import torch
from safetensors.torch import load_file

def load_model(path='model.safetensors'):
    return load_file(path)

def decode_4to16(a3, a2, a1, a0, weights):
    """4-to-16 decoder: converts 4-bit binary to one-hot 16-bit output."""
    inp = torch.tensor([float(a3), float(a2), float(a1), float(a0)])
    outputs = []
    for i in range(16):
        y = int((inp * weights[f'y{i}.weight']).sum() + weights[f'y{i}.bias'] >= 0)
        outputs.append(y)
    return outputs

if __name__ == '__main__':
    w = load_model()
    print('4-to-16 Decoder')
    for val in range(16):
        a3, a2, a1, a0 = (val >> 3) & 1, (val >> 2) & 1, (val >> 1) & 1, val & 1
        outputs = decode_4to16(a3, a2, a1, a0, w)
        print(f"  {val:2d} ({a3}{a2}{a1}{a0}) -> {''.join(map(str, outputs))}")