from federatedscope.register import register_model
import torch
import torch.nn as nn
from federatedscope.trafficflow.model.DGCRUCell import DGCRUCell

class DGCRM(nn.Module):
    def __init__(self, node_num, dim_in, dim_out, cheb_k, embed_dim, num_layers=1):
        super(DGCRM, self).__init__()
        assert num_layers >= 1, 'At least one DCRNN layer in the Encoder.'
        self.node_num = node_num
        self.input_dim = dim_in
        self.num_layers = num_layers
        self.DGCRM_cells = nn.ModuleList()
        self.DGCRM_cells.append(DGCRUCell(node_num, dim_in, dim_out, cheb_k, embed_dim))
        for _ in range(1, num_layers):
            self.DGCRM_cells.append(DGCRUCell(node_num, dim_out, dim_out, cheb_k, embed_dim))

    def forward(self, x, init_state, node_embeddings):
        assert x.shape[2] == self.node_num and x.shape[3] == self.input_dim
        seq_length = x.shape[1]
        current_inputs = x
        output_hidden = []
        for i in range(self.num_layers):
            state = init_state[i]
            inner_states = []
            for t in range(seq_length):
                state = self.DGCRM_cells[i](current_inputs[:, t, :, :], state, [node_embeddings[0][:, t, :, :], node_embeddings[1]])
                inner_states.append(state)
            output_hidden.append(state)
            current_inputs = torch.stack(inner_states, dim=1)
        return current_inputs, output_hidden

    def init_hidden(self, batch_size):
        init_states = []
        for i in range(self.num_layers):
            init_states.append(self.DGCRM_cells[i].init_hidden_state(batch_size))
        return torch.stack(init_states, dim=0)      #(num_layers, B, N, hidden_dim)

# Build you torch or tf model class here
class FedDGCN(nn.Module):
    def __init__(self, args):
        super(FedDGCN, self).__init__()
        self.num_node = args.tfp.num_nodes
        self.input_dim = args.tfp.input_dim
        self.hidden_dim = args.tfp.rnn_units
        self.output_dim = args.tfp.output_dim
        self.horizon = args.tfp.horizon
        self.num_layers = args.tfp.num_layers
        self.use_D = args.tfp.use_day
        self.use_W = args.tfp.use_week
        self.dropout1 = nn.Dropout(p=args.tfp.dropout) # 0.1
        self.dropout2 = nn.Dropout(p=args.tfp.dropout)
        self.node_embeddings1 = nn.Parameter(torch.randn(self.num_node, args.tfp.embed_dim), requires_grad=True)
        self.node_embeddings2 = nn.Parameter(torch.randn(self.num_node, args.tfp.embed_dim), requires_grad=True)
        self.T_i_D_emb = nn.Parameter(torch.empty(288, args.tfp.embed_dim))
        self.D_i_W_emb = nn.Parameter(torch.empty(7, args.tfp.embed_dim))
        # Initialize parameters
        nn.init.xavier_uniform_(self.node_embeddings1)
        nn.init.xavier_uniform_(self.T_i_D_emb)
        nn.init.xavier_uniform_(self.D_i_W_emb)

        self.encoder1 = DGCRM(args.tfp.num_nodes, args.tfp.input_dim, args.tfp.rnn_units, args.tfp.cheb_order,
                              args.tfp.embed_dim, args.tfp.num_layers)
        self.encoder2 = DGCRM(args.tfp.num_nodes, args.tfp.input_dim, args.tfp.rnn_units, args.tfp.cheb_order,
                              args.tfp.embed_dim, args.tfp.num_layers)
        # predictor
        self.end_conv1 = nn.Conv2d(1, args.tfp.horizon * self.output_dim, kernel_size=(1, self.hidden_dim), bias=True)
        self.end_conv2 = nn.Conv2d(1, args.tfp.horizon * self.output_dim, kernel_size=(1, self.hidden_dim), bias=True)
        self.end_conv3 = nn.Conv2d(1, args.tfp.horizon * self.output_dim, kernel_size=(1, self.hidden_dim), bias=True)

    def forward(self, source, i=2):
        node_embedding1 = self.node_embeddings1
        if self.use_D:
            t_i_d_data   = source[..., 1]
            T_i_D_emb = self.T_i_D_emb[(t_i_d_data * 288).type(torch.LongTensor)]
            node_embedding1 = torch.mul(node_embedding1, T_i_D_emb)

        if self.use_W:
            d_i_w_data   = source[..., 2]
            D_i_W_emb = self.D_i_W_emb[(d_i_w_data).type(torch.LongTensor)]
            node_embedding1 = torch.mul(node_embedding1, D_i_W_emb)

        node_embeddings=[node_embedding1,self.node_embeddings1]

        source = source[..., 0].unsqueeze(-1)

        init_state1 = self.encoder1.init_hidden(source.shape[0])
        output, _ = self.encoder1(source, init_state1, node_embeddings)
        output = self.dropout1(output[:, -1:, :, :])

        output1 = self.end_conv1(output)
        source1 = self.end_conv2(output)

        source2 = source - source1

        init_state2 = self.encoder2.init_hidden(source2.shape[0])
        output2, _ = self.encoder2(source2, init_state2, node_embeddings)
        output2 = self.dropout2(output2[:, -1:, :, :])
        output2 = self.end_conv3(output2)

        return output1 + output2


# Instantiate your model class with config and data
def ModelBuilder(model_config, local_data):
    model = FedDGCN(model_config)
    return model


def call_feddgcn(model_config, local_data):
    if model_config.type == "FedDGCN":
        model = ModelBuilder(model_config, local_data)
        return model


register_model("FedDGCN", call_feddgcn)