# Copyright (c) 2016-present, Facebook, Inc.
#
# 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.
##############################################################################

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals

from caffe2.python import scope
from caffe2.python.modeling.parameter_sharing import (
    ParameterSharing,
)
from caffe2.python.layer_test_util import LayersTestCase


class ParameterSharingTest(LayersTestCase):

    def test_layer_parameter_name(self):
        output_dims = 2
        with scope.NameScope('global_scope'):
            fc1_output = self.model.FC(
                self.model.input_feature_schema.float_features,
                output_dims
            )
            self.assertEquals(self.model.layers[-1].w, 'global_scope/fc/w')
            self.assertEquals(fc1_output(), 'global_scope/fc/output')

            with scope.NameScope('nested_scope'):
                fc2_output = self.model.FC(
                    fc1_output,
                    output_dims
                )
                self.assertEquals(self.model.layers[-1].w,
                                  'global_scope/nested_scope/fc/w')
                self.assertEquals(fc2_output(),
                                  'global_scope/nested_scope/fc/output')

                fc3_output = self.model.FC(
                    fc1_output,
                    output_dims
                )
                self.assertEquals(self.model.layers[-1].w,
                                  'global_scope/nested_scope/fc_auto_0/w')
                self.assertEquals(fc3_output(),
                                  'global_scope/nested_scope/fc_auto_0/output')

    def test_layer_shared_parameter_name_different_namescopes(self):
        output_dims = 2
        with scope.NameScope('global_scope'):
            with ParameterSharing({'scope_1': 'scope_0'}):
                with scope.NameScope('scope_0'):
                    fc1_output = self.model.FC(
                        self.model.input_feature_schema.float_features,
                        output_dims
                    )
                    self.assertEquals(self.model.layers[-1].w,
                                      'global_scope/scope_0/fc/w')
                    self.assertEquals(fc1_output(),
                                      'global_scope/scope_0/fc/output')

                with scope.NameScope('scope_1'):
                    fc2_output = self.model.FC(
                        self.model.input_feature_schema.float_features,
                        output_dims
                    )
                    self.assertEquals(self.model.layers[-1].w,
                                      'global_scope/scope_0/fc/w')
                    self.assertEquals(fc2_output(),
                                      'global_scope/scope_1/fc/output')

    def test_layer_shared_parameter_name_within_same_namescope(self):
        output_dims = 2
        with scope.NameScope('global_scope'):
            with ParameterSharing({'fc_auto_0': 'fc'}):
                self.model.FC(
                    self.model.input_feature_schema.float_features,
                    output_dims
                )
                self.assertEquals(self.model.layers[-1].w,
                                  'global_scope/fc/w')

                self.model.FC(
                    self.model.input_feature_schema.float_features,
                    output_dims
                )
                self.assertEquals(self.model.layers[-1].w,
                                  'global_scope/fc/w')

    def test_layer_shared_parameter_name_within_same_namescope_customized_name(self):
        output_dims = 2
        with scope.NameScope('global_scope'):
            with ParameterSharing({'new_fc': 'shared_fc'}):
                self.model.FC(
                    self.model.input_feature_schema.float_features,
                    output_dims,
                    name='shared_fc'
                )
                self.assertEquals(self.model.layers[-1].w,
                                  'global_scope/shared_fc/w')

                self.model.FC(
                    self.model.input_feature_schema.float_features,
                    output_dims,
                    name='new_fc'
                )
                self.assertEquals(self.model.layers[-1].w,
                                  'global_scope/shared_fc/w')

    def test_layer_shared_parameter_name_different_shapes(self):
        output_dims = 2
        with scope.NameScope('global_scope'):
            with ParameterSharing({'fc_auto_0': 'fc'}):
                self.model.FC(
                    self.model.input_feature_schema.float_features,
                    output_dims
                )
                self.assertEquals(self.model.layers[-1].w,
                                  'global_scope/fc/w')

                with self.assertRaisesRegexp(ValueError, 'Got inconsistent shapes .*'):
                    self.model.FC(
                        self.model.input_feature_schema.float_features,
                        output_dims + 1
                    )
