"""每日花园状态服务：连续天数 + 树渴了提醒"""

from datetime import date, datetime, timedelta

from sqlalchemy import select, or_
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.user_streak import UserStreak
from app.models.friendship_tree import FriendshipTree
from app.models.friend import Friend
from app.models.user import User


class DailyService:
    def __init__(self, db: AsyncSession):
        self.db = db

    async def get_daily_status(self, user_id: str) -> dict:
        """获取/更新今日花园状态"""
        today = date.today()
        result = await self.db.execute(
            select(UserStreak).where(UserStreak.user_id == user_id)
        )
        streak_row = result.scalars().first()

        is_new_day_open = False
        if not streak_row:
            streak_row = UserStreak(
                user_id=user_id, streak=1, last_open_date=today, total_days=1,
            )
            self.db.add(streak_row)
            is_new_day_open = True
        elif streak_row.last_open_date != today:
            # 计算连续天数
            if streak_row.last_open_date == today - timedelta(days=1):
                streak_row.streak += 1  # 连续
            else:
                streak_row.streak = 1  # 断了，重新计数
            streak_row.last_open_date = today
            streak_row.total_days += 1
            is_new_day_open = True
        await self.db.flush()

        # 找口渴的树（24 小时没浇水的）
        thirsty_trees = await self._get_thirsty_trees(user_id)

        return {
            "streak": streak_row.streak,
            "total_days": streak_row.total_days,
            "is_new_day_open": is_new_day_open,
            "thirsty_count": len(thirsty_trees),
            "thirsty_trees": thirsty_trees[:3],  # 最多提示 3 棵
        }

    async def _get_thirsty_trees(self, user_id: str) -> list[dict]:
        """获取口渴的好友之树（24h 未浇水）"""
        cutoff = datetime.utcnow() - timedelta(hours=24)
        # 查该用户参与的所有树
        result = await self.db.execute(
            select(FriendshipTree).where(
                or_(
                    FriendshipTree.user_a_id == user_id,
                    FriendshipTree.user_b_id == user_id,
                )
            )
        )
        thirsty = []
        for tree in result.scalars().all():
            if tree.last_watered_at is None or tree.last_watered_at < cutoff:
                friend_id = tree.user_b_id if tree.user_a_id == user_id else tree.user_a_id
                # 取好友信息
                fr = await self.db.execute(select(User).where(User.id == friend_id))
                friend = fr.scalars().first()
                if friend:
                    thirsty.append({
                        "friend_id": friend_id,
                        "friend_name": friend.nickname or friend.username,
                        "hours_since": int((datetime.utcnow() - (tree.last_watered_at or tree.created_at)).total_seconds() / 3600),
                    })
        return thirsty