from datetime import datetime
from typing import Optional, List
from pydantic import BaseModel, ConfigDict, Field, field_validator


class InstanceGroupCreate(BaseModel):
    name: str = Field(..., min_length=1, max_length=100)
    description: Optional[str] = None
    db_type: str = Field(default="all", pattern=r"^(mysql|redis|pg|mongo|all)$")
    access_type: str = Field(
        default="readonly",
        pattern=r"^(readonly|write)$",
        description="权限组类型: readonly(只读查看) / write(写入变更)",
    )
    allowed_databases: Optional[List[str]] = Field(
        default=None,
        description="允许访问的数据库名列表，为空表示关联实例的所有库",
    )
    # Legacy field kept for backward compatibility
    permissions: Optional[List[str]] = None
    is_active: bool = True


class InstanceGroupUpdate(BaseModel):
    name: Optional[str] = Field(default=None, min_length=1, max_length=100)
    description: Optional[str] = None
    db_type: Optional[str] = Field(default=None, pattern=r"^(mysql|redis|pg|mongo|all)$")
    access_type: Optional[str] = Field(
        default=None,
        pattern=r"^(readonly|write)$",
        description="权限组类型: readonly(只读查看) / write(写入变更)",
    )
    allowed_databases: Optional[List[str]] = Field(
        default=None,
        description="允许访问的数据库名列表，为空表示关联实例的所有库",
    )
    # Legacy field kept for backward compatibility
    permissions: Optional[List[str]] = None
    is_active: Optional[bool] = None


class InstanceGroupResponse(BaseModel):
    id: int
    name: str
    description: Optional[str] = None
    db_type: str
    # Legacy field
    permissions: Optional[List[str]] = None
    # New fields
    access_type: Optional[str] = None
    allowed_databases: Optional[List[str]] = None
    is_active: bool
    created_at: Optional[datetime] = None
    updated_at: Optional[datetime] = None
    instance_count: int = 0
    user_count: int = 0

    model_config = ConfigDict(from_attributes=True)


class InstanceGroupDetailResponse(InstanceGroupResponse):
    instances: List[dict] = []
    users: List[dict] = []


class InstanceAssignRequest(BaseModel):
    instance_ids: List[int] = Field(..., min_length=1)


class UserAssignRequest(BaseModel):
    user_ids: List[int] = Field(..., min_length=1)
    permissions: Optional[List[str]] = None


class UserGroupUpdateRequest(BaseModel):
    group_ids: List[int] = Field(default_factory=list)