import numpy as np
import tensorflow as tf
from tensorflow.keras.layers import Dropout, Dense, GRU
import matplotlib.pyplot as plt
import os
import pandas as pd
from sklearn.preprocessing import MinMaxScaler
from sklearn.metrics import mean_squared_error, mean_absolute_error
import math

CSV_PATH = './1.csv'
maotai = pd.read_csv(CSV_PATH)
# 划分测试集和验证集
training_set = maotai.iloc[0:2426-300, 2:3].values
test_set = maotai.iloc[2426-300:, 2:3].values
# 归一化到 0-1 之间
sc = MinMaxScaler(feature_range=(0, 1))
training_set_scaled = sc.fit_transform(training_set)
# print(training_set_scaled)
# print(test_set)
test_set = sc.transform(test_set)
# print(test_set)
x_train = []
y_train = []
x_test = []
y_test = []

print(len(x_train), len(y_train))

for i in range(60, len(training_set_scaled)):
    x_train.append(training_set_scaled[i-60:i, 0])
    y_train.append(training_set_scaled[i, 0])
np.random.seed(7)
np.random.shuffle(x_train)
np.random.seed(7)
np.random.shuffle(y_train)
tf.random.set_seed(7)

x_train, y_train = np.array(x_train), np.array(y_train)
x_train = np.reshape(x_train, (x_train.shape[0], 60, 1))

for i in range(60, len(test_set)):
    x_test.append(test_set[i-60:i, 0])
    y_test.append(test_set[i, 0])
x_test, y_test = np.array(x_test), np.array(y_test)
x_test = np.reshape(x_test, (x_test.shape[0], 60, 1))

model = tf.keras.Sequential([
    GRU(80, return_sequences=True),
    Dropout(0.2),
    GRU(100),
    Dropout(0.2),
    Dense(1)
])
model.compile(optimizer=tf.keras.optimizers.Adam(0.001), loss='mean_squared_error')
checkpoint_save_path = "./checkpoint/stock.ckpt"

if os.path.exists(checkpoint_save_path + '.index'):
    print('-------------load the model-----------------')
    model.load_weights(checkpoint_save_path)

cp_callback = tf.keras.callbacks.ModelCheckpoint(filepath=checkpoint_save_path,
                                                 save_weights_only=True,
                                                 save_best_only=True,
                                                 monitor='val_loss')

history = model.fit(x_train, y_train, batch_size=64, epochs=10, validation_data=(x_test, y_test), validation_freq=1,
                    callbacks=[cp_callback])

model.summary()

file = open('./weights.txt', 'w')  # 参数提取
for v in model.trainable_variables:
    file.write(str(v.name) + '\n')
    file.write(str(v.shape) + '\n')
    file.write(str(v.numpy()) + '\n')
file.close()

loss = history.history['loss']
val_loss = history.history['val_loss']

plt.plot(loss, label='Training Loss')
plt.plot(val_loss, label='Validation Loss')
plt.title('Training and Validation Loss')
plt.legend()
plt.show()

################## predict ######################
# 测试集输入模型进行预测
predicted_stock_price = model.predict(x_test)
# 对预测数据还原---从（0，1）反归一化到原始范围
predicted_stock_price = sc.inverse_transform(predicted_stock_price)
# 对真实数据还原---从（0，1）反归一化到原始范围
real_stock_price = sc.inverse_transform(test_set[60:])
# 画出真实数据和预测数据的对比曲线
plt.plot(real_stock_price, color='red', label='MaoTai Stock Price')
plt.plot(predicted_stock_price, color='blue', label='Predicted MaoTai Stock Price')
plt.title('MaoTai Stock Price Prediction')
plt.xlabel('Time')
plt.ylabel('MaoTai Stock Price')
plt.legend()
plt.show()

##########evaluate##############
# calculate MSE 均方误差 ---> E[(预测值-真实值)^2] (预测值减真实值求平方后求均值)
mse = mean_squared_error(predicted_stock_price, real_stock_price)
# calculate RMSE 均方根误差--->sqrt[MSE]    (对均方误差开方)
rmse = math.sqrt(mean_squared_error(predicted_stock_price, real_stock_price))
# calculate MAE 平均绝对误差----->E[|预测值-真实值|](预测值减真实值求绝对值后求均值）
mae = mean_absolute_error(predicted_stock_price, real_stock_price)
print('均方误差: %.6f' % mse)
print('均方根误差: %.6f' % rmse)
print('平均绝对误差: %.6f' % mae)