import uuid

from decimal import Decimal

from pydantic import BaseModel, ConfigDict, Field, field_validator, model_validator

from . import to_camel
from .customer import CustomerLink
from .modifier import ModifierLink
from .product_link import ProductLink
from .table import TableLink
from .tax import TaxLink


class Inventory(BaseModel):
    id_: uuid.UUID | None = None
    product: ProductLink
    quantity: Decimal
    price: Decimal | None = None
    tax: TaxLink | None = None
    tax_rate: Decimal | None = None
    discount: Decimal = Field(ge=0, le=1)
    is_happy_hour: bool
    modifiers: list[ModifierLink]
    amount: Decimal | None = None
    model_config = ConfigDict(alias_generator=to_camel, populate_by_name=True)

    @field_validator("quantity")
    @classmethod
    def _quantity(cls, value: Decimal | None) -> Decimal:
        if value is None:
            return Decimal(0)
        return round(value, 2)

    @field_validator("price")
    @classmethod
    def _price(cls, value: Decimal | None) -> Decimal:
        if value is None:
            return Decimal(0)
        return round(value, 2)

    @field_validator("tax_rate")
    @classmethod
    def _tax_rate(cls, value: Decimal | None) -> Decimal:
        if value is None:
            return Decimal(0)
        return round(value, 5)

    @field_validator("discount")
    @classmethod
    def _discount(cls, value: Decimal | None) -> Decimal:
        if value is None:
            return Decimal(0)
        return round(value, 5)

    @model_validator(mode="after")
    def calculate_amount(self) -> "Inventory":
        self.amount = round(
            Decimal(
                (self.price or Decimal(0)) * self.quantity * (1 - self.discount) * (1 + (self.tax_rate or Decimal(0)))
            ),
            2,
        )
        return self


class Kot(BaseModel):
    id_: uuid.UUID | None = None
    inventories: list[Inventory]
    model_config = ConfigDict(str_strip_whitespace=True, alias_generator=to_camel, populate_by_name=True)


class VoucherIn(BaseModel):
    pax: int
    table: TableLink
    customer: CustomerLink | None = None
    kots: list[Kot]
    model_config = ConfigDict(str_strip_whitespace=True, alias_generator=to_camel, populate_by_name=True)


class Voucher(VoucherIn):
    id_: uuid.UUID
    model_config = ConfigDict(str_strip_whitespace=True, alias_generator=to_camel, populate_by_name=True)