import os
import zipfile
import chromadb
from sentence_transformers import SentenceTransformer
import gradio as gr
from fastapi import FastAPI
from pydantic import BaseModel

# Extract and load database
DB_PATH = "./medqa_db"
if not os.path.exists(DB_PATH) and os.path.exists("./medqa_db.zip"):
    with zipfile.ZipFile("./medqa_db.zip", 'r') as z:
        z.extractall(".")

client = chromadb.PersistentClient(path=DB_PATH)
collection = client.get_collection("medqa")
model = SentenceTransformer('ncbi/MedCPT-Query-Encoder')

# Search function
def search(query, num_results=3):
    emb = model.encode(query).tolist()
    return collection.query(query_embeddings=[emb], n_results=int(num_results))

# Gradio UI
def ui_search(query, num_results=3):
    if not query.strip():
        return "Enter a query"
    try:
        r = search(query, num_results)
        out = ""
        for i in range(len(r['documents'][0])):
            out += f"\n{'='*60}\nExample {i+1}\n{'='*60}\n"
            out += r['documents'][0][i] + f"\n\nAnswer: {r['metadatas'][0][i].get('answer', 'N/A')}\n"
            out += f"Similarity: {1 - r['distances'][0][i]:.3f}\n"
        return out
    except Exception as e:
        return f"Error: {e}"

demo = gr.Interface(
    fn=ui_search,
    inputs=[
        gr.Textbox(label="Medical Query", placeholder="e.g., hyponatremia"),
        gr.Slider(1, 5, value=3, step=1, label="Results")
    ],
    outputs=gr.Textbox(label="Similar USMLE Questions", lines=20),
    title="MedQA Search",
    examples=[["hyponatremia", 3], ["myocardial infarction", 2]]
)

# FastAPI
app = FastAPI()

class SearchRequest(BaseModel):
    query: str
    num_results: int = 3

@app.post("/search_medqa")
def api_search(req: SearchRequest):
    r = search(req.query, req.num_results)
    return {"results": [{
        "example_number": i+1,
        "question": r['documents'][0][i],
        "answer": r['metadatas'][0][i].get('answer', 'N/A'),
        "distance": r['distances'][0][i]
    } for i in range(len(r['documents'][0]))]}

app = gr.mount_gradio_app(app, demo, path="/")