# `SnakeBridge.WheelSelector`
[🔗](https://github.com/nshkrdotcom/snakebridge/blob/v0.14.0/lib/snakebridge/wheel_selector.ex#L1)

Selects the appropriate wheel variant for Python packages based on hardware.

PyTorch and related packages (torchvision, torchaudio) have different wheel
variants for different hardware configurations:

- `cpu` - CPU-only build
- `cu118` - CUDA 11.8
- `cu121` - CUDA 12.1
- `cu124` - CUDA 12.4
- `rocm5.7` - AMD ROCm 5.7

This module detects the current hardware and selects the appropriate variant.

## Examples

    # Get the PyTorch variant for current hardware
    variant = SnakeBridge.WheelSelector.pytorch_variant()
    #=> "cu121" or "cpu"

    # Get the index URL for pip
    url = SnakeBridge.WheelSelector.pytorch_index_url()
    #=> "https://download.pytorch.org/whl/cu121"

    # Generate pip install command
    cmd = SnakeBridge.WheelSelector.pip_install_command("torch", "2.1.0")
    #=> "pip install torch==2.1.0 --index-url https://download.pytorch.org/whl/cu121"

# `wheel_info`
[🔗](https://github.com/nshkrdotcom/snakebridge/blob/v0.14.0/lib/snakebridge/wheel_selector.ex#L32)

```elixir
@type wheel_info() :: %{
  package: String.t(),
  version: String.t(),
  variant: String.t() | nil,
  index_url: String.t() | nil
}
```

# `available_variants`
[🔗](https://github.com/nshkrdotcom/snakebridge/blob/v0.14.0/lib/snakebridge/wheel_selector.ex#L151)

```elixir
@spec available_variants() :: [String.t()]
```

Returns all available PyTorch variants for the given CUDA versions.

Useful for generating lock files that support multiple hardware configurations.

# `available_variants`
[🔗](https://github.com/nshkrdotcom/snakebridge/blob/v0.14.0/lib/snakebridge/wheel_selector.ex#L156)

```elixir
@spec available_variants(String.t()) :: [String.t()]
```

# `best_cuda_variant`
[🔗](https://github.com/nshkrdotcom/snakebridge/blob/v0.14.0/lib/snakebridge/wheel_selector.ex#L176)

```elixir
@spec best_cuda_variant(String.t() | nil) :: String.t()
```

Returns the best matching CUDA variant for a given CUDA version.

Falls back to the closest available version.

## Examples

    SnakeBridge.WheelSelector.best_cuda_variant("12.3")
    #=> "cu124"

    SnakeBridge.WheelSelector.best_cuda_variant("12.1")
    #=> "cu121"

# `normalize_cuda_version`
[🔗](https://github.com/nshkrdotcom/snakebridge/blob/v0.14.0/lib/snakebridge/wheel_selector.ex#L109)

```elixir
@spec normalize_cuda_version(String.t() | nil) :: String.t() | nil
```

Normalizes a CUDA version string for wheel naming.

## Examples

    SnakeBridge.WheelSelector.normalize_cuda_version("12.1")
    #=> "121"

    SnakeBridge.WheelSelector.normalize_cuda_version("11.8")
    #=> "118"

# `pip_install_command`
[🔗](https://github.com/nshkrdotcom/snakebridge/blob/v0.14.0/lib/snakebridge/wheel_selector.ex#L85)

```elixir
@spec pip_install_command(String.t(), String.t()) :: String.t()
```

Generates a pip install command for a package.

For PyTorch packages (torch, torchvision, torchaudio), includes the
appropriate --index-url for hardware-specific wheels.

## Examples

    SnakeBridge.WheelSelector.pip_install_command("torch", "2.1.0")
    #=> "pip install torch==2.1.0 --index-url https://download.pytorch.org/whl/cu121"

    SnakeBridge.WheelSelector.pip_install_command("numpy", "1.26.4")
    #=> "pip install numpy==1.26.4"

# `pytorch_index_url`
[🔗](https://github.com/nshkrdotcom/snakebridge/blob/v0.14.0/lib/snakebridge/wheel_selector.ex#L65)

```elixir
@spec pytorch_index_url() :: String.t()
```

Returns the PyTorch index URL for pip based on current hardware.

## Examples

    SnakeBridge.WheelSelector.pytorch_index_url()
    #=> "https://download.pytorch.org/whl/cu121"

# `pytorch_package?`
[🔗](https://github.com/nshkrdotcom/snakebridge/blob/v0.14.0/lib/snakebridge/wheel_selector.ex#L141)

```elixir
@spec pytorch_package?(String.t()) :: boolean()
```

Checks if a package is a PyTorch package that needs hardware-specific wheels.

# `pytorch_variant`
[🔗](https://github.com/nshkrdotcom/snakebridge/blob/v0.14.0/lib/snakebridge/wheel_selector.ex#L50)

```elixir
@spec pytorch_variant() :: String.t()
```

Returns the PyTorch wheel variant for the current hardware.

## Examples

    SnakeBridge.WheelSelector.pytorch_variant()
    #=> "cu121"  # On CUDA 12.1 system
    #=> "cpu"    # On CPU-only system

# `select_wheel`
[🔗](https://github.com/nshkrdotcom/snakebridge/blob/v0.14.0/lib/snakebridge/wheel_selector.ex#L133)

```elixir
@spec select_wheel(String.t(), String.t()) :: wheel_info()
```

Selects the appropriate wheel for a package based on current hardware.

Returns wheel info including variant and index URL if applicable.

## Examples

    SnakeBridge.WheelSelector.select_wheel("torch", "2.1.0")
    #=> %{package: "torch", version: "2.1.0", variant: "cu121", index_url: "..."}

    SnakeBridge.WheelSelector.select_wheel("numpy", "1.26.4")
    #=> %{package: "numpy", version: "1.26.4", variant: nil, index_url: nil}

---

*Consult [api-reference.md](api-reference.md) for complete listing*