import torch.nn as nn

# generator
class NetG(nn.Module):
    def __init__(self, ngf, nz):
        super(NetG, self).__init__()
        # layer1: random noise [z, 1, 1] => [ngf*8, 4, 4]
        self.layer1 = nn.Sequential(
            nn.ConvTranspose2d(nz, ngf * 8, kernel_size=4, stride=1, padding=0, bias=False),
            nn.BatchNorm2d(ngf * 8),
            nn.ReLU(inplace=True)
        )
        # layer2: [ngf*8, 4, 4] => [ngf*8, 4, 4]
        self.layer2 = nn.Sequential(
            nn.ConvTranspose2d(ngf * 8, ngf * 4, 4, 2, 1, bias=False),
            nn.BatchNorm2d(ngf * 4),
            nn.ReLU(inplace=True)
        )
        # layer3: [ngf*8, 4, 4] => [ngf*2, 16, 16]
        self.layer3 = nn.Sequential(
            nn.ConvTranspose2d(ngf * 4, ngf * 2, 4, 2, 1, bias=False),
            nn.BatchNorm2d(ngf * 2),
            nn.ReLU(inplace=True)
        )
        # layer4: [ngf*2, 16, 16] => [ngf, 32, 32]
        self.layer4 = nn.Sequential(
            nn.ConvTranspose2d(ngf * 2, ngf, 4, 2, 1, bias=False),
            nn.BatchNorm2d(ngf),
            nn.ReLU(inplace=True)
        )
        # layer5: [ngf, 32, 32] => [3, 96, 96]
        self.layer5 = nn.Sequential(
            nn.ConvTranspose2d(ngf, 3, 5, 3, 1, bias=False),
            nn.Tanh()
        )

    # forward
    def forward(self, x):
        out = self.layer1(x)
        out = self.layer2(out)
        out = self.layer3(out)
        out = self.layer4(out)
        out = self.layer5(out)
        return out


# discriminator
class NetD(nn.Module):
    def __init__(self, ndf):
        super(NetD, self).__init__()
        # layer1: [3, 96, 96] => [ndf, 32, 32]
        self.layer1 = nn.Sequential(
            nn.Conv2d(3, ndf, kernel_size=5, stride=3, padding=1, bias=False),
            nn.BatchNorm2d(ndf),
            nn.LeakyReLU(0.2, inplace=True)
        )
        # layer2: [ndf, 32, 32] => [ndf*2, 16, 16]
        self.layer2 = nn.Sequential(
            nn.Conv2d(ndf, ndf * 2, 4, 2, 1, bias=False),
            nn.BatchNorm2d(ndf * 2),
            nn.LeakyReLU(0.2, inplace=True)
        )
        # layer3: [ndf*2, 16, 16] => [ndf*4, 8, 8]
        self.layer3 = nn.Sequential(
            nn.Conv2d(ndf * 2, ndf * 4, 4, 2, 1, bias=False),
            nn.BatchNorm2d(ndf * 4),
            nn.LeakyReLU(0.2, inplace=True)
        )
        # layer4: [ndf*4, 8, 8] => [ndf*8, 4, 4]
        self.layer4 = nn.Sequential(
            nn.Conv2d(ndf * 4, ndf * 8, 4, 2, 1, bias=False),
            nn.BatchNorm2d(ndf * 8),
            nn.LeakyReLU(0.2, inplace=True)
        )
        # layer5: [ndf*8, 4, 4] => probability
        self.layer5 = nn.Sequential(
            nn.Conv2d(ndf * 8, 1, 4, 1, 0, bias=False),
            nn.Sigmoid()
        )

    # forward
    def forward(self,x):
        out = self.layer1(x)
        out = self.layer2(out)
        out = self.layer3(out)
        out = self.layer4(out)
        out = self.layer5(out)
        return out
