import { SelectionModel } from '@angular/cdk/collections';
import { Component, EventEmitter, Input, OnInit, Output, ViewChild, ViewEncapsulation } from '@angular/core';
import { FormControl } from '@angular/forms';
import { MatListOption, MatSelectionList } from '@angular/material';
import { Observable } from 'rxjs';
import { takeUntil } from 'rxjs/operators';
import { BaseComponent } from '../../../../core/common/base/base.component';

@Component({
	selector: 'app-facet-section-component',
	templateUrl: './facet-search-section.component.html',
	styleUrls: ['./facet-search-section.component.scss'],
	encapsulation: ViewEncapsulation.None,
})
export class FacetSearchSectionComponent extends BaseComponent implements OnInit {

	@Input()
	searchEnabled = false;

	@Input()
	requestDelay = 200;

	@Input()
	multipleSelect = true;

	@Input()
	filterOptions: (value) => Observable<any[]>;

	@Input()
	options: Observable<any[]> = Observable.of([]);

	@Input()
	displayTitleFunc: (value) => string;

	@Input()
	displayValueFunc: (value) => string;

	@Output()
	selectedChanged = new EventEmitter();

	@Output()
	optionRemoved = new EventEmitter();

	optionSearchControl = new FormControl('');

	private selectedOptions: any[] = [];

	@ViewChild('optionsList') selectionList: MatSelectionList;


	ngOnInit(): void {
		if (!this.multipleSelect) { this.selectionList.selectedOptions = new SelectionModel<MatListOption>(this.multipleSelect); }
		this.optionSearchControl.valueChanges.debounceTime(this.requestDelay)
			.distinctUntilChanged()
			.pipe(takeUntil(this._destroyed))
			.subscribe(x => { if (this.filterOptions) { this.options = this.filterOptions(x); } });
	}

	public selectionChanged(event: any) {
		const eventValue = event.option.value;
		if (event.option.selected) { this.selectedOptions.push(eventValue); }
		if (!event.option.selected) {
			const index = this.selectedOptions.map(x => this.displayValue(x)).indexOf(this.displayValue(eventValue));
			this.selectedOptions.splice(index, 1);
		}
		this.selectedChanged.emit(event);
	}

	public removeOption(project) {
		const list = this.selectionList.selectedOptions.selected.map(x => x.value);
		const indexOfProject = list.indexOf(project);
		if (this.selectionList.selectedOptions.selected[indexOfProject]) {
			this.selectionList.selectedOptions.selected[indexOfProject].selected = false;
			this.selectionList.selectedOptions.selected.splice(indexOfProject, 1);
		}
		this.selectedOptions.splice(this.selectedOptions.map(x => this.displayValue(x)).indexOf(this.displayValue(project)), 1);
		this.optionRemoved.emit(project);
	}

	public isOptionSelected(value) {
		return this.selectedOptions.map(x => this.displayValue(x)).indexOf(this.displayValue(value)) !== -1;
	}

	displayLabel(value) {
		return this.displayTitleFunc ? this.displayTitleFunc(value) : value;
	}

	displayValue(value) {
		return this.displayValueFunc ? this.displayValueFunc(value) : value;
	}

}