# backend/app/api/v1/endpoints/billing.py
from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select
from app.api.deps import get_db, get_current_user
from app.models.identity import User, Wallet, UserRole
from app.models.audit import FinancialLedger
from app.services.config_service import config

router = APIRouter()

@router.post("/upgrade")
async def upgrade_account(target_package: str, db: AsyncSession = Depends(get_db), current_user: User = Depends(get_current_user)):
    """
    Univerzális csomagváltó. 
    Kezeli az 5+ csomagot, a Rank-ugrást és a különleges 'Service Coin' bónuszokat.
    """
    # 1. Lekérjük a teljes csomagmátrixot az adminból
    # Példa JSON: {"premium": {"price": 2000, "rank": 5, "type": "credit"}, "service_pro": {"price": 10000, "rank": 30, "type": "coin"}}
    package_matrix = await config.get_setting(db, "subscription_packages_matrix")
    
    if target_package not in package_matrix:
        raise HTTPException(status_code=400, detail="Érvénytelen csomagválasztás.")

    pkg_info = package_matrix[target_package]
    price = pkg_info["price"]
    
    # 2. Pénztárca ellenőrzése
    stmt = select(Wallet).where(Wallet.user_id == current_user.id)
    wallet = (await db.execute(stmt)).scalar_one_or_none()

    total_balance = wallet.purchased_credits + wallet.earned_credits
    
    if total_balance < price:
        raise HTTPException(status_code=402, detail="Nincs elég kredited a csomagváltáshoz.")

    # 3. Levonási logika (Purchased -> Earned sorrend)
    if wallet.purchased_credits >= price:
        wallet.purchased_credits -= price
    else:
        remaining = price - wallet.purchased_credits
        wallet.purchased_credits = 0
        wallet.earned_credits -= remaining

    # 4. Speciális Szerviz Logika (Service Coins)
    # Ha a csomag típusa 'coin', akkor a szerviz kap egy kezdő Coin csomagot is
    if pkg_info.get("type") == "coin":
        initial_coins = pkg_info.get("initial_coin_bonus", 100)
        wallet.service_coins += initial_coins
        logger.info(f"User {current_user.id} upgraded to Service Pro, awarded {initial_coins} coins.")

    # 5. Rang frissítése és naplózás
    current_user.role = target_package # Pl. 'service_pro' vagy 'vip'
    
    db.add(FinancialLedger(
        user_id=current_user.id,
        amount=-price,
        transaction_type=f"UPGRADE_{target_package.upper()}",
        details=pkg_info
    ))
    
    await db.commit()
    return {"status": "success", "package": target_package, "rank_granted": pkg_info["rank"]}