import gradio as gr
import requests
from datetime import datetime, timezone

API_URL = "https://huggingface.co/api/daily_papers"

class PaperManager:
    def __init__(self, papers_per_page=10):
        self.papers_per_page = papers_per_page
        self.current_page = 1
        self.papers = []
        self.total_pages = 1

    def fetch_initial_papers(self):
        try:
            response = requests.get(f"{API_URL}?limit=50")
            response.raise_for_status()
            data = response.json()
            # Sort papers by upvotes (descending order)
            self.papers = sorted(data, key=lambda x: x.get('paper', {}).get('upvotes', 0), reverse=True)
            self.total_pages = (len(self.papers) + self.papers_per_page - 1) // self.papers_per_page
            return True
        except requests.RequestException as e:
            print(f"Error fetching papers: {e}")
            return False

    def format_paper(self, paper):
        title = paper.get('title', 'No title')
        url = f"https://huggingface.co/papers/{paper['paper'].get('id', '')}"
        authors = ', '.join([author.get('name', '') for author in paper['paper'].get('authors', [])])
        upvotes = paper.get('paper', {}).get('upvotes', 0)
        comments = paper.get('numComments', 0)
        published_time = datetime.fromisoformat(paper.get('publishedAt', datetime.now(timezone.utc).isoformat()).replace('Z', '+00:00'))
        time_ago = (datetime.now(timezone.utc) - published_time).days
        
        return f"""<div style='border-bottom: 1px solid #eee; padding: 10px 0;'>
        <a href='{url}' target='_blank' style='color: #000; text-decoration: none; font-weight: bold;'>{title}</a>
        <div style='font-size: 0.8em; color: #666; margin-top: 5px;'>
        {upvotes} upvotes | by {authors} | {time_ago} days ago | {comments} comments
        </div>
        </div>"""

    def render_papers(self):
        start = (self.current_page - 1) * self.papers_per_page
        end = start + self.papers_per_page
        current_papers = self.papers[start:end]
        
        if not current_papers:
            return "<div>No papers available for this page.</div>"
        
        return "".join([self.format_paper(paper) for paper in current_papers])

    def search_papers(self, query):
        if not query:
            self.current_page = 1
            return self.render_papers()
        
        filtered_papers = [paper for paper in self.papers if query.lower() in paper.get('title', '').lower()]
        return "".join([self.format_paper(paper) for paper in filtered_papers[:self.papers_per_page]])

    def next_page(self):
        if self.current_page < self.total_pages:
            self.current_page += 1
        return self.render_papers(), f"Page {self.current_page} of {self.total_pages}"

    def prev_page(self):
        if self.current_page > 1:
            self.current_page -= 1
        return self.render_papers(), f"Page {self.current_page} of {self.total_pages}"

css = """
html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #f0f0f0;
}
.container {
    font-family: Arial, sans-serif;
    max-width: 800px;
    width: 100%;
    background-color: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}
.paper-list { 
    max-height: 400px; 
    overflow-y: auto;
    border: 1px solid #eee;
    border-radius: 5px;
    padding: 10px;
    margin-bottom: 10px;
}
.search-row {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}
.title {
    text-align: center;
    color: #333;
}
.footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 10px;
}
"""

paper_manager = PaperManager()

def initialize_app():
    if paper_manager.fetch_initial_papers():
        return paper_manager.render_papers(), f"Page {paper_manager.current_page} of {paper_manager.total_pages}"
    else:
        return "<div>Failed to fetch papers. Please try again later.</div>", "Error"

def refresh_papers():
    paper_manager.current_page = 1
    if paper_manager.fetch_initial_papers():
        return paper_manager.render_papers(), f"Page {paper_manager.current_page} of {paper_manager.total_pages}"
    else:
        return "<div>Failed to refresh papers. Please try again later.</div>", "Error"

demo = gr.Blocks(css=css)

with demo:
    with gr.Column(elem_classes=["container"]):
        gr.Markdown("# Daily Papers - HackerNews Style", elem_classes=["title"])
        with gr.Row(elem_classes=["search-row"]):
            search_input = gr.Textbox(label="Search papers", placeholder="Enter search term...")
            refresh_button = gr.Button("Refresh")
        paper_list = gr.HTML(elem_classes=["paper-list"])
        
        with gr.Row(elem_classes=["footer"]):
            prev_button = gr.Button("Previous Page")
            page_info = gr.Markdown()
            next_button = gr.Button("Next Page")
    
    demo.load(initialize_app, outputs=[paper_list, page_info])
    search_input.change(paper_manager.search_papers, inputs=[search_input], outputs=[paper_list])
    refresh_button.click(refresh_papers, outputs=[paper_list, page_info])
    prev_button.click(paper_manager.prev_page, outputs=[paper_list, page_info])
    next_button.click(paper_manager.next_page, outputs=[paper_list, page_info])

demo.launch()