name: Check Release PR

on:
  pull_request:
    types:
      - opened
      - synchronize
    branches:
      - main

jobs:
  check-commits:
    runs-on: ubuntu-latest
    if: startsWith(github.head_ref, 'release/')
    steps:
    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
      with:
        ref: ${{ github.head_ref }}
        fetch-depth: 0

    - name: Check all PR commits are empty or cherry-picked from main
      run: |
        git fetch origin main

        CHERRY_OUTPUT=$(git cherry origin/main HEAD)

        if [ -z "$CHERRY_OUTPUT" ]; then
          echo "✅ All commits already exist in main"
          exit 0
        fi

        echo "Cherry check results:"
        echo "$CHERRY_OUTPUT"

        MISSING_COMMITS=$(echo "$CHERRY_OUTPUT" | grep '^+' | cut -d' ' -f2)

        if [ -z "$MISSING_COMMITS" ]; then
          echo "✅ All commits exist in main"
          exit 0
        fi

        ALL_EMPTY=true
        for commit in $MISSING_COMMITS; do
          if [ -n "$(git diff-tree --no-commit-id --name-only -r "$commit")" ]; then
            ALL_EMPTY=false
            break
          fi
        done

        if [ "$ALL_EMPTY" = true ]; then
          echo "✅ Only empty commits (release branch markers) are unique"
          for commit in $MISSING_COMMITS; do
            git log --oneline -1 "$commit"
          done
          exit 0
        fi

        echo "❌ Found commits with changes that don't exist in main:"
        for commit in $MISSING_COMMITS; do
          git log --oneline -1 "$commit"
        done
        echo "Cherry-pick these commits into main first, or re-run this job after updating main."
        exit 1