"""
 Copyright (C) 2018-2020 Intel Corporation

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
"""
import logging as log

import numpy as np

from extensions.ops.upsample import UpsampleOp
from mo.front.common.partial_infer.utils import int64_array
from mo.front.common.replacement import FrontReplacementSubgraph
from mo.graph.graph import Graph, Node


class BatchToSpaceToUpsample(FrontReplacementSubgraph):
    """
    The transformation looks for pattern that performs NX upscale of the input image specified in the NHWC layout.
    """
    enabled = True

    def run_before(self):
        from extensions.front.tf.space_to_batch import BatchToSpaceNormalizer
        return [BatchToSpaceNormalizer]

    @staticmethod
    def pattern(**kwargs):
        return dict(
            nodes=[
                ('transpose', dict(op='Transpose')),
                ('expand_dims', dict(op='Unsqueeze')),
                ('tile', dict(op='Tile')),
                ('batch_to_space_nd', dict(op='BatchToSpace')),
                ('strided_slice', dict(op='StridedSlice')),
                ('transpose_back', dict(op='Transpose')),
            ],
            edges=[
                ('transpose', 'expand_dims', {'out': 0}),
                ('expand_dims', 'tile', {'out': 0}),
                ('tile', 'batch_to_space_nd', {'out': 0}),
                ('batch_to_space_nd', 'strided_slice', {'out': 0}),
                ('strided_slice', 'transpose_back', {'out': 0})
            ]
        )

    @staticmethod
    def replace_sub_graph(graph: Graph, match: dict, **kwargs):
        def _input_node_value(node: Node, port_ind: int):
            input_node = node.in_port(port_ind).get_source().node
            return input_node.value if input_node.op == 'Const' else None

        transpose = match['transpose']
        transpose_order = _input_node_value(transpose, 1)
        if transpose_order is None or not np.all(np.equal(transpose_order, int64_array([1, 2, 3, 0]))):
            log.debug('The transpose order {} for node {} is not equal to [1, 2, 3, 0]. Cannot apply '
                      'BatchToSpaceToUpsample transformation.'.format(transpose_order, transpose.name))
            return

        expand_axis = match['expand_dims']
        expand_axis_value = _input_node_value(expand_axis, 1)
        if expand_axis_value != 0:
            log.debug('The expand axis {} for node {} is not equal to 0. Cannot apply BatchToSpaceToUpsample '
                      'transformation.'.format(expand_axis_value, expand_axis.name))
            return

        tile = match['tile']
        tile_value = _input_node_value(tile, 1)
        if tile_value is None:
            log.debug('The tile value is not defined for node {}. Cannot apply BatchToSpaceToUpsample '
                      'transformation.'.format(tile.name))
            return

        if len(np.where(tile_value != 1)) != 1:
            log.debug('The number of tiles not equal to 1 not equal to 1. Cannot apply BatchToSpaceToUpsample '
                      'transformation.')
            return
        tile_batch = tile_value[0]

        batch_to_space_nd = match['batch_to_space_nd']
        block_shape = _input_node_value(batch_to_space_nd, 1)
        if block_shape is None or tile_batch != np.prod(block_shape):
            log.debug('The block shape {} for node {} is not defined or inconsistent with the tile size. Cannot apply '
                      'BatchToSpaceToUpsample transformation.'.format(block_shape, batch_to_space_nd.name))
            return
        if len(block_shape) != 2:
            log.debug('The block shape len is not equal to 2 for node {}. Cannot apply BatchToSpaceToUpsample '
                      'transformation.'.format(batch_to_space_nd.name))
            return

        transpose_back = match['transpose_back']
        transpose_back_order = _input_node_value(transpose_back, 1)
        if transpose_back_order is None or not np.all(np.equal(transpose_back_order, int64_array([3, 0, 1, 2]))):
            log.debug('The transpose order {} for node {} is not equal to [3, 0, 1, 2]. Cannot apply '
                      'BatchToSpaceToUpsample transformation.'.format(transpose_back_order, transpose_back.name))
            return

        upsample_node = UpsampleOp(graph, {'height_scale': block_shape[0], 'width_scale': block_shape[1],
                                           'mode': 'nearest',
                                           'name': transpose.name + '/upsample'}).create_node()

        match['transpose'].in_port(0).get_connection().set_destination(upsample_node.in_port(0))
        match['transpose_back'].out_port(0).get_connection().set_source(upsample_node.out_port(0))
