import logging
from datetime import datetime, timedelta
from typing import List, Optional
from sqlalchemy import select, and_, func
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import selectinload

from app.database.models import ReferralEarning, User

logger = logging.getLogger(__name__)


async def create_referral_earning(
    db: AsyncSession,
    user_id: int,
    referral_id: int,
    amount_kopeks: int,
    reason: str,
    referral_transaction_id: Optional[int] = None
) -> ReferralEarning:
    
    earning = ReferralEarning(
        user_id=user_id,
        referral_id=referral_id,
        amount_kopeks=amount_kopeks,
        reason=reason,
        referral_transaction_id=referral_transaction_id
    )
    
    db.add(earning)
    await db.commit()
    await db.refresh(earning)
    
    logger.info(f"💰 Создан реферальный заработок: {amount_kopeks/100}₽ для пользователя {user_id}")
    return earning


async def get_referral_earnings_by_user(
    db: AsyncSession,
    user_id: int,
    limit: int = 50,
    offset: int = 0
) -> List[ReferralEarning]:
    
    result = await db.execute(
        select(ReferralEarning)
        .options(
            selectinload(ReferralEarning.referral),
            selectinload(ReferralEarning.referral_transaction)
        )
        .where(ReferralEarning.user_id == user_id)
        .order_by(ReferralEarning.created_at.desc())
        .offset(offset)
        .limit(limit)
    )
    return result.scalars().all()


async def get_referral_earnings_by_referral(
    db: AsyncSession,
    referral_id: int
) -> List[ReferralEarning]:
    
    result = await db.execute(
        select(ReferralEarning)
        .where(ReferralEarning.referral_id == referral_id)
        .order_by(ReferralEarning.created_at.desc())
    )
    return result.scalars().all()


async def get_referral_earnings_sum(
    db: AsyncSession,
    user_id: int,
    start_date: Optional[datetime] = None,
    end_date: Optional[datetime] = None
) -> int:
    
    query = select(func.coalesce(func.sum(ReferralEarning.amount_kopeks), 0)).where(
        ReferralEarning.user_id == user_id
    )
    
    if start_date:
        query = query.where(ReferralEarning.created_at >= start_date)
    
    if end_date:
        query = query.where(ReferralEarning.created_at <= end_date)
    
    result = await db.execute(query)
    return result.scalar()


async def get_referral_statistics(db: AsyncSession) -> dict:
    
    users_with_referrals_result = await db.execute(
        select(func.count(func.distinct(User.id)))
        .where(User.referred_by_id.isnot(None))
    )
    users_with_referrals = users_with_referrals_result.scalar()
    
    active_referrers_result = await db.execute(
        select(func.count(func.distinct(User.referred_by_id)))
        .where(User.referred_by_id.isnot(None))
    )
    active_referrers = active_referrers_result.scalar()
    
    referral_paid_result = await db.execute(
        select(func.coalesce(func.sum(ReferralEarning.amount_kopeks), 0))
    )
    referral_paid = referral_paid_result.scalar()
    
    from app.database.models import Transaction, TransactionType
    transaction_paid_result = await db.execute(
        select(func.coalesce(func.sum(Transaction.amount_kopeks), 0))
        .where(Transaction.type == TransactionType.REFERRAL_REWARD.value)
    )
    transaction_paid = transaction_paid_result.scalar()
    
    total_paid = referral_paid + transaction_paid
    
    referrals_stats_result = await db.execute(
        select(
            User.referred_by_id.label('referrer_id'),
            func.count(User.id).label('referrals_count')
        )
        .where(User.referred_by_id.isnot(None))
        .group_by(User.referred_by_id)
    )
    referrals_stats = {row.referrer_id: row.referrals_count for row in referrals_stats_result.all()}
    
    referral_earnings_result = await db.execute(
        select(
            ReferralEarning.user_id.label('referrer_id'),
            func.sum(ReferralEarning.amount_kopeks).label('referral_earnings')
        )
        .group_by(ReferralEarning.user_id)
    )
    referral_earnings = {row.referrer_id: row.referral_earnings for row in referral_earnings_result.all()}
    
    transaction_earnings_result = await db.execute(
        select(
            Transaction.user_id.label('referrer_id'),
            func.sum(Transaction.amount_kopeks).label('transaction_earnings')
        )
        .where(Transaction.type == TransactionType.REFERRAL_REWARD.value)
        .group_by(Transaction.user_id)
    )
    transaction_earnings = {row.referrer_id: row.transaction_earnings for row in transaction_earnings_result.all()}
    
    top_referrers_data = {}
    
    for referrer_id, count in referrals_stats.items():
        if referrer_id not in top_referrers_data:
            top_referrers_data[referrer_id] = {
                'referrals_count': 0,
                'total_earned': 0
            }
        top_referrers_data[referrer_id]['referrals_count'] = count
    
    for referrer_id, earnings in referral_earnings.items():
        if referrer_id not in top_referrers_data:
            top_referrers_data[referrer_id] = {
                'referrals_count': 0,
                'total_earned': 0
            }
        top_referrers_data[referrer_id]['total_earned'] += earnings or 0
    
    for referrer_id, earnings in transaction_earnings.items():
        if referrer_id not in top_referrers_data:
            top_referrers_data[referrer_id] = {
                'referrals_count': 0,
                'total_earned': 0
            }
        top_referrers_data[referrer_id]['total_earned'] += earnings or 0
    
    sorted_referrers = sorted(
        top_referrers_data.items(),
        key=lambda x: (x[1]['total_earned'], x[1]['referrals_count']),
        reverse=True
    )
    
    top_referrers = []
    for referrer_id, stats in sorted_referrers[:5]:
        user_result = await db.execute(
            select(User.id, User.username, User.first_name, User.last_name, User.telegram_id)
            .where(User.id == referrer_id)
        )
        user = user_result.first()
        
        if user:
            display_name = ""
            if user.first_name:
                display_name = user.first_name
                if user.last_name:
                    display_name += f" {user.last_name}"
            elif user.username:
                display_name = f"@{user.username}"
            else:
                display_name = f"ID{user.telegram_id}"
            
            top_referrers.append({
                "user_id": user.telegram_id, 
                "display_name": display_name,
                "username": user.username,
                "telegram_id": user.telegram_id,
                "total_earned_kopeks": stats['total_earned'],
                "referrals_count": stats['referrals_count']
            })
    
    today = datetime.utcnow().replace(hour=0, minute=0, second=0, microsecond=0)
    
    today_referral_earnings_result = await db.execute(
        select(func.coalesce(func.sum(ReferralEarning.amount_kopeks), 0))
        .where(ReferralEarning.created_at >= today)
    )
    today_transaction_earnings_result = await db.execute(
        select(func.coalesce(func.sum(Transaction.amount_kopeks), 0))
        .where(
            and_(
                Transaction.type == TransactionType.REFERRAL_REWARD.value,
                Transaction.created_at >= today
            )
        )
    )
    today_earnings = today_referral_earnings_result.scalar() + today_transaction_earnings_result.scalar()
    
    week_ago = datetime.utcnow() - timedelta(days=7)
    week_referral_earnings_result = await db.execute(
        select(func.coalesce(func.sum(ReferralEarning.amount_kopeks), 0))
        .where(ReferralEarning.created_at >= week_ago)
    )
    week_transaction_earnings_result = await db.execute(
        select(func.coalesce(func.sum(Transaction.amount_kopeks), 0))
        .where(
            and_(
                Transaction.type == TransactionType.REFERRAL_REWARD.value,
                Transaction.created_at >= week_ago
            )
        )
    )
    week_earnings = week_referral_earnings_result.scalar() + week_transaction_earnings_result.scalar()
    
    month_ago = datetime.utcnow() - timedelta(days=30)
    month_referral_earnings_result = await db.execute(
        select(func.coalesce(func.sum(ReferralEarning.amount_kopeks), 0))
        .where(ReferralEarning.created_at >= month_ago)
    )
    month_transaction_earnings_result = await db.execute(
        select(func.coalesce(func.sum(Transaction.amount_kopeks), 0))
        .where(
            and_(
                Transaction.type == TransactionType.REFERRAL_REWARD.value,
                Transaction.created_at >= month_ago
            )
        )
    )
    month_earnings = month_referral_earnings_result.scalar() + month_transaction_earnings_result.scalar()
    
    logger.info(f"Реферальная статистика: {users_with_referrals} рефералов, {active_referrers} рефереров, выплачено {total_paid} копеек")
    
    return {
        "users_with_referrals": users_with_referrals,
        "active_referrers": active_referrers,
        "total_paid_kopeks": total_paid,
        "today_earnings_kopeks": today_earnings,
        "week_earnings_kopeks": week_earnings,
        "month_earnings_kopeks": month_earnings,
        "top_referrers": top_referrers
    }


async def get_top_referrers_by_period(
    db: AsyncSession,
    period: str = "week",  # "week" или "month"
    sort_by: str = "earnings",  # "earnings" или "invited"
    limit: int = 20
) -> list:
    """
    Получает топ рефереров за период.

    Args:
        period: "week" (7 дней) или "month" (30 дней)
        sort_by: "earnings" (по заработку) или "invited" (по приглашённым)
        limit: количество записей

    Returns:
        Список словарей с данными рефереров
    """
    from app.database.models import Transaction, TransactionType

    now = datetime.utcnow()
    if period == "week":
        start_date = now - timedelta(days=7)
    else:  # month
        start_date = now - timedelta(days=30)

    if sort_by == "invited":
        # Топ по количеству приглашённых за период
        referrals_result = await db.execute(
            select(
                User.referred_by_id.label('referrer_id'),
                func.count(User.id).label('invited_count')
            )
            .where(
                and_(
                    User.referred_by_id.isnot(None),
                    User.created_at >= start_date
                )
            )
            .group_by(User.referred_by_id)
            .order_by(func.count(User.id).desc())
            .limit(limit)
        )

        top_data = []
        for row in referrals_result:
            # Получаем заработок за период для этого реферера
            earnings_result = await db.execute(
                select(func.coalesce(func.sum(ReferralEarning.amount_kopeks), 0))
                .where(
                    and_(
                        ReferralEarning.user_id == row.referrer_id,
                        ReferralEarning.created_at >= start_date
                    )
                )
            )
            earnings = earnings_result.scalar() or 0

            # Добавляем транзакции REFERRAL_REWARD
            trans_earnings_result = await db.execute(
                select(func.coalesce(func.sum(Transaction.amount_kopeks), 0))
                .where(
                    and_(
                        Transaction.user_id == row.referrer_id,
                        Transaction.type == TransactionType.REFERRAL_REWARD.value,
                        Transaction.created_at >= start_date
                    )
                )
            )
            earnings += trans_earnings_result.scalar() or 0

            top_data.append({
                'referrer_id': row.referrer_id,
                'invited_count': row.invited_count,
                'earnings_kopeks': earnings
            })
    else:
        # Топ по заработку за период
        # Собираем заработки из ReferralEarning
        referral_earnings_result = await db.execute(
            select(
                ReferralEarning.user_id.label('referrer_id'),
                func.sum(ReferralEarning.amount_kopeks).label('ref_earnings')
            )
            .where(ReferralEarning.created_at >= start_date)
            .group_by(ReferralEarning.user_id)
        )
        referral_earnings = {row.referrer_id: row.ref_earnings for row in referral_earnings_result}

        # Добавляем транзакции REFERRAL_REWARD
        transaction_earnings_result = await db.execute(
            select(
                Transaction.user_id.label('referrer_id'),
                func.sum(Transaction.amount_kopeks).label('trans_earnings')
            )
            .where(
                and_(
                    Transaction.type == TransactionType.REFERRAL_REWARD.value,
                    Transaction.created_at >= start_date
                )
            )
            .group_by(Transaction.user_id)
        )

        # Объединяем заработки
        combined_earnings = dict(referral_earnings)
        for row in transaction_earnings_result:
            if row.referrer_id in combined_earnings:
                combined_earnings[row.referrer_id] += row.trans_earnings or 0
            else:
                combined_earnings[row.referrer_id] = row.trans_earnings or 0

        # Сортируем и берём топ
        sorted_referrers = sorted(
            combined_earnings.items(),
            key=lambda x: x[1],
            reverse=True
        )[:limit]

        top_data = []
        for referrer_id, earnings in sorted_referrers:
            # Получаем количество приглашённых за период
            invited_result = await db.execute(
                select(func.count(User.id))
                .where(
                    and_(
                        User.referred_by_id == referrer_id,
                        User.created_at >= start_date
                    )
                )
            )
            invited_count = invited_result.scalar() or 0

            top_data.append({
                'referrer_id': referrer_id,
                'invited_count': invited_count,
                'earnings_kopeks': earnings
            })

    # Добавляем информацию о пользователях
    result = []
    for data in top_data:
        user_result = await db.execute(
            select(User.id, User.username, User.first_name, User.last_name, User.telegram_id)
            .where(User.id == data['referrer_id'])
        )
        user = user_result.first()

        if user:
            display_name = ""
            if user.first_name:
                display_name = user.first_name
                if user.last_name:
                    display_name += f" {user.last_name}"
            elif user.username:
                display_name = f"@{user.username}"
            else:
                display_name = f"ID{user.telegram_id}"

            result.append({
                'user_id': user.id,
                'telegram_id': user.telegram_id,
                'username': user.username,
                'display_name': display_name,
                'invited_count': data['invited_count'],
                'earnings_kopeks': data['earnings_kopeks']
            })

    return result


async def get_user_referral_stats(db: AsyncSession, user_id: int) -> dict:
    
    invited_count_result = await db.execute(
        select(func.count(User.id)).where(User.referred_by_id == user_id)
    )
    invited_count = invited_count_result.scalar()
    
    total_earned = await get_referral_earnings_sum(db, user_id)
    
    month_ago = datetime.utcnow() - timedelta(days=30)
    month_earned = await get_referral_earnings_sum(db, user_id, start_date=month_ago)
    
    from app.database.models import Subscription, SubscriptionStatus
    current_time = datetime.utcnow()
    
    active_referrals_result = await db.execute(
        select(func.count(User.id))
        .join(Subscription, User.id == Subscription.user_id)
        .where(
            and_(
                User.referred_by_id == user_id,
                Subscription.status == SubscriptionStatus.ACTIVE.value,
                Subscription.end_date > current_time
            )
        )
    )
    active_referrals = active_referrals_result.scalar()
    
    return {
        "invited_count": invited_count,
        "active_referrals": active_referrals,
        "total_earned_kopeks": total_earned,
        "month_earned_kopeks": month_earned
    }