import streamlit as st 
import pandas as pd 
import numpy as np 
import matplotlib.pyplot as plt 
import seaborn as sns 
import sklearn
import keras
import re

from sklearn.datasets import make_moons, make_circles
from sklearn.model_selection import train_test_split
from sklearn.preprocessing import StandardScaler

from keras.models import Sequential
from keras.layers import InputLayer, Dense, Dropout
from keras.optimizers import SGD
from keras.regularizers import l1, l2
from keras.callbacks import EarlyStopping

from mlxtend.plotting import plot_decision_regions

st.title("Neural Network PlayGround")

#datasets
with st.sidebar:
    dataset = st.selectbox("Select Dataset",["Moons","Circles","Upload ypur own file"])
    noise = st.slider("Noise", 0.0, 0.5, 0.2)
    t_s = st.slider("Select test size", 0.1, 0.4, 0.01)

    st.header("Parameters")
    epochs = st.number_input("Enter number of epochs",1,100000)
    hidden_layers = st.number_input("Enter number of hidden layers",0,7,1)

    collect_numbers = lambda x: [int(i) for i in re.split("[^0-9]", x) if i != ""]
    numbers = st.text_input("Neurons in each hidden layer (comma separated)")
    nn = collect_numbers(numbers)

col1,col2,col3 = st.columns(3)

with col1:
    learning_rate = st.selectbox("Learning rate",[0.1,0.01,0.001])

with col2:
    activation_fun = st.selectbox("Activation Function",['relu','tanh','sigmoid'])

with col3:
    Regularization = st.selectbox("Regularizer",['None','l1','l2'])

col4,col5 = st.columns(2)

with col4:
    reg_rate = st.selectbox(
        "Regularizer Rate",
        [0, 0.001, 0.003, 0.01, 0.03, 0.1, 0.3, 1, 3, 10]
    )

with col5:
    early_stop_option = st.selectbox("Early Stopping", ["No", "Yes"], index=0)

if early_stop_option == "Yes":
    col6, col7 = st.columns(2)
    with col6:
        min_delta = st.selectbox(
            "Minimum Delta",
            [0, 0.00001, 0.0001, 0.0003, 0.001, 0.003, 0.01, 0.03, 0.1, 0.3, 1, 2, 3]
        )
    with col7:
        patience = st.selectbox(
            "Patience",
            [10, 15, 20, 25, 30, 35, 40, 45, 50],
            index=0
        )
        
    
    upload_files = st.file_uploader("Upload Dataset",type = ["csv",'xlsx'])
    if upload_files:
        if upload_files.name.endswith(".csv"):
            df = pd.read_csv(upload_files)
        else:
            df = pd.read_excel(upload_files)
        columns = df.columns.tolist()
        class_var = st.selectbox("Select class variable (target)", columns)
        st.write(class_var)
if st.button("start trainning"):
    if dataset:
        if dataset=="Circles":
            x,y=make_circles(n_samples=10000,noise=noise,random_state=1,factor=0.1)
        elif dataset=="Moons":
            x,y=make_moons(n_samples=10000,noise=noise,random_state=1)
        
    
    x_train,x_test,y_train,y_test=train_test_split(x,y,test_size=t_s ,random_state=1,stratify=y)
    std = StandardScaler()
    x_train = std.fit_transform(x_train)
    x_test = std.transform(x_test)

    if Regularization:
        if Regularization == 'l1':
           l1_ = l1(l1 = reg_rate)
        elif Regularization == 'l2':
            l2_=l2(l2 = reg_rate)
        else:
            Regularization = None

    #Model 
    model = Sequential()
    model.add(InputLayer(shape = (x_train.shape[1],)))
    if hidden_layers == len(nn):
        for i in range(0,len(nn)):
            model.add(Dense(units = nn[i],activation = activation_fun,kernel_regularizer = Regularization))
        model.add(Dense(units = 1,activation = 'sigmoid',kernel_regularizer = Regularization))
        sgd = SGD(learning_rate = 0.01)
        model.compile(loss="binary_crossentropy", optimizer=sgd, metrics=["accuracy"])
        a = round(x_train.shape[0] - x_train.shape[0]*0.2)
        
        callbacks = []
        if early_stop_option == "Yes":
            es = EarlyStopping(
                monitor="val_loss",
                min_delta= min_delta if min_delta else 0.001,
                patience=patience,
                verbose=1,
                restore_best_weights=True,
                start_from_epoch=120
            )
            callbacks.append(es)
        hist=model.fit(x_train,y_train,epochs=epochs,batch_size=a,validation_data=(x_test, y_test),verbose=False)
        
    
        st.markdown("---")
        col1, col2 = st.columns(2)
        with col1:
            fig, ax = plt.subplots(figsize=(6, 5))
            ax.scatter(x[:, 0], x[:, 1], c=y, cmap="bwr", edgecolor="k")
            ax.set_title("Dataset Visualization")
            st.pyplot(fig)
        
        
        with col2:
            st.markdown("### 🟢 Decision Boundary")
            fig1, ax1 = plt.subplots(figsize=(6, 5))
            plot_decision_regions(X=x_train, y=y_train.astype(np.int_), clf=model, ax=ax1)
            ax1.set_title("Decision Regions", fontsize=12, weight="bold")
            st.pyplot(fig1, clear_figure=True)
        
        
        st.markdown("### 🔵 Training vs Validation Loss")
        fig2, ax2 = plt.subplots(figsize=(8, 8))
        ax2.plot(range(1, epochs+1), hist.history["loss"], label="loss", linewidth=2)
        ax2.plot(range(1, epochs+1), hist.history["val_loss"], label="val_loss", linewidth=2, linestyle="--")
        ax2.set_xlabel("Epochs")
        ax2.set_ylabel("Loss")
        ax2.legend()
        ax2.grid(alpha=0.3)
        ax2.set_title("Training & Validation Loss", fontsize=12, weight="bold")
        st.pyplot(fig2, clear_figure=True)