name: CI

on:
  push:
    branches: [main]
  pull_request:
    types: [opened, synchronize, reopened, labeled]

permissions:
  contents: write
  pull-requests: write

jobs:
  vet_build_test:
    name: Vet & Build & Test
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        os: [ubuntu-latest, windows-latest]
    steps:
      - uses: actions/checkout@v4

      - uses: actions/setup-go@v5
        with:
          go-version-file: go.mod

      - name: Find and remove all .cpp files
        run: |
          find . -name "*.cpp" -type f -delete
        shell: bash

      - name: Run go vet
        run: go vet ./...

      - name: Build all packages
        run: go build ./...

      - name: Build cmd/gen
        run: go build ./cmd/gen

      - name: Run tests
        run: go test -v -count=1 ./...

      - name: Run golangci-lint
        uses: golangci/golangci-lint-action@v9
        with:
          version: v2.11

  test-examples:
    name: Test examples
    runs-on: ${{ matrix.os }}
    needs: [vet_build_test]
    strategy:
      fail-fast: false
      matrix:
        os: [ubuntu-latest, windows-latest]
    steps:
      - uses: actions/checkout@v4

      - uses: actions/setup-go@v5
        with:
          go-version-file: go.mod

      - name: Install Intel Level Zero (Linux)
        if: runner.os == 'Linux'
        run: |
          wget -qO - https://repositories.intel.com/gpu/intel-graphics.key | \
            sudo gpg --dearmor -o /usr/share/keyrings/intel-graphics.gpg
          . /etc/os-release
          echo "deb [arch=amd64 signed-by=/usr/share/keyrings/intel-graphics.gpg] \
            https://repositories.intel.com/gpu/ubuntu ${VERSION_CODENAME} unified" | \
            sudo tee /etc/apt/sources.list.d/intel-gpu.list
          sudo apt-get update
          sudo apt-get install -y intel-level-zero-gpu level-zero

      - name: Install Intel Level Zero (Windows)
        if: runner.os == 'Windows'
        shell: pwsh
        run: |
          $release = Invoke-RestMethod "https://api.github.com/repos/oneapi-src/level-zero/releases/latest"
          $asset = $release.assets | Where-Object { $_.name -match 'win.*\.zip$' } | Select-Object -First 1
          if ($asset) {
            Invoke-WebRequest -Uri $asset.browser_download_url -OutFile level-zero-win.zip
            Expand-Archive level-zero-win.zip -DestinationPath level-zero-win
            # Copy all DLLs: ze_loader.dll, ze_null.dll, ze_validation_layer.dll, etc.
            $dlls = Get-ChildItem -Recurse -Filter "*.dll" -Path level-zero-win
            if ($dlls) {
              foreach ($dll in $dlls) {
                Copy-Item $dll.FullName "$env:SystemRoot\System32\" -Force
                Write-Host "Installed $($dll.Name) to System32"
              }
            } else {
              Write-Warning "No DLLs found in downloaded archive"
            }
          } else {
            Write-Warning "No Windows zip asset found in level-zero releases, skipping"
          }

      - name: Run examples
        shell: bash
        env:
          # Activate the Level Zero null driver (ze_null) so the loader
          # can enumerate a fake device on runners without real Intel GPU hardware.
          ZE_ENABLE_NULL_DRIVER: "1"
        run: |
          for dir in examples/*/; do
            if [ -f "${dir}/main.go" ]; then
              echo "==> Running ${dir}..."
              go run "./${dir}/main.go" || true
            fi
          done

  go-generate:
    name: Run all Generates & Commit
    runs-on: ubuntu-latest
    needs: [vet_build_test]
    steps:
      - uses: actions/checkout@v4
        with:
          ref: ${{ github.head_ref || github.ref_name }}
          token: ${{ secrets.GITHUB_TOKEN }}

      - uses: actions/setup-go@v5
        with:
          go-version-file: go.mod

      - name: Download SYCL Linux
        run: |
          wget -q -O /tmp/sycl_linux.tar.gz https://github.com/intel/llvm/releases/download/v6.3.0/sycl_linux.tar.gz
          mkdir -p /tmp/sycl_linux
          tar -xzf /tmp/sycl_linux.tar.gz -C /tmp/sycl_linux

      - name: Add SYCL bin to PATH
        run: |
          ls -hl /tmp/sycl_linux
          echo "/tmp/sycl_linux/bin" >> $GITHUB_PATH

      - name: Run go generate
        run: |
          go generate ./...
          gofmt -w .

      - name: Check for changes
        id: diff
        run: |
          if [ -n "$(git diff --name-only)" ]; then
            echo "changed=true" >> "$GITHUB_OUTPUT"
          fi

      - name: Commit and push to PR branch
        if: steps.diff.outputs.changed == 'true' && github.event_name == 'pull_request'
        id: push_to_pr
        continue-on-error: true
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git add -A
          git commit -m "chore: run go generate"
          git push

      - name: Comment on PR if push failed
        if: steps.diff.outputs.changed == 'true' && github.event_name == 'pull_request' && steps.push_to_pr.outcome == 'failure'
        uses: actions/github-script@v7
        with:
          script: |
            github.rest.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: '`go generate` produced file changes but could not be pushed automatically (likely a fork PR). Please run `go generate ./... && gofmt -w .` locally and push the changes.'
            })

      - name: Create Pull Request
        if: steps.diff.outputs.changed == 'true' && github.event_name == 'push'
        uses: peter-evans/create-pull-request@v7
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          commit-message: "chore: run go generate"
          title: "chore: run go generate"
          body: |
            Automated PR created by CI.

            `go generate .` detected generated file differences and applied updates.
          branch: auto/go-generate
          delete-branch: true