from datetime import datetime
from typing import Optional, List, Any, Dict, Union
from uuid import UUID

from pydantic import BaseModel, Field, field_validator, model_validator

from app.models.gift import GiftStatus, GiftPriority


# Base Gift Schema
class GiftItemBase(BaseModel):
    name: str
    description: Optional[str] = None
    price: Optional[float] = None
    currency: Optional[str] = "USD"
    quantity_requested: Optional[int] = 1
    quantity_received: Optional[int] = 0
    status: Optional[GiftStatus] = GiftStatus.AVAILABLE
    priority: Optional[GiftPriority] = GiftPriority.MEDIUM
    purchase_url: Optional[str] = None
    store_name: Optional[str] = None
    brand: Optional[str] = None
    model: Optional[str] = None
    image_url: Optional[str] = None
    display_order: Optional[int] = None
    is_visible: Optional[bool] = True
    notes: Optional[str] = None
    custom_fields: Optional[Dict[str, Any]] = None


# Schema for creating a gift
class GiftItemCreate(GiftItemBase):
    event_id: UUID
    added_by: UUID
    category_id: Optional[UUID] = None

    @field_validator('price')
    @classmethod
    def validate_price(cls, v: Optional[float]) -> Optional[float]:
        if v is not None and v < 0:
            raise ValueError("Price cannot be negative")
        return v

    @field_validator('quantity_requested')
    @classmethod
    def validate_quantity(cls, v: Optional[int]) -> Optional[int]:
        if v is not None and v < 1:
            raise ValueError("Quantity requested must be at least 1")
        return v


# Schema for updating a gift
class GiftItemUpdate(BaseModel):
    name: Optional[str] = None
    description: Optional[str] = None
    price: Optional[float] = None
    currency: Optional[str] = None
    quantity_requested: Optional[int] = None
    quantity_received: Optional[int] = None
    status: Optional[GiftStatus] = None
    priority: Optional[GiftPriority] = None
    purchase_url: Optional[str] = None
    store_name: Optional[str] = None
    brand: Optional[str] = None
    model: Optional[str] = None
    image_url: Optional[str] = None
    display_order: Optional[int] = None
    is_visible: Optional[bool] = None
    notes: Optional[str] = None
    custom_fields: Optional[Dict[str, Any]] = None
    category_id: Optional[UUID] = None

    @field_validator('price')
    @classmethod
    def validate_price(cls, v: Optional[float]) -> Optional[float]:
        if v is not None and v < 0:
            raise ValueError("Price cannot be negative")
        return v

    @field_validator('quantity_requested')
    @classmethod
    def validate_quantity(cls, v: Optional[int]) -> Optional[int]:
        if v is not None and v < 1:
            raise ValueError("Quantity requested must be at least 1")
        return v


# Schema for reading a gift
class GiftItemInDB(GiftItemBase):
    id: UUID
    event_id: UUID
    added_by: UUID
    category_id: Optional[UUID] = None
    last_status_change: Optional[datetime] = None
    created_at: datetime
    updated_at: datetime

    class Config:
        from_attributes = True


# Public gift item response
class GiftItem(GiftItemInDB):
    remaining_quantity: int
    is_fully_received: bool
    formatted_price: str
    reserved: bool = False

    class Config:
        from_attributes = True


# Gift Category Schemas
class GiftCategoryBase(BaseModel):
    name: str
    description: Optional[str] = None
    icon: Optional[str] = None
    color: Optional[str] = None
    custom_fields: Optional[Dict[str, Any]] = None


# Schema for creating a category
class GiftCategoryCreate(GiftCategoryBase):
    created_by: UUID


# Schema for updating a category
class GiftCategoryUpdate(BaseModel):
    name: Optional[str] = None
    description: Optional[str] = None
    icon: Optional[str] = None
    color: Optional[str] = None
    custom_fields: Optional[Dict[str, Any]] = None


# Schema for reading a category
class GiftCategoryInDB(GiftCategoryBase):
    id: UUID
    created_by: UUID
    created_at: datetime
    updated_at: datetime

    class Config:
        from_attributes = True


# Event-Category association schemas
class EventGiftCategoryBase(BaseModel):
    event_id: UUID
    category_id: UUID
    display_order: int = 0
    is_visible: bool = True


# Schema for creating an event-category association
class EventGiftCategoryCreate(EventGiftCategoryBase):
    pass


# Schema for updating an event-category association
class EventGiftCategoryUpdate(BaseModel):
    display_order: Optional[int] = None
    is_visible: Optional[bool] = None


# Schema for reading an event-category association
class EventGiftCategoryInDB(EventGiftCategoryBase):
    created_at: datetime

    class Config:
        from_attributes = True


# Public category response with statistics
class GiftCategory(GiftCategoryInDB):
    # These properties will be calculated for a specific event in the API
    total_gifts: Optional[int] = None
    available_gifts: Optional[int] = None
    gifts: Optional[List[GiftItem]] = None
    # For display in a specific event context
    display_order: Optional[int] = None
    is_visible: Optional[bool] = None

    class Config:
        from_attributes = True


# Gift Purchase Schemas
class GiftPurchaseBase(BaseModel):
    gift_id: UUID
    guest_id: UUID
    quantity: int = 1
    purchase_price: Optional[float] = None
    purchase_currency: Optional[str] = None
    notes: Optional[str] = None


# Schema for creating a purchase
class GiftPurchaseCreate(GiftPurchaseBase):
    pass


# Schema for updating a purchase
class GiftPurchaseUpdate(BaseModel):
    quantity: Optional[int] = None
    purchase_price: Optional[float] = None
    purchase_currency: Optional[str] = None
    notes: Optional[str] = None


# Schema for reading a purchase
class GiftPurchaseInDB(GiftPurchaseBase):
    id: UUID
    purchased_at: datetime

    class Config:
        from_attributes = True


# Public gift purchase response
class GiftPurchase(GiftPurchaseInDB):
    class Config:
        from_attributes = True