from pydantic import BaseModel, Field, field_validator
from typing import Optional, List, Any, Dict
from datetime import datetime
from enum import Enum


class FieldType(str, Enum):
    TEXT = "text"
    NUMBER = "number"
    DROPDOWN = "dropdown"
    DATE = "date"
    PERSON = "person"
    FORMULA = "formula"


class CustomFieldBase(BaseModel):
    name: str = Field(..., min_length=1, max_length=100)
    field_type: FieldType
    options: Optional[List[str]] = None  # For dropdown type
    formula: Optional[str] = None  # For formula type
    is_required: bool = False

    @field_validator('options')
    @classmethod
    def validate_options(cls, v, info):
        field_type = info.data.get('field_type')
        if field_type == FieldType.DROPDOWN:
            if not v or len(v) == 0:
                raise ValueError('Dropdown fields must have at least one option')
            if len(v) > 50:
                raise ValueError('Dropdown fields can have at most 50 options')
        return v

    @field_validator('formula')
    @classmethod
    def validate_formula(cls, v, info):
        field_type = info.data.get('field_type')
        if field_type == FieldType.FORMULA and not v:
            raise ValueError('Formula fields must have a formula expression')
        return v


class CustomFieldCreate(CustomFieldBase):
    pass


class CustomFieldUpdate(BaseModel):
    name: Optional[str] = Field(None, min_length=1, max_length=100)
    options: Optional[List[str]] = None
    formula: Optional[str] = None
    is_required: Optional[bool] = None


class CustomFieldResponse(CustomFieldBase):
    id: str
    project_id: str
    position: int
    created_at: datetime
    updated_at: datetime

    class Config:
        from_attributes = True


class CustomFieldListResponse(BaseModel):
    fields: List[CustomFieldResponse]
    total: int


# Task custom value schemas
class CustomValueInput(BaseModel):
    field_id: str
    value: Optional[Any] = None  # Can be string, number, date string, or user id


class CustomValueResponse(BaseModel):
    field_id: str
    field_name: str
    field_type: FieldType
    value: Optional[Any] = None
    display_value: Optional[str] = None  # Formatted for display

    class Config:
        from_attributes = True


class TaskCustomValuesUpdate(BaseModel):
    custom_values: List[CustomValueInput]