import streamlit as st
import numpy as np
import torch
from torch import nn
import tensorflow as tf
from tensorflow import keras
from tensorflow.keras import layers

# Set page config
st.set_page_config(page_title='Advanced NLP with Deep Learning', layout='wide')

# Title with styled emoji
st.markdown('<h1 style="color:#4CAF50; text-align:center;">🤖 Advanced NLP with Deep Learning 🚀</h1>', unsafe_allow_html=True)

# Section 1: Word Embeddings
st.markdown('<h2 style="color:#FF5733">📌 1. Word Embeddings</h2>', unsafe_allow_html=True)

st.subheader('🔎 Definition:')
st.write("""
Word embeddings are dense vector representations of words where similar words have similar representations. They are essential for text-based deep learning models.

- **🔹 Word2Vec (Skip-gram & CBOW)**: Learns word representations based on context.
- **🔹 GloVe (Global Vectors)**: Uses word co-occurrence statistics to learn embeddings.
- **🔹 FastText**: Handles subword information, helping with out-of-vocabulary words.
""")

# Word2Vec Example
st.subheader('🧩 Word2Vec Example:')
sentence = st.text_area("Enter a sentence to visualize Word2Vec embeddings", "NLP is amazing and very useful.")

if st.button('🎨 Visualize Word2Vec'):
    words = sentence.split()
    embeddings = {word: np.random.rand(1, 50) for word in words}
    st.write("**Word2Vec Embeddings (Random Example):**")
    for word, emb in embeddings.items():
        st.write(f"{word}: {emb.flatten()[:5]}...")

# Section 2: Sequence Models
st.markdown('<h2 style="color:#3E7FCB">📌 2. Sequence Models</h2>', unsafe_allow_html=True)

st.subheader('🔎 Definition:')
st.write("""
Sequence models process sequential data like sentences and play a key role in NLP tasks like translation, summarization, and sentiment analysis.

- **🔹 RNN (Recurrent Neural Networks)**: Maintains memory of previous words.
- **🔹 LSTM (Long Short-Term Memory)**: Handles long-range dependencies.
- **🔹 GRU (Gated Recurrent Units)**: A simplified LSTM version.
""")

# RNN Example
st.subheader('🛠️ RNN Example (PyTorch):')
if st.button('🖥️ Show RNN Model Architecture'):
    class SimpleRNN(nn.Module):
        def __init__(self, input_size, hidden_size, output_size):
            super(SimpleRNN, self).__init__()
            self.rnn = nn.RNN(input_size, hidden_size, batch_first=True)
            self.fc = nn.Linear(hidden_size, output_size)
        
        def forward(self, x):
            out, _ = self.rnn(x)
            out = self.fc(out[:, -1, :])
            return out
    
    rnn_model = SimpleRNN(input_size=10, hidden_size=20, output_size=1)
    st.write("**RNN Architecture:**")
    st.write(rnn_model)

# Section 3: Attention Mechanisms
st.markdown('<h2 style="color:#E67E22">📌 3. Attention Mechanisms</h2>', unsafe_allow_html=True)

st.subheader('🔎 Definition:')
st.write("""
Attention mechanisms allow models to focus on key parts of an input sequence, improving performance on tasks that require long-range dependencies.

- **🔹 Self-attention**: Assigns importance to different words.
- **🔹 Seq2Seq Models**: Encoder-decoder models used for translation.
- **🔹 Transformer**: Parallel processing for high efficiency.
""")

# Transformer Example
st.subheader('🛠️ Transformer Example (Simplified):')
if st.button('🖥️ Show Transformer Architecture'):
    input_layer = keras.Input(shape=(None, 512))
    attention_output = layers.MultiHeadAttention(num_heads=8, key_dim=512)(input_layer, input_layer)
    pooled_output = layers.GlobalAveragePooling1D()(attention_output)
    dense1 = layers.Dense(256, activation="relu")(pooled_output)
    output_layer = layers.Dense(1)(dense1)
    
    transformer_model = keras.Model(inputs=input_layer, outputs=output_layer)
    st.write("**Transformer Architecture (Fixed Version):**")
    st.write(transformer_model)

# Section 4: Key Attention Components
st.markdown('<h2 style="color:#9C27B0">📌 4. Attention Components</h2>', unsafe_allow_html=True)

st.subheader('🔍 Self-attention:')
st.write("""
Each word in a sequence attends to all other words and assigns an importance weight, capturing long-range dependencies.
""")

st.subheader('🔄 Seq2Seq:')
st.write("""
Used for translation, where an encoder processes input and a decoder generates output.
""")

st.subheader('⚡ Transformer:')
st.write("""
Revolutionized NLP by using self-attention in both encoder and decoder while processing all tokens in parallel.
""")

st.markdown('<h3 style="color:#4CAF50; text-align:center;">✨ Thanks for Exploring NLP! ✨</h3>', unsafe_allow_html=True)