from datetime import datetime
from typing import Optional, List, Annotated
from pydantic import BaseModel, EmailStr, Field, field_validator, ConfigDict
from pydantic_core import core_schema
from bson import ObjectId


class PyObjectId(str):
    """Custom ObjectId type for Pydantic v2"""

    @classmethod
    def __get_pydantic_core_schema__(cls, source_type, handler):
        return core_schema.union_schema([
            core_schema.is_instance_schema(ObjectId),
            core_schema.chain_schema([
                core_schema.str_schema(),
                core_schema.no_info_plain_validator_function(cls.validate),
            ])
        ],
        serialization=core_schema.plain_serializer_function_ser_schema(
            lambda x: str(x)
        ))

    @classmethod
    def validate(cls, v):
        if isinstance(v, ObjectId):
            return v
        if isinstance(v, str) and ObjectId.is_valid(v):
            return ObjectId(v)
        raise ValueError("Invalid ObjectId")


class UserRole(str):
    """User roles"""
    ADMIN = "admin"
    EDITOR = "editor"
    VIEWER = "viewer"


class OAuthProvider(BaseModel):
    """OAuth provider information"""
    provider: str = Field(..., description="OAuth provider name (google, github, azure)")
    provider_user_id: str = Field(..., description="User ID from the provider")
    access_token: Optional[str] = Field(None, description="Access token (encrypted)")
    refresh_token: Optional[str] = Field(None, description="Refresh token (encrypted)")


class UserProfile(BaseModel):
    """User profile information"""
    avatar_url: Optional[str] = None
    department: Optional[str] = None
    timezone: str = "Asia/Seoul"


class User(BaseModel):
    """User model"""
    id: Optional[PyObjectId] = Field(alias="_id", default=None)
    email: EmailStr = Field(..., description="User email")
    username: str = Field(..., min_length=3, max_length=50, description="Username")
    hashed_password: str = Field(..., description="Hashed password")
    full_name: Optional[str] = Field(None, description="Full name")
    role: str = Field(default=UserRole.VIEWER, description="User role")
    permissions: List[str] = Field(default_factory=list, description="User permissions")
    oauth_providers: List[OAuthProvider] = Field(default_factory=list)
    profile: UserProfile = Field(default_factory=UserProfile)
    status: str = Field(default="active", description="User status")
    is_active: bool = Field(default=True)
    created_at: datetime = Field(default_factory=datetime.utcnow)
    updated_at: datetime = Field(default_factory=datetime.utcnow)
    last_login_at: Optional[datetime] = None

    model_config = ConfigDict(
        populate_by_name=True,
        arbitrary_types_allowed=True,
        json_encoders={ObjectId: str},
        json_schema_extra={
            "example": {
                "email": "user@example.com",
                "username": "johndoe",
                "full_name": "John Doe",
                "role": "viewer"
            }
        }
    )


class UserInDB(User):
    """User model with password hash"""
    pass