schemas

"""
Pydantic schemas for request/response validation.
"""

from pydantic import BaseModel, EmailStr, Field
from datetime import datetime
from typing import Optional
from enum import Enum


# =============================================================================
# Enums
# =============================================================================

class TaskPriority(str, Enum):
    LOW = "low"
    MEDIUM = "medium"
    HIGH = "high"
    URGENT = "urgent"


# =============================================================================
# User Schemas
# =============================================================================

class UserBase(BaseModel):
    """Base user schema."""
    email: EmailStr
    username: str = Field(..., min_length=3, max_length=50)


class UserCreate(UserBase):
    """Schema for creating a user."""
    password: str = Field(..., min_length=8)


class UserResponse(UserBase):
    """Schema for user response."""
    id: int
    is_active: bool
    created_at: datetime
    
    class Config:
        from_attributes = True  # Allow ORM model conversion


class UserLogin(BaseModel):
    """Schema for user login."""
    username: str
    password: str


# =============================================================================
# Token Schemas
# =============================================================================

class Token(BaseModel):
    """JWT token response."""
    access_token: str
    token_type: str = "bearer"


class TokenData(BaseModel):
    """Token payload data."""
    username: Optional[str] = None


# =============================================================================
# Task Schemas
# =============================================================================

class TaskBase(BaseModel):
    """Base task schema."""
    title: str = Field(..., min_length=1, max_length=200)
    description: Optional[str] = Field(None, max_length=1000)
    priority: TaskPriority = TaskPriority.MEDIUM
    category: Optional[str] = Field(None, max_length=50)
    due_date: Optional[datetime] = None


class TaskCreate(TaskBase):
    """Schema for creating a task."""
    pass


class TaskUpdate(BaseModel):
    """Schema for updating a task (all fields optional)."""
    title: Optional[str] = Field(None, min_length=1, max_length=200)
    description: Optional[str] = Field(None, max_length=1000)
    completed: Optional[bool] = None
    priority: Optional[TaskPriority] = None
    category: Optional[str] = Field(None, max_length=50)
    due_date: Optional[datetime] = None


class TaskResponse(TaskBase):
    """Schema for task response."""
    id: int
    completed: bool
    created_at: datetime
    updated_at: Optional[datetime]
    owner_id: int
    
    class Config:
        from_attributes = True


# =============================================================================
# Pagination
# =============================================================================

class PaginatedResponse(BaseModel):
    """Generic paginated response."""
    items: list
    total: int
    page: int
    per_page: int
    pages: int