"""
Subscription 管理 Use Case
"""
from typing import Optional
from datetime import datetime, timedelta, timezone

from packages.domain.entities import WorkspaceMemberRole


class UpgradeSubscriptionRequest:
    """升级订阅请求"""
    
    def __init__(
        self,
        workspace_id: str,
        requester_user_id: str,
        new_plan: str,
    ):
        self.workspace_id = workspace_id
        self.requester_user_id = requester_user_id
        self.new_plan = new_plan


class UpgradeSubscriptionResponse:
    """升级订阅响应"""
    
    def __init__(
        self,
        workspace_id: str,
        old_plan: str,
        new_plan: str,
        max_projects: int,
        max_storage_gb: int,
    ):
        self.workspace_id = workspace_id
        self.old_plan = old_plan
        self.new_plan = new_plan
        self.max_projects = max_projects
        self.max_storage_gb = max_storage_gb


class UpgradeSubscriptionUseCase:
    """升级订阅用例"""
    
    # 订阅计划配额
    PLAN_QUOTAS = {
        "free": {"max_projects": 3, "max_storage_gb": 10, "price": 0},
        "pro": {"max_projects": 999999, "max_storage_gb": 100, "price": 99},
        "enterprise": {"max_projects": 999999, "max_storage_gb": 1000, "price": 999},
    }
    
    # 计划等级
    PLAN_LEVELS = {
        "free": 0,
        "pro": 1,
        "enterprise": 2,
    }
    
    def __init__(
        self,
        workspace_repository,
        workspace_member_repository,
    ):
        self.workspace_repository = workspace_repository
        self.workspace_member_repository = workspace_member_repository
    
    def execute(self, request: UpgradeSubscriptionRequest) -> tuple[Optional[UpgradeSubscriptionResponse], Optional[str]]:
        """
        执行升级订阅
        
        Args:
            request: 升级请求
        
        Returns:
            (响应, 错误信息)
        """
        try:
            # 1. 验证输入
            if not request.workspace_id:
                return None, "Workspace ID is required"
            
            if not request.requester_user_id:
                return None, "Requester user ID is required"
            
            if not request.new_plan:
                return None, "New plan is required"
            
            # 2. 验证新计划有效
            if request.new_plan not in self.PLAN_QUOTAS:
                return None, f"Invalid plan: {request.new_plan}"
            
            # 3. 验证工作空间存在
            workspace = self.workspace_repository.find_by_id(request.workspace_id)
            if not workspace:
                return None, "Workspace not found"
            
            # 4. 验证权限（只有 Owner 可以管理订阅）
            member = self.workspace_member_repository.find_by_workspace_and_user(
                request.workspace_id,
                request.requester_user_id,
            )
            if not member:
                return None, "You are not a member of this workspace"
            
            if member.role != WorkspaceMemberRole.OWNER:
                return None, "Only workspace owner can manage subscription"
            
            # 5. 检查是否是升级（不能降级到免费计划，需要用取消订阅）
            current_level = self.PLAN_LEVELS.get(workspace.subscription_plan, 0)
            new_level = self.PLAN_LEVELS.get(request.new_plan, 0)
            
            if new_level < current_level:
                return None, "Cannot downgrade plan. Use cancel subscription to return to free plan."
            
            if new_level == current_level:
                return None, f"Workspace is already on {request.new_plan} plan"
            
            # 6. 更新订阅
            old_plan = workspace.subscription_plan
            quota = self.PLAN_QUOTAS[request.new_plan]
            
            workspace.subscription_plan = request.new_plan
            workspace.subscription_status = "active"
            workspace.max_projects = quota["max_projects"]
            workspace.max_storage_gb = quota["max_storage_gb"]
            
            # 设置过期时间（假设按月订阅）
            workspace.subscription_expires_at = datetime.now(timezone.utc) + timedelta(days=30)
            
            self.workspace_repository.save(workspace)
            
            # 7. 返回响应
            return UpgradeSubscriptionResponse(
                workspace_id=workspace.id,
                old_plan=old_plan,
                new_plan=workspace.subscription_plan,
                max_projects=workspace.max_projects,
                max_storage_gb=workspace.max_storage_gb,
            ), None
        
        except Exception as e:
            return None, f"Failed to upgrade subscription: {str(e)}"


class CancelSubscriptionRequest:
    """取消订阅请求"""
    
    def __init__(self, workspace_id: str, requester_user_id: str):
        self.workspace_id = workspace_id
        self.requester_user_id = requester_user_id


class CancelSubscriptionUseCase:
    """取消订阅用例"""
    
    def __init__(
        self,
        workspace_repository,
        workspace_member_repository,
    ):
        self.workspace_repository = workspace_repository
        self.workspace_member_repository = workspace_member_repository
    
    def execute(self, request: CancelSubscriptionRequest) -> tuple[bool, Optional[str]]:
        """
        执行取消订阅
        
        Args:
            request: 取消请求
        
        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"
            
            # 2. 验证工作空间存在
            workspace = self.workspace_repository.find_by_id(request.workspace_id)
            if not workspace:
                return False, "Workspace not found"
            
            # 3. 验证权限（只有 Owner 可以管理订阅）
            member = self.workspace_member_repository.find_by_workspace_and_user(
                request.workspace_id,
                request.requester_user_id,
            )
            if not member:
                return False, "You are not a member of this workspace"
            
            if member.role != WorkspaceMemberRole.OWNER:
                return False, "Only workspace owner can manage subscription"
            
            # 4. 检查当前计划
            if workspace.subscription_plan == "free":
                return False, "Workspace is already on free plan"
            
            # 5. 降级到 free 计划
            workspace.subscription_plan = "free"
            workspace.subscription_status = "active"
            workspace.subscription_expires_at = None
            workspace.max_projects = 3
            workspace.max_storage_gb = 10
            
            self.workspace_repository.save(workspace)
            
            return True, None
        
        except Exception as e:
            return False, f"Failed to cancel subscription: {str(e)}"