import { DataFrame } from '../../data/DataFrame';
import { SourceNode, SourceNodeOptions } from '../SourceNode';

/**
 * This source node is initialized with an array of data. This data
 * is popped when pulling from this node.
 * @category Source node
 */
export class ListSourceNode<Out extends DataFrame> extends SourceNode<Out> {
    private _inputData: Out[] = [];

    constructor(inputData: Out[], options?: SourceNodeOptions) {
        super(options);
        this._inputData = inputData;
    }

    public get inputData(): Out[] {
        return this._inputData;
    }

    public set inputData(inputData: Out[]) {
        this._inputData = inputData;
    }

    public get size(): number {
        return this._inputData.length;
    }

    public onPull(): Promise<Out> {
        return new Promise<Out>((resolve) => {
            if (this._inputData.length !== 0) {
                resolve(this._inputData.shift());
            }
            resolve(null);
        });
    }
}