import gradio as gr
from transformers import pipeline
import feedparser
from datetime import datetime, timedelta
import pytz
from bs4 import BeautifulSoup
import hashlib
import threading

# Global settings
SUMMARIZER_MODELS = {
    "Default (facebook/bart-large-cnn)": "facebook/bart-large-cnn",
    "Free Model (distilbart-cnn-6-6)": "sshleifer/distilbart-cnn-6-6"
}
CACHE_SIZE = 500
RSS_FETCH_INTERVAL = timedelta(hours=8)
ARTICLE_LIMIT = 5

NEWS_SOURCES = {
    "Technology": {"TheNewYorkTimes": "https://rss.nytimes.com/services/xml/rss/nyt/Technology.xml"},
    "Business": {"TheNewYorkTimes": "https://rss.nytimes.com/services/xml/rss/nyt/Business.xml"},
    "World News": {"BBC": "http://feeds.bbci.co.uk/news/world/rss.xml"}
}

class NewsCache:
    def __init__(self, size):
        self.cache = {}
        self.size = size
        self.lock = threading.Lock()

    def get(self, key):
        with self.lock:
            return self.cache.get(key)

    def set(self, key, value):
        with self.lock:
            if len(self.cache) >= self.size:
                oldest_key = next(iter(self.cache))
                del self.cache[oldest_key]
            self.cache[key] = value

cache = NewsCache(CACHE_SIZE)

def fetch_rss_news(categories):
    articles = []
    cutoff_time = datetime.now(pytz.UTC) - RSS_FETCH_INTERVAL
    for category in categories:
        for source, url in NEWS_SOURCES.get(category, {}).items():
            try:
                feed = feedparser.parse(url)
                for entry in feed.entries:
                    published = datetime(*entry.published_parsed[:6], tzinfo=pytz.UTC)
                    if published > cutoff_time:
                        articles.append({
                            "title": entry.title,
                            "description": BeautifulSoup(entry.description, "html.parser").get_text(),
                            "link": entry.link,
                            "category": category,
                            "source": source,
                            "published": published
                        })
            except Exception:
                continue
    articles = sorted(articles, key=lambda x: x["published"], reverse=True)[:ARTICLE_LIMIT]
    return articles

def summarize_text(text, model_name):
    summarizer = pipeline("summarization", model=model_name, device=-1)
    content_hash = hashlib.md5(text.encode()).hexdigest()
    cached_summary = cache.get(content_hash)
    if cached_summary:
        return cached_summary
    try:
        result = summarizer(text, max_length=120, min_length=40, truncation=True)
        summary = result[0]['summary_text']
        cache.set(content_hash, summary)
        return summary
    except Exception:
        return "Summary unavailable."

def summarize_articles(articles, model_name):
    summaries = []
    for article in articles:
        content = article["description"]
        summary = summarize_text(content, model_name)
        summaries.append(f"""
        📰 {article['title']}
        - 📁 Category: {article['category']}
        - 💡 Source: {article['source']}
        - 🔗 Read More: {article['link']}
        📃 Summary: {summary}
        """)
    return "\n".join(summaries)

def generate_summary(selected_categories, model_name):
    if not selected_categories:
        return "Please select at least one category."
    articles = fetch_rss_news(selected_categories)
    if not articles:
        return "No recent news found in the selected categories."
    return summarize_articles(articles, model_name)

# Gradio Interface
demo = gr.Blocks()

with demo:
    gr.Markdown("# 📰 AI News Summarizer")
    with gr.Row():
        categories = gr.CheckboxGroup(
            choices=list(NEWS_SOURCES.keys()),
            label="Select News Categories"
        )
        model_selector = gr.Radio(
            choices=list(SUMMARIZER_MODELS.keys()),
            label="Choose Summarization Model",
            value="Default (facebook/bart-large-cnn)"
        )
    summarize_button = gr.Button("Get News Summary")
    summary_output = gr.Textbox(label="News Summary", lines=20)

    def get_summary(selected_categories, selected_model):
        model_name = SUMMARIZER_MODELS[selected_model]
        return generate_summary(selected_categories, model_name)

    summarize_button.click(get_summary, inputs=[categories, model_selector], outputs=summary_output)

if __name__ == "__main__":
    demo.launch()