name: Clang-Tidy

on:
  workflow_call:
  workflow_dispatch:

permissions:
  contents: read

jobs:
  clang_tidy:
    name: Clang-Tidy Checks
    runs-on: ubuntu-24.04
    steps:
      - name: Shallow checkout (no submodules)
        uses: actions/checkout@v7
        with:
          submodules: false
          fetch-depth: 0

      - name: Collect changed C/C++ files
        id: changed_files
        uses: tj-actions/changed-files@v47
        with:
          files: |
            **/*.c
            **/*.cc
            **/*.cpp
            **/*.cxx
            **/*.h
            **/*.hpp
          files_ignore: |
            thirdparty/**
            build/**
            src/db/sqlengine/antlr/gen/**
            src/db/index/column/fts_column/gen/**

      - name: No C/C++ files changed - skip
        if: steps.changed_files.outputs.any_changed != 'true'
        run: echo "No C/C++ files changed. Skipping clang-tidy."

      - name: Checkout submodules
        if: steps.changed_files.outputs.any_changed == 'true'
        run: git submodule update --init --recursive --depth 1

      - name: Install dependencies
        if: steps.changed_files.outputs.any_changed == 'true'
        run: |
          sudo apt-get update
          sudo apt-get install -y clang-tidy=1:18.0-59~exp2 cmake ninja-build libomp-dev libaio-dev

      - name: Setup ccache
        if: steps.changed_files.outputs.any_changed == 'true'
        uses: hendrikmuhs/ccache-action@v1.2
        with:
          key: clang-tidy
          max-size: 500M

      - name: Configure CMake and export compile commands
        if: steps.changed_files.outputs.any_changed == 'true'
        run: |
          cmake -S . -B build -G Ninja \
            -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
            -DBUILD_TOOLS=ON \
            -DCMAKE_C_COMPILER_LAUNCHER=ccache \
            -DCMAKE_CXX_COMPILER_LAUNCHER=ccache

      - name: Filter changed files against compile_commands.json
        id: tidy_files
        if: steps.changed_files.outputs.any_changed == 'true'
        run: |
          python3 - <<'PY'
          import json
          import os
          from pathlib import Path

          raw = os.environ.get("ALL_CHANGED_FILES", "")
          changed = [f for f in raw.split() if f]

          compile_db_path = Path("build/compile_commands.json")
          with compile_db_path.open("r", encoding="utf-8") as fh:
              compile_db = json.load(fh)

          compile_entries = set()
          for entry in compile_db:
              file_field = entry.get("file", "")
              if file_field:
                  compile_entries.add(os.path.normpath(file_field))

          cwd = Path.cwd().resolve()
          selected = []
          skipped = []

          for rel_path in changed:
              abs_path = os.path.normpath(str((cwd / rel_path).resolve()))
              if abs_path in compile_entries:
                  selected.append(rel_path)
              elif not Path(rel_path).is_file():
                  skipped.append(f"{rel_path} (file not found)")
              else:
                  skipped.append(f"{rel_path} (not in compile_commands.json)")

          github_output = os.environ["GITHUB_OUTPUT"]
          with open(github_output, "a", encoding="utf-8") as out:
              out.write(f"any_tidy_files={'true' if selected else 'false'}\n")
              out.write("all_tidy_files<<TIDY_EOF\n")
              out.write("\n".join(selected) + "\n")
              out.write("TIDY_EOF\n")
              out.write("skipped_files<<SKIP_EOF\n")
              out.write("\n".join(skipped) + "\n")
              out.write("SKIP_EOF\n")
          PY
        env:
          ALL_CHANGED_FILES: ${{ steps.changed_files.outputs.all_changed_files }}

      - name: Show skipped files
        if: steps.changed_files.outputs.any_changed == 'true' && steps.tidy_files.outputs.skipped_files != ''
        run: |
          echo "=== Files skipped by clang-tidy ==="
          printf '%s\n' "${{ steps.tidy_files.outputs.skipped_files }}"

      - name: Compute submodule commits hash
        id: submodule_hash
        if: steps.changed_files.outputs.any_changed == 'true'
        run: |
          hash=$(git submodule status --recursive | awk '{print $1}' | sort | sha256sum | awk '{print $1}')
          echo "value=${hash}" >> "$GITHUB_OUTPUT"

      - name: Restore generated headers cache
        id: cache_headers
        if: steps.changed_files.outputs.any_changed == 'true'
        uses: actions/cache/restore@v6
        with:
          path: |
            build/external
            build/thirdparty
            build/src/db/proto
          key: clang-tidy-headers-${{ runner.os }}-${{ hashFiles('thirdparty/**/*.cmake', 'thirdparty/**/CMakeLists.txt', 'thirdparty/**/*.patch', 'src/db/proto/*.proto') }}-${{ steps.submodule_hash.outputs.value }}

      - name: Build generated headers only
        if: steps.tidy_files.outputs.any_tidy_files == 'true' && steps.cache_headers.outputs.cache-hit != 'true'
        run: |
          ninja -C build clang_tidy_deps

      - name: Save generated headers cache
        if: steps.tidy_files.outputs.any_tidy_files == 'true' && steps.cache_headers.outputs.cache-hit != 'true'
        uses: actions/cache/save@v6
        with:
          path: |
            build/external
            build/thirdparty
            build/src/db/proto
          key: clang-tidy-headers-${{ runner.os }}-${{ hashFiles('thirdparty/**/*.cmake', 'thirdparty/**/CMakeLists.txt', 'thirdparty/**/*.patch', 'src/db/proto/*.proto') }}-${{ steps.submodule_hash.outputs.value }}

      - name: Run clang-tidy on changed files (parallel)
        if: steps.tidy_files.outputs.any_tidy_files == 'true'
        run: |
          mapfile -t files_to_check <<'TIDY_EOF'
          ${{ steps.tidy_files.outputs.all_tidy_files }}
          TIDY_EOF

          log_dir=$(mktemp -d)
          printf '%s\n' "${files_to_check[@]}" \
            | grep -v '^\s*$' \
            | xargs -I{} -P "$(nproc)" sh -c '
                file="{}"
                if [ -f "$file" ]; then
                  log="'"$log_dir"'/$$.log"
                  echo "$file" > "$log"
                  if clang-tidy -p build --quiet --warnings-as-errors="*" "$file" >> "$log" 2>&1; then
                    echo "PASS: $file"
                    rm -f "$log"
                  else
                    echo "FAIL: $file"
                  fi
                fi'

          failed=0
          for f in "$log_dir"/*.log; do
            [ -e "$f" ] || break
            failed=1
            src=$(head -1 "$f")
            echo ""
            echo "::group::clang-tidy errors: $src"
            tail -n +2 "$f"
            echo "::endgroup::"
          done

          rm -rf "$log_dir"
          if [ "$failed" -eq 1 ]; then
            echo "::error::clang-tidy found issues in one or more files"
            exit 1
          fi

      - name: No files to analyse
        if: steps.changed_files.outputs.any_changed == 'true' && steps.tidy_files.outputs.any_tidy_files != 'true'
        run: echo "Changed C/C++ files not in compile_commands.json. Nothing to analyse."