name: Build CUDA Backend

on:
  workflow_dispatch:
  push:
    tags:
      - "v*"

jobs:
  build-cuda-windows:
    runs-on: windows-latest
    permissions:
      contents: write

    steps:
      - uses: actions/checkout@v4

      - name: Setup Python
        uses: actions/setup-python@v5
        with:
          python-version: "3.12"
          cache: "pip"

      - name: Install Python dependencies
        run: |
          python -m pip install --upgrade pip
          pip install pyinstaller
          pip install -r backend/requirements.txt

      - name: Install PyTorch with CUDA 12.1
        run: |
          pip install torch --index-url https://download.pytorch.org/whl/cu121 --force-reinstall --no-deps
          pip install torchaudio --index-url https://download.pytorch.org/whl/cu121

      - name: Verify CUDA support in torch
        run: |
          python -c "import torch; print(f'CUDA available in build: {torch.cuda.is_available()}'); print(f'CUDA version: {torch.version.cuda}')"

      - name: Build CUDA server binary
        shell: bash
        working-directory: backend
        run: python build_binary.py --cuda

      - name: Split binary for GitHub Releases
        shell: bash
        run: |
          python scripts/split_binary.py \
            backend/dist/voicebox-server-cuda.exe \
            --output release-assets/

      - name: Upload split parts to GitHub Release
        if: startsWith(github.ref, 'refs/tags/')
        uses: softprops/action-gh-release@v1
        with:
          files: |
            release-assets/voicebox-server-cuda.part*.exe
            release-assets/voicebox-server-cuda.sha256
            release-assets/voicebox-server-cuda.manifest
          draft: true
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Upload binary as workflow artifact (for testing)
        uses: actions/upload-artifact@v4
        with:
          name: voicebox-server-cuda-windows
          path: backend/dist/voicebox-server-cuda.exe
          retention-days: 7

  # Linux CUDA build can be added later with:
  # build-cuda-linux:
  #   runs-on: ubuntu-22.04
  #   ...