import streamlit as st
import nltk
from nltk.corpus import stopwords
from nltk.tokenize import word_tokenize, sent_tokenize

nltk.download('stopwords')
# Download the required punkt tokenizer
nltk.download('punkt_tab')

# Define the summarization function
def summarize_text(text, num_sentences=2):
    # Tokenize the text into sentences
    sentences = sent_tokenize(text)

    # Tokenize the text into words and remove stopwords
    stop_words = set(stopwords.words('english'))
    word_tokens = word_tokenize(text.lower())
    filtered_tokens = [word for word in word_tokens if word.isalnum() and word not in stop_words]

    # Calculate word frequency
    word_freq = nltk.FreqDist(filtered_tokens)

    # Assign scores to sentences based on the sum of their word frequencies
    sent_scores = {}
    for sentence in sentences:
        for word in word_tokenize(sentence.lower()):
            if word in word_freq.keys():
                if len(sentence.split(' ')) < 30:  # Consider only sentences with less than 30 words
                    if sentence not in sent_scores.keys():
                        sent_scores[sentence] = word_freq[word]
                    else:
                        sent_scores[sentence] += word_freq[word]

    # Select the top N sentences with highest scores for summarization
    summary_sentences = sorted(sent_scores, key=sent_scores.get, reverse=True)[:num_sentences]

    # Generate the summary
    summary = ' '.join(summary_sentences)
    return summary

# Streamlit app
def main():
    st.title("Text Summarization App")

    st.write("Enter your text below and select the number of sentences for the summary.")

    # Text input
    text_input = st.text_area("Text", "Paste your text here...")
    
    # Number of sentences for summary
    num_sentences = st.slider("Number of sentences in summary", min_value=1, max_value=10, value=2)
    
    if st.button("Generate Summary"):
        if text_input:
            summary = summarize_text(text_input, num_sentences)
            st.write("### Summary:")
            st.write(summary)
        else:
            st.write("Please enter some text to summarize.")

if __name__ == "__main__":
    main()