from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select
import json
from app.database import get_db
from app.models.user import User
from app.models.scan import Scan
from app.models.product import Product
from app.utils.security import get_current_user
from app.services.achievements import check_achievements

router = APIRouter(prefix="/api", tags=["compare"])

@router.post("/compare")
async def compare_products(data: dict, user: User = Depends(get_current_user), db: AsyncSession = Depends(get_db)):
    scan_ids = data.get("scan_ids", [])
    if len(scan_ids) < 2 or len(scan_ids) > 4:
        raise HTTPException(status_code=400, detail="Selecione entre 2 e 4 produtos")
    
    results = []
    for sid in scan_ids:
        res = await db.execute(select(Scan).where(Scan.id == sid, Scan.user_id == user.id))
        scan = res.scalar_one_or_none()
        if not scan:
            raise HTTPException(status_code=404, detail=f"Scan {sid} não encontrado")
        
        analysis = json.loads(scan.analysis_json or '{}')
        prod_res = await db.execute(select(Product).where(Product.barcode == scan.barcode))
        product = prod_res.scalar_one_or_none()
        
        results.append({
            "scan_id": scan.id,
            "product_name": scan.product_name,
            "brand": scan.brand,
            "score": scan.score,
            "image_url": product.image_url if product else None,
            "nutri_score": product.nutri_score if product else None,
            "nova_group": product.nova_group if product else None,
            "positives": analysis.get("positives", []),
            "negatives": analysis.get("negatives", []),
            "nutrition": analysis.get("nutrition", {}),
            "nutrition_verdict": analysis.get("nutrition_verdict", ""),
        })
    
    # Check comparison achievement
    await check_achievements(user.id, db, action="compare")
    
    return {"products": results}