from datetime import datetime
from typing import Optional
from uuid import UUID
from pydantic import BaseModel, Field
import re


# Valid hex color pattern
HEX_COLOR_PATTERN = r'^#[0-9A-Fa-f]{6}$'


class FolderBase(BaseModel):
    name: str = Field(..., min_length=1, max_length=100)
    color: str = Field("#6366f1", pattern=HEX_COLOR_PATTERN)
    icon: str = Field("folder", max_length=50)


class FolderCreate(FolderBase):
    parent_id: Optional[UUID] = Field(None, description="Parent folder ID for creating subfolders")


class FolderUpdate(BaseModel):
    name: Optional[str] = Field(None, min_length=1, max_length=100)
    color: Optional[str] = Field(None, pattern=HEX_COLOR_PATTERN)
    icon: Optional[str] = Field(None, max_length=50)
    display_order: Optional[int] = None
    parent_id: Optional[UUID] = Field(None, description="Parent folder ID to move folder")


class FolderResponse(FolderBase):
    id: UUID
    parent_id: Optional[UUID] = None
    display_order: int
    tree_count: int = 0  # Computed field
    created_at: datetime
    updated_at: datetime

    class Config:
        from_attributes = True


class FolderListResponse(BaseModel):
    id: UUID
    name: str
    color: str
    icon: str
    parent_id: Optional[UUID] = None
    display_order: int
    tree_count: int = 0

    class Config:
        from_attributes = True


class FolderReorderRequest(BaseModel):
    """Request body for reordering folders."""
    folder_ids: list[UUID] = Field(..., min_length=1, description="Folder IDs in desired order")


class FolderTreeRequest(BaseModel):
    """Request body for adding a tree to a folder."""
    tree_id: UUID