#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Python version: 3.6

from torch import nn
import torch.nn.functional as F
import numpy as np
import math
import torch.nn as nn
import torch.nn.init as init


class MLP(nn.Module):
    def __init__(self, dim_in, dim_hidden, dim_out):
        super(MLP, self).__init__()
        self.layer_input = nn.Linear(dim_in, dim_hidden)
        self.relu = nn.ReLU()
        self.dropout = nn.Dropout()
        self.layer_hidden = nn.Linear(dim_hidden, dim_out)
        self.softmax = nn.Softmax(dim=1)
        self.grads = {'layer_input':None,'relu':None,'layer_hidden':None,'softmax':None}

    def forward(self, x):
        x = x.view(-1, x.shape[1]*x.shape[-2]*x.shape[-1])
        x = self.layer_input(x)
        x = self.dropout(x)
        x = self.relu(x)
        x = self.layer_hidden(x)
        return self.softmax(x)
    
    def stash_grads(self):
        self.grads['layer_input'] = np.copy(self.layer_input.weight.grad.numpy())
        self.grads['relu'] = np.copy(self.relu.weight.grad.numpy())
        self.grads['layer_hidden'] = np.copy(self.layer_hidden.weight.grad.numpy())
        self.grads['softmax'] = np.copy(self.softmax.weight.grad.numpy())


class CNNMnist(nn.Module):
    def __init__(self, args):
        super(CNNMnist, self).__init__()
        self.conv1 = nn.Conv2d(args.num_channels, 10, kernel_size=5)
        self.conv2 = nn.Conv2d(10, 20, kernel_size=5)
        self.conv2_drop = nn.Dropout2d()
        self.fc1 = nn.Linear(320, 50)
        self.fc2 = nn.Linear(50, args.num_classes)
        self.grads = {'conv1':None,'conv2':None}

    def forward(self, x):
        x = F.relu(F.max_pool2d(self.conv1(x), 2))
        x = F.relu(F.max_pool2d(self.conv2_drop(self.conv2(x)), 2))
        x = x.view(-1, x.shape[1]*x.shape[2]*x.shape[3])
        x = F.relu(self.fc1(x))
        x = F.dropout(x, training=self.training)
        x = self.fc2(x)
        return F.log_softmax(x, dim=1)
    
    def stash_grads(self):
        self.grads['conv1'] = np.copy(self.conv1.weight.grad.numpy())
        self.grads['conv2'] = np.copy(self.conv1.weight.grad.numpy())


class CNNFashion_Mnist(nn.Module):
    def __init__(self, args):
        super(CNNFashion_Mnist, self).__init__()
        self.layer1 = nn.Sequential(
            nn.Conv2d(1, 16, kernel_size=5, padding=2),
            nn.BatchNorm2d(16),
            nn.ReLU(),
            nn.MaxPool2d(2))
        self.layer2 = nn.Sequential(
            nn.Conv2d(16, 32, kernel_size=5, padding=2),
            nn.BatchNorm2d(32),
            nn.ReLU(),
            nn.MaxPool2d(2))
        self.fc = nn.Linear(7*7*32, 10)
        self.grads = {'conv1':None,'relu1':None,'conv2':None,'relu2':None}

    def forward(self, x):
        out = self.layer1(x)
        out = self.layer2(out)
        out = out.view(out.size(0), -1)
        out = self.fc(out)
        return out
    
    def stash_grads(self):
        self.grads['conv1'] = np.copy(self.conv1.weight.grad.numpy())
        self.grads['relu1'] = np.copy(self.relu1.weight.grad.numpy())
        self.grads['conv2'] = np.copy(self.conv2.weight.grad.numpy())
        self.grads['relu2'] = np.copy(self.relu2.weight.grad.numpy())

class CNNCifar(nn.Module):
    def __init__(self, args):
        super(CNNCifar, self).__init__()
        self.conv1 = nn.Conv2d(3, 6, 5)
        self.pool = nn.MaxPool2d(2, 2)
        self.conv2 = nn.Conv2d(6, 16, 5)
        self.fc1 = nn.Linear(16 * 5 * 5, 120)
        self.fc2 = nn.Linear(120, 84)
        self.fc3 = nn.Linear(84, args.num_classes)
        self.grads = {'conv1':None,'conv2':None}

    def forward(self, x):
        x = self.pool(F.relu(self.conv1(x)))
        x = self.pool(F.relu(self.conv2(x)))
        x = x.view(-1, 16 * 5 * 5)
        x = F.relu(self.fc1(x))
        x = F.relu(self.fc2(x))
        x = self.fc3(x)
        return F.log_softmax(x, dim=1)
    
    def stash_grads(self):
        self.grads['conv1'] = np.copy(self.conv1.weight.grad.numpy())
        self.grads['conv2'] = np.copy(self.conv2.weight.grad.numpy())
        # self.grads['fc1'].append(np.copy(self.fc1.weight.grad.numpy()))
        # self.grads['fc2'].append(np.copy(self.fc2.weight.grad.numpy()))
        # self.grads['fc3'].append(np.copy(self.fc3.weight.grad.numpy()))

class modelC(nn.Module):
    def __init__(self, input_size, n_classes=10, **kwargs):
        super(AllConvNet, self).__init__()
        self.conv1 = nn.Conv2d(input_size, 96, 3, padding=1)
        self.conv2 = nn.Conv2d(96, 96, 3, padding=1)
        self.conv3 = nn.Conv2d(96, 96, 3, padding=1, stride=2)
        self.conv4 = nn.Conv2d(96, 192, 3, padding=1)
        self.conv5 = nn.Conv2d(192, 192, 3, padding=1)
        self.conv6 = nn.Conv2d(192, 192, 3, padding=1, stride=2)
        self.conv7 = nn.Conv2d(192, 192, 3, padding=1)
        self.conv8 = nn.Conv2d(192, 192, 1)

        self.class_conv = nn.Conv2d(192, n_classes, 1)
        self.grads = {'conv1':None,'conv2':None,'conv3':None,'conv4':None,'conv5':None,
                    'conv6':None,'conv7':None,'conv8':None,'class_conv':None}

    def forward(self, x):
        x_drop = F.dropout(x, .2)
        conv1_out = F.relu(self.conv1(x_drop))
        conv2_out = F.relu(self.conv2(conv1_out))
        conv3_out = F.relu(self.conv3(conv2_out))
        conv3_out_drop = F.dropout(conv3_out, .5)
        conv4_out = F.relu(self.conv4(conv3_out_drop))
        conv5_out = F.relu(self.conv5(conv4_out))
        conv6_out = F.relu(self.conv6(conv5_out))
        conv6_out_drop = F.dropout(conv6_out, .5)
        conv7_out = F.relu(self.conv7(conv6_out_drop))
        conv8_out = F.relu(self.conv8(conv7_out))

        class_out = F.relu(self.class_conv(conv8_out))
        pool_out = F.adaptive_avg_pool2d(class_out, 1)
        pool_out.squeeze_(-1)
        pool_out.squeeze_(-1)
        return pool_out

    def stash_grads(self):
        self.grads['conv1'] = np.copy(self.conv1.weight.grad.numpy())
        self.grads['conv2'] = np.copy(self.conv2.weight.grad.numpy())
        self.grads['conv3'] = np.copy(self.conv3.weight.grad.numpy())
        self.grads['conv4'] = np.copy(self.conv4.weight.grad.numpy())
        self.grads['conv5'] = np.copy(self.conv5.weight.grad.numpy())
        self.grads['conv6'] = np.copy(self.conv6.weight.grad.numpy())
        self.grads['conv7'] = np.copy(self.conv7.weight.grad.numpy())
        self.grads['conv8'] = np.copy(self.conv8.weight.grad.numpy())
        self.grads['class_conv'] = np.copy(self.class_conv.weight.grad.numpy())

'''
The code below has been taken from https://github.com/chengyangfu/pytorch-vgg-cifar10/blob/master/vgg.py
Originally "Modified from https://github.com/pytorch/vision.git"
In this project it is modified to include the "grads" dictionary and "stash_grads" method.
'''

__all__ = [
    'VGG', 'vgg11', 'vgg11_bn', 'vgg13', 'vgg13_bn', 'vgg16', 'vgg16_bn',
    'vgg19_bn', 'vgg19',
]


class VGG(nn.Module):
    '''
    VGG model 
    '''
    def __init__(self, features):
        super(VGG, self).__init__()
        self.features = features
        self.classifier = nn.Sequential(
            nn.Dropout(),
            nn.Linear(512, 512),
            nn.ReLU(True),
            nn.Dropout(),
            nn.Linear(512, 512),
            nn.ReLU(True),
            nn.Linear(512, 10),
        )
        self.grads = {}
         # Initialize weights
        counter = 1
        for m in self.modules():
            if isinstance(m, nn.Conv2d):
                n = m.kernel_size[0] * m.kernel_size[1] * m.out_channels
                m.weight.data.normal_(0, math.sqrt(2. / n))
                m.bias.data.zero_()
                self.grads['conv' + str(counter)] = None
                counter += 1


    def forward(self, x):
        x = self.features(x)
        x = x.view(x.size(0), -1)
        x = self.classifier(x)
        return x
    
    def stash_grads(self):
        counter = 1
        for m in self.modules():
            self.grads['conv' + str(counter)] = np.copy(m.weight.grad.numpy())
            counter += 1

def make_layers(cfg, batch_norm=False):
    layers = []
    in_channels = 3
    for v in cfg:
        if v == 'M':
            layers += [nn.MaxPool2d(kernel_size=2, stride=2)]
        else:
            conv2d = nn.Conv2d(in_channels, v, kernel_size=3, padding=1)
            if batch_norm:
                layers += [conv2d, nn.BatchNorm2d(v), nn.ReLU(inplace=True)]
            else:
                layers += [conv2d, nn.ReLU(inplace=True)]
            in_channels = v
    return nn.Sequential(*layers)


cfg = {
    'A': [64, 'M', 128, 'M', 256, 256, 'M', 512, 512, 'M', 512, 512, 'M'],
    'B': [64, 64, 'M', 128, 128, 'M', 256, 256, 'M', 512, 512, 'M', 512, 512, 'M'],
    'D': [64, 64, 'M', 128, 128, 'M', 256, 256, 256, 'M', 512, 512, 512, 'M', 512, 512, 512, 'M'],
    'E': [64, 64, 'M', 128, 128, 'M', 256, 256, 256, 256, 'M', 512, 512, 512, 512, 'M', 
          512, 512, 512, 512, 'M'],
}


def vgg11():
    """VGG 11-layer model (configuration "A")"""
    return VGG(make_layers(cfg['A']))


def vgg11_bn():
    """VGG 11-layer model (configuration "A") with batch normalization"""
    return VGG(make_layers(cfg['A'], batch_norm=True))


def vgg13():
    """VGG 13-layer model (configuration "B")"""
    return VGG(make_layers(cfg['B']))


def vgg13_bn():
    """VGG 13-layer model (configuration "B") with batch normalization"""
    return VGG(make_layers(cfg['B'], batch_norm=True))


def vgg16():
    """VGG 16-layer model (configuration "D")"""
    return VGG(make_layers(cfg['D']))


def vgg16_bn():
    """VGG 16-layer model (configuration "D") with batch normalization"""
    return VGG(make_layers(cfg['D'], batch_norm=True))


def vgg19():
    """VGG 19-layer model (configuration "E")"""
    return VGG(make_layers(cfg['E']))


def vgg19_bn():
    """VGG 19-layer model (configuration 'E') with batch normalization"""
    return VGG(make_layers(cfg['E'], batch_norm=True))