#
# Copyright (C) Stanislaw Adaszewski, 2020
# License: GPLv3
#


import torch
from .data import Data
from .trainprep import PreparedData, \
    TrainValTest
from typing import Type, \
    List, \
    Callable, \
    Union, \
    Dict, \
    Tuple
from .decode import DEDICOMDecoder
from dataclasses import dataclass
import time


@dataclass
class RelationPredictions(object):
    edges_pos: TrainValTest
    edges_neg: TrainValTest
    edges_back_pos: TrainValTest
    edges_back_neg: TrainValTest


@dataclass
class RelationFamilyPredictions(object):
    relation_types: List[RelationPredictions]


@dataclass
class Predictions(object):
    relation_families: List[RelationFamilyPredictions]


class DecodeLayer(torch.nn.Module):
    def __init__(self,
        input_dim: List[int],
        data: PreparedData,
        keep_prob: float = 1.,
        activation: Callable[[torch.Tensor], torch.Tensor] = torch.sigmoid,
        **kwargs) -> None:

        super().__init__(**kwargs)

        if not isinstance(input_dim, list):
            raise TypeError('input_dim must be a List')

        if len(input_dim) != len(data.node_types):
            raise ValueError('input_dim must have length equal to num_node_types')

        if not all([ a == input_dim[0] for a in input_dim ]):
            raise ValueError('All elements of input_dim must have the same value')

        if not isinstance(data, PreparedData):
            raise TypeError('data must be an instance of PreparedData')

        self.input_dim = input_dim[0]
        self.output_dim = 1
        self.data = data
        self.keep_prob = keep_prob
        self.activation = activation

        self.decoders = None
        self.build()

    def build(self) -> None:
        self.decoders = torch.nn.ModuleList()
        for fam in self.data.relation_families:
            dec = fam.decoder_class(self.input_dim, len(fam.relation_types),
                self.keep_prob, self.activation)
            self.decoders.append(dec)

    def _get_tvt(self, r, edge_list_attr_names, row, column, k, last_layer_repr, dec):
        start_time = time.time()
        pred = []
        for p in edge_list_attr_names:
            tvt = []
            for t in ['train', 'val', 'test']:
                # print('r:', r)
                edges = getattr(getattr(r, p), t)
                inputs_row = last_layer_repr[row][edges[:, 0]]
                inputs_column = last_layer_repr[column][edges[:, 1]]
                tvt.append(dec(inputs_row, inputs_column, k))
            tvt = TrainValTest(*tvt)
            pred.append(tvt)
        print('DecodeLayer._get_tvt() took:', time.time() - start_time)
        return pred

    def forward(self, last_layer_repr: List[torch.Tensor]) -> List[List[torch.Tensor]]:
        t = time.time()
        res = []
        for i, fam in enumerate(self.data.relation_families):
            fam_pred = []
            for k, r in enumerate(fam.relation_types):
                pred = []
                pred += self._get_tvt(r, ['edges_pos', 'edges_neg'],
                    r.node_type_row, r.node_type_column, k, last_layer_repr, self.decoders[i])
                pred += self._get_tvt(r, ['edges_back_pos', 'edges_back_neg'],
                    r.node_type_column, r.node_type_row, k, last_layer_repr, self.decoders[i])
                pred = RelationPredictions(*pred)
                fam_pred.append(pred)
            fam_pred = RelationFamilyPredictions(fam_pred)
            res.append(fam_pred)
        res = Predictions(res)
        print('DecodeLayer.forward() took', time.time() - t)
        return res