import gradio as gr
import json
from backend.tools.metadata import fetch_metadata, recover_metadata
from .utils import format_error

async def metadata_handler(doi, url, title, action):
    if not doi and not url and not title:
        return "**Error:** Proporcione al menos un DOI, URL o título."
    try:
        if action == "fetch":
            result = await fetch_metadata(doi=doi or None, url=url or None, title=title or None)
        elif action == "recover":
            result = await recover_metadata(doi=doi or None, url=url or None, title=title or None)
        elif action == "enrich":
            result = await fetch_metadata(doi=doi or None, url=url or None, title=title or None)
        else:
            return "**Error:** Acción no válida."
        
        if "error" in result:
            return f"**Error:** {result['error']}"
        return json.dumps(result, indent=2, ensure_ascii=False, default=str)
    except Exception as e:
        return format_error(e)

def create_metadata_tab():
    with gr.Tab("📋 Metadatos", id="metadata"):
        gr.Markdown("## Gestión de Metadatos Académicos")
        with gr.Row():
            with gr.Column():
                doi = gr.Textbox(label="DOI", placeholder="10.1038/s41586-020-2649-2")
                url = gr.Textbox(label="URL / Handle", placeholder="https://hdl.handle.net/20.500.12672/12345")
                title = gr.Textbox(label="Título", placeholder="Attention Is All You Need")
                action = gr.Radio(choices=["fetch", "recover", "enrich"], value="fetch", label="Acción")
                meta_btn = gr.Button("📋 Obtener Metadatos", variant="primary", size="lg")
            with gr.Column():
                output_json = gr.Code(label="Resultado JSON", language="json")
        meta_btn.click(fn=metadata_handler, inputs=[doi, url, title, action], outputs=[output_json])