import json
import os
import pdf2doi
import gradio as gr
import requests
import html

def download_pdf(url):
    file_path = f"{url.split('/')[-1]}.pdf"
    response = requests.get(url)
    with open(file_path, 'wb') as file:
        file.write(response.content)
    return file_path

import json

def get_doi(pdf_path):
    pdf2doi.config.set('verbose', False)
    results = pdf2doi.pdf2doi(pdf_path)
    validation_info = results.get('validation_info', {})
    if isinstance(validation_info, str):  
        try:
            validation_info = json.loads(validation_info)  # Convert JSON string to dic
        except json.JSONDecodeError as e:
            print(f"Error decoding JSON: {e}")
            return None, None, None
    if not isinstance(validation_info, dict):
        print("Validation info is not a dictionary")
        return None, None, None
    doi = validation_info.get('DOI', None)
    title = validation_info.get('title', None)
    url = validation_info.get('URL', None)
    return doi, title, url

def get_paper_data(doi):
    api_url = f"https://api.citeas.org/product/{doi}"
    response = requests.get(api_url)
    return response.json()

def main(pdf_url):
    pdf_path = download_pdf(pdf_url)
    doi, title, url = get_doi(pdf_path)
    if doi is None:
        return json.dumps({"error": "DOI not found"}, indent=4)
    paper_data = get_paper_data(doi)
    if not paper_data:
        return json.dumps({"error": "Paper data not found"}, indent=4)
    citation_text = None
    for citation in paper_data.get('citations', []):
        if citation.get('style_shortname') == 'apa':
            citation_text = citation.get('citation')
            break
    title = title or paper_data.get('name')
    url = url or f"https://doi.org/{doi}"
    if citation_text:
        citation_text = citation_text.encode('utf-8').decode('utf-8')
        citation_text = html.unescape(
            citation_text.replace("<i>", "").replace("</i>", "").replace("\u2026", "...").replace("\n", " ")
        )
    else:
        citation_text = "Citation not found"
    data = {
        "doi": doi,
        "title": title if title else "Title not found",
        "citation_text": citation_text,
        "url": url
    }
    os.remove(pdf_path)
    return json.dumps(data, ensure_ascii=False, indent=4)


theme = gr.themes.Soft(
    primary_hue="purple",
    secondary_hue="cyan",
    neutral_hue="slate",
    font=[
        gr.themes.GoogleFont("Syne"), 
        gr.themes.GoogleFont("Poppins"), 
        gr.themes.GoogleFont("Poppins"), 
        gr.themes.GoogleFont("Poppins")
    ],
)

with gr.Blocks(theme=theme) as app:
    with gr.Row():
        pdf_path = gr.Textbox(lines=1, label="PDF URL", placeholder="Enter the URL of the PDF")
        doi_data = gr.Textbox(lines=7, label="DOI Data", placeholder="DOI data will be displayed here", show_copy_button=True)
    get_data = gr.Button(value="Get DOI Data", variant='primary')

    get_data.click(main, inputs=[pdf_path], outputs=[doi_data], api_name="getDOIData")

app.queue(default_concurrency_limit=250).launch()