name: Skill PR Check

on:
  pull_request:
    branches: [main]

jobs:
  check:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Check for mixed skill + source changes
        run: |
          # Check if PR adds new skill files (not just modifies existing)
          ADDED_SKILLS=$(git diff --name-only --diff-filter=A origin/main...HEAD | grep '^\.claude/skills/' || true)

          # Check if PR touches source
          CHANGED=$(git diff --name-only origin/main...HEAD)
          SOURCE=$(echo "$CHANGED" | grep -E '^src/|^container/|^package\.json|^package-lock\.json' || true)

          # Block if new skills are added AND source is modified
          if [ -n "$ADDED_SKILLS" ] && [ -n "$SOURCE" ]; then
            echo "❌ PRs that add skills should not modify source files."
            echo ""
            echo "New skill files:"
            echo "$ADDED_SKILLS"
            echo ""
            echo "Source files:"
            echo "$SOURCE"
            echo ""
            echo "Please read CONTRIBUTING.md"
            exit 1
          fi

      - name: Comment on failure
        if: failure()
        uses: actions/github-script@v7
        with:
          script: |
            github.rest.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
              body: `This PR adds a skill while also modifying source code. A skill PR should not change source files—the skill should contain **instructions** for Claude to follow. See \`/convert-to-docker\` for an example.

            If you're fixing a bug or simplifying code, please submit that as a separate PR.

            See [CONTRIBUTING.md](https://github.com/${context.repo.owner}/${context.repo.repo}/blob/main/CONTRIBUTING.md) for details.`
            })