main.py

from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
import psycopg2
from psycopg2.extras import RealDictCursor
import os
import google.generativeai as genai

app = FastAPI()

# Enable CORS
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Get secrets from Hugging Face Repository Secrets (not .env file)
DATABASE_URL = os.getenv("DATABASE_URL")
GEMINI_API_KEY = os.getenv("GEMINI_API_KEY")

# Configure Gemini if key exists
if GEMINI_API_KEY:
    genai.configure(api_key=GEMINI_API_KEY)
    print("✅ Gemini configured on cloud")
else:
    print("⚠️ No Gemini API key found")

def get_db():
    conn = psycopg2.connect(DATABASE_URL, cursor_factory=RealDictCursor)
    return conn

def create_table():
    conn = get_db()
    cursor = conn.cursor()
    cursor.execute("""
        CREATE TABLE IF NOT EXISTS tasks (
            id SERIAL PRIMARY KEY,
            title TEXT NOT NULL
        )
    """)
    conn.commit()
    conn.close()

create_table()

@app.get("/")
def hello():
    return {"message": "Hello, Agentic AI! (Cloud with Gemini)"}

@app.post("/tasks")
def create_task(title: str):
    conn = get_db()
    cursor = conn.cursor()
    cursor.execute("INSERT INTO tasks (title) VALUES (%s) RETURNING id", (title,))
    task_id = cursor.fetchone()["id"]
    conn.commit()
    conn.close()
    return {"id": task_id, "title": title}

@app.get("/tasks")
def get_tasks():
    conn = get_db()
    cursor = conn.cursor()
    cursor.execute("SELECT * FROM tasks ORDER BY id DESC")
    tasks = cursor.fetchall()
    conn.close()
    return [{"id": t["id"], "title": t["title"]} for t in tasks]

@app.delete("/tasks/{task_id}")
def delete_task(task_id: int):
    conn = get_db()
    cursor = conn.cursor()
    cursor.execute("DELETE FROM tasks WHERE id = %s", (task_id,))
    deleted = cursor.rowcount > 0
    conn.commit()
    conn.close()
    if not deleted:
        raise HTTPException(status_code=404, detail="Task not found")
    return {"message": "Task deleted"}

# AI endpoint with Gemini
@app.get("/ai-tag")
def ai_tag_paper(title: str, authors: str = ""):
    if not GEMINI_API_KEY:
        return {"tags": keyword_tag(title), "title": title, "authors": authors}
    
    try:
        # This points to a stable, newer model that is currently supported
        model = genai.GenerativeModel('gemini-2.5-flash-lite')
        prompt = f"""Paper title: "{title}". Authors: "{authors}". 
        Generate 2-3 relevant tags with emojis. Return ONLY comma-separated tags.
        Example: "🤖 LLM/AI, 🧠 Deep Learning"
        Tags:"""
        
        response = model.generate_content(prompt)
        tags = response.text.strip()
        tags = tags.replace("```", "").replace("tags:", "").strip()
        
        if not tags:
            tags = keyword_tag(title)
            
        return {"tags": tags, "title": title, "authors": authors}
        
    except Exception as e:
        print(f"Gemini error: {e}")
        return {"tags": keyword_tag(title), "title": title, "authors": authors}

def keyword_tag(title):
    """Fallback keyword-based tagging"""
    title_lower = title.lower()
    
    if any(word in title_lower for word in ['attention', 'transformer', 'llm', 'gpt', 'bert']):
        return "🤖 LLM/AI, 🧠 Deep Learning"
    elif any(word in title_lower for word in ['big data', 'data processing', 'heterogeneous']):
        return "📊 Big Data, 🤖 AI-Driven Processing"
    elif any(word in title_lower for word in ['solar', 'wind', 'battery', 'energy']):
        return "🔋 Energy, ☀️ Renewable"
    elif any(word in title_lower for word in ['quantum', 'qubit']):
        return "⚛️ Quantum Computing, 🔬 Physics"
    else:
        return "📄 General Research"

@app.get("/health")
def health():
    return {
        "status": "ok",
        "gemini": "configured" if GEMINI_API_KEY else "missing",
        "database": "connected"
    }