### dropout has been removed in this code. original code had dropout#####
import torch
import torch.nn as nn
import torch.nn.init as init
import torch.nn.functional as F
from torch.autograd import Variable

import sys, os
import numpy as np
import random

sys.path.append(os.path.dirname(os.path.abspath(__file__)))

act = torch.nn.ReLU()


def conv3x3(in_planes, out_planes, stride=1):
    return nn.Conv2d(in_planes, out_planes, kernel_size=3, stride=stride, padding=1, bias=True)


def conv_init(m):
    classname = m.__class__.__name__
    if classname.find('Conv') != -1:
        init.xavier_uniform(m.weight, gain=np.sqrt(2))
        init.constant(m.bias, 0)
    elif classname.find('BatchNorm') != -1:
        init.constant(m.weight, 1)
        init.constant(m.bias, 0)


class wide_basic(nn.Module):
    def __init__(self, in_planes, planes, stride=1):
        super(wide_basic, self).__init__()
        self.bn1 = nn.BatchNorm2d(in_planes)
        self.conv1 = nn.Conv2d(in_planes, planes, kernel_size=3, padding=1, bias=True)
        self.bn2 = nn.BatchNorm2d(planes)
        self.conv2 = nn.Conv2d(planes, planes, kernel_size=3, stride=stride, padding=1, bias=True)

        self.shortcut = nn.Sequential()
        if stride != 1 or in_planes != planes:
            self.shortcut = nn.Sequential(
                nn.Conv2d(in_planes, planes, kernel_size=1, stride=stride, bias=True),
            )

    def forward(self, x):
        out = self.conv1(act(self.bn1(x)))
        out = self.conv2(act(self.bn2(out)))
        out += self.shortcut(x)

        return out


class Wide_ResNet(nn.Module):
    def __init__(self, depth, widen_factor, num_classes, stride=1):
        super(Wide_ResNet, self).__init__()
        self.num_classes = num_classes
        self.in_planes = 16

        assert ((depth - 4) % 6 == 0), 'Wide-resnet_v2 depth should be 6n+4'
        n = int((depth - 4) / 6)
        k = widen_factor

        print('| Wide-Resnet %dx%d' % (depth, k))
        nStages = [16, 16 * k, 32 * k, 64 * k]

        self.conv1 = conv3x3(3, nStages[0], stride=stride)
        self.layer1 = self._wide_layer(wide_basic, nStages[1], n, stride=1)
        self.layer2 = self._wide_layer(wide_basic, nStages[2], n, stride=2)
        self.layer3 = self._wide_layer(wide_basic, nStages[3], n, stride=2)
        self.bn1 = nn.BatchNorm2d(nStages[3], momentum=0.9)
        self.linear = nn.Linear(nStages[3], num_classes)

    def _wide_layer(self, block, planes, num_blocks, stride):
        strides = [stride] + [1] * (num_blocks - 1)
        layers = []

        for stride in strides:
            layers.append(block(self.in_planes, planes, stride))
            self.in_planes = planes

        return nn.Sequential(*layers)

    def forward(self, x):

        out = x



        out = self.conv1(out)
        out = self.layer1(out)


        out = self.layer2(out)


        out = self.layer3(out)



        out = act(self.bn1(out))
        out = F.avg_pool2d(out, 8)
        out = out.reshape(out.size(0), -1)
        out = self.linear(out)


        return out


def wrn28_10(num_classes=10, dropout=False, stride=1):
    # print ('this')
    model = Wide_ResNet(depth=28, widen_factor=10, num_classes=num_classes, stride=stride)
    return model


def wrn28_2(num_classes=10, dropout=False, stride=1):
    # print ('this')
    model = Wide_ResNet(depth=28, widen_factor=2, num_classes=num_classes, stride=stride)
    return model


if __name__ == '__main__':
    net = Wide_ResNet(28, 10, 0.3, 10)
    y = net(Variable(torch.randn(1, 3, 32, 32)))

    print(y.size())
