import streamlit as st
import pandas as pd
import numpy as np
from sklearn.preprocessing import MinMaxScaler
from sklearn.metrics import mean_squared_error, mean_absolute_percentage_error
from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import LSTM, Dense, Dropout
import matplotlib.pyplot as plt
from datetime import timedelta

# Load and preprocess data
@st.cache_data
def load_data():
    data = pd.read_csv("nyc_energy_consumption.csv")
    data.columns = ['timeStamp', 'demand', 'precip', 'temp']
    data['timeStamp'] = pd.to_datetime(data['timeStamp'])
    data.set_index('timeStamp', inplace=True)
    data = data.dropna()  # Drop any missing values
    return data

data = load_data()

# Scale the data
scaler = MinMaxScaler(feature_range=(0, 1))
scaled_data = scaler.fit_transform(data[['demand', 'precip', 'temp']])

# Create dataset function for LSTM
def create_dataset(dataset, look_back=60):
    X, y = [], []
    for i in range(look_back, len(dataset)):
        X.append(dataset[i-look_back:i])
        y.append(dataset[i, 0])  # Predicting demand
    return np.array(X), np.array(y)

# Set look-back period
look_back = 60
X, y = create_dataset(scaled_data, look_back)

# Split the dataset into train and test sets
split_ratio = 0.8
split_index = int(len(X) * split_ratio)
X_train, X_test = X[:split_index], X[split_index:]
y_train, y_test = y[:split_index], y[split_index:]

# Build and compile LSTM model
model = Sequential([
    LSTM(units=50, return_sequences=True, input_shape=(X_train.shape[1], X_train.shape[2])),
    Dropout(0.2),
    LSTM(units=50, return_sequences=False),
    Dropout(0.2),
    Dense(units=25),
    Dense(units=1)
])

model.compile(optimizer='adam', loss='mean_squared_error')

# Train the model with validation
history = model.fit(X_train, y_train, epochs=20, batch_size=64, validation_data=(X_test, y_test))

# Make predictions
train_predict = model.predict(X_train)
test_predict = model.predict(X_test)

# Inverse transform predictions to original scale
train_predict = scaler.inverse_transform(np.concatenate((train_predict, np.zeros((train_predict.shape[0], 2))), axis=1))[:, 0]
test_predict = scaler.inverse_transform(np.concatenate((test_predict, np.zeros((test_predict.shape[0], 2))), axis=1))[:, 0]
y_train_inv = scaler.inverse_transform(np.concatenate((y_train.reshape(-1, 1), np.zeros((y_train.shape[0], 2))), axis=1))[:, 0]
y_test_inv = scaler.inverse_transform(np.concatenate((y_test.reshape(-1, 1), np.zeros((y_test.shape[0], 2))), axis=1))[:, 0]

# Calculate error metrics
rmse = np.sqrt(mean_squared_error(y_test_inv, test_predict))
mape = mean_absolute_percentage_error(y_test_inv, test_predict) * 100
accuracy = 100 - mape

# Streamlit App with filter for future prediction periods
st.title("NYC Energy Consumption Forecasting with LSTM")
st.subheader("Dataset Preview")
st.write(data.head())

# Forecasting options
st.subheader("Forecasting Options")
forecast_period = st.slider("Select number of future hours to predict", min_value=1, max_value=365, value=30)

# Future prediction
future_X = scaled_data[-look_back:]
future_X = np.reshape(future_X, (1, look_back, scaled_data.shape[1]))

future_predictions = []
for _ in range(forecast_period):
    future_pred = model.predict(future_X)
    future_predictions.append(future_pred[0, 0])
    
    # Update future_X for the next prediction
    future_pred_expanded = np.array([[future_pred[0, 0], 0, 0]])  # Expand future_pred to match the 3 features
    future_X = np.append(future_X[:, 1:, :], [future_pred_expanded], axis=1)

# Scale back future predictions
future_predictions = scaler.inverse_transform(
    np.concatenate((np.array(future_predictions).reshape(-1, 1), np.zeros((forecast_period, 2))), axis=1))[:, 0]

# Generate dates for future predictions
last_date = data.index[-1]
future_dates = [last_date + timedelta(hours=i) for i in range(1, forecast_period + 1)]
future_predictions_df = pd.DataFrame({
    'DateTime': future_dates,
    'Predicted Demand': future_predictions
})

# Display evaluation metrics
st.subheader("Forecasting and Model Evaluation")
st.write(f"Root Mean Squared Error (RMSE): {rmse:.2f}")
st.write(f"Mean Absolute Percentage Error (MAPE): {mape:.2f}%")
st.write(f"Model Accuracy: {accuracy:.2f}%")

# Plotting actual vs predicted
st.subheader("Actual vs Predicted Demand")
plt.figure(figsize=(14,5))
plt.plot(y_test_inv, color='blue', label='Actual Demand')
plt.plot(test_predict, color='orange', linestyle='--', label='Predicted Demand')
plt.legend()
plt.xlabel('Time')
plt.ylabel('Demand')
st.pyplot(plt)

# Display future predictions in a DataFrame
st.subheader("Future Predictions with Date and Time")
st.write(future_predictions_df)

# Plotting future predictions
st.subheader("Future Predictions Plot")
plt.figure(figsize=(14,5))
plt.plot(range(len(y_test_inv), len(y_test_inv) + forecast_period), future_predictions, color='green', linestyle='--', label='Future Prediction')
plt.legend()
plt.xlabel('Future Time')
plt.ylabel('Demand')
st.pyplot(plt)