import ArrayProxy from "kinibind/ts/proxy/array-proxy";
import FilterQuery from "kinibind/ts/proxy/filter-query";
import FilteredResults from "kinibind/ts/proxy/filtered-results";
import Loader from "../util/loader";
import Config from "../config";

// Data proxy - lazy loading implementation
export default class EntityDataProxy extends ArrayProxy {

    // Name of the entity this wraps
    private _entityName: any;

    // All results
    private _dataByKey: any;

    constructor(entityName: string) {
        super();
        this._entityName = entityName;
    }


    /**
     * Filter results for data proxy
     *
     * @param filterQuery
     */
    filterResults(filterQuery: FilterQuery): Promise<FilteredResults> {

        return this.ensureData().then(dataByKey => {
            let values: any = [];
            Object.keys(this._dataByKey).forEach(key => {
                values.push(this._dataByKey[key]);
            })
            return new FilteredResults(values, values.length);
        });


    }


    // Ensure data is loaded
    private ensureData(): Promise<any> {
        if (!this._dataByKey) {
            return Loader.loadSiteJsonFile(Config.instance().siteDataBasePath + "/data/" + this._entityName + ".json").then(dataByKey => {
                this._dataByKey = dataByKey;
                return this._dataByKey;
            });
        } else {
            return Promise.resolve(this._dataByKey);
        }
    }


}