import {ArgumentProcessorContext, ParamType} from "./types";
import {InputHelper} from "./input-helper";

export interface FileFilter<ReqType, ResType> {
	(this: ArgumentProcessorContext<ReqType, ResType>, object: Express.Multer.File): boolean;
}

export class FileInputHelper<ReqType, ResType> extends InputHelper<ReqType, ResType> {
	private fileCount: number;
	
	toJSON(): ParamType<ReqType, ResType> {
		return Object.assign(super._toJSON(), {
			upload: {
				fileCount: this.fileCount,
			}
		});
	}
	
	filter(fn: FileFilter<ReqType, ResType>) {
		this.state.filter = function (flist) {
			return flist.every(fn, this);
		};
		return this;
	}
	
	single() {
		this.fileCount = 1;
		this.state.handler = (flist) => {
			return flist[0];
		};
		return this;
	}
	
	multi(max: number = 5) {
		this.fileCount = max;
		return this;
	}
}