import math
import random
import functools
import operator

import torch
import torchvision
from torch import nn
from torch.nn import functional as F
from torch.autograd import Function

from .op import FusedLeakyReLU, fused_leaky_relu, upfirdn2d


class PixelNorm(nn.Module):
    def __init__(self):
        super().__init__()

    def forward(self, input):
        return input * torch.rsqrt(torch.mean(input ** 2, dim=1, keepdim=True) + 1e-8)

class To4d(nn.Module):
    def __init__(self):
        super().__init__()

    def forward(self, input):
        return input.view(*input.size(),1,1)

def make_kernel(k):
    k = torch.tensor(k, dtype=torch.float32)

    if k.ndim == 1:
        k = k[None, :] * k[:, None]

    k /= k.sum()

    return k


class Upsample(nn.Module):
    def __init__(self, kernel, factor=2):
        super().__init__()

        self.factor = factor
        kernel = make_kernel(kernel) * (factor ** 2)
        self.register_buffer('kernel', kernel)

        p = kernel.shape[0] - factor

        pad0 = (p + 1) // 2 + factor - 1
        pad1 = p // 2

        self.pad = (pad0, pad1)

    def forward(self, input):
        out = upfirdn2d(input, self.kernel, up=self.factor, down=1, pad=self.pad)

        return out


class Downsample(nn.Module):
    def __init__(self, kernel, factor=2):
        super().__init__()

        self.factor = factor
        kernel = make_kernel(kernel)
        self.register_buffer('kernel', kernel)

        p = kernel.shape[0] - factor

        pad0 = (p + 1) // 2
        pad1 = p // 2

        self.pad = (pad0, pad1)

    def forward(self, input):
        out = upfirdn2d(input, self.kernel, up=1, down=self.factor, pad=self.pad)

        return out


class Blur(nn.Module):
    def __init__(self, kernel, pad, upsample_factor=1):
        super().__init__()

        kernel = make_kernel(kernel)

        if upsample_factor > 1:
            kernel = kernel * (upsample_factor ** 2)

        self.register_buffer('kernel', kernel)

        self.pad = pad

    def forward(self, input):
        out = upfirdn2d(input, self.kernel, pad=self.pad)

        return out


class EqualConv2d(nn.Module):
    def __init__(
        self, in_channel, out_channel, kernel_size, groups=1, stride=1, padding=0, bias=True, lr_mul=1
    ):
        super().__init__()

        self.weight = nn.Parameter(
            torch.randn(out_channel, in_channel//groups, kernel_size, kernel_size).div_(lr_mul)
        )
        self.scale = lr_mul / math.sqrt((in_channel//groups) * kernel_size ** 2)

        self.stride = stride
        self.padding = padding
        self.groups = groups
        self.lr_mul =lr_mul

        if bias:
            self.bias = nn.Parameter(torch.zeros(out_channel))

        else:
            self.bias = None

    def forward(self, input):
        bias = self.bias * self.lr_mul if self.bias is not None else None
        out = F.conv2d(
            input,
            self.weight * self.scale,
            bias=self.bias,
            stride=self.stride,
            padding=self.padding,
            groups=self.groups
        )

        return out

    def __repr__(self):
        return (
            f'{self.__class__.__name__}({self.weight.shape[1]}, {self.weight.shape[0]},'
            f' {self.weight.shape[2]}, stride={self.stride}, padding={self.padding})'
        )


class EqualLinear(nn.Module):
    def __init__(
        self, in_dim, out_dim, bias=True, bias_init=0, lr_mul=1, activation=None
    ):
        super().__init__()

        self.weight = nn.Parameter(torch.randn(out_dim, in_dim).div_(lr_mul))

        if bias:
            self.bias = nn.Parameter(torch.zeros(out_dim).fill_(bias_init))

        else:
            self.bias = None

        self.activation = activation

        self.scale = (1 / math.sqrt(in_dim)) * lr_mul
        self.lr_mul = lr_mul

    def forward(self, input):
        weight = self.weight * self.scale
        bias = self.bias * self.lr_mul
        if self.activation:
            out = F.linear(input, weight)
            out = fused_leaky_relu(out, bias)

        else:
            out = F.linear(
                input, weight, bias=bias
            )

        return out

    def __repr__(self):
        return (
            f'{self.__class__.__name__}({self.weight.shape[1]}, {self.weight.shape[0]})'
        )


class ScaledLeakyReLU(nn.Module):
    def __init__(self, negative_slope=0.2):
        super().__init__()

        self.negative_slope = negative_slope

    def forward(self, input):
        out = F.leaky_relu(input, negative_slope=self.negative_slope)

        return out * math.sqrt(2)


class ModulatedConv2d(nn.Module):
    def __init__(
        self,
        in_channel,
        out_channel,
        kernel_size,
        style_dim,
        demodulate=True,
        upsample=False,
        downsample=False,
        blur_kernel=[1, 3, 3, 1],
    ):
        super().__init__()

        self.eps = 1e-8
        self.kernel_size = kernel_size
        self.in_channel = in_channel
        self.out_channel = out_channel
        self.upsample = upsample
        self.downsample = downsample

        if upsample:
            factor = 2
            p = (len(blur_kernel) - factor) - (kernel_size - 1)
            pad0 = (p + 1) // 2 + factor - 1
            pad1 = p // 2 + 1

            self.blur = Blur(blur_kernel, pad=(pad0, pad1), upsample_factor=factor)

        if downsample:
            factor = 2
            p = (len(blur_kernel) - factor) + (kernel_size - 1)
            pad0 = (p + 1) // 2
            pad1 = p // 2

            self.blur = Blur(blur_kernel, pad=(pad0, pad1))

        fan_in = in_channel * kernel_size ** 2
        self.scale = 1 / math.sqrt(fan_in)
        self.padding = kernel_size // 2

        self.weight = nn.Parameter(
            torch.randn(1, out_channel, in_channel, kernel_size, kernel_size)
        )

        self.modulation = EqualLinear(style_dim, in_channel, bias_init=1)

        self.demodulate = demodulate

    def __repr__(self):
        return (
            f'{self.__class__.__name__}({self.in_channel}, {self.out_channel}, {self.kernel_size}, '
            f'upsample={self.upsample}, downsample={self.downsample})'
        )
    def get_latent(self, style):
        style = self.modulation(style)
        return style

    def forward(self, input, style, weights_delta=None):
        batch, in_channel, height, width = input.shape

        # style = self.modulation(style).view(batch, 1, in_channel, 1, 1)
        style = style.view(batch, 1, in_channel, 1, 1)
        

        if weights_delta is None:
            weight = self.scale * self.weight * style
        else:
            weight = self.scale * (self.weight * (1 + weights_delta) * style)


        if self.demodulate:
            demod = torch.rsqrt(weight.pow(2).sum([2, 3, 4]) + 1e-8)
            weight = weight * demod.view(batch, self.out_channel, 1, 1, 1)

        weight = weight.view(
            batch * self.out_channel, in_channel, self.kernel_size, self.kernel_size
        )

        if self.upsample:
            input = input.view(1, batch * in_channel, height, width)
            weight = weight.view(
                batch, self.out_channel, in_channel, self.kernel_size, self.kernel_size
            )
            weight = weight.transpose(1, 2).reshape(
                batch * in_channel, self.out_channel, self.kernel_size, self.kernel_size
            )
            out = F.conv_transpose2d(input, weight, padding=0, stride=2, groups=batch)
            _, _, height, width = out.shape
            out = out.view(batch, self.out_channel, height, width)
            out = self.blur(out)

        elif self.downsample:
            input = self.blur(input)
            _, _, height, width = input.shape
            input = input.view(1, batch * in_channel, height, width)
            out = F.conv2d(input, weight, padding=0, stride=2, groups=batch)
            _, _, height, width = out.shape
            out = out.view(batch, self.out_channel, height, width)

        else:
            input = input.view(1, batch * in_channel, height, width)
            out = F.conv2d(input, weight, padding=self.padding, groups=batch)
            _, _, height, width = out.shape
            out = out.view(batch, self.out_channel, height, width)

        return out


class NoiseInjection(nn.Module):
    def __init__(self):
        super().__init__()

        self.weight = nn.Parameter(torch.zeros(1))

    def forward(self, image, noise=None):
        if noise is None:
            batch, _, height, width = image.shape
            noise = image.new_empty(batch, 1, height, width).normal_()

        return image + self.weight * noise


class ConstantInput(nn.Module):
    def __init__(self, channel, size=4):
        super().__init__()

        self.input = nn.Parameter(torch.randn(1, channel, size, size))

    def forward(self, input):
        batch = input.shape[0]
        out = self.input.repeat(batch, 1, 1, 1)

        return out


class StyledConv(nn.Module):
    def __init__(
        self,
        in_channel,
        out_channel,
        kernel_size,
        style_dim,
        upsample=False,
        blur_kernel=[1, 3, 3, 1],
        demodulate=True,
    ):
        super().__init__()

        self.conv = ModulatedConv2d(
            in_channel,
            out_channel,
            kernel_size,
            style_dim,
            upsample=upsample,
            blur_kernel=blur_kernel,
            demodulate=demodulate,
        )

        self.noise = NoiseInjection()
        # self.bias = nn.Parameter(torch.zeros(1, out_channel, 1, 1))
        # self.activate = ScaledLeakyReLU(0.2)
        self.activate = FusedLeakyReLU(out_channel)

    def get_latent(self, style):
        return self.conv.get_latent(style)
    def forward(self, input, style, noise=None, weights_delta=None):
        out_t = self.conv(input, style, weights_delta=weights_delta)
        out = self.noise(out_t, noise=noise)
        # out = out + self.bias
        out = self.activate(out)

        return out, out_t


class ToRGB(nn.Module):
    def __init__(self, in_channel, style_dim, upsample=True, blur_kernel=[1, 3, 3, 1]):
        super().__init__()

        if upsample:
            self.upsample = Upsample(blur_kernel)

        self.conv = ModulatedConv2d(in_channel, 3, 1, style_dim, demodulate=False)
        self.bias = nn.Parameter(torch.zeros(1, 3, 1, 1))

    def get_latent(self, style):
        return self.conv.get_latent(style)
    def forward(self, input, style, skip=None, weights_delta=None):
        out = self.conv(input, style, weights_delta)
        out = out + self.bias

        if skip is not None:
            skip = self.upsample(skip)

            out = out + skip

        return out


class Generator(nn.Module):
    def __init__(
        self,
        size,
        style_dim,
        n_mlp,
        channel_multiplier=2,
        blur_kernel=[1, 3, 3, 1],
        lr_mlp=0.01,
    ):
        super().__init__()

        self.size = size

        self.style_dim = style_dim

        layers = [PixelNorm()]

        for i in range(n_mlp):
            layers.append(
                EqualLinear(
                    style_dim, style_dim, lr_mul=lr_mlp, activation='fused_lrelu'
                )
            )

        self.style = nn.Sequential(*layers)

        self.channels = {
            4: 512,
            8: 512,
            16: 512,
            32: 512,
            64: 256 * channel_multiplier,
            128: 128 * channel_multiplier,
            256: 64 * channel_multiplier,
            512: 32 * channel_multiplier,
            1024: 16 * channel_multiplier,
        }

        self.input = ConstantInput(self.channels[4])
        self.conv1 = StyledConv(
            self.channels[4], self.channels[4], 3, style_dim, blur_kernel=blur_kernel
        )
        self.to_rgb1 = ToRGB(self.channels[4], style_dim, upsample=False)

        self.log_size = int(math.log(size, 2))
        self.num_layers = (self.log_size - 2) * 2 + 1

        self.convs = nn.ModuleList()
        self.upsamples = nn.ModuleList()
        self.to_rgbs = nn.ModuleList()
        self.noises = nn.Module()

        in_channel = self.channels[4]

        for layer_idx in range(self.num_layers):
            res = (layer_idx + 5) // 2
            shape = [1, 1, 2 ** res, 2 ** res]
            self.noises.register_buffer(f'noise_{layer_idx}', torch.randn(*shape))

        for i in range(3, self.log_size + 1):
            out_channel = self.channels[2 ** i]

            self.convs.append(
                StyledConv(
                    in_channel,
                    out_channel,
                    3,
                    style_dim,
                    upsample=True,
                    blur_kernel=blur_kernel,
                )
            )

            self.convs.append(
                StyledConv(
                    out_channel, out_channel, 3, style_dim, blur_kernel=blur_kernel
                )
            )

            self.to_rgbs.append(ToRGB(out_channel, style_dim))

            in_channel = out_channel

        self.n_latent = self.log_size * 2 - 2

    def make_noise(self):
        device = self.input.input.device

        noises = [torch.randn(1, 1, 2 ** 2, 2 ** 2, device=device)]

        for i in range(3, self.log_size + 1):
            for _ in range(2):
                noises.append(torch.randn(1, 1, 2 ** i, 2 ** i, device=device))

        return noises

    def mean_latent(self, n_latent):
        latent_in = torch.randn( n_latent, self.style_dim, device=self.input.input.device)
        latent = self.get_latent(latent_in)#.mean(0, keepdim=True)
        latent = [latent[i].mean(0, keepdim=True) for i in range(len(latent))]

        return latent

    def get_w(self, input):
        latent = self.style(input)
        latent = fused_leaky_relu(latent, torch.zeros_like(latent).cuda(), 5.)
        return latent

    def get_latent(self, input, is_latent=False, truncation=1, mean_latent=None):
        output = []
        if not is_latent:
            latent = self.style(input)
            latent = latent.unsqueeze(1).repeat(1, self.n_latent, 1) #[B, 14, 512]
        else:
            latent = input
        output.append(self.conv1.get_latent(latent[:, 0]))
        output.append(self.to_rgb1.get_latent(latent[:, 1]))

        i = 1
        for conv1, conv2, to_rgb in zip(self.convs[::2], self.convs[1::2], self.to_rgbs):
            output.append(conv1.get_latent(latent[:, i]))
            output.append(conv2.get_latent(latent[:, i+1]))
            output.append(to_rgb.get_latent(latent[:, i+2]))
            i += 2

#         output = torch.cat(output, 1)

        if truncation < 1 and mean_latent is not None:
            output = [mean_latent[i] + truncation * (output[i] - mean_latent[i]) for i in range(len(output))]
            
        return output

    def forward(
        self,
        styles,
        stop_idx=99,
        is_cluster=False,
        noise=None,
        randomize_noise=False,
        weights_deltas=None,
    ):
        total_convs = len(self.convs) + len(self.to_rgbs) +2
        if weights_deltas is None:
            weights_deltas = [None]* total_convs
        if noise is None:
            if randomize_noise:
                noise = [None] * self.num_layers
            else:
                noise = [
                    getattr(self.noises, f'noise_{i}') for i in range(self.num_layers)
                ]
                
        outputs = []
        idx_count = 0
        
        latent = styles
        out = self.input(latent[0])
        outputs.append([out, out])
        if idx_count == stop_idx:
            return outputs
        
        out, out_t = self.conv1(out, latent[idx_count], noise=noise[0],weights_delta=weights_deltas[0])
        outputs.append([out_t, out])
        idx_count += 1
        if idx_count == stop_idx:
            return outputs

        skip = self.to_rgb1(out, latent[idx_count], weights_delta=weights_deltas[1])

        i = 1
        weight_idx = 2
        for conv1, conv2, noise1, noise2, to_rgb in zip(
            self.convs[::2], self.convs[1::2], noise[1::2], noise[2::2], self.to_rgbs
        ):
            outputs.append([out_t, out])
            idx_count += 1
            if idx_count == stop_idx:
                return outputs

            out, out_t = conv1(out, latent[idx_count], noise=noise1, weights_delta=weights_deltas[weight_idx])
            outputs.append([out_t, out])
            idx_count += 1
            if idx_count == stop_idx:
                return outputs

            out, out_t = conv2(out, latent[idx_count], noise=noise2, weights_delta=weights_deltas[weight_idx+1])
            outputs.append([out_t, out])
            idx_count += 1
            if idx_count == stop_idx:
                return outputs

            skip = to_rgb(out, latent[idx_count], skip, weights_delta=weights_deltas[weight_idx+2])

            i += 2
            weight_idx += 3
        image = skip.clamp(-1,1)
        return image, outputs


class ConvLayer(nn.Sequential):
    def __init__(
        self,
        in_channel,
        out_channel,
        kernel_size,
        groups=1,
        downsample=False,
        blur_kernel=[1, 3, 3, 1],
        bias=True,
        activate=True,
        lr_mul=1,
    ):
        layers = []

        if downsample:
            factor = 2
            p = (len(blur_kernel) - factor) + (kernel_size - 1)
            pad0 = (p + 1) // 2
            pad1 = p // 2

            layers.append(Blur(blur_kernel, pad=(pad0, pad1)))

            stride = 2
            self.padding = 0

        else:
            stride = 1
            self.padding = kernel_size // 2

        layers.append(
            EqualConv2d(
                in_channel,
                out_channel,
                kernel_size,
                groups=groups,
                padding=self.padding,
                stride=stride,
                bias=bias and not activate,
                lr_mul=lr_mul,
            )
        )

        if activate:
            if bias:
                layers.append(FusedLeakyReLU(out_channel, lr_mul=lr_mul))

            else:
                layers.append(ScaledLeakyReLU(0.2))

        super().__init__(*layers)



class ResBlock(nn.Module):
    def __init__(self, in_channel, out_channel, blur_kernel=[1, 3, 3, 1]):
        super().__init__()

        self.conv1 = ConvLayer(in_channel, in_channel, 3)
        self.conv2 = ConvLayer(in_channel, out_channel, 3, downsample=True)

        self.skip = ConvLayer(
            in_channel, out_channel, 1, downsample=True, activate=False, bias=False
        )

    def forward(self, input):
        out = self.conv1(input)
        out = self.conv2(out)

        skip = self.skip(input)
        out = (out + skip) / math.sqrt(2)

        return out


class Discriminator(nn.Module):
    def __init__(self, size, channel_multiplier=2, blur_kernel=[1, 3, 3, 1]):
        super().__init__()

        channels = {
            4: 512,
            8: 512,
            16: 512,
            32: 512,
            64: 256 * channel_multiplier,
            128: 128 * channel_multiplier,
            256: 64 * channel_multiplier,
            512: 32 * channel_multiplier,
            1024: 16 * channel_multiplier,
        }

        convs = [ConvLayer(3, channels[size], 1)]

        log_size = int(math.log(size, 2))

        in_channel = channels[size]

        for i in range(log_size, 2, -1):
            out_channel = channels[2 ** (i - 1)]

            convs.append(ResBlock(in_channel, out_channel, blur_kernel))

            in_channel = out_channel

        self.convs = nn.Sequential(*convs)

        self.stddev_group = 4
        self.stddev_feat = 1

        self.final_conv = ConvLayer(in_channel + 1, channels[4], 3)
        self.final_linear = nn.Sequential(
            EqualLinear(channels[4] * 4 * 4, channels[4], activation='fused_lrelu'),
            EqualLinear(channels[4], 1),
        )

    def forward(self, input):
        out = self.convs(input)

        batch, channel, height, width = out.shape
        group = min(batch, self.stddev_group)
        #group = batch
        stddev = out.view(
            group, -1, self.stddev_feat, channel // self.stddev_feat, height, width
        )
        stddev = torch.sqrt(stddev.var(0, unbiased=False) + 1e-8)
        stddev = stddev.mean([2, 3, 4], keepdims=True).squeeze(2)
        stddev = stddev.repeat(group, 1, height, width)
        out = torch.cat([out, stddev], 1)

        out = self.final_conv(out)

        out = out.view(batch, -1)
        out = self.final_linear(out)

        return out

class VGGExtractor(torch.nn.Module):
    def __init__(self, resize=False):
        super(VGGExtractor, self).__init__()
        vgg16 = torchvision.models.vgg16(pretrained=True).eval()
        blocks = vgg16.features[:23]
        for p in blocks:
            p.requires_grad = False
        self.blocks = blocks
        self.transform = torch.nn.functional.interpolate
        self.mean = torch.nn.Parameter(torch.tensor([0.485, 0.456, 0.406]).view(1,3,1,1))
        self.std = torch.nn.Parameter(torch.tensor([0.229, 0.224, 0.225]).view(1,3,1,1))
        self.resize = resize

    def forward(self, input):
        if input.shape[1] != 3:
            input = input.repeat(1, 3, 1, 1)
        input = (input + 1) / 2
        input = (input-self.mean) / self.std
        if self.resize:
            input = self.transform(input, mode='bilinear', size=(224, 224), align_corners=False)
        return self.blocks(input)

class Encoder(nn.Module):
    def __init__(self, size, groups, channel_multiplier=1, blur_kernel=[1, 3, 3, 1]):
        '''
        [16]: [14,15,16,17,18,19]
        [8]: [8,9,10,11,12,13]
        [4]: [0,1,2,3,4,5,6,7]
        '''
        super().__init__()
        in_channel = 3
        out_channel = 64

        convs = nn.ModuleList()
        for i in range(6):
            convs.append(ResBlock(in_channel, out_channel, blur_kernel))
            in_channel = out_channel
            out_channel = min(1024, in_channel*2)

        self.fc_high = nn.Sequential(nn.AdaptiveAvgPool2d(4),
                                    nn.Flatten(),
                                    EqualLinear(512*4*4, 4*512+3*256+2*128))
        self.fc_mid = nn.Sequential(nn.AdaptiveAvgPool2d(4),
                                    nn.Flatten(),
                                    EqualLinear(1024*4*4, 512*6))
        self.fc_low = nn.Sequential(nn.AdaptiveAvgPool2d(4),
                                    nn.Flatten(),
                                    EqualLinear(1024*4*4, 512*5))

    def forward(self, input):
        shared = self.convs(input)
        local = self.local_fc(shared)
        glob = self.global_fc(shared)
        return local.view(local.size(0), -1), glob