
   
import math
import torch
from torch import nn
from torch.nn import init
from torch.nn import functional as F
from timm.models.layers import DropPath, to_2tuple, trunc_normal_

class KANLinear(torch.nn.Module):
    def __init__(
        self,
        in_features,
        out_features,
        grid_size=5,
        spline_order=3,
        scale_noise=0.1,
        scale_base=1.0,
        scale_spline=1.0,
        enable_standalone_scale_spline=True,
        base_activation=torch.nn.SiLU,
        grid_eps=0.02,
        grid_range=[-1, 1],
    ):
        super(KANLinear, self).__init__()
        self.in_features = in_features
        self.out_features = out_features
        self.grid_size = grid_size
        self.spline_order = spline_order

        h = (grid_range[1] - grid_range[0]) / grid_size
        grid = (
            (
                torch.arange(-spline_order, grid_size + spline_order + 1) * h
                + grid_range[0]
            )
            .expand(in_features, -1)
            .contiguous()
        )
        self.register_buffer("grid", grid)

        self.base_weight = torch.nn.Parameter(torch.Tensor(out_features, in_features))
        self.spline_weight = torch.nn.Parameter(
            torch.Tensor(out_features, in_features, grid_size + spline_order)
        )
        if enable_standalone_scale_spline:
            self.spline_scaler = torch.nn.Parameter(
                torch.Tensor(out_features, in_features)
            )

        self.scale_noise = scale_noise
        self.scale_base = scale_base
        self.scale_spline = scale_spline
        self.enable_standalone_scale_spline = enable_standalone_scale_spline
        self.base_activation = base_activation()
        self.grid_eps = grid_eps

        self.reset_parameters()

    def reset_parameters(self):
        torch.nn.init.kaiming_uniform_(self.base_weight, a=math.sqrt(5) * self.scale_base)
        with torch.no_grad():
            noise = (
                (
                    torch.rand(self.grid_size + 1, self.in_features, self.out_features)
                    - 1 / 2
                )
                * self.scale_noise
                / self.grid_size
            )
            self.spline_weight.data.copy_(
                (self.scale_spline if not self.enable_standalone_scale_spline else 1.0)
                * self.curve2coeff(
                    self.grid.T[self.spline_order : -self.spline_order],
                    noise,
                )
            )
            if self.enable_standalone_scale_spline:
                # torch.nn.init.constant_(self.spline_scaler, self.scale_spline)
                torch.nn.init.kaiming_uniform_(self.spline_scaler, a=math.sqrt(5) * self.scale_spline)

    def b_splines(self, x: torch.Tensor):
        """
        Compute the B-spline bases for the given input tensor.

        Args:
            x (torch.Tensor): Input tensor of shape (batch_size, in_features).

        Returns:
            torch.Tensor: B-spline bases tensor of shape (batch_size, in_features, grid_size + spline_order).
        """
        assert x.dim() == 2 and x.size(1) == self.in_features

        grid: torch.Tensor = (
            self.grid
        )  # (in_features, grid_size + 2 * spline_order + 1)
        x = x.unsqueeze(-1)
        bases = ((x >= grid[:, :-1]) & (x < grid[:, 1:])).to(x.dtype)
        for k in range(1, self.spline_order + 1):
            bases = (
                (x - grid[:, : -(k + 1)])
                / (grid[:, k:-1] - grid[:, : -(k + 1)])
                * bases[:, :, :-1]
            ) + (
                (grid[:, k + 1 :] - x)
                / (grid[:, k + 1 :] - grid[:, 1:(-k)])
                * bases[:, :, 1:]
            )

        assert bases.size() == (
            x.size(0),
            self.in_features,
            self.grid_size + self.spline_order,
        )
        return bases.contiguous()

    def curve2coeff(self, x: torch.Tensor, y: torch.Tensor):
        """
        Compute the coefficients of the curve that interpolates the given points.

        Args:
            x (torch.Tensor): Input tensor of shape (batch_size, in_features).
            y (torch.Tensor): Output tensor of shape (batch_size, in_features, out_features).

        Returns:
            torch.Tensor: Coefficients tensor of shape (out_features, in_features, grid_size + spline_order).
        """
        assert x.dim() == 2 and x.size(1) == self.in_features
        assert y.size() == (x.size(0), self.in_features, self.out_features)

        A = self.b_splines(x).transpose(
            0, 1
        )  # (in_features, batch_size, grid_size + spline_order)
        B = y.transpose(0, 1)  # (in_features, batch_size, out_features)
        solution = torch.linalg.lstsq(
            A, B
        ).solution  # (in_features, grid_size + spline_order, out_features)
        result = solution.permute(
            2, 0, 1
        )  # (out_features, in_features, grid_size + spline_order)

        assert result.size() == (
            self.out_features,
            self.in_features,
            self.grid_size + self.spline_order,
        )
        return result.contiguous()

    @property
    def scaled_spline_weight(self):
        return self.spline_weight * (
            self.spline_scaler.unsqueeze(-1)
            if self.enable_standalone_scale_spline
            else 1.0
        )

    def forward(self, x: torch.Tensor):
        assert x.dim() == 2 and x.size(1) == self.in_features

        base_output = F.linear(self.base_activation(x), self.base_weight)
        spline_output = F.linear(
            self.b_splines(x).view(x.size(0), -1),
            self.scaled_spline_weight.view(self.out_features, -1),
        )
        return base_output + spline_output

    @torch.no_grad()
    def update_grid(self, x: torch.Tensor, margin=0.01):
        assert x.dim() == 2 and x.size(1) == self.in_features
        batch = x.size(0)

        splines = self.b_splines(x)  # (batch, in, coeff)
        splines = splines.permute(1, 0, 2)  # (in, batch, coeff)
        orig_coeff = self.scaled_spline_weight  # (out, in, coeff)
        orig_coeff = orig_coeff.permute(1, 2, 0)  # (in, coeff, out)
        unreduced_spline_output = torch.bmm(splines, orig_coeff)  # (in, batch, out)
        unreduced_spline_output = unreduced_spline_output.permute(
            1, 0, 2
        )  # (batch, in, out)

        # sort each channel individually to collect data distribution
        x_sorted = torch.sort(x, dim=0)[0]
        grid_adaptive = x_sorted[
            torch.linspace(
                0, batch - 1, self.grid_size + 1, dtype=torch.int64, device=x.device
            )
        ]

        uniform_step = (x_sorted[-1] - x_sorted[0] + 2 * margin) / self.grid_size
        grid_uniform = (
            torch.arange(
                self.grid_size + 1, dtype=torch.float32, device=x.device
            ).unsqueeze(1)
            * uniform_step
            + x_sorted[0]
            - margin
        )

        grid = self.grid_eps * grid_uniform + (1 - self.grid_eps) * grid_adaptive
        grid = torch.concatenate(
            [
                grid[:1]
                - uniform_step
                * torch.arange(self.spline_order, 0, -1, device=x.device).unsqueeze(1),
                grid,
                grid[-1:]
                + uniform_step
                * torch.arange(1, self.spline_order + 1, device=x.device).unsqueeze(1),
            ],
            dim=0,
        )

        self.grid.copy_(grid.T)
        self.spline_weight.data.copy_(self.curve2coeff(x, unreduced_spline_output))

    def regularization_loss(self, regularize_activation=1.0, regularize_entropy=1.0):
        """
        Compute the regularization loss.

        This is a dumb simulation of the original L1 regularization as stated in the
        paper, since the original one requires computing absolutes and entropy from the
        expanded (batch, in_features, out_features) intermediate tensor, which is hidden
        behind the F.linear function if we want an memory efficient implementation.

        The L1 regularization is now computed as mean absolute value of the spline
        weights. The authors implementation also includes this term in addition to the
        sample-based regularization.
        """
        l1_fake = self.spline_weight.abs().mean(-1)
        regularization_loss_activation = l1_fake.sum()
        p = l1_fake / regularization_loss_activation
        regularization_loss_entropy = -torch.sum(p * p.log())
        return (
            regularize_activation * regularization_loss_activation
            + regularize_entropy * regularization_loss_entropy
        )


class KAN(torch.nn.Module):
    def __init__(
        self,
        layers_hidden,
        grid_size=5,
        spline_order=3,
        scale_noise=0.1,
        scale_base=1.0,
        scale_spline=1.0,
        base_activation=torch.nn.SiLU,
        grid_eps=0.02,
        grid_range=[-1, 1],
    ):
        super(KAN, self).__init__()
        self.grid_size = grid_size
        self.spline_order = spline_order

        self.layers = torch.nn.ModuleList()
        for in_features, out_features in zip(layers_hidden, layers_hidden[1:]):
            self.layers.append(
                KANLinear(
                    in_features,
                    out_features,
                    grid_size=grid_size,
                    spline_order=spline_order,
                    scale_noise=scale_noise,
                    scale_base=scale_base,
                    scale_spline=scale_spline,
                    base_activation=base_activation,
                    grid_eps=grid_eps,
                    grid_range=grid_range,
                )
            )

    def forward(self, x: torch.Tensor, update_grid=False):
        for layer in self.layers:
            if update_grid:
                layer.update_grid(x)
            x = layer(x)
        return x

    def regularization_loss(self, regularize_activation=1.0, regularize_entropy=1.0):
        return sum(
            layer.regularization_loss(regularize_activation, regularize_entropy)
            for layer in self.layers
        )


def conv1x1(in_planes: int, out_planes: int, stride: int = 1) -> nn.Conv2d:
    """1x1 convolution"""
    return nn.Conv2d(in_planes, out_planes, kernel_size=1, stride=1, bias=False)


def shift(dim):
            x_shift = [ torch.roll(x_c, shift, dim) for x_c, shift in zip(xs, range(-self.pad, self.pad+1))]
            x_cat = torch.cat(x_shift, 1)
            x_cat = torch.narrow(x_cat, 2, self.pad, H)
            x_cat = torch.narrow(x_cat, 3, self.pad, W)
            return x_cat


class OverlapPatchEmbed(nn.Module):
    """ Image to Patch Embedding
    """

    def __init__(self, img_size=224, patch_size=7, stride=4, in_chans=3, embed_dim=768):
        super().__init__()
        img_size = to_2tuple(img_size)
        patch_size = to_2tuple(patch_size)

        self.img_size = img_size
        self.patch_size = patch_size
        self.H, self.W = img_size[0] // patch_size[0], img_size[1] // patch_size[1]
        self.num_patches = self.H * self.W
        self.proj = nn.Conv2d(in_chans, embed_dim, kernel_size=patch_size, stride=stride,
                              padding=(patch_size[0] // 2, patch_size[1] // 2))
        self.norm = nn.LayerNorm(embed_dim)

        self.apply(self._init_weights)

    def _init_weights(self, m):
        if isinstance(m, nn.Linear):
            trunc_normal_(m.weight, std=.02)
            if isinstance(m, nn.Linear) and m.bias is not None:
                nn.init.constant_(m.bias, 0)
        elif isinstance(m, nn.LayerNorm):
            nn.init.constant_(m.bias, 0)
            nn.init.constant_(m.weight, 1.0)
        elif isinstance(m, nn.Conv2d):
            fan_out = m.kernel_size[0] * m.kernel_size[1] * m.out_channels
            fan_out //= m.groups
            m.weight.data.normal_(0, math.sqrt(2.0 / fan_out))
            if m.bias is not None:
                m.bias.data.zero_()

    def forward(self, x):
        x = self.proj(x)
        _, _, H, W = x.shape
        x = x.flatten(2).transpose(1, 2)
        x = self.norm(x)

        return x, H, W


class Swish(nn.Module):
    def forward(self, x):
        return x * torch.sigmoid(x)
def swish(x):
    
    return x * torch.sigmoid(x)


class TimeEmbedding(nn.Module):
    def __init__(self, T, d_model, dim):
        assert d_model % 2 == 0
        super().__init__()
        emb = torch.arange(0, d_model, step=2) / d_model * math.log(10000)
        emb = torch.exp(-emb)
        pos = torch.arange(T).float()
        emb = pos[:, None] * emb[None, :]
        assert list(emb.shape) == [T, d_model // 2]
        emb = torch.stack([torch.sin(emb), torch.cos(emb)], dim=-1)
        assert list(emb.shape) == [T, d_model // 2, 2]
        emb = emb.view(T, d_model)

        self.timembedding = nn.Sequential(
            nn.Embedding.from_pretrained(emb),
            nn.Linear(d_model, dim),
            Swish(),
            nn.Linear(dim, dim),
        )
        self.initialize()

    def initialize(self):
        for module in self.modules():
            if isinstance(module, nn.Linear):
                init.xavier_uniform_(module.weight)
                init.zeros_(module.bias)

    def forward(self, t):
        emb = self.timembedding(t)
        return emb


class DownSample(nn.Module):
    def __init__(self, in_ch):
        super().__init__()
        self.main = nn.Conv2d(in_ch, in_ch, 3, stride=2, padding=1)
        self.initialize()

    def initialize(self):
        init.xavier_uniform_(self.main.weight)
        init.zeros_(self.main.bias)

    def forward(self, x, temb):
        x = self.main(x)
        return x


class UpSample(nn.Module):
    def __init__(self, in_ch):
        super().__init__()
        self.main = nn.Conv2d(in_ch, in_ch, 3, stride=1, padding=1)
        self.initialize()

    def initialize(self):
        init.xavier_uniform_(self.main.weight)
        init.zeros_(self.main.bias)

    def forward(self, x, temb):
        _, _, H, W = x.shape
        x = F.interpolate(
            x, scale_factor=2, mode='nearest')
        x = self.main(x)
        return x
    
class kan(nn.Module):
    def __init__(self, in_features, hidden_features=None, out_features=None):
        super().__init__()
        out_features = out_features or in_features
        hidden_features = hidden_features or in_features
        self.dim = in_features
        
        grid_size=5
        spline_order=3
        scale_noise=0.1
        scale_base=1.0
        scale_spline=1.0
        base_activation=Swish
        grid_eps=0.02
        grid_range=[-1, 1]

        self.fc1 = KANLinear(
                    in_features,
                    hidden_features,
                    grid_size=grid_size,
                    spline_order=spline_order,
                    scale_noise=scale_noise,
                    scale_base=scale_base,
                    scale_spline=scale_spline,
                    base_activation=base_activation,
                    grid_eps=grid_eps,
                    grid_range=grid_range,
                )

        self.apply(self._init_weights)

    def _init_weights(self, m):
        if isinstance(m, nn.Linear):
            trunc_normal_(m.weight, std=.02)
            if isinstance(m, nn.Linear) and m.bias is not None:
                nn.init.constant_(m.bias, 0)
        elif isinstance(m, nn.LayerNorm):
            nn.init.constant_(m.bias, 0)
            nn.init.constant_(m.weight, 1.0)
        elif isinstance(m, nn.Conv2d):
            fan_out = m.kernel_size[0] * m.kernel_size[1] * m.out_channels
            fan_out //= m.groups
            m.weight.data.normal_(0, math.sqrt(2.0 / fan_out))
            if m.bias is not None:
                m.bias.data.zero_()
    

    def forward(self, x, H, W):
        B, N, C = x.shape
        x = self.fc1(x.reshape(B*N,C))
        x = x.reshape(B,N,C).contiguous()

        return x

class shiftedBlock(nn.Module):
    def __init__(self, dim,  mlp_ratio=4.,drop_path=0.,norm_layer=nn.LayerNorm):
        super().__init__()

        self.drop_path = DropPath(drop_path) if drop_path > 0. else nn.Identity()
        self.norm2 = norm_layer(dim)
        mlp_hidden_dim = int(dim * mlp_ratio)

        self.temb_proj = nn.Sequential(
            Swish(),
            nn.Linear(256, dim),
        )

        self.kan = kan(in_features=dim, hidden_features=mlp_hidden_dim)

        self.apply(self._init_weights)

    def _init_weights(self, m):
        if isinstance(m, nn.Linear):
            trunc_normal_(m.weight, std=.02)
            if isinstance(m, nn.Linear) and m.bias is not None:
                nn.init.constant_(m.bias, 0)
        elif isinstance(m, nn.LayerNorm):
            nn.init.constant_(m.bias, 0)
            nn.init.constant_(m.weight, 1.0)
        elif isinstance(m, nn.Conv2d):
            fan_out = m.kernel_size[0] * m.kernel_size[1] * m.out_channels
            fan_out //= m.groups
            m.weight.data.normal_(0, math.sqrt(2.0 / fan_out))
            if m.bias is not None:
                m.bias.data.zero_()

    def forward(self, x, H, W, temb):

        temb = self.temb_proj(temb)
        x = self.drop_path(self.kan(self.norm2(x), H, W))
        x = x + temb.unsqueeze(1)

        return x

class DWConv(nn.Module):
    def __init__(self, dim=768):
        super(DWConv, self).__init__()
        self.dwconv = nn.Conv2d(dim, dim, 3, 1, 1, bias=True, groups=dim)

    def forward(self, x, H, W):
        B, N, C = x.shape
        x = x.transpose(1, 2).view(B, C, H, W)
        x = self.dwconv(x)
        x = x.flatten(2).transpose(1, 2)

        return x

class DW_bn_relu(nn.Module):
    def __init__(self, dim=768):
        super(DW_bn_relu, self).__init__()
        self.dwconv = nn.Conv2d(dim, dim, 3, 1, 1, bias=True, groups=dim)
        self.bn = nn.GroupNorm(32, dim)
        # self.relu = Swish()

    def forward(self, x, H, W):
        B, N, C = x.shape
        x = x.transpose(1, 2).view(B, C, H, W)
        x = self.dwconv(x)
        x = self.bn(x)
        x = swish(x)
        x = x.flatten(2).transpose(1, 2)

        return x

class SingleConv(nn.Module):
    def __init__(self, in_ch, h_ch):
        super(SingleConv, self).__init__()
        self.conv = nn.Sequential(
            nn.GroupNorm(32, in_ch),
            Swish(),
            nn.Conv2d(in_ch, h_ch, 3, padding=1),
        )

        self.temb_proj = nn.Sequential(
            Swish(),
            nn.Linear(256, h_ch),
        )
    def forward(self, input, temb):
        return self.conv(input) + self.temb_proj(temb)[:,:,None, None]


class DoubleConv(nn.Module):
    def __init__(self, in_ch, h_ch):
        super(DoubleConv, self).__init__()
        self.conv = nn.Sequential(
            nn.Conv2d(in_ch, h_ch, 3, padding=1),
            nn.GroupNorm(32, h_ch),
            Swish(),
            nn.Conv2d(h_ch, h_ch, 3, padding=1),
            nn.GroupNorm(32, h_ch),
            Swish()
        )
        self.temb_proj = nn.Sequential(
            Swish(),
            nn.Linear(256, h_ch),
        )
    def forward(self, input, temb):
        return self.conv(input) + self.temb_proj(temb)[:,:,None, None]


class D_SingleConv(nn.Module):
    def __init__(self, in_ch, h_ch):
        super(D_SingleConv, self).__init__()
        self.conv = nn.Sequential(
            nn.GroupNorm(32,in_ch),
            Swish(),
            nn.Conv2d(in_ch, h_ch, 3, padding=1),
        )
        self.temb_proj = nn.Sequential(
            Swish(),
            nn.Linear(256, h_ch),
        )
    def forward(self, input, temb):
        return self.conv(input) + self.temb_proj(temb)[:,:,None, None]


class D_DoubleConv(nn.Module):
    def __init__(self, in_ch, h_ch):
        super(D_DoubleConv, self).__init__()
        self.conv = nn.Sequential(
            nn.Conv2d(in_ch, in_ch, 3, padding=1),
            nn.GroupNorm(32,in_ch),
            Swish(),
            nn.Conv2d(in_ch, h_ch, 3, padding=1),
             nn.GroupNorm(32,h_ch),
            Swish()
        )
        self.temb_proj = nn.Sequential(
            Swish(),
            nn.Linear(256, h_ch),
        )
    def forward(self, input,temb):
        return self.conv(input) + self.temb_proj(temb)[:,:,None, None]

class AttnBlock(nn.Module):
    def __init__(self, in_ch):
        super().__init__()
        self.group_norm = nn.GroupNorm(32, in_ch)
        self.proj_q = nn.Conv2d(in_ch, in_ch, 1, stride=1, padding=0)
        self.proj_k = nn.Conv2d(in_ch, in_ch, 1, stride=1, padding=0)
        self.proj_v = nn.Conv2d(in_ch, in_ch, 1, stride=1, padding=0)
        self.proj = nn.Conv2d(in_ch, in_ch, 1, stride=1, padding=0)
        self.initialize()

    def initialize(self):
        for module in [self.proj_q, self.proj_k, self.proj_v, self.proj]:
            init.xavier_uniform_(module.weight)
            init.zeros_(module.bias)
        init.xavier_uniform_(self.proj.weight, gain=1e-5)

    def forward(self, x):
        B, C, H, W = x.shape
        h = self.group_norm(x)
        q = self.proj_q(h)
        k = self.proj_k(h)
        v = self.proj_v(h)

        q = q.permute(0, 2, 3, 1).view(B, H * W, C)
        k = k.view(B, C, H * W)
        w = torch.bmm(q, k) * (int(C) ** (-0.5))
        assert list(w.shape) == [B, H * W, H * W]
        w = F.softmax(w, dim=-1)

        v = v.permute(0, 2, 3, 1).view(B, H * W, C)
        h = torch.bmm(w, v)
        assert list(h.shape) == [B, H * W, C]
        h = h.view(B, H, W, C).permute(0, 3, 1, 2)
        h = self.proj(h)

        return x + h


class ResBlock(nn.Module):
    def __init__(self, in_ch, h_ch, tdim, dropout, attn=False):
        super().__init__()
        self.block1 = nn.Sequential(
            nn.GroupNorm(32, in_ch),
            Swish(),
            nn.Conv2d(in_ch, h_ch, 3, stride=1, padding=1),
        )
        self.temb_proj = nn.Sequential(
            Swish(),
            nn.Linear(tdim, h_ch),
        )
        self.block2 = nn.Sequential(
            nn.GroupNorm(32, h_ch),
            Swish(),
            nn.Dropout(dropout),
            nn.Conv2d(h_ch, h_ch, 3, stride=1, padding=1),
        )
        if in_ch != h_ch:
            self.shortcut = nn.Conv2d(in_ch, h_ch, 1, stride=1, padding=0)
        else:
            self.shortcut = nn.Identity()
        if attn:
            self.attn = AttnBlock(h_ch)
        else:
            self.attn = nn.Identity()
        self.initialize()

    def initialize(self):
        for module in self.modules():
            if isinstance(module, (nn.Conv2d, nn.Linear)):
                init.xavier_uniform_(module.weight)
                init.zeros_(module.bias)
        init.xavier_uniform_(self.block2[-1].weight, gain=1e-5)

    def forward(self, x, temb):
        h = self.block1(x)
        h += self.temb_proj(temb)[:, :, None, None]
        h = self.block2(h)

        h = h + self.shortcut(x)
        h = self.attn(h)
        return h


class UKan_Hybrid(nn.Module):
    def __init__(self, T, ch, ch_mult, attn, num_res_blocks, dropout):
        super().__init__()
        assert all([i < len(ch_mult) for i in attn]), 'attn index h of bound'
        tdim = ch * 4
        self.time_embedding = TimeEmbedding(T, ch, tdim)
        attn = []
        self.head = nn.Conv2d(3, ch, kernel_size=3, stride=1, padding=1)
        self.downblocks = nn.ModuleList()
        chs = [ch]  # record hput channel when dowmsample for upsample
        now_ch = ch
        for i, mult in enumerate(ch_mult):
            h_ch = ch * mult
            for _ in range(num_res_blocks):
                self.downblocks.append(ResBlock(
                    in_ch=now_ch, h_ch=h_ch, tdim=tdim,
                    dropout=dropout, attn=(i in attn)))
                now_ch = h_ch
                chs.append(now_ch)
            if i != len(ch_mult) - 1:
                self.downblocks.append(DownSample(now_ch))
                chs.append(now_ch)

        self.upblocks = nn.ModuleList()
        for i, mult in reversed(list(enumerate(ch_mult))):
            h_ch = ch * mult
            for _ in range(num_res_blocks + 1):
                self.upblocks.append(ResBlock(
                    in_ch=chs.pop() + now_ch, h_ch=h_ch, tdim=tdim,
                    dropout=dropout, attn=(i in attn)))
                now_ch = h_ch
            if i != 0:
                self.upblocks.append(UpSample(now_ch))
        assert len(chs) == 0

        self.tail = nn.Sequential(
            nn.GroupNorm(32, now_ch),
            Swish(),
            nn.Conv2d(now_ch, 3, 3, stride=1, padding=1)
        )

        # 
        embed_dims = [256, 320, 512]
        norm_layer = nn.LayerNorm
        dpr = [0.0, 0.0, 0.0]
        self.patch_embed3 = OverlapPatchEmbed(img_size=64 // 4, patch_size=3, stride=2, in_chans=embed_dims[0], embed_dim=embed_dims[1])
        self.patch_embed4 = OverlapPatchEmbed(img_size=64 // 8, patch_size=3, stride=2, in_chans=embed_dims[1], embed_dim=embed_dims[2])

        self.norm3 = norm_layer(embed_dims[1])
        self.norm4 = norm_layer(embed_dims[2])
        self.dnorm3 = norm_layer(embed_dims[1])

        self.kan_block1 = nn.ModuleList([shiftedBlock(
            dim=embed_dims[1],  mlp_ratio=1, drop_path=dpr[0], norm_layer=norm_layer)])

        self.kan_block2 = nn.ModuleList([shiftedBlock(
            dim=embed_dims[2],  mlp_ratio=1, drop_path=dpr[1], norm_layer=norm_layer)])

        self.kan_dblock1 = nn.ModuleList([shiftedBlock(
            dim=embed_dims[1], mlp_ratio=1, drop_path=dpr[0], norm_layer=norm_layer)])

        self.decoder1 = D_SingleConv(embed_dims[2], embed_dims[1])  
        self.decoder2 = D_SingleConv(embed_dims[1], embed_dims[0])  

        self.initialize()

    def initialize(self):
        init.xavier_uniform_(self.head.weight)
        init.zeros_(self.head.bias)
        init.xavier_uniform_(self.tail[-1].weight, gain=1e-5)
        init.zeros_(self.tail[-1].bias)

    def forward(self, x, t):
        # Timestep embedding
        temb = self.time_embedding(t)
        # Downsampling
        h = self.head(x)
        hs = [h]
        for layer in self.downblocks:
            h = layer(h, temb)
            hs.append(h)
    
        t3 = h

        B = x.shape[0]
        h, H, W = self.patch_embed3(h)
 
        for i, blk in enumerate(self.kan_block1):
            h = blk(h, H, W, temb)
        h = self.norm3(h)
        h = h.reshape(B, H, W, -1).permute(0, 3, 1, 2).contiguous()
        t4 = h

        h, H, W= self.patch_embed4(h)
        for i, blk in enumerate(self.kan_block2):
            h = blk(h, H, W, temb)
        h = self.norm4(h)
        h = h.reshape(B, H, W, -1).permute(0, 3, 1, 2).contiguous()

        ### Stage 4
        h = swish(F.interpolate(self.decoder1(h, temb), scale_factor=(2,2), mode ='bilinear'))

        h = torch.add(h, t4)

        _, _, H, W = h.shape
        h = h.flatten(2).transpose(1,2)
        for i, blk in enumerate(self.kan_dblock1):
            h = blk(h, H, W, temb)

            
        ### Stage 3
        h = self.dnorm3(h)
        h = h.reshape(B, H, W, -1).permute(0, 3, 1, 2).contiguous()
        h = swish(F.interpolate(self.decoder2(h, temb),scale_factor=(2,2),mode ='bilinear'))

        h = torch.add(h,t3)

        # Upsampling
        for layer in self.upblocks:
            if isinstance(layer, ResBlock):
                h = torch.cat([h, hs.pop()], dim=1)
            h = layer(h, temb)
        h = self.tail(h)

        assert len(hs) == 0
        return h


if __name__ == '__main__':
    batch_size = 8
    model = UKan_Hybrid(
        T=1000, ch=64, ch_mult=[1, 2, 2, 2], attn=[],
        num_res_blocks=2, dropout=0.1)

