"""每日心情叶服务"""

import hashlib
import uuid
from datetime import date

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

from app.models.daily_leaf import DailyMoodLeaf


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

    async def get_or_create_today(self, user_id: str) -> dict:
        """获取或创建今日心情叶"""
        today = date.today()
        result = await self.db.execute(
            select(DailyMoodLeaf).where(
                DailyMoodLeaf.user_id == user_id,
                DailyMoodLeaf.leaf_date == today,
            )
        )
        leaf = result.scalars().first()
        if not leaf:
            seed = hashlib.md5(f"{user_id}:{today.isoformat()}".encode()).hexdigest()[:16]
            leaf = DailyMoodLeaf(
                id=str(uuid.uuid4()),
                user_id=user_id,
                leaf_date=today,
                leaf_seed=seed,
            )
            self.db.add(leaf)
            await self.db.flush()
        return self._leaf_to_dict(leaf)

    async def update_leaf(self, user_id: str, leaf_id: str, mood: str | None,
                          note: str | None) -> dict:
        """更新今日叶子的心情和备注"""
        result = await self.db.execute(
            select(DailyMoodLeaf).where(DailyMoodLeaf.id == leaf_id)
        )
        leaf = result.scalars().first()
        if not leaf:
            raise ValueError("叶子不存在")
        if leaf.user_id != user_id:
            raise ValueError("无权操作此叶子")
        if mood is not None:
            leaf.mood = mood
        if note is not None:
            leaf.note = note
        await self.db.flush()
        return self._leaf_to_dict(leaf)

    async def get_collection(self, user_id: str, limit: int = 60) -> list[dict]:
        """获取叶子收藏（历史）"""
        result = await self.db.execute(
            select(DailyMoodLeaf)
            .where(DailyMoodLeaf.user_id == user_id)
            .order_by(DailyMoodLeaf.leaf_date.desc())
            .limit(limit)
        )
        return [self._leaf_to_dict(l) for l in result.scalars().all()]

    async def get_grove(self, user_id: str) -> dict:
        """获取情绪共鸣林：自己 + 好友今日的心情叶，聚合成俯瞰森林"""
        from app.models.friend import Friend
        today = date.today()

        # 自己 + 好友 ID
        friends_result = await self.db.execute(
            select(Friend.friend_user_id).where(Friend.user_id == user_id)
        )
        visible_ids = [user_id] + [r[0] for r in friends_result.all()]

        # 查今日所有人的叶子
        result = await self.db.execute(
            select(DailyMoodLeaf).where(
                DailyMoodLeaf.user_id.in_(visible_ids),
                DailyMoodLeaf.leaf_date == today,
            )
        )
        leaves = result.scalars().all()

        # 排布：自己在中心（position 0），好友按确定性环绕
        import math
        positioned = []
        others = [l for l in leaves if l.user_id != user_id]
        my_leaf = next((l for l in leaves if l.user_id == user_id), None)
        if my_leaf:
            positioned.append({
                "is_self": True, "user_id": my_leaf.user_id,
                "mood": my_leaf.mood, "leaf_seed": my_leaf.leaf_seed,
                "angle": 0, "radius": 0,
            })
        n = len(others)
        for i, l in enumerate(others):
            angle = (2 * math.pi * i / n) if n > 0 else 0
            positioned.append({
                "is_self": False, "user_id": l.user_id,
                "mood": l.mood, "leaf_seed": l.leaf_seed,
                "angle": angle, "radius": 1,
            })

        # 聚合情绪天气
        mood_counts: dict[str, int] = {}
        for l in leaves:
            mood_counts[l.mood or "unknown"] = mood_counts.get(l.mood or "unknown", 0) + 1

        return {
            "leaves": positioned,
            "total": len(leaves),
            "mood_counts": mood_counts,
            "date": today.isoformat(),
        }

    def _leaf_to_dict(self, leaf: DailyMoodLeaf) -> dict:
        return {
            "id": leaf.id,
            "user_id": leaf.user_id,
            "leaf_date": leaf.leaf_date.isoformat() if leaf.leaf_date else None,
            "mood": leaf.mood,
            "note": leaf.note,
            "leaf_seed": leaf.leaf_seed,
            "created_at": leaf.created_at,
        }