import {
  Component, ElementRef,
  EventEmitter, HostListener,
  Input,
  OnChanges,
  OnDestroy,
  OnInit,
  Output,
  SimpleChanges,
  ViewChild
} from "@angular/core";
import {AbstractControl, FormArray, FormControl} from "@angular/forms";
import {HelperFunctions} from "../../utils/HelperFunctions.class";
import {Observable, of, Subscription} from "rxjs";
import {MatSelect} from "@angular/material/select";
import {MatAutocompleteSelectedEvent} from "@angular/material/autocomplete";
import {map, startWith} from "rxjs/operators";
import {MatChipInputEvent} from "@angular/material/chips";


export interface Option {
  icon?: string,
  iconClass?: string,
  value: any,
  label: string
}

@Component({
  selector: '[dashboard-input]',
  template: `
    <div *ngIf="label && type != 'checkbox'"
         class="uk-text-bold uk-form-label uk-margin-small-bottom">{{label + (required ? ' *' : '')}}</div>
    <div *ngIf="hint" class="uk-margin-bottom uk-form-hint">{{hint}}</div>
    <div class="uk-grid uk-flex" [ngClass]="'uk-flex-' + flex" [class.uk-grid-small]="gridSmall" uk-grid>
      <ng-content></ng-content>
      <div [class.uk-hidden]="hideControl" class="uk-width-expand uk-position-relative"
           [class.uk-flex-first]="!extraLeft">
        <ng-template [ngIf]="icon && formControl.enabled">
          <span class="uk-text-muted" [ngClass]="iconLeft?('left'):'right'">
            <icon [name]="icon"></icon>
          </span>
        </ng-template>
        <ng-template [ngIf]="formControl.disabled">
          <span class="uk-text-muted left">
            <icon [name]="'lock'"></icon>
          </span>
        </ng-template>
        <ng-template [ngIf]="type === 'text'">
          <div [ngClass]="inputClass"
               [class.uk-form-danger]="formControl.invalid && formControl.touched"
               [attr.uk-tooltip]="formControl.disabled?'title: This field is not editable; pos: bottom-left':''">
            <input class="uk-input" [placeholder]="placeholder" [formControl]="formControl">
          </div>
        </ng-template>
        <ng-template [ngIf]="type === 'textarea'">
          <div [ngClass]="inputClass" class="uk-padding-remove-right"
               [class.uk-form-danger]="formControl.invalid && formControl.touched"
               [attr.uk-tooltip]="formControl.disabled?'title: This field is not editable; pos: bottom-left':''">
              <textarea class="uk-textarea"
                        [rows]="rows" [placeholder]="placeholder"
                        [formControl]="formControl">
              </textarea>
              <div class="tools" [class.focused]="focused">
                <ng-content select="[options]"></ng-content>
              </div>
          </div>
        </ng-template>
        <ng-template [ngIf]="type === 'select'">
          <div [ngClass]="inputClass"
               [attr.uk-tooltip]="formControl.disabled?'title: This field is not editable; pos: bottom-left':null"
               [class.clickable]="formControl.enabled"
               [class.uk-form-danger]="formControl.invalid && formControl.touched" (click)="openSelect()">
            <mat-form-field class="uk-width-1-1">
              <mat-select #select [required]="required" [value]="null"
                          (openedChange)="stopPropagation()" [formControl]="formControl"
                          [disableOptionCentering]="true">
                <mat-option *ngIf="placeholder" class="uk-hidden" [value]="''">{{placeholder}}</mat-option>
                <mat-option *ngFor="let option of options" [value]="option.value">
                  {{option.label}}
                </mat-option>
              </mat-select>
            </mat-form-field>
          </div>
        </ng-template>
        <ng-template [ngIf]="type === 'chips'">
          <div [ngClass]="inputClass"
               [attr.uk-tooltip]="formControl.disabled?'title: This field is not editable; pos: bottom-left':null"
               [class.clickable]="formControl.enabled"
               [class.uk-form-danger]="formControl.invalid && formControl.touched" (click)="openSelect()">
            <mat-form-field class="uk-width-1-1">
              <mat-chip-list #chipList>
                <mat-chip *ngFor="let chip of formAsArray.controls; let i=index" [selectable]="false"
                          [removable]="removable" [attr.uk-tooltip]="getLabel(chip.value)">
                  <span class="uk-width-expand uk-text-truncate" [class.uk-text-small]="smallChip">{{getLabel(chip.value)}}</span>
                  <icon name="remove_circle" class="mat-chip-remove" [ratio]="smallChip?0.8:1" (click)="removed(i)"></icon>
                </mat-chip>
                <div class="uk-width-expand uk-position-relative chip-input">
                  <input #searchInput class="uk-width-1-1" [formControl]="searchControl" [matAutocomplete]="auto"
                         [matChipInputFor]="chipList" [matAutocompleteConnectedTo]="origin"
                         [matChipInputAddOnBlur]="addExtraChips && searchControl.value"
                         (matChipInputTokenEnd)="add($event)">
                  <div *ngIf="placeholder && !searchControl.value" class="placeholder uk-width-1-1"
                       (click)="searchInput.focus()">{{placeholder}}</div>
                </div>
                <div class="uk-width-1-1 uk-invisible" matAutocompleteOrigin #origin="matAutocompleteOrigin"></div>
              </mat-chip-list>
              <mat-autocomplete #auto="matAutocomplete" (optionSelected)="selected($event)" [class]="panelClass" [panelWidth]="panelWidth">
                <mat-option *ngFor="let option of filteredOptions | async" [value]="option.value">
                  {{option.label}}
                </mat-option>
              </mat-autocomplete>
            </mat-form-field>
          </div>
        </ng-template>
        <span *ngIf="formControl.invalid && formControl.errors.error"
              class="uk-text-danger input-message">{{formControl.errors.error}}</span>
        <span *ngIf="warning" class="uk-text-warning input-message">{{warning}}</span>
        <span *ngIf="note" class="input-message">{{note}}</span>
      </div>
    </div>
    <mat-checkbox *ngIf="type === 'checkbox'" [formControl]="formControl">{{label}}</mat-checkbox>
  `,
  styleUrls: ['input.component.css']
})
export class InputComponent implements OnInit, OnDestroy, OnChanges {
  /** Basic information */
  @Input('formInput') formControl: AbstractControl;
  @Input('type') type: 'text' | 'textarea' | 'select' | 'checkbox' | 'chips' = 'text';
  @Input('label') label: string;
  @Input('rows') rows: number = 3;
  /** Select | chips available options */
  @Input('options') options: Option[];
  @Input('hint') hint = null;
  @Input('placeholder') placeholder = '';
  @Input() inputClass: string = 'input-box';
  /** Extra element Right or Left of the input */
  @Input() extraLeft: boolean = true;
  @Input() gridSmall: boolean = false;
  @Input() hideControl: boolean = false;
  @Input() flex: 'middle' | 'top' | 'bottom' = 'middle';
  /** Icon Right or Left on the input */
  @Input() icon: string = null;
  @Input() iconLeft: boolean = false;
  /** Custom messages */
  @Input() warning: string = null;
  @Input() note: string = null;
  /** Chip options */
  @Input() removable: boolean = true;
  @Input() addExtraChips: boolean = false;
  @Input() smallChip: boolean = false;
  @Input() panelWidth: number = 300;
  @Input() panelClass: string = null;
  @Input() showOptionsOnEmpty: boolean = true;
  @Output() focusEmitter: EventEmitter<boolean> = new EventEmitter<boolean>();
  /** Internal basic information */
  public required: boolean = false;
  private initValue: any;
  /** Chips */
  public filteredOptions: Observable<Option[]>;
  public searchControl: FormControl;
  private subscriptions: any[] = [];
  @ViewChild('select') select: MatSelect;
  @ViewChild('searchInput') searchInput: ElementRef;
  focused: boolean = false;
  
  constructor(private elementRef: ElementRef) {
  }
  
  @HostListener('document:click', ['$event'])
  clickOut(event) {
    this.focused = !!this.elementRef.nativeElement.contains(event.target);
    this.focusEmitter.emit(this.focused);
  }
  
  ngOnInit(): void {
    this.reset();
  }
  
  ngOnChanges(changes: SimpleChanges) {
    if (changes.formControl) {
      this.reset();
    }
  }
  
  get formAsArray(): FormArray {
    return (<FormArray>this.formControl);
  }
  
  reset() {
    this.unsubscribe();
    this.initValue = HelperFunctions.copy(this.formControl.value);
    if (this.options && this.type === 'chips') {
      this.filteredOptions = of(this.options);
      this.searchControl = new FormControl('');
      this.filteredOptions = this.searchControl.valueChanges.pipe(startWith(''),
        map(option => this.filter(option)));
    }
    if (this.formControl && this.formControl.validator) {
      let validator = this.formControl.validator({} as AbstractControl);
      this.required = (validator && validator.required);
    }
    this.subscriptions.push(this.formControl.valueChanges.subscribe(value => {
      value = (value === '') ? null : value;
      if (this.initValue === value || (this.initValue === '' && value === null)) {
        this.formControl.markAsPristine();
      }
    }));
    if (!this.formControl.value) {
      this.formControl.setValue('');
    }
  }
  
  unsubscribe() {
    this.subscriptions.forEach(subscription => {
      if (subscription instanceof Subscription) {
        subscription.unsubscribe();
      }
    });
  }
  
  openSelect() {
    if (this.select) {
      this.select.open();
    }
  }
  
  ngOnDestroy(): void {
    this.unsubscribe();
  }
  
  stopPropagation() {
    event.stopPropagation();
  }
  
  removed(index: number) {
    this.formAsArray.removeAt(index);
    this.formAsArray.markAsDirty();
    this.searchControl.setValue('');
    this.searchInput.nativeElement.focus();
    this.searchInput.nativeElement.value = '';
    this.stopPropagation();
  }
  
  selected(event: MatAutocompleteSelectedEvent): void {
    this.formAsArray.push(new FormControl(event.option.value));
    this.formAsArray.markAsDirty();
    this.searchControl.setValue('');
    this.searchInput.nativeElement.focus();
    this.searchInput.nativeElement.value = '';
    this.stopPropagation();
  }
  
  private filter(value: string): Option[] {
    let options = this.options.filter(option => !this.formAsArray.value.find(value => option.value === value));
    if ((!value || value.length == 0) && !this.showOptionsOnEmpty) {
      return [];
    }
    const filterValue = value.toString().toLowerCase();
    return options.filter(option => option.label.toLowerCase().indexOf(filterValue) != -1);
  }
  
  add(event: MatChipInputEvent) {
    if (this.addExtraChips && event.value) {
      this.stopPropagation();
      this.formAsArray.push(new FormControl(event.value));
      this.formAsArray.markAsDirty();
      this.searchControl.setValue('');
      this.searchInput.nativeElement.value = '';
    }
  }
  
  getLabel(value: any) {
    let option = this.options.find(option => option.value === value);
    return (option) ? option.label : value;
  }
}