#   Copyright (c) 2019  PaddlePaddle Authors. All Rights Reserved.
#
# 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 x2paddle.core.graph import GraphNode, Graph
from tensorflow.python.platform import gfile
import tensorflow as tf
import copy

class TFGraphNode(GraphNode):
    def __init__(self, layer, layer_name=None):
        super(TFGraphNode, self).__init__(layer, layer_name)
        self.layer_type = layer.op


class TFGraph(Graph):
    def __init__(self, model):
        super(TFGraph, self).__init__(model)
        self.multi_output_ops = [
                            'Split',
                            'Unpack']

    def build(self):
        for layer in self.model.node:
            self.node_map[layer.name] = TFGraphNode(layer)

        for layer_name, node in self.node_map.items():
            for in_node in node.layer.input:
                if in_node not in self.node_map:
                    if in_node.strip().split(':')[0] in self.node_map:
                        self.connect(in_node, layer_name)
                    else:
                        raise Exception('input[{}] of node[{}] does not exist in node_map'.format(in_node, layer_name))
                else:
                    if self.node_map[in_node].layer_type in self.multi_output_ops:
                        in_node += ":0"
                    self.connect(in_node, layer_name)

        super(TFGraph, self).build()

class TFParser(object):
    def __init__(self, pb_model, in_nodes=None, out_nodes=None, in_shapes=None):
        assert in_nodes is not None, "in_nodes should not be None"
        assert out_nodes is not None, "out_nodes should not be None"
        assert in_shapes is not None, "in_shapes should not be None"
        assert len(in_shapes) == len(in_nodes), "length of in_shapes and in_nodes should be equal"

        sess = tf.Session()
        with gfile.FastGFile(pb_model, 'rb') as f:
            graph_def = tf.GraphDef()
            graph_def.ParseFromString(f.read())
            sess.graph.as_default()
            tf.import_graph_def(graph_def, name='')
        
        sess.run(tf.global_variables_initializer())

        self.tf_graph = TFGraph(sess.graph._as_graph_def(add_shapes=True)[0])
        self.tf_graph.build()