"""
 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 numpy as np

from mo.middle.passes.convert_data_type import data_type_str_to_np, np_data_type_to_destination_type, \
    precision_to_destination_type
from mo.ops.op import Op


class Const(Op):
    """
    Operation producing constant value stored in the attribute 'value' of shape 'shape'.
    """
    op = 'Const'

    def __init__(self, graph, attrs: dict = None):
        super().__init__(graph, {
            'type': self.op,
            'op': self.op,
            'version': 'opset1',
            'infer': self.infer,
            'value': None,
            'shape': None,
            'data_type': None,
            'out_ports_count': 1,
            'type_infer': self.type_infer,
        }, attrs)
        if not isinstance(self.attrs['value'], np.ndarray):
            self.attrs['value'] = np.array(self.attrs['value'])

        self.attrs['shape'] = np.array(self.attrs['value'].shape, dtype=np.int64)
        if 'force_shape' in self.attrs and self.attrs['force_shape'] is not None:
            self.attrs['shape'] = np.array(self.attrs['force_shape'], dtype=np.int64)

        self.attrs['data_type'] = self.attrs['value'].dtype
        if 'force_type' in self.attrs and self.attrs['force_type'] is not None:
            self.attrs['data_type'] = data_type_str_to_np(self.attrs['force_type'])

    def supported_attrs(self):
        return [
            'offset',
            'size',
            ('shape', lambda node: ','.join([str(i) for i in node.shape])),
            ('element_type', lambda node: precision_to_destination_type(node.force_type)
            if node.has_valid('force_type') else np_data_type_to_destination_type(node.value.dtype)),
        ]

    @staticmethod
    def type_infer(node):
        node.out_port(0).set_data_type(node.value.dtype, override=True)
        if node.has_valid('force_type'):
            node.out_port(0).set_data_type(node.data_type, override=True)

    @staticmethod
    def infer(node):
        # no broadcast, copy as-is (tensor or scalar) or apply broadcast depending on value and shape
        output_value = node.value if isinstance(node.value, np.ndarray) or len(node.shape) == 0 \
            else np.full(node.shape, node.value)

        node.out_port(0).data.set_value(output_value)