example-arweave-nft-interfaces.js

export interface Entity {
    id: string;
    forSale: boolean,
    price: number,
    // A list of components
    components: Component[],
}

export interface Component {
    // STUB.
    // static Schema
    // public data
}

export interface NFTStateInterface {
    name: string;
    ticker: string;
    entities: Entity[];
    ownership: OwnershipInterface;
}

interface ActionInterface {
    input: InputInterface;
    caller: string;
}

export interface InputInterface extends NFTInteractionInterface {
    function: GetFunctionType | SetFunctionType;
}

export interface NFTInteractionInterface {
    entityId?: string,
    entity?: Entity;
    price?: number;
}

interface OwnershipInterface {
    [owner: string]: string;
}

export type GetFunctionType = 'owner' | 'entities';
export type SetFunctionType = 'create' | 'purchase' | 'setPrice';

function handle(state: NFTStateInterface, action: ActionInterface): { state: NFTStateInterface } | { result: any } {
    const entities: Entity[] = state.entities;
    const ownership: OwnershipInterface = state.ownership;
    const caller: string = action.caller;

    const input: InputInterface = action.input;

    if (input.function === 'create') {
        const { entity } = input;
        const { id: entityId } = entity;

        // Add to registry and assign ownership.
        entities.push(entity);
        ownership[entityId] = caller;
    }

    if (input.function === 'setPrice') {
        const {entityId, price} = input;

        if (ownership[entityId] === caller) {
            const entity = entities.filter((entity) => entity.id === entityId)[0];
            entity.price = price;

        }

        return { state };
    }

    if (input.function === 'purchase') {
        const {entityId} = input;

        const {
            forSale,
            price
        } = entities.filter(entity => entity.id = entityId)[0];

        if (forSale) {
            ownership[entityId] = caller;
        }

        return { state };
    }
}