import streamlit as st
import pandas as pd
import re
import nltk
from nltk.corpus import stopwords
from sklearn.feature_extraction.text import CountVectorizer
from sklearn.decomposition import LatentDirichletAllocation
import matplotlib.pyplot as plt
from wordcloud import WordCloud
import seaborn as sns

# Download stopwords
nltk.download('stopwords')
stop_words = set(stopwords.words('english'))

def preprocess_text(text):
    text = re.sub(r'[^a-zA-Z\s]', '', text, re.I)
    text = text.lower()
    tokens = text.split()
    tokens = [word for word in tokens if word not in stop_words]
    return ' '.join(tokens)

def perform_lda(text_data, num_topics=5):
    vectorizer = CountVectorizer(stop_words='english')
    dtm = vectorizer.fit_transform(text_data)
    lda = LatentDirichletAllocation(n_components=num_topics, random_state=42)
    lda.fit(dtm)
    return lda, vectorizer, dtm

def plot_wordcloud(term_dict):
    wordcloud = WordCloud(width=800, height=400, background_color="white").generate_from_frequencies(term_dict)
    fig, ax = plt.subplots(figsize=(10, 5))
    ax.imshow(wordcloud, interpolation='bilinear')
    ax.axis('off')
    st.pyplot(fig)

def plot_topic_proportions(proportions, num_topics):
    fig, ax = plt.subplots(figsize=(10, 6))
    ax.bar(range(num_topics), proportions, color='skyblue')
    ax.set_title("Proportions of Different Topics in Text Data")
    ax.set_xlabel("Topic")
    ax.set_ylabel("Proportion")
    ax.set_xticks(range(num_topics))
    ax.set_xticklabels([f"Topic {i+1}" for i in range(num_topics)])
    st.pyplot(fig)

def print_topics(lda, vectorizer, num_words=10):
    terms = vectorizer.get_feature_names_out()
    topics = []
    for index, topic in enumerate(lda.components_):
        top_terms_idx = topic.argsort()[-num_words:][::-1]
        top_terms = [terms[i] for i in top_terms_idx]
        topics.append(f"Topic #{index + 1}: {', '.join(top_terms)}")
    return topics

def display_document_topic_distribution(topic_proportions):
    topic_df = pd.DataFrame(topic_proportions, columns=[f"Topic {i+1}" for i in range(topic_proportions.shape[1])])
    topic_df['Dominant Topic'] = topic_df.idxmax(axis=1)
    return topic_df

# Streamlit UI
st.title("Text Analysis and Topic Modeling")
st.write("Upload a CSV file containing a column with text data.")

uploaded_file = st.file_uploader("Upload CSV", type=["csv"])

if uploaded_file:
    data = pd.read_csv(uploaded_file)
    text_column = st.selectbox("Select the text column", data.columns)
    data['text_clean'] = data[text_column].apply(preprocess_text)
    
    st.write("Sample Processed Text:")
    st.write(data[['text_clean']].head())
    
    # Extract key terms
    vectorizer = CountVectorizer(max_features=50, stop_words='english')
    X = vectorizer.fit_transform(data['text_clean'])
    terms = vectorizer.get_feature_names_out()
    term_frequencies = X.sum(axis=0).A1
    term_dict = dict(zip(terms, term_frequencies))
    
    st.subheader("Word Cloud of Key Terms")
    plot_wordcloud(term_dict)
    
    # Perform LDA
    num_topics = st.slider("Select number of topics", min_value=2, max_value=10, value=5)
    lda, vectorizer_lda, dtm = perform_lda(data['text_clean'], num_topics)
    
    # Display topics
    st.subheader("Identified Topics")
    topics = print_topics(lda, vectorizer_lda)
    for topic in topics:
        st.write(topic)
    
    # Topic proportions
    topic_proportions = lda.transform(dtm)
    avg_topic_proportions = topic_proportions.mean(axis=0)
    st.subheader("Topic Proportions")
    plot_topic_proportions(avg_topic_proportions, lda.components_.shape[0])
    
    # Display document topic distribution
    st.subheader("Document Topic Distribution")
    document_topic_distribution = display_document_topic_distribution(topic_proportions)
    st.write(document_topic_distribution.head())