syncbot.yml

name: Branch sync

on:
  pull_request_target:
    branches:
      - main
      - ootb

permissions:
  contents: write
  pull-requests: write

jobs:
  mirror-changes:
    runs-on: ubuntu-latest
    if: github.actor != 'dependabot[bot]'
    steps:
      - uses: actions/checkout@v6

      - name: Get target branch
        id: target-branch
        run: |
          if [ "${{ github.base_ref }}" == "main" ]; then
            echo "branch=ootb" >> $GITHUB_OUTPUT
          else
            echo "branch=main" >> $GITHUB_OUTPUT
          fi
          echo "Target branch for sync: $(cat $GITHUB_OUTPUT | grep branch | cut -d= -f2)"

      - name: Cherry-pick commits to target branch
        id: cherry-pick
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          git config user.name syncbot
          git config user.email github-actions@github.com
          
          # Fetch all branches and the PR head (which may be from a fork)
          git fetch origin
          git fetch origin pull/${{ github.event.pull_request.number }}/head
          
          # Get the source branch name and target branch
          SOURCE_BRANCH="${{ github.head_ref }}"
          TARGET_BRANCH="${{ steps.target-branch.outputs.branch }}"
          SYNC_BRANCH="sync-${SOURCE_BRANCH}-to-${TARGET_BRANCH}"
          
          echo "Source branch: $SOURCE_BRANCH"
          echo "Target branch: $TARGET_BRANCH"
          echo "Sync branch: $SYNC_BRANCH"
          
          # Store branch names for next step
          echo "source_branch=$SOURCE_BRANCH" >> $GITHUB_OUTPUT
          echo "target_branch=$TARGET_BRANCH" >> $GITHUB_OUTPUT
          echo "sync_branch=$SYNC_BRANCH" >> $GITHUB_OUTPUT
          
          # Delete local sync branch if it exists
          git branch -D $SYNC_BRANCH 2>/dev/null || true
          
          # Create sync branch from target branch (will reset if remote exists)
          git checkout -b $SYNC_BRANCH origin/$TARGET_BRANCH
          
          # Get only the commits that are part of the PR
          COMMITS=$(gh api repos/${{ github.repository }}/pulls/${{ github.event.pull_request.number }}/commits --jq '.[].sha')
          
          # Cherry-pick each commit
          echo "Cherry-picking commits..."
          SKIPPED_COMMITS=""
          for commit in $COMMITS; do
            echo "Cherry-picking $commit"
            git cherry-pick $commit || {
              # If the cherry-pick is empty (change already exists on target), skip it
              if git diff --cached --quiet; then
                echo "Cherry-pick of $commit is empty (already applied), skipping"
                git cherry-pick --skip
              else
                echo "Cherry-pick of $commit conflicted, skipping"
                git cherry-pick --abort
                SKIPPED_COMMITS="$SKIPPED_COMMITS $commit"
              fi
            }
          done

          if [ -n "$SKIPPED_COMMITS" ]; then
            echo "skipped_commits=$SKIPPED_COMMITS" >> $GITHUB_OUTPUT
            echo "Some commits were skipped due to conflicts:$SKIPPED_COMMITS"
          fi

          echo "Cherry-pick complete"

      - name: Push sync branch and create PR
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          SOURCE_BRANCH="${{ steps.cherry-pick.outputs.source_branch }}"
          TARGET_BRANCH="${{ steps.cherry-pick.outputs.target_branch }}"
          SYNC_BRANCH="${{ steps.cherry-pick.outputs.sync_branch }}"
          SKIPPED="${{ steps.cherry-pick.outputs.skipped_commits }}"

          # Push the sync branch
          git push origin $SYNC_BRANCH --force
          echo "Successfully pushed sync branch"

          # Create PR using GitHub CLI
          PR_TITLE="[Sync -> ${TARGET_BRANCH}] $(gh pr view ${{ github.event.pull_request.number }} --json title --jq .title)"
          PR_BODY="Automated sync of PR #${{ github.event.pull_request.number }} from \`$SOURCE_BRANCH\` to \`$TARGET_BRANCH\`

          Syncbot will not be offended if the sync isn't appropriate and you close this PR.

          Original PR: #${{ github.event.pull_request.number }}"

          if [ -n "$SKIPPED" ]; then
            PR_BODY="$PR_BODY

          **Note:** The following commits were skipped due to conflicts and may need manual syncing:
          $(for sha in $SKIPPED; do echo "- \`$sha\`"; done)"
          fi

          # Check if PR already exists
          EXISTING_PR=$(gh pr list --head $SYNC_BRANCH --base $TARGET_BRANCH --json number --jq '.[0].number' || echo "")

          if [ -n "$EXISTING_PR" ]; then
            echo "PR already exists: #$EXISTING_PR"
            gh pr edit $EXISTING_PR --body "$PR_BODY"
          else
            NEW_PR=$(gh pr create --base $TARGET_BRANCH --head $SYNC_BRANCH --title "$PR_TITLE" --body "$PR_BODY" --label "sync")
            echo "Created new PR: $NEW_PR"
          fi

      - name: Update PR comment on success
        if: steps.cherry-pick.outputs.skipped_commits == ''
        uses: quarkusio/action-helpers@main
        with:
          action: maintain-one-comment
          github-token: ${{ secrets.GITHUB_TOKEN }}
          body: |
            🤖 This PR has been synchronized to the `${{ steps.cherry-pick.outputs.target_branch }}` branch. 🔄
          pr-number: ${{ github.event.pull_request.number }}

      - name: Update PR comment on partial sync
        if: steps.cherry-pick.outputs.skipped_commits != ''
        uses: quarkusio/action-helpers@main
        with:
          action: maintain-one-comment
          github-token: ${{ secrets.GITHUB_TOKEN }}
          body: |
            🤖 This PR has been partially synchronized to the `${{ steps.cherry-pick.outputs.target_branch }}` branch. Some commits were skipped due to conflicts and may need manual syncing. 🔄
          pr-number: ${{ github.event.pull_request.number }}