import { variantModule, TypeNames, VariantOf, fields, match } from "@rbxts/variant";

export const Animal = variantModule({
    dog: fields<{name: string, favoriteBall?: string}>(),
    cat: fields<{name: string, furnitureDamaged: number}>(),
    snake: (name: string, pattern = 'striped') => ({name, pattern}),
});

export type Animal<T extends TypeNames<typeof Animal> = undefined>
    = VariantOf<typeof Animal, T>;

const aDog = Animal.dog({name: "Wally"}); // will result in a discriminate value of { type: "dog", name: "Wally" }
const aCat = Animal.cat({name: "Whiskers", furnitureDamaged: true}); // will result in a discriminate value of { type: "cat", name: "Whiskers", 
const aSnake = Animal.snake("Nyx", "dotted")

const describeAnimal = (animal: Animal) => match(animal, {
    cat: ({name}) => `${name} is sleeping on a sunlit window sill.`,
    dog: ({name, favoriteBall}) => [
        `${name} is on the rug`,
        favoriteBall ? `nuzzling a ${favoriteBall} ball.` : '.' 
    ].join(' '),
    snake: s => `${s.name} is enjoying the heat of the lamp on his ${s.pattern} skin`,
});

print(describeAnimal(aDog)) //  Wally is on the rug
print(describeAnimal(aCat)) // Whiskers is sleeping on a sunlit window sill.
print(describeAnimal(aSnake)) // Nyx is enjoying the heat of the lamp on his spotted skin