import {Directive, ElementRef, EventEmitter, Input, Output, OnInit, OnDestroy, HostListener} from '@angular/core';
import {isPlatformServer} from '@angular/common';
import {NgUploaderService, UploadOutput, UploadInput, UploadFile} from '../classes/ngx-uploader.class';

@Directive({
    selector: '[ngFileDrop]'
})
export class NgFileDropDirective implements OnInit, OnDestroy {
    @Input() uploadInput: EventEmitter<UploadInput>;
    @Output() uploadOutput: EventEmitter<UploadOutput>;

    upload: NgUploaderService;
    el: HTMLInputElement;

    constructor(private elementRef: ElementRef) {
        this.upload = new NgUploaderService();
        this.uploadOutput = new EventEmitter<UploadOutput>();
    }

    ngOnInit() {
        this.el = this.elementRef.nativeElement;

        this.upload.serviceEvents.subscribe((event: UploadOutput) => {
            this.uploadOutput.emit(event);
        });

        if (this.uploadInput instanceof EventEmitter) {
            this.upload.initInputEvents(this.uploadInput);
        }

        this.el.addEventListener('drop', this.stopEvent, false);
        this.el.addEventListener('dragenter', this.stopEvent, false);
        this.el.addEventListener('dragover', this.stopEvent, false);
        this.el.addEventListener('dragover', this.stopEvent, false);
    }

    ngOnDestroy() {
        if (this.uploadInput) {
            this.uploadInput.unsubscribe();
        }
    }

    stopEvent = (e: Event) => {
        e.stopPropagation();
        e.preventDefault();
    }

    @HostListener('drop', ['$event'])
    public onDrop(e: any) {
        e.stopPropagation();
        e.preventDefault();

        const event: UploadOutput = {type: 'drop'};
        this.uploadOutput.emit(event);
        this.upload.handleFiles(e.dataTransfer.files);
    }

    @HostListener('dragover', ['$event'])
    public onDragOver(e: Event) {
        if (!e) {
            return;
        }

        const event: UploadOutput = {type: 'dragOver'};
        this.uploadOutput.emit(event);
    }

    @HostListener('dragleave', ['$event'])
    public onDragLeave(e: Event) {
        if (!e) {
            return;
        }

        const event: UploadOutput = {type: 'dragOut'};
        this.uploadOutput.emit(event);
    }
}