# SPDX-License-Identifier: Apache-2.0

import os
import sys
import unittest
from os.path import abspath, dirname

import mock_keras2onnx
import numpy as np
from mock_keras2onnx.proto import keras
from onnxconverter_common.onnx_ex import get_maximum_opset_supported

sys.path.insert(0, os.path.join(dirname(abspath(__file__)), '../../keras2onnx_tests/'))
from test_utils import run_keras_and_ort

K = keras.backend

Activation = keras.layers.Activation
AveragePooling2D = keras.layers.AveragePooling2D
Add = keras.layers.Add
add = keras.layers.add
BatchNormalization = keras.layers.BatchNormalization
Concatenate = keras.layers.Concatenate
concatenate = keras.layers.concatenate
Conv2D = keras.layers.Conv2D
Dense = keras.layers.Dense
DepthwiseConv2D = keras.layers.DepthwiseConv2D
Dropout = keras.layers.Dropout
Embedding = keras.layers.Embedding
Flatten = keras.layers.Flatten
GlobalAveragePooling2D = keras.layers.GlobalAveragePooling2D
Input = keras.layers.Input
Lambda = keras.layers.Lambda
LeakyReLU = keras.layers.LeakyReLU
MaxPooling2D = keras.layers.MaxPooling2D
multiply = keras.layers.multiply
Permute = keras.layers.Permute
Reshape = keras.layers.Reshape
SeparableConv2D = keras.layers.SeparableConv2D
UpSampling2D = keras.layers.UpSampling2D
ZeroPadding2D = keras.layers.ZeroPadding2D

Sequential = keras.models.Sequential
Model = keras.models.Model
import tensorflow as tf


def SepConv_BN(x, filters, prefix, stride=1, kernel_size=3, rate=1, depth_activation=False, epsilon=1e-3):
    if stride == 1:
        depth_padding = 'same'
    else:
        kernel_size_effective = kernel_size + (kernel_size - 1) * (rate - 1)
        pad_total = kernel_size_effective - 1
        pad_beg = pad_total // 2
        pad_end = pad_total - pad_beg
        x = ZeroPadding2D((pad_beg, pad_end))(x)
        depth_padding = 'valid'

    if not depth_activation:
        x = Activation(tf.nn.relu)(x)
    x = DepthwiseConv2D((kernel_size, kernel_size), strides=(stride, stride), dilation_rate=(rate, rate),
                        padding=depth_padding, use_bias=False, name=prefix + '_depthwise')(x)
    x = BatchNormalization(name=prefix + '_depthwise_BN', epsilon=epsilon)(x)
    if depth_activation:
        x = Activation(tf.nn.relu)(x)
    x = Conv2D(filters, (1, 1), padding='same',
               use_bias=False, name=prefix + '_pointwise')(x)
    x = BatchNormalization(name=prefix + '_pointwise_BN', epsilon=epsilon)(x)
    if depth_activation:
        x = Activation(tf.nn.relu)(x)

    return x


def _conv2d_same(x, filters, prefix, stride=1, kernel_size=3, rate=1):
    if stride == 1:
        return Conv2D(filters,
                      (kernel_size, kernel_size),
                      strides=(stride, stride),
                      padding='same', use_bias=False,
                      dilation_rate=(rate, rate),
                      name=prefix)(x)
    else:
        kernel_size_effective = kernel_size + (kernel_size - 1) * (rate - 1)
        pad_total = kernel_size_effective - 1
        pad_beg = pad_total // 2
        pad_end = pad_total - pad_beg
        x = ZeroPadding2D((pad_beg, pad_end))(x)
        return Conv2D(filters,
                      (kernel_size, kernel_size),
                      strides=(stride, stride),
                      padding='valid', use_bias=False,
                      dilation_rate=(rate, rate),
                      name=prefix)(x)


def _xception_block(inputs, depth_list, prefix, skip_connection_type, stride,
                    rate=1, depth_activation=False, return_skip=False):
    residual = inputs
    for i in range(3):
        residual = SepConv_BN(residual,
                              depth_list[i],
                              prefix + '_separable_conv{}'.format(i + 1),
                              stride=stride if i == 2 else 1,
                              rate=rate,
                              depth_activation=depth_activation)
        if i == 1:
            skip = residual
    if skip_connection_type == 'conv':
        shortcut = _conv2d_same(inputs, depth_list[-1], prefix + '_shortcut',
                                kernel_size=1,
                                stride=stride)
        shortcut = BatchNormalization(name=prefix + '_shortcut_BN')(shortcut)
        outputs = add([residual, shortcut])
    elif skip_connection_type == 'sum':
        outputs = add([residual, inputs])
    elif skip_connection_type == 'none':
        outputs = residual
    if return_skip:
        return outputs, skip
    else:
        return outputs


def _make_divisible(v, divisor, min_value=None):
    if min_value is None:
        min_value = divisor
    new_v = max(min_value, int(v + divisor / 2) // divisor * divisor)
    # Make sure that round down does not go down by more than 10%.
    if new_v < 0.9 * v:
        new_v += divisor
    return new_v


def _inverted_res_block(inputs, expansion, stride, alpha, filters, block_id, skip_connection, rate=1):
    in_channels = inputs.shape[-1].value  # inputs._keras_shape[-1]
    pointwise_conv_filters = int(filters * alpha)
    pointwise_filters = _make_divisible(pointwise_conv_filters, 8)
    x = inputs
    prefix = 'expanded_conv_{}_'.format(block_id)
    if block_id:
        # Expand

        x = Conv2D(expansion * in_channels, kernel_size=1, padding='same',
                   use_bias=False, activation=None,
                   name=prefix + 'expand')(x)
        x = BatchNormalization(epsilon=1e-3, momentum=0.999,
                               name=prefix + 'expand_BN')(x)
        x = Activation(tf.nn.relu6, name=prefix + 'expand_relu')(x)
    else:
        prefix = 'expanded_conv_'
    # Depthwise
    x = DepthwiseConv2D(kernel_size=3, strides=stride, activation=None,
                        use_bias=False, padding='same', dilation_rate=(rate, rate),
                        name=prefix + 'depthwise')(x)
    x = BatchNormalization(epsilon=1e-3, momentum=0.999,
                           name=prefix + 'depthwise_BN')(x)

    x = Activation(tf.nn.relu6, name=prefix + 'depthwise_relu')(x)

    # Project
    x = Conv2D(pointwise_filters,
               kernel_size=1, padding='same', use_bias=False, activation=None,
               name=prefix + 'project')(x)
    x = BatchNormalization(epsilon=1e-3, momentum=0.999,
                           name=prefix + 'project_BN')(x)

    if skip_connection:
        return Add(name=prefix + 'add')([inputs, x])

    # if in_channels == pointwise_filters and stride == 1:
    #    return Add(name='res_connect_' + str(block_id))([inputs, x])

    return x


def Deeplabv3(weights='pascal_voc', input_tensor=None, input_shape=(512, 512, 3), classes=21, backbone='mobilenetv2',
              OS=16, alpha=1., activation=None):

    img_input = Input(shape=input_shape)

    if backbone == 'xception':
        if OS == 8:
            entry_block3_stride = 1
            middle_block_rate = 2  # ! Not mentioned in paper, but required
            exit_block_rates = (2, 4)
            atrous_rates = (12, 24, 36)
        else:
            entry_block3_stride = 2
            middle_block_rate = 1
            exit_block_rates = (1, 2)
            atrous_rates = (6, 12, 18)

        x = Conv2D(32, (3, 3), strides=(2, 2),
                   name='entry_flow_conv1_1', use_bias=False, padding='same')(img_input)
        x = BatchNormalization(name='entry_flow_conv1_1_BN')(x)
        x = Activation(tf.nn.relu)(x)

        x = _conv2d_same(x, 64, 'entry_flow_conv1_2', kernel_size=3, stride=1)
        x = BatchNormalization(name='entry_flow_conv1_2_BN')(x)
        x = Activation(tf.nn.relu)(x)

        x = _xception_block(x, [128, 128, 128], 'entry_flow_block1',
                            skip_connection_type='conv', stride=2,
                            depth_activation=False)
        x, skip1 = _xception_block(x, [256, 256, 256], 'entry_flow_block2',
                                   skip_connection_type='conv', stride=2,
                                   depth_activation=False, return_skip=True)

        x = _xception_block(x, [728, 728, 728], 'entry_flow_block3',
                            skip_connection_type='conv', stride=entry_block3_stride,
                            depth_activation=False)
        for i in range(16):
            x = _xception_block(x, [728, 728, 728], 'middle_flow_unit_{}'.format(i + 1),
                                skip_connection_type='sum', stride=1, rate=middle_block_rate,
                                depth_activation=False)

        x = _xception_block(x, [728, 1024, 1024], 'exit_flow_block1',
                            skip_connection_type='conv', stride=1, rate=exit_block_rates[0],
                            depth_activation=False)
        x = _xception_block(x, [1536, 1536, 2048], 'exit_flow_block2',
                            skip_connection_type='none', stride=1, rate=exit_block_rates[1],
                            depth_activation=True)

    else:
        OS = 8
        first_block_filters = _make_divisible(32 * alpha, 8)
        x = Conv2D(first_block_filters,
                   kernel_size=3,
                   strides=(2, 2), padding='same',
                   use_bias=False, name='Conv')(img_input)
        x = BatchNormalization(
            epsilon=1e-3, momentum=0.999, name='Conv_BN')(x)
        x = Activation(tf.nn.relu6, name='Conv_Relu6')(x)

        x = _inverted_res_block(x, filters=16, alpha=alpha, stride=1,
                                expansion=1, block_id=0, skip_connection=False)

        x = _inverted_res_block(x, filters=24, alpha=alpha, stride=2,
                                expansion=6, block_id=1, skip_connection=False)
        x = _inverted_res_block(x, filters=24, alpha=alpha, stride=1,
                                expansion=6, block_id=2, skip_connection=True)

        x = _inverted_res_block(x, filters=32, alpha=alpha, stride=2,
                                expansion=6, block_id=3, skip_connection=False)
        x = _inverted_res_block(x, filters=32, alpha=alpha, stride=1,
                                expansion=6, block_id=4, skip_connection=True)
        x = _inverted_res_block(x, filters=32, alpha=alpha, stride=1,
                                expansion=6, block_id=5, skip_connection=True)

        # stride in block 6 changed from 2 -> 1, so we need to use rate = 2
        x = _inverted_res_block(x, filters=64, alpha=alpha, stride=1,  # 1!
                                expansion=6, block_id=6, skip_connection=False)
        x = _inverted_res_block(x, filters=64, alpha=alpha, stride=1, rate=2,
                                expansion=6, block_id=7, skip_connection=True)
        x = _inverted_res_block(x, filters=64, alpha=alpha, stride=1, rate=2,
                                expansion=6, block_id=8, skip_connection=True)
        x = _inverted_res_block(x, filters=64, alpha=alpha, stride=1, rate=2,
                                expansion=6, block_id=9, skip_connection=True)

        x = _inverted_res_block(x, filters=96, alpha=alpha, stride=1, rate=2,
                                expansion=6, block_id=10, skip_connection=False)
        x = _inverted_res_block(x, filters=96, alpha=alpha, stride=1, rate=2,
                                expansion=6, block_id=11, skip_connection=True)
        x = _inverted_res_block(x, filters=96, alpha=alpha, stride=1, rate=2,
                                expansion=6, block_id=12, skip_connection=True)

        x = _inverted_res_block(x, filters=160, alpha=alpha, stride=1, rate=2,  # 1!
                                expansion=6, block_id=13, skip_connection=False)
        x = _inverted_res_block(x, filters=160, alpha=alpha, stride=1, rate=4,
                                expansion=6, block_id=14, skip_connection=True)
        x = _inverted_res_block(x, filters=160, alpha=alpha, stride=1, rate=4,
                                expansion=6, block_id=15, skip_connection=True)

        x = _inverted_res_block(x, filters=320, alpha=alpha, stride=1, rate=4,
                                expansion=6, block_id=16, skip_connection=False)

    # end of feature extractor

    # branching for Atrous Spatial Pyramid Pooling

    # Image Feature branch
    shape_before = tf.shape(x)
    b4 = GlobalAveragePooling2D()(x)
    # from (b_size, channels)->(b_size, 1, 1, channels)
    b4 = Lambda(lambda x: K.expand_dims(x, 1))(b4)
    b4 = Lambda(lambda x: K.expand_dims(x, 1))(b4)
    b4 = Conv2D(256, (1, 1), padding='same',
                use_bias=False, name='image_pooling')(b4)
    b4 = BatchNormalization(name='image_pooling_BN', epsilon=1e-5)(b4)
    b4 = Activation(tf.nn.relu)(b4)
    # upsample. have to use compat because of the option align_corners
    size_before = tf.keras.backend.int_shape(x)
    b4 = Lambda(lambda x: tf.compat.v1.image.resize(x, size_before[1:3],
                                                    method='bilinear', align_corners=True))(b4)
    # simple 1x1
    b0 = Conv2D(256, (1, 1), padding='same', use_bias=False, name='aspp0')(x)
    b0 = BatchNormalization(name='aspp0_BN', epsilon=1e-5)(b0)
    b0 = Activation(tf.nn.relu, name='aspp0_activation')(b0)

    # there are only 2 branches in mobilenetV2. not sure why
    if backbone == 'xception':
        # rate = 6 (12)
        b1 = SepConv_BN(x, 256, 'aspp1',
                        rate=atrous_rates[0], depth_activation=True, epsilon=1e-5)
        # rate = 12 (24)
        b2 = SepConv_BN(x, 256, 'aspp2',
                        rate=atrous_rates[1], depth_activation=True, epsilon=1e-5)
        # rate = 18 (36)
        b3 = SepConv_BN(x, 256, 'aspp3',
                        rate=atrous_rates[2], depth_activation=True, epsilon=1e-5)

        # concatenate ASPP branches & project
        x = Concatenate()([b4, b0, b1, b2, b3])
    else:
        x = Concatenate()([b4, b0])

    x = Conv2D(256, (1, 1), padding='same',
               use_bias=False, name='concat_projection')(x)
    x = BatchNormalization(name='concat_projection_BN', epsilon=1e-5)(x)
    x = Activation(tf.nn.relu)(x)
    x = Dropout(0.1)(x)
    # DeepLab v.3+ decoder

    if backbone == 'xception':
        # Feature projection
        # x4 (x2) block
        skip_size = tf.keras.backend.int_shape(skip1)
        x = Lambda(lambda xx: tf.compat.v1.image.resize(xx,
                                                        skip_size[1:3],
                                                        method='bilinear', align_corners=True))(x)

        dec_skip1 = Conv2D(48, (1, 1), padding='same',
                           use_bias=False, name='feature_projection0')(skip1)
        dec_skip1 = BatchNormalization(
            name='feature_projection0_BN', epsilon=1e-5)(dec_skip1)
        dec_skip1 = Activation(tf.nn.relu)(dec_skip1)
        x = Concatenate()([x, dec_skip1])
        x = SepConv_BN(x, 256, 'decoder_conv0',
                       depth_activation=True, epsilon=1e-5)
        x = SepConv_BN(x, 256, 'decoder_conv1',
                       depth_activation=True, epsilon=1e-5)

    # you can use it with arbitary number of classes
    if (weights == 'pascal_voc' and classes == 21) or (weights == 'cityscapes' and classes == 19):
        last_layer_name = 'logits_semantic'
    else:
        last_layer_name = 'custom_logits_semantic'

    x = Conv2D(classes, (1, 1), padding='same', name=last_layer_name)(x)
    size_before3 = tf.keras.backend.int_shape(img_input)
    x = Lambda(lambda xx: tf.compat.v1.image.resize(xx,
                                                    size_before3[1:3],
                                                    method='bilinear', align_corners=True))(x)

    inputs = img_input

    if activation in {'softmax', 'sigmoid'}:
        x = tf.keras.layers.Activation(activation)(x)

    model = Model(inputs, x, name='deeplabv3plus')
    return model

# Model from https://github.com/bonlime/keras-deeplab-v3-plus
class TestDeepLabV3(unittest.TestCase):

    def setUp(self):
        self.model_files = []

    def tearDown(self):
        for fl in self.model_files:
            os.remove(fl)

    @unittest.skipIf(get_maximum_opset_supported() < 11,
                     "DeeplabV3 is not supported for opset < 11.")
    def test_Deeplab_v3(self):
        K.clear_session()
        keras_model = Deeplabv3(weights=None)
        data = np.random.rand(2, 512, 512, 3).astype(np.float32)
        expected = keras_model.predict(data)
        onnx_model = mock_keras2onnx.convert_keras(keras_model, keras_model.name)
        self.assertTrue(
            run_keras_and_ort(onnx_model.graph.name, onnx_model, keras_model, data, expected, self.model_files))


if __name__ == "__main__":
    unittest.main()
