name: Lint

on:
  push:
    branches: [main]
  pull_request:

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

      - name: Reject changes under legacy docs/
        if: github.event_name == 'pull_request'
        run: |
          set -euo pipefail
          BASE_REF="${{ github.base_ref }}"
          # Refresh origin/<base_ref> with full history; --depth=1 would
          # shallow the ref and break the merge-base used by `...`.
          git fetch --no-tags origin "$BASE_REF"
          # First, verify the diff itself succeeds and check whether any
          # files changed. A silent failure here would let docs/ changes
          # through, so the explicit `if !` guard is important.
          if ! CHANGED=$(git diff --name-only --diff-filter=ACMRDTUXB "origin/${BASE_REF}...HEAD"); then
            echo "git diff origin/${BASE_REF}...HEAD failed; aborting." >&2
            exit 2
          fi
          if [ -z "$CHANGED" ]; then
            echo "No changed files vs origin/${BASE_REF}; skipping."
            exit 0
          fi
          # Re-emit with -z so xargs can safely handle whitespace in paths.
          git diff -z --name-only --diff-filter=ACMRDTUXB "origin/${BASE_REF}...HEAD" \
            | xargs -0 python3 scripts/ci/check_no_docs_changes.py

      - name: Set up Python
        uses: actions/setup-python@v4
        with:
          python-version: "3.12"

      - name: Install pre-commit hook
        run: |
          python -m pip install pre-commit
          pre-commit install

      - name: Run pre-commit checks
        run: SKIP=no-commit-to-branch pre-commit run --all-files --show-diff-on-failure

      - name: Run lychee docs checks (offline references)
        uses: lycheeverse/lychee-action@8646ba30535128ac92d33dfc9133794bfdd9b411 # v2
        with:
          args: --config .github/linters/lychee.toml README.md "docs/**/*.md" "docs/**/*.rst" "docs/**/*.ipynb"

      - name: Run sgl-kernel clang-format checks
        uses: DoozyX/clang-format-lint-action@v0.20
        with:
          source: sgl-kernel
          extensions: h,c,cpp,hpp,cu,cuh,cc
          clangFormatVersion: 20
          style: file