export class Cache {
    constructor(root) {
        this.root = root;
        this.handlers = new Map();
        this.promises = new Map();
    }

    register(kind, handler) {
        this.handlers.set(kind, handler);
    }

    get(id, kind) {
        const [namespace, resource] = id.includes(':') ? id.split(':', 2) : ["minecraft", id];
        id = `${namespace}:${resource}`;
        const url = `${this.root}/${namespace}/${kind}/${resource}`;

        const key = `${kind}:${namespace}:${resource}`;
        if (this.promises.has(key)) return this.promises.get(key);

        const handler = this.handlers.get(kind);
        if (!handler) throw new Error(`No handler registered for resource kind: ${kind}`);

        if (handler.prepare) {
            handler.prepare(this, id, url);
        }

        const promise = handler.process(this, id, url);
        this.promises.set(key, promise);
        return promise;
    }
}