"""
This code is modified version of MesoNet DeepFake detection solution
from FakeAVCeleb repository - https://github.com/DASH-Lab/FakeAVCeleb/blob/main/models/MesoNet.py.
"""
import torch
import torch.nn as nn

class Meso4(nn.Module):

    def __init__(self, num_classes=1, **kwargs):
        super().__init__()

        fc1_dim = kwargs.get("fc1_dim", 16*7*7)
        input_channels = kwargs.get("input_channels", 3)
        self.num_classes = num_classes

        self.conv1 = nn.Conv2d(input_channels, 8, 3, padding=1, bias=False)
        self.bn1 = nn.BatchNorm2d(8)
        self.relu = nn.ReLU(inplace=True)
        self.leakyrelu = nn.LeakyReLU(0.1)
        self.conv2 = nn.Conv2d(8, 8, 5, padding=2, bias=False)
        self.bn2 = nn.BatchNorm2d(16)
        self.conv3 = nn.Conv2d(8, 16, 5, padding=2, bias=False)
        self.conv4 = nn.Conv2d(16, 16, 5, padding=2, bias=False)
        self.maxpooling1 = nn.MaxPool2d(kernel_size=(2, 2))
        self.maxpooling2 = nn.MaxPool2d(kernel_size=(4, 4))
        #flatten: x = x.view(x.size(0), -1)
        self.dropout = nn.Dropout2d(0.5)
        self.fc1 = nn.Linear(fc1_dim, 16)
        self.fc2 = nn.Linear(16, num_classes)

    def forward(self, input):
        x = self.conv1(input) #(8, 256, 256)
        x = self.relu(x)
        x = self.bn1(x)

        x = self.maxpooling1(x) #(8, 128, 128)
        x = self.conv2(x) #(8, 128, 128)
        x = self.relu(x)
        x = self.bn1(x)
        x = self.maxpooling1(x) #(8, 64, 64)

        x = self.conv3(x) #(16, 64, 64)
        x = self.relu(x)
        x = self.bn2(x)
        x = self.maxpooling1(x) #(16, 32, 32)

        x = self.conv4(x) #(16, 32, 32)
        x = self.relu(x)
        x = self.bn2(x)
        x = self.maxpooling2(x) #(16, 8, 8)

        x = x.view(x.size(0), -1) #(Batch, 16*8*8)
        # x = self.fla(x)
        x = self.fc1(x) #(Batch, 16)
        x = self.leakyrelu(x)
        x = self.dropout(x)
        x = self.fc2(x)
        return x


class MesoInception4(nn.Module):
    """
    Pytorch Implemention of MesoInception4
    Author: Honggu Liu
    Date: July 7, 2019
    """
    def __init__(self, num_classes=1, **kwargs):
        super().__init__()

        fc1_dim = kwargs.get("fc1_dim", 16*7*7)
        input_channels = kwargs.get("input_channels", 3)
        self.num_classes = num_classes

        #InceptionLayer1
        self.Incption1_conv1 = nn.Conv2d(input_channels, 1, 1, padding=0, bias=False)
        self.Incption1_conv2_1 = nn.Conv2d(input_channels, 4, 1, padding=0, bias=False)
        self.Incption1_conv2_2 = nn.Conv2d(4, 4, 3, padding=1, bias=False)
        self.Incption1_conv3_1 = nn.Conv2d(input_channels, 4, 1, padding=0, bias=False)
        self.Incption1_conv3_2 = nn.Conv2d(4, 4, 3, padding=2, dilation=2, bias=False)
        self.Incption1_conv4_1 = nn.Conv2d(input_channels, 2, 1, padding=0, bias=False)
        self.Incption1_conv4_2 = nn.Conv2d(2, 2, 3, padding=3, dilation=3, bias=False)
        self.Incption1_bn = nn.BatchNorm2d(11)


        #InceptionLayer2
        self.Incption2_conv1 = nn.Conv2d(11, 2, 1, padding=0, bias=False)
        self.Incption2_conv2_1 = nn.Conv2d(11, 4, 1, padding=0, bias=False)
        self.Incption2_conv2_2 = nn.Conv2d(4, 4, 3, padding=1, bias=False)
        self.Incption2_conv3_1 = nn.Conv2d(11, 4, 1, padding=0, bias=False)
        self.Incption2_conv3_2 = nn.Conv2d(4, 4, 3, padding=2, dilation=2, bias=False)
        self.Incption2_conv4_1 = nn.Conv2d(11, 2, 1, padding=0, bias=False)
        self.Incption2_conv4_2 = nn.Conv2d(2, 2, 3, padding=3, dilation=3, bias=False)
        self.Incption2_bn = nn.BatchNorm2d(12)

        #Normal Layer
        self.conv1 = nn.Conv2d(12, 16, 5, padding=2, bias=False)
        self.relu = nn.ReLU(inplace=True)
        self.leakyrelu = nn.LeakyReLU(0.1)
        self.bn1 = nn.BatchNorm2d(16)
        self.maxpooling1 = nn.MaxPool2d(kernel_size=(2, 2))

        self.conv2 = nn.Conv2d(16, 16, 5, padding=2, bias=False)
        self.maxpooling2 = nn.MaxPool2d(kernel_size=(4, 4))

        self.dropout = nn.Dropout2d(0.5)
        self.fc1 = nn.Linear(fc1_dim, 16)
        self.fc2 = nn.Linear(16, num_classes)


    #InceptionLayer
    def InceptionLayer1(self, input):
        x1 = self.Incption1_conv1(input)
        x2 = self.Incption1_conv2_1(input)
        x2 = self.Incption1_conv2_2(x2)
        x3 = self.Incption1_conv3_1(input)
        x3 = self.Incption1_conv3_2(x3)
        x4 = self.Incption1_conv4_1(input)
        x4 = self.Incption1_conv4_2(x4)
        y = torch.cat((x1, x2, x3, x4), 1)
        y = self.Incption1_bn(y)
        y = self.maxpooling1(y)

        return y

    def InceptionLayer2(self, input):
        x1 = self.Incption2_conv1(input)
        x2 = self.Incption2_conv2_1(input)
        x2 = self.Incption2_conv2_2(x2)
        x3 = self.Incption2_conv3_1(input)
        x3 = self.Incption2_conv3_2(x3)
        x4 = self.Incption2_conv4_1(input)
        x4 = self.Incption2_conv4_2(x4)
        y = torch.cat((x1, x2, x3, x4), 1)
        y = self.Incption2_bn(y)
        y = self.maxpooling1(y)

        return y

    def forward(self, input):
        x = self.InceptionLayer1(input) #(Batch, 11, 128, 128)
        x = self.InceptionLayer2(x) #(Batch, 12, 64, 64)

        x = self.conv1(x) #(Batch, 16, 64 ,64)
        x = self.relu(x)
        x = self.bn1(x)
        x = self.maxpooling1(x) #(Batch, 16, 32, 32)

        x = self.conv2(x) #(Batch, 16, 32, 32)
        x = self.relu(x)
        x = self.bn1(x)
        x = self.maxpooling2(x) #(Batch, 16, 8, 8)

        x = x.view(x.size(0), -1) #(Batch, 16*8*8)
        x = self.dropout(x)
        x = self.fc1(x) #(Batch, 16)
        x = self.leakyrelu(x)
        x = self.dropout(x)
        x = self.fc2(x)

        return x



if __name__ == "__main__":
    model = MesoInception4(fc1_dim=384, input_channels=4)
    x = torch.rand((12,4,80,404))
    output = model(x)
    print(output)

