import { Channel } from '../data-types';
import ClientController from '../client-controller.js';
import BaseElements from './require/base-elements.js';
import IState from './require/elements-state.js';

import { $, $$, $$$, $$$$ } from './require/q-module';

class ShouldNeverHappenError extends Error {
    constructor(...args: any[]) {
        super(...args);
        this.name = 'ShouldNeverHappenError';
    }
}

export default function createUploadOverlayFromDataTransferItem(state: IState, server: ClientController, channel: Channel, dataTransferItem: DataTransferItem): HTMLElement {
    const { document } = state;
    $.setDocument(document);

    let file = dataTransferItem.getAsFile();
    if (file === null) throw new ShouldNeverHappenError('no file in the data transfer item');
    let element = BaseElements.createUploadOverlay(document, {
        server: server, channel: channel, resourceName: file.name,
        resourceBuffFunc: async () => {
            if (file === null) throw new ShouldNeverHappenError('no file in the data transfer item');
            return Buffer.from(await file.arrayBuffer());
        },
        resourceSizeFunc: () => {
            if (file === null) throw new ShouldNeverHappenError('no file in the data transfer item');
            return file.size;
        }
    });
    return element;
}