#-*- coding:utf-8 -*-
#author:zhangwei

'''
   此脚本是采用Densenet网络构建端到端声学模型，目前最好的识别效果是32.27%;
'''

from general_function.file_wav import *
from general_function.file_wav import *
from general_function.file_dict import *
from general_function.feature_extract import *
from general_function.edit_distance import *

import keras as kr
import numpy as np
import random

from keras.utils import plot_model
from keras.models import Model
from keras.utils import plot_model
from keras.layers import Dense , Dropout , Input , Reshape , multiply
from keras.layers import Conv2D , MaxPooling2D , Lambda , Activation , regularizers , AveragePooling2D , concatenate
from keras.layers.normalization import BatchNormalization
from keras import backend as K
from keras.optimizers import SGD , Adadelta , Adam
from keras.layers.advanced_activations import ELU, LeakyReLU

from readdata_densenet_01 import DataSpeech

class ModelSpeech():
    def __init__(self , datapath):
        MS_OUTPUT_SIZE = 1422
        k = 8
        self.MS_OUTPUT_SIZE = MS_OUTPUT_SIZE
        self.label_max_string_length = 64
        self.AUDIO_LENGTH = 1600
        self.AUDIO_FEATURE_LENGTH = 120
        self.k = k
        self.datapath = datapath
        self._model , self.base_model = self.creat_model()

        self.slash = '/'
        if self.datapath[-1] != self.slash:
            self.datapath = self.datapath + self.slash
        pass

    def creat_model(self):
        k = self.k
        input_data = Input(shape=[self.AUDIO_LENGTH , self.AUDIO_FEATURE_LENGTH , 1] , name='Input')
        conv1 = Conv2D(filters=k * 2, kernel_size=[3, 3] , padding='same' , use_bias=True , kernel_initializer='he_normal')(input_data)
        conv1 = BatchNormalization()(conv1)
        conv1 = Activation(activation='relu')(conv1)
        x = MaxPooling2D(pool_size=[2, 1] , strides=[2 , 1])(conv1)

        b1_1 = self.dense_block(x, k)
        b1_1_conc = concatenate([x, b1_1], axis=-1)
        b1_2 = self.dense_block(b1_1_conc, k)
        b1_2_conc = concatenate([x, b1_1, b1_2], axis=-1)
        b1_3 = self.dense_block(b1_2_conc, k)
        b1_3_conc = concatenate([x, b1_1, b1_2, b1_3], axis=-1)
        b1_4 = self.dense_block(b1_3_conc, k)
        b1_4_conc = concatenate([x, b1_1, b1_2, b1_3, b1_4], axis=-1)
        b1_5 = self.dense_block(b1_4_conc, k)
        b1_5_conc = concatenate([x, b1_1, b1_2, b1_3, b1_4, b1_5], axis=-1)
        transion_1 = self.transition_layer(b1_5_conc, k)

        b2_1 = self.dense_block(transion_1, k)
        b2_1_conc = concatenate([transion_1, b2_1], axis=-1)
        b2_2 = self.dense_block(b2_1_conc, k)
        b2_2_conc = concatenate([transion_1, b2_1, b2_2], axis=-1)
        b2_3 = self.dense_block(b2_2_conc, k)
        b2_3_conc = concatenate([transion_1, b2_1, b2_2, b2_3], axis=-1)
        b2_4 = self.dense_block(b2_3_conc, k)
        b2_4_conc = concatenate([transion_1, b2_1, b2_2, b2_3, b2_4], axis=-1)
        b2_5 = self.dense_block(b2_4_conc, k)
        b2_5_conc = concatenate([transion_1, b2_1, b2_2, b2_3, b2_4, b2_5], axis=-1)
        transion_2 = self.transition_layer(b2_5_conc, k)

        b3_1 = self.dense_block(transion_2, k)
        b3_1_conc = concatenate([transion_2, b3_1], axis=-1)
        b3_2 = self.dense_block(b3_1_conc, k)
        b3_2_conc = concatenate([transion_2, b3_1 , b3_2], axis=-1)
        b3_3 = self.dense_block(b3_2_conc, k)
        b3_3_conc = concatenate([transion_2, b3_1 , b3_2 , b3_3], axis=-1)
        b3_4 = self.dense_block(b3_3_conc, k)
        b3_4_conc = concatenate([transion_2, b3_1 , b3_2 , b3_3 , b3_4], axis=-1)
        b3_5 = self.dense_block(b3_4_conc, k)
        b3_5_conc = concatenate([transion_2, b3_1 , b3_2 , b3_3 , b3_4 , b3_5], axis=-1)
        transion_3 = self.transition_layer(b3_5_conc, k)

        reshape_layer = Reshape([100 , 120])(transion_3)
        # dense1 = Dense(units=256 , use_bias=True , kernel_initializer='he_normal')(reshape_layer)
        # dense1 = BatchNormalization()(dense1)
        # dense1 = Activation(activation='relu')(dense1)
        # dense1 = Dropout(rate=0.1)(dense1)
        dense2 = Dense(units=1024 , use_bias=True , kernel_initializer='he_normal')(reshape_layer)
        dense2 = BatchNormalization()(dense2)
        dense2 = Activation(activation='relu')(dense2)
        dense2 = Dropout(rate=0.2)(dense2)
        dense3 = Dense(units=self.MS_OUTPUT_SIZE , use_bias=True)(dense2)
        y_pred = Activation(activation='softmax')(dense3)

        model_data = Model(inputs=input_data , outputs=y_pred)

        model_data.summary()
        plot_model(model_data , '/home/zhangwei/01.png' , show_shapes=True)

        labels = Input(shape=[self.label_max_string_length], name='labels', dtype='float32')
        input_length = Input(shape=[1], name='input_length', dtype='int64')
        label_length = Input(shape=[1], name='label_length', dtype='int64')
        loss_out = Lambda(self.ctc_lambda_func, output_shape=[1, ], name='ctc')([y_pred , labels, input_length, label_length])
        model = Model(inputs=[input_data, labels, input_length, label_length], outputs=loss_out)
        sgd = SGD(lr=0.00001, decay=1e-6, momentum=0.9, nesterov=True, clipnorm=5)
        ada_d = Adadelta(lr=0.0005 , rho=0.95, epsilon=1e-6)
        adam = Adam(lr=0.001, epsilon=1e-6, decay=10e-3)

        model.compile(optimizer=adam , loss={'ctc': lambda y_true, y_pred: y_pred})

        print('==========================模型创建成功=================================')
        return model, model_data

    def dense_block(self , input_tensor , channels):
        bn1 = BatchNormalization()(input_tensor)
        relu = Activation(activation='relu')(bn1)
        conv1 = Conv2D(filters=4 * channels, kernel_size=[1, 1], padding='same' , use_bias=True , kernel_initializer='he_normal')(relu)
        bn2 = BatchNormalization()(conv1)
        relu2 = Activation(activation='relu')(bn2)
        conv2 = Conv2D(filters=channels, kernel_size=[3, 3], padding='same' , use_bias=True , kernel_initializer='he_normal')(relu2)
        return conv2

    def transition_layer(self , input_tensor , channels):
        conv = Conv2D(filters=channels , kernel_size=[1, 1], padding='same' , use_bias=True , kernel_initializer='he_normal')(input_tensor)
        pool = MaxPooling2D(pool_size=[2, 2], strides=[2, 2])(conv)
        return pool

    def ctc_lambda_func(self , args):
        y_pred, labels, input_length, label_length = args
        y_pred = y_pred[:, :, :]
        return K.ctc_batch_cost(y_true=labels , y_pred=y_pred , input_length=input_length , label_length=label_length)

    def train_model(self , datapath , epoch=4 , save_step=2000 , batch_size=4):
        data = DataSpeech(datapath , 'train')
        num_data = data.get_datanum()
        yielddatas = data.data_generator(batch_size , self.AUDIO_LENGTH)
        for epoch in range(epoch):
            print('[*running] train epoch %d .' % epoch)
            n_step = 0
            while True:
                try:
                    print('[*message] epoch %d , Having training data %d+' % (epoch , n_step * save_step))
                    self._model.fit_generator(yielddatas , save_step)
                    n_step += 1
                except StopIteration:
                    print('======================Error StopIteration==============================')
                    break
                self.save_model(comments='_e_' + str(epoch) + '_step_' + str(n_step * save_step))
                self.test_model(datapath=self.datapath , str_dataset='train' , data_count=4)
                self.test_model(datapath=self.datapath , str_dataset='dev' , data_count=16)

    def load_model(self , filename='model_speech_e_0_step_16000.model'):
        self._model.load_weights(filename)
        self.base_model.load_weights(filename + '.base')

    def test_model(self , datapath='' , str_dataset='dev' , data_count=1):
        data = DataSpeech(self.datapath , str_dataset)
        num_data = data.get_datanum()
        # print num_data
        if data_count <=0 and data_count > num_data:
            data_count = num_data
        try:
            ran_num = random.randint(0 , num_data - 1)
            words_num = 0.
            word_error_num = 0.
            for i in range(data_count):
                data_input , data_labels = data.get_data((ran_num + i) % num_data)
                # print data_input
                num_bias = 0
                while data_input.shape[0] > self.AUDIO_LENGTH:
                    print('[*Error] data input is too long %d' % ((ran_num + i) % num_data))
                    num_bias += 1
                    data_input , data_labels = data.get_data((ran_num + i + num_bias) % num_data)

                pre = self.predict(data_input=data_input , input_len=data_input.shape[0] // 16)                   #1
                words_n = data_labels.shape[0]
                words_num += words_n
                edit_distance = get_edit_distance(data_labels , pre)
                if edit_distance <= words_n:
                    word_error_num += edit_distance
                else:
                    word_error_num += words_n
            # print type(words_num)
            print('[*Test Result] Speech Recognition ' + str_dataset + ' set word error ratio : ' + str(word_error_num / words_num * 100) , '%')
        except StopIteration:
            print('=======================Error StopIteration 01======================')

    def save_model(self , filename='/home/zhangwei/speech_model/speech_model' , comments=''):
        self._model.save_weights(filename + comments + '.model')
        self.base_model.save_weights(filename + comments + '.model.base')
        f = open('steps24.txt' , 'w')
        f.write(filename + comments)
        f.close()

    def predict(self , data_input , input_len):
        batch_size = 1
        in_len = np.zeros((batch_size) , dtype=np.int32)
        in_len[0] = input_len
        x_in = np.zeros(shape=[batch_size , 1600 , self.AUDIO_FEATURE_LENGTH , 1] , dtype=np.float)
        for i in range(batch_size):
            x_in[i , 0 : len(data_input)] = data_input
        base_pred = self.base_model.predict(x=x_in)
        base_pred = base_pred[: , : , :]
        r = K.ctc_decode(base_pred , in_len , greedy=True , beam_width=100 , top_paths=1)
        r1 = K.get_value(r[0][0])
        r1 = r1[0]
        return r1

    def recognize_speech(self , wavsignal , fs):
        data_input = get_frequency_feature(wavsignal , fs)
        input_length = len(data_input)
        input_length = input_length // 16                     #2
        data_input = np.array(data_input , dtype=np.float)
        data_input = data_input.reshape(data_input.shape[0] , data_input.shape[1] , 1)
        r1 = self.predict(data_input , input_length)
        # print r1
        list_symbol_dic = get_list_symbol(self.datapath)
        r_str = []
        for i in r1:
            r_str.append(list_symbol_dic[i])
        return r_str

    def recognize_speech_fromfile(self , filename):
        wavsignal , fs = read_wav_data(filename)
        r = self.recognize_speech(wavsignal , fs)
        return r

    def recognize_speech_pinzhen(self , wavsignal , fs):
        data_input = get_frequency_feature(wavsignal , fs)
        input_length = len(data_input)
        input_length = input_length // 16                                                                          #2
        data_input = np.array(data_input , dtype=np.float)
        data_input = data_input.reshape(data_input.shape[0] , data_input.shape[1] , 1)
        r1 = self.predict(data_input , input_length)
        # print r1
        list_symbol_dic = get_list_symbol(self.datapath)
        r_str = []
        for i in r1:
            r_str.append(list_symbol_dic[i])
        return r_str



if __name__ == '__main__':
    import tensorflow as tf
    from keras.backend.tensorflow_backend import set_session
    config = tf.ConfigProto()
    config.gpu_options.per_process_gpu_memory_fraction = 0.95
    set_session(tf.Session(config=config))

    datapath = '/home/zhangwei/PycharmProjects/ASR_Thchs30/data_list/'
    speech = ModelSpeech(datapath=datapath)
    # speech.creat_model()
    speech.train_model(datapath=datapath)