name: ci

on:
  pull_request:
  merge_group:
  push:
    branches: [main]

jobs:
  # Required merge-queue gate: every task directory must keep the native task.md
  # structure.
  validate-tasks:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - name: Install PyYAML (task.md frontmatter parsing)
        run: python3 -m pip install pyyaml
      - name: Validate task structure
        run: python3 .github/scripts/validate_tasks.py tasks tasks-extra
      - name: Validate skill frontmatter
        run: python3 .github/scripts/lint_skill_frontmatter.py
      - name: Test skill frontmatter linter
        run: python3 .github/scripts/test_lint_skill_frontmatter.py

  # Lints only the Python files this PR changed, so the repo's pre-existing
  # ruff debt does not block merges — it gets paid down as files are touched.
  # Scoped this way the check is safe to promote to a required merge-queue
  # gate (see the main-merge-queue ruleset).
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - uses: astral-sh/setup-uv@v5
      - name: Ruff (changed Python files)
        run: |
          case "${{ github.event_name }}" in
            merge_group)  base="${{ github.event.merge_group.base_sha }}" ;;
            pull_request) base="${{ github.event.pull_request.base.sha }}" ;;
            *)            base="$(git rev-parse HEAD~1)" ;;  # push: best-effort (last commit)
          esac
          # NUL-delimited so paths with spaces survive. Pure renames are skipped:
          # the task.md cutover moves many existing verifier files and should not
          # turn historical task-style debt into a repo-lint blocker.
          git diff -z --name-only --diff-filter=ACM "${base}...HEAD" -- '*.py' \
            > "$RUNNER_TEMP/changed_py.z"
          echo "Changed Python files:"
          tr '\0' '\n' < "$RUNNER_TEMP/changed_py.z" | sed 's/^/  /'
          # xargs -r skips ruff entirely when no Python files changed.
          xargs -0 -r uvx ruff@0.14.10 check < "$RUNNER_TEMP/changed_py.z"