cleanup-branch.yml

name: Suggest Cleaned-up Branch

on:
  workflow_call:
    inputs:
      commit_threshold:
        description: 'Number of commits after which to suggest cleanup'
        required: false
        default: 10
        type: number
      days_stale:
        description: 'Number of days since last commit to consider branch stale'
        required: false
        default: 30
        type: number
      base_branch:
        description: 'Base branch for cleanup (default: main)'
        required: false
        default: 'main'
        type: string
      dry_run:
        description: 'If true, only report, do not open PR'
        required: false
        default: true
        type: boolean

concurrency:
  group: cleanup-branch-${{ github.ref }}-${{ github.event_name }}
  cancel-in-progress: true

jobs:
  check-and-suggest:
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write
    steps:
      - name: Checkout
        uses: actions/checkout@v5
        with:
          fetch-depth: 0

      - name: Get current branch name
        id: branch
        run: echo "branch_name=${GITHUB_REF##*/}" >> $GITHUB_OUTPUT

      - name: Count commits on branch
        id: count
        run: |
          COMMITS=$(git rev-list --count origin/${{ steps.branch.outputs.branch_name }})
          echo "commit_count=$COMMITS" >> $GITHUB_OUTPUT

      - name: Get last commit date
        id: lastdate
        run: |
          LAST_DATE=$(git log -1 --format=%ct origin/${{ steps.branch.outputs.branch_name }})
          NOW=$(date +%s)
          AGE_DAYS=$(( (NOW - LAST_DATE) / 86400 ))
          echo "age_days=$AGE_DAYS" >> $GITHUB_OUTPUT

      - name: Decide if cleanup needed
        id: need_cleanup
        run: |
          NEED_CLEANUP=false
          REASON=""
          COMMIT_COUNT="${{ steps.count.outputs.commit_count }}"
          DAYS_STALE="${{ steps.lastdate.outputs.age_days }}"
          echo "[cleanup-branch] Commit count: $COMMIT_COUNT (threshold: ${{ inputs.commit_threshold }})"
          echo "[cleanup-branch] Days since last commit: $DAYS_STALE (threshold: ${{ inputs.days_stale }})"
          if [ "$COMMIT_COUNT" -gt "${{ inputs.commit_threshold }}" ]; then
            NEED_CLEANUP=true
            REASON="Commit count ($COMMIT_COUNT) exceeds threshold (${{ inputs.commit_threshold }})"
          fi
          if [ "$DAYS_STALE" -gt "${{ inputs.days_stale }}" ]; then
            NEED_CLEANUP=true
            if [ -n "$REASON" ]; then
              REASON="$REASON; "
            fi
            REASON+="Branch is stale ($DAYS_STALE days > ${{ inputs.days_stale }})"
          fi
          if [ "$NEED_CLEANUP" = true ]; then
            echo "[cleanup-branch] Cleanup needed: true. Reason: $REASON"
          else
            echo "[cleanup-branch] Cleanup needed: false."
          fi
          echo "need_cleanup=$NEED_CLEANUP" >> $GITHUB_OUTPUT
          echo "cleanup_reason=$REASON" >> $GITHUB_OUTPUT

      - name: Squash and push cleaned branch
        if: steps.need_cleanup.outputs.need_cleanup == 'true' && inputs.dry_run == false
        run: |
          set -e
          git config user.name "github-actions[bot]"
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
          git checkout -b cleaned-${{ steps.branch.outputs.branch_name }} origin/${{ steps.branch.outputs.branch_name }}
          git reset --soft origin/${{ inputs.base_branch }}
          git commit -m "Squashed commit for branch cleanup" --allow-empty
          git push -f origin cleaned-${{ steps.branch.outputs.branch_name }}

      - name: Create PR for cleaned branch
        if: steps.need_cleanup.outputs.need_cleanup == 'true' && inputs.dry_run == false
        uses: peter-evans/create-pull-request@v7
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          branch: cleaned-${{ steps.branch.outputs.branch_name }}
          base: ${{ steps.branch.outputs.branch_name }}
          committer: "github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>"
          author: "github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>"
          title: "Suggest: Cleaned-up branch (squashed commits)"
          body: |
            This PR was automatically created to suggest a cleaned-up (squashed) version of `${{ steps.branch.outputs.branch_name }}`.
            - Original commit count: ${{ steps.count.outputs.commit_count }}
            - Days since last commit: ${{ steps.lastdate.outputs.age_days }}
            - Base branch: ${{ inputs.base_branch }}
            
            Please review and merge if you want to clean up the branch history.

      - name: Report (dry run or no cleanup needed)
        if: steps.need_cleanup.outputs.need_cleanup == 'false' || inputs.dry_run == true
        run: |
          echo "No cleanup needed or dry run enabled."
          echo "Commit count: ${{ steps.count.outputs.commit_count }}"
          echo "Days since last commit: ${{ steps.lastdate.outputs.age_days }}"
          echo "Cleanup needed: ${{ steps.need_cleanup.outputs.need_cleanup }}"
          echo "Reason: ${{ steps.need_cleanup.outputs.cleanup_reason }}"