determine if the commit is associated with a PR, and if not exit gracefully.
# 2. Extract relevant details (change type, release note, and bump type) from the PR body
#    and use them to update the changelog if applicable (change type is not "OTHER").
# 3. Trigger a release action if warranted by the bump type (MAJOR, MINOR), or skip if WAIT is selected.

on:
  push:
    branches:
      - main

env:
  GH_TOKEN: ${{ secrets.ACTIONS_PAT }}

jobs:
  determine-pr:
    runs-on: ubuntu-latest
    outputs:
      pr_number: ${{ steps.check-pr.outputs.pr_number }}
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          token: ${{ secrets.ACTIONS_PAT }}
          fetch-depth: 0

      - name: Check if this is a PR commit
        id: check-pr
        run: |
          commit_sha=$(git log -1 --format="%H")
          echo "Commit SHA: $commit_sha"

          pr_number=$(gh api -X GET "repos/${{ github.repository }}/commits/$commit_sha/pulls" --jq '.[0].number')

          if [ -z "$pr_number" ]; then
            echo "No PR associated with commit $commit_sha."
            echo "pr_number=" >> $GITHUB_OUTPUT
            exit 0
          fi

          echo "PR Number: $pr_number"
          echo "pr_number=${pr_number}" >> $GITHUB_OUTPUT

  update-changelog:
    runs-on: ubuntu-latest
    needs: determine-pr
    outputs:
      bump_type: ${{ steps.extract-details.outputs.bump_type }}
    if: needs.determine-pr.outputs.pr_number != ''
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          token: ${{ secrets.ACTIONS_PAT }}
          fetch-depth: 0

      - name: Extract change type, bump type, and release note
        id: extract-details
        run: |
          pr_number="${{ needs.determine-pr.outputs.pr_number }}"
          echo "Fetching PR details for PR #$pr_number..."

          # Fetch PR body
          pr_body=$(gh api -X GET "repos/${{ github.repository }}/pulls/$pr_number" --jq '.body' | sed 's/\r//g')
          echo "Extracting details from PR Body: $pr_body"

          # Extract release note
          release_note=$(echo "$pr_body" | awk 'BEGIN { found=0 } /```release-note/ { found=1; next } /```/ { found=0 } found { print }' | sed '/^\s*$/d')
          echo "Release Note: $release_note"
          if [ -z "$release_note" ]; then
            echo "No release note found."
            exit 1
          fi
          echo "release_note=${release_note}" >> $GITHUB_OUTPUT

          # Determine change type
          change_type=$(echo "$pr_body" | grep -oP '(?<=- \[x\] \*\*`)[A-Z]+(?=`\*\*)' | head -n 1)
          echo "Change Type: $change_type"
          case "$change_type" in
            "ADDITION")
              section="### Added"
              ;;
            "CHANGE")
              section="### Changed"
              ;;
            "FIX")
              section="### Fixed"
              ;;
            "OTHER")
              echo "Change type is 'OTHER'. Skipping changelog update."
              exit 0
              ;;
            *)
              echo "Invalid change type: $change_type."
              exit 1
              ;;
          esac
          echo "section=${section}" >> $GITHUB_OUTPUT

          # Check for bump type
          major_checked=$(echo "$pr_body" | grep -q '\[x\] \*\*`MAJOR`' && echo "true" || echo "false")
          minor_checked=$(echo "$pr_body" | grep -q '\[x\] \*\*`MINOR`' && echo "true" || echo "false")
          wait_checked=$(echo "$pr_body" | grep -q '\[x\] \*\*`WAIT`' && echo "true" || echo "false")
          if [ "$major_checked" == "true" ]; then
            echo "bump type: MAJOR"
            echo "bump_type=major" >> $GITHUB_OUTPUT
          elif [ "$minor_checked" == "true" ]; then
            echo "bump type: MINOR"
            echo "bump_type=minor" >> $GITHUB_OUTPUT
          elif [ "$wait_checked" == "true" ]; then
            echo "bump type WAIT was checked. No release required."
            echo "bump_type=" >> $GITHUB_OUTPUT
          else
            echo "No valid bump type specified. Skipping release."
            echo "bump_type=" >> $GITHUB_OUTPUT
          fi

      - name: Update changelog
        run: |
          echo "Updating changelog under section: ${{ steps.extract-details.outputs.section }}"
          sed -i "0,/${{ steps.extract-details.outputs.section }}/s@${{ steps.extract-details.outputs.section }}@${{ steps.extract-details.outputs.section }}\n- ${{ steps.extract-details.outputs.release_note }}@" CHANGELOG.md
          cat CHANGELOG.md

      - name: Commit and push changelog update
        uses: EndBug/add-and-commit@v7
        with:
          add: 'CHANGELOG.md'
          message: "Update CHANGELOG.md with release note from PR #${{ needs.determine-pr.outputs.pr_number }}"
          author_email: git-action-bot@example.com
          author_name: Git Action Bot
          token: ${{ secrets.GITHUB_TOKEN }}
          push: true

  dispatch-release:
    runs-on: ubuntu-latest
    needs: update-changelog
    if: needs.update-changelog.outputs.bump_type != ''
    steps:
      - name: Dispatch GitHub Release Action
        run: |
          echo "Dispatching release action with bump type: ${{ needs.update-changelog.outputs.bump_type }}"
          curl -X POST -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
          -H "Accept: application/vnd.github.everest-preview+json" \
          https://api.github.com/repos/${{ github.repository }}/dispatches \
          -d '{"event_type": "trigger-release", "client_payload": {"bump_type": "${{ needs.update-changelog.outputs.bump_type }}"}}'