"""
用户管理 API
"""
from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, func, delete, or_
from typing import List, Optional
from pydantic import BaseModel, EmailStr

from app.core.database import get_db
from app.core.deps import get_current_user
from app.core.security import get_password_hash
from app.core.config import settings
from app.models.user import User
from app.models.role import Role, UserRole
from app.models.project import Project, ProjectMember
from app.schemas.response import success_response, error_response

router = APIRouter()


# === Pydantic Schemas ===

class UserCreateRequest(BaseModel):
    """创建用户请求"""
    username: str
    nickname: Optional[str] = None
    email: Optional[EmailStr] = None
    phone: Optional[str] = None
    role_ids: List[int] = []  # 分配的角色ID列表


class UserUpdateRequest(BaseModel):
    """更新用户请求"""
    nickname: Optional[str] = None
    email: Optional[EmailStr] = None
    phone: Optional[str] = None
    status: Optional[int] = None


class UserRolesUpdateRequest(BaseModel):
    """更新用户角色请求"""
    role_ids: List[int]


# === API Endpoints ===

@router.get("/", response_model=dict)
async def get_users(
    page: int = Query(1, ge=1),
    page_size: int = Query(10, ge=1, le=100),
    keyword: Optional[str] = Query(None, description="搜索关键词（用户名、昵称、邮箱）"),
    status: Optional[int] = Query(None, description="状态筛选：0-禁用 1-启用"),
    role_id: Optional[int] = Query(None, description="角色ID筛选"),
    current_user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db)
):
    """获取用户列表（分页）"""

    # 构建查询条件
    conditions = []
    if keyword:
        conditions.append(
            or_(
                User.username.like(f"%{keyword}%"),
                User.nickname.like(f"%{keyword}%"),
                User.email.like(f"%{keyword}%")
            )
        )
    if status is not None:
        conditions.append(User.status == status)

    # 如果需要按角色筛选
    if role_id is not None:
        # 查询用户列表时需要JOIN UserRole表
        query = (
            select(User)
            .join(UserRole, UserRole.user_id == User.id)
            .where(UserRole.role_id == role_id)
        )
        if conditions:
            query = query.where(*conditions)
        query = query.order_by(User.created_at.desc())

        # 查询总数
        count_query = (
            select(func.count(User.id.distinct()))
            .join(UserRole, UserRole.user_id == User.id)
            .where(UserRole.role_id == role_id)
        )
        if conditions:
            count_query = count_query.where(*conditions)
        total_result = await db.execute(count_query)
        total = total_result.scalar()
    else:
        # 查询总数
        count_query = select(func.count(User.id))
        if conditions:
            count_query = count_query.where(*conditions)
        total_result = await db.execute(count_query)
        total = total_result.scalar()

        # 查询用户列表
        query = select(User).order_by(User.created_at.desc())
        if conditions:
            query = query.where(*conditions)

    query = query.offset((page - 1) * page_size).limit(page_size)
    result = await db.execute(query)
    users = result.scalars().all()

    # 获取每个用户的角色信息
    users_data = []
    for user in users:
        # 获取用户角色
        roles_result = await db.execute(
            select(Role)
            .join(UserRole, UserRole.role_id == Role.id)
            .where(UserRole.user_id == user.id)
        )
        roles = roles_result.scalars().all()

        users_data.append({
            "id": user.id,
            "username": user.username,
            "nickname": user.nickname,
            "email": user.email,
            "phone": user.phone,
            "avatar": user.avatar,
            "status": user.status,
            "is_superuser": user.is_superuser,
            "last_login_at": user.last_login_at.isoformat() if user.last_login_at else None,
            "created_at": user.created_at.isoformat() if user.created_at else None,
            "roles": [{"id": r.id, "role_name": r.role_name, "role_code": r.role_code} for r in roles]
        })

    return {
        "code": 200,
        "message": "success",
        "data": users_data,
        "total": total,
        "page": page,
        "page_size": page_size
    }


@router.post("/", response_model=dict)
async def create_user(
    user_data: UserCreateRequest,
    current_user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db)
):
    """创建新用户"""

    # 检查用户名是否已存在
    result = await db.execute(
        select(User).where(User.username == user_data.username)
    )
    existing_user = result.scalar_one_or_none()
    if existing_user:
        raise HTTPException(status_code=400, detail="用户名已存在")

    # 检查邮箱是否已存在
    if user_data.email:
        result = await db.execute(
            select(User).where(User.email == user_data.email)
        )
        existing_email = result.scalar_one_or_none()
        if existing_email:
            raise HTTPException(status_code=400, detail="邮箱已被使用")

    # 创建用户
    new_user = User(
        username=user_data.username,
        password_hash=get_password_hash(settings.DEFAULT_USER_PASSWORD),
        nickname=user_data.nickname or user_data.username,
        email=user_data.email,
        phone=user_data.phone,
        status=1,
        is_superuser=0
    )

    db.add(new_user)
    await db.flush()

    # 分配角色
    if user_data.role_ids:
        # 验证角色ID是否存在
        roles_result = await db.execute(
            select(Role.id).where(Role.id.in_(user_data.role_ids))
        )
        valid_role_ids = [row[0] for row in roles_result.all()]

        for role_id in valid_role_ids:
            user_role = UserRole(user_id=new_user.id, role_id=role_id)
            db.add(user_role)

    await db.commit()
    await db.refresh(new_user)

    return success_response(
        data={
            "id": new_user.id,
            "username": new_user.username,
            "default_password": settings.DEFAULT_USER_PASSWORD
        },
        message="用户创建成功，请记住初始密码"
    )


@router.get("/{user_id}", response_model=dict)
async def get_user(
    user_id: int,
    current_user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db)
):
    """获取用户详情"""

    # 查询用户
    result = await db.execute(
        select(User).where(User.id == user_id)
    )
    user = result.scalar_one_or_none()
    if not user:
        raise HTTPException(status_code=404, detail="用户不存在")

    # 获取用户角色
    roles_result = await db.execute(
        select(Role)
        .join(UserRole, UserRole.role_id == Role.id)
        .where(UserRole.user_id == user.id)
    )
    roles = roles_result.scalars().all()

    return success_response(data={
        "id": user.id,
        "username": user.username,
        "nickname": user.nickname,
        "email": user.email,
        "phone": user.phone,
        "avatar": user.avatar,
        "status": user.status,
        "is_superuser": user.is_superuser,
        "last_login_at": user.last_login_at.isoformat() if user.last_login_at else None,
        "created_at": user.created_at.isoformat() if user.created_at else None,
        "roles": [{"id": r.id, "role_name": r.role_name, "role_code": r.role_code} for r in roles]
    })


@router.put("/{user_id}", response_model=dict)
async def update_user(
    user_id: int,
    user_data: UserUpdateRequest,
    current_user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db)
):
    """更新用户信息"""

    # 查询用户
    result = await db.execute(
        select(User).where(User.id == user_id)
    )
    user = result.scalar_one_or_none()
    if not user:
        raise HTTPException(status_code=404, detail="用户不存在")

    # 更新字段
    if user_data.nickname is not None:
        user.nickname = user_data.nickname
    if user_data.email is not None:
        # 检查邮箱是否被其他用户使用
        if user_data.email != user.email:
            email_result = await db.execute(
                select(User).where(User.email == user_data.email, User.id != user_id)
            )
            if email_result.scalar_one_or_none():
                raise HTTPException(status_code=400, detail="邮箱已被其他用户使用")
        user.email = user_data.email
    if user_data.phone is not None:
        user.phone = user_data.phone
    if user_data.status is not None:
        user.status = user_data.status

    await db.commit()
    await db.refresh(user)

    return success_response(data={"id": user.id}, message="用户信息更新成功")


@router.delete("/{user_id}", response_model=dict)
async def delete_user(
    user_id: int,
    current_user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db)
):
    """删除用户（需要检查是否有归属项目）"""

    # 查询用户
    result = await db.execute(
        select(User).where(User.id == user_id)
    )
    user = result.scalar_one_or_none()
    if not user:
        raise HTTPException(status_code=404, detail="用户不存在")

    # 不允许删除超级管理员
    if user.is_superuser == 1:
        raise HTTPException(status_code=400, detail="不允许删除超级管理员")

    # 不允许删除自己
    if user_id == current_user.id:
        raise HTTPException(status_code=400, detail="不允许删除当前登录用户")

    # 检查用户是否拥有项目
    owned_projects_result = await db.execute(
        select(func.count(Project.id)).where(Project.owner_id == user_id)
    )
    owned_projects_count = owned_projects_result.scalar()
    if owned_projects_count > 0:
        raise HTTPException(
            status_code=400,
            detail=f"该用户拥有 {owned_projects_count} 个项目，无法删除。请先转移或删除这些项目。"
        )

    # 删除用户的角色关联
    await db.execute(
        delete(UserRole).where(UserRole.user_id == user_id)
    )

    # 删除用户的项目成员关联
    await db.execute(
        delete(ProjectMember).where(ProjectMember.user_id == user_id)
    )

    # 删除用户
    await db.delete(user)
    await db.commit()

    return success_response(message="用户删除成功")


@router.put("/{user_id}/status", response_model=dict)
async def update_user_status(
    user_id: int,
    status: int = Query(..., ge=0, le=1, description="状态：0-禁用 1-启用"),
    current_user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db)
):
    """更新用户状态（停用/启用）"""

    # 查询用户
    result = await db.execute(
        select(User).where(User.id == user_id)
    )
    user = result.scalar_one_or_none()
    if not user:
        raise HTTPException(status_code=404, detail="用户不存在")

    # 不允许停用超级管理员
    if user.is_superuser == 1 and status == 0:
        raise HTTPException(status_code=400, detail="不允许停用超级管理员")

    # 不允许停用自己
    if user_id == current_user.id and status == 0:
        raise HTTPException(status_code=400, detail="不允许停用当前登录用户")

    user.status = status
    await db.commit()

    status_text = "启用" if status == 1 else "停用"
    return success_response(message=f"用户已{status_text}")


@router.put("/{user_id}/roles", response_model=dict)
async def update_user_roles(
    user_id: int,
    roles_data: UserRolesUpdateRequest,
    current_user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db)
):
    """更新用户角色"""

    # 查询用户
    result = await db.execute(
        select(User).where(User.id == user_id)
    )
    user = result.scalar_one_or_none()
    if not user:
        raise HTTPException(status_code=404, detail="用户不存在")

    # 验证角色ID是否存在
    if roles_data.role_ids:
        roles_result = await db.execute(
            select(Role.id).where(Role.id.in_(roles_data.role_ids))
        )
        valid_role_ids = [row[0] for row in roles_result.all()]

        invalid_ids = set(roles_data.role_ids) - set(valid_role_ids)
        if invalid_ids:
            raise HTTPException(
                status_code=400,
                detail=f"以下角色ID不存在: {', '.join(map(str, invalid_ids))}"
            )
    else:
        valid_role_ids = []

    # 删除原有角色关联
    await db.execute(
        delete(UserRole).where(UserRole.user_id == user_id)
    )

    # 添加新角色关联
    for role_id in valid_role_ids:
        user_role = UserRole(user_id=user_id, role_id=role_id)
        db.add(user_role)

    await db.commit()

    return success_response(message="用户角色更新成功")


@router.post("/{user_id}/reset-password", response_model=dict)
async def reset_user_password(
    user_id: int,
    current_user: User = Depends(get_current_user),
    db: AsyncSession = Depends(get_db)
):
    """重置用户密码为初始密码"""

    # 查询用户
    result = await db.execute(
        select(User).where(User.id == user_id)
    )
    user = result.scalar_one_or_none()
    if not user:
        raise HTTPException(status_code=404, detail="用户不存在")

    # 重置密码
    user.password_hash = get_password_hash(settings.DEFAULT_USER_PASSWORD)
    await db.commit()

    return success_response(
        data={"default_password": settings.DEFAULT_USER_PASSWORD},
        message="密码已重置为初始密码"
    )