"""
移除成员 Use Case
"""
from typing import Optional

from packages.domain.entities import WorkspaceMemberRole


class RemoveMemberRequest:
    """移除成员请求"""
    
    def __init__(
        self,
        workspace_id: str,
        requester_user_id: str,
        target_user_id: str,
    ):
        self.workspace_id = workspace_id
        self.requester_user_id = requester_user_id
        self.target_user_id = target_user_id


class RemoveMemberUseCase:
    """移除成员用例"""
    
    def __init__(
        self,
        workspace_repository,
        workspace_member_repository,
    ):
        self.workspace_repository = workspace_repository
        self.workspace_member_repository = workspace_member_repository
    
    def execute(self, request: RemoveMemberRequest) -> tuple[bool, Optional[str]]:
        """
        执行移除成员
        
        Args:
            request: 移除请求
        
        Returns:
            (是否成功, 错误信息)
        """
        try:
            # 1. 验证输入
            if not request.workspace_id:
                return False, "Workspace ID is required"
            
            if not request.requester_user_id:
                return False, "Requester user ID is required"
            
            if not request.target_user_id:
                return False, "Target user ID is required"
            
            # 2. 验证 Workspace 存在
            workspace = self.workspace_repository.find_by_id(request.workspace_id)
            if not workspace:
                return False, "Workspace not found"
            
            # 3. 验证请求者是成员且有权限
            requester_member = self.workspace_member_repository.find_by_workspace_and_user(
                request.workspace_id,
                request.requester_user_id,
            )
            if not requester_member:
                return False, "You are not a member of this workspace"
            
            if requester_member.role not in [WorkspaceMemberRole.OWNER, WorkspaceMemberRole.ADMIN]:
                return False, "Only owners and admins can remove members"
            
            # 4. 验证目标成员存在
            target_member = self.workspace_member_repository.find_by_workspace_and_user(
                request.workspace_id,
                request.target_user_id,
            )
            if not target_member:
                return False, "Target user is not a member of this workspace"
            
            # 5. 不能移除自己（应该用离开 workspace 的功能）
            if request.requester_user_id == request.target_user_id:
                return False, "Cannot remove yourself. Use leave workspace instead."
            
            # 6. 不能移除 owner
            if target_member.role == WorkspaceMemberRole.OWNER:
                return False, "Cannot remove the workspace owner"
            
            # 7. Admin 不能移除另一个 Admin（只有 owner 可以）
            if (requester_member.role == WorkspaceMemberRole.ADMIN and 
                target_member.role == WorkspaceMemberRole.ADMIN):
                return False, "Admins cannot remove other admins"
            
            # 8. 删除成员记录
            success = self.workspace_member_repository.delete(target_member.id)
            if not success:
                return False, "Failed to remove member"
            
            return True, None
        
        except Exception as e:
            return False, f"Failed to remove member: {str(e)}"


class LeaveWorkspaceRequest:
    """离开 Workspace 请求"""
    
    def __init__(self, workspace_id: str, user_id: str):
        self.workspace_id = workspace_id
        self.user_id = user_id


class LeaveWorkspaceUseCase:
    """离开 Workspace 用例"""
    
    def __init__(
        self,
        workspace_repository,
        workspace_member_repository,
    ):
        self.workspace_repository = workspace_repository
        self.workspace_member_repository = workspace_member_repository
    
    def execute(self, request: LeaveWorkspaceRequest) -> tuple[bool, Optional[str]]:
        """
        执行离开 Workspace
        
        Args:
            request: 离开请求
        
        Returns:
            (是否成功, 错误信息)
        """
        try:
            # 1. 验证输入
            if not request.workspace_id:
                return False, "Workspace ID is required"
            
            if not request.user_id:
                return False, "User ID is required"
            
            # 2. 验证 Workspace 存在
            workspace = self.workspace_repository.find_by_id(request.workspace_id)
            if not workspace:
                return False, "Workspace not found"
            
            # 3. 验证用户是成员
            member = self.workspace_member_repository.find_by_workspace_and_user(
                request.workspace_id,
                request.user_id,
            )
            if not member:
                return False, "You are not a member of this workspace"
            
            # 4. Owner 不能离开（需要先转移 ownership 或删除 workspace）
            if member.role == WorkspaceMemberRole.OWNER:
                return False, "Owner cannot leave workspace. Transfer ownership or delete workspace first."
            
            # 5. 删除成员记录
            success = self.workspace_member_repository.delete(member.id)
            if not success:
                return False, "Failed to leave workspace"
            
            return True, None
        
        except Exception as e:
            return False, f"Failed to leave workspace: {str(e)}"