from fastapi import APIRouter, Depends
from sqlalchemy.orm import Session
from typing import List, Optional
from app.models.community import (
    CommunityDB, CommunityCreate, CommunityUpdate, 
    CommunityInfo, CommunityStatus
)
from app.models.database import get_db
from app.api.deps import get_admin_user
from app.models.user import UserDB
from app.core.response import success_response, error_response, ResponseModel

router = APIRouter()

@router.post("/", response_model=ResponseModel)
async def create_community(
    community: CommunityCreate,
    db: Session = Depends(get_db),
    admin: UserDB = Depends(get_admin_user)
):
    """创建社区"""
    db_community = CommunityDB(**community.model_dump())
    db.add(db_community)
    db.commit()
    db.refresh(db_community)
    return success_response(data=CommunityInfo.model_validate(db_community))

@router.get("", response_model=ResponseModel)
async def get_communities(
    latitude: Optional[float] = None,
    longitude: Optional[float] = None,
    status: Optional[CommunityStatus] = None,
    skip: int = 0,
    limit: int = 10,
    db: Session = Depends(get_db)
):
    """获取社区列表"""
    # 构建查询
    query = db.query(CommunityDB)
    
    # 状态过滤
    if status:
        query = query.filter(CommunityDB.status == status)
    
    # 获取总数
    total = query.count()
    
    # 查询数据
    communities = query.offset(skip).limit(limit).all()
    
    community_list = []
    for community in communities:
        community_info = CommunityInfo.model_validate(community)
        
        # 如果提供了经纬度，则计算距离
        if latitude is not None and longitude is not None:
            distance = calculate_distance(
                latitude, longitude,
                community.latitude, community.longitude
            )
            community_info.distance = distance
        
        community_list.append(community_info)
    
    # 如果计算了距离，则按距离排序
    if latitude is not None and longitude is not None:
        community_list.sort(key=lambda x: x.distance)
    
    return success_response(data={
        "total": total,
        "items": community_list
    })

def calculate_distance(lat1: float, lon1: float, lat2: float, lon2: float) -> float:
    """计算两点之间的距离（米）"""
    from math import radians, sin, cos, sqrt, atan2
    
    R = 6371000  # 地球半径（米）
    
    # 转换为弧度
    lat1, lon1, lat2, lon2 = map(radians, [lat1, lon1, lat2, lon2])
    
    # Haversine 公式
    dlat = lat2 - lat1
    dlon = lon2 - lon1
    a = sin(dlat/2)**2 + cos(lat1) * cos(lat2) * sin(dlon/2)**2
    c = 2 * atan2(sqrt(a), sqrt(1-a))
    distance = R * c
    
    return round(distance, 2)  # 保留2位小数

@router.get("/{community_id}", response_model=ResponseModel)
async def get_community(
    community_id: int,
    db: Session = Depends(get_db)
):
    """获取社区详情"""
    community = db.query(CommunityDB).filter(CommunityDB.id == community_id).first()
    if not community:
        return error_response(code=404, message="社区不存在")
    return success_response(data=CommunityInfo.model_validate(community))

@router.put("/{community_id}", response_model=ResponseModel)
async def update_community(
    community_id: int,
    community: CommunityUpdate,
    db: Session = Depends(get_db),
    admin: UserDB = Depends(get_admin_user)
):
    """更新社区信息"""
    db_community = db.query(CommunityDB).filter(CommunityDB.id == community_id).first()
    if not db_community:
        return error_response(code=404, message="社区不存在")
    
    update_data = community.model_dump(exclude_unset=True)
    for key, value in update_data.items():
        setattr(db_community, key, value)
    
    db.commit()
    db.refresh(db_community)
    return success_response(data=CommunityInfo.model_validate(db_community))

@router.delete("/{community_id}", response_model=ResponseModel)
async def delete_community(
    community_id: int,
    db: Session = Depends(get_db),
    admin: UserDB = Depends(get_admin_user)
):
    """删除社区"""
    result = db.query(CommunityDB).filter(CommunityDB.id == community_id).delete()
    if not result:
        return error_response(code=404, message="社区不存在")
    
    db.commit()
    return success_response(message="社区已删除")