from datetime import datetime, timedelta
from app.db.database import users_collection, db

coins_sessions_collection = db.coins_sessions

class DailyRewardService:
    async def claim_daily(self, username: str) -> dict:
        now = datetime.utcnow()
        today = now.date()

        user = await users_collection.find_one({"username": username})
        if not user:
            return {"claimed": False, "reason": "user_not_found"}

        last_claim_at = user.get("daily_last_claim_at")
        last_claim_day = last_claim_at.date() if last_claim_at else None

        # уже получал сегодня
        if last_claim_day == today:
            return {"claimed": False, "reason": "already_claimed_today", "streak": user.get("daily_streak", 0)}

        # вычисляем новый стрик
        yesterday = today - timedelta(days=1)
        prev_streak = int(user.get("daily_streak", 0) or 0)

        if last_claim_day == yesterday:
            new_streak = prev_streak + 1
        else:
            new_streak = 1

        # формула награды (пример)
        base = 10
        bonus = min(new_streak, 7) * 2   # кап на 7 дней
        reward = base + bonus

        # КЛЮЧЕВО: атомарная защита от двойного клика/параллельных запросов
        # обновляем только если last_claim_day != today
        result = await users_collection.update_one(
            {
                "username": username,
                "$or": [
                    {"daily_last_claim_at": {"$exists": False}},
                    {"daily_last_claim_at": {"$lt": datetime(today.year, today.month, today.day)}},
                ],
            },
            {
                "$inc": {"coins": reward},
                "$set": {"daily_last_claim_at": now, "daily_streak": new_streak},
            },
        )

        if result.modified_count == 0:
            # кто-то уже успел получить сегодня (гонка)
            user2 = await users_collection.find_one({"username": username})
            return {"claimed": False, "reason": "already_claimed_today", "streak": user2.get("daily_streak", 0)}

        # лог в coins_sessions (у тебя уже так сделано для coins_update) :contentReference[oaicite:4]{index=4}
        await coins_sessions_collection.insert_one({
            "player_name": username,
            "update_type": "daily_login",
            "timestamp": now,
            "coins_added": reward,
            "streak": new_streak,
        })

        return {"claimed": True, "coins_added": reward, "streak": new_streak}
    
    async def get_status(self, username: str) -> dict:
        now = datetime.utcnow()
        today = now.date()

        user = await users_collection.find_one({"username": username})
        if not user:
            return {"ok": False, "reason": "user_not_found"}

        last_claim_at = user.get("daily_last_claim_at")
        last_claim_day = last_claim_at.date() if last_claim_at else None

        start_of_today = datetime(today.year, today.month, today.day)
        start_of_tomorrow = start_of_today + timedelta(days=1)

        can_claim = (last_claim_day != today)
        seconds_to_next = 0 if can_claim else int((start_of_tomorrow - now).total_seconds())
        if seconds_to_next < 0:
            seconds_to_next = 0

        return {
            "ok": True,
            "can_claim": can_claim,
            "seconds_to_next": seconds_to_next,
            "next_claim_at": start_of_tomorrow.isoformat() + "Z",
            "streak": int(user.get("daily_streak", 0) or 0),
        }