import torch
from safetensors.torch import load_file

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

def mux8(d0, d1, d2, d3, d4, d5, d6, d7, s2, s1, s0, weights):
    """8:1 Multiplexer: returns d[s] where s = 4*s2 + 2*s1 + s0"""
    inp = torch.tensor([float(d0), float(d1), float(d2), float(d3),
                        float(d4), float(d5), float(d6), float(d7),
                        float(s2), float(s1), float(s0)])
    l1 = (inp @ weights['layer1.weight'].T + weights['layer1.bias'] >= 0).float()
    out = (l1 @ weights['layer2.weight'].T + weights['layer2.bias'] >= 0).float()
    return int(out.item())

if __name__ == '__main__':
    w = load_model()
    print('MUX8 verification:')
    for s in range(8):
        s2, s1, s0 = (s >> 2) & 1, (s >> 1) & 1, s & 1
        d = [0] * 8
        d[s] = 1
        result = mux8(*d, s2, s1, s0, w)
        print(f'  s={s} ({s2}{s1}{s0}), d[{s}]=1 -> {result}')