import { Component, EventEmitter, Input, OnInit, Output } from '@angular/core';
import { FormControl } from '@angular/forms';
import { Observable } from 'rxjs';
import { map, startWith } from 'rxjs/operators';
import { MatChipsModule } from '@angular/material/chips'; // Importiere MatChipsModule
​
import * as WebFont from 'webfontloader'; // Verwende import * as
export interface ItemData {
  item: string;
  selected: boolean;
}

@Component({
  selector: 'multiselect-autocomplete',
  templateUrl: './multiselect-autocomplete.component.html',
  styleUrls: ['./multiselect-autocomplete.component.css']
})

/**
* The MultiselectAutocompleteComponent mixes a angular material multiselect and a angular material autocomplete
* it builds the base for many filter select option
*/
export class MultiselectAutocompleteComponent implements OnInit {

  @Output() result = new EventEmitter<{ key: string, data: Array<string> }>();
  @Input() placeholder: string = 'Select Data';
  @Input() data: Array<string> = [];
  @Input() key: string = '';
  @Input() appliedFilters: Array<string> = [];
  selectControl = new FormControl();

  rawData: Array<ItemData> = [];
  selectData: Array<ItemData> = [];
  filteredData: Observable<Array<ItemData>>;
  filterString: string = '';
  showCheckbox: boolean = true;
  allSelected: boolean = false;
  indeterminate: boolean = false;

  /**
  * The constructor maps the default values
  */
  constructor() {
    this.filteredData = this.selectControl.valueChanges.pipe(
      startWith<string>(''),
      map(value => typeof value === 'string' ? value : this.filterString),
      map(filter => this.filter(filter))
    );


  }
  /**
  * The function ngOnInit imports the data (filter options) and maps it
  */
  ngOnInit(): void {
    this.data.forEach((item: string) => {
      this.rawData.push({ item, selected: false });
    });

    WebFont.load({
       google: {
          families: [
             'Material Icons',
          ],
       },
    });
    //console.log(this.appliedFilters);
    //console.log(this.rawData);

    if(this.appliedFilters.length > 0){
      for (const filter of this.appliedFilters) {
        for (const item of this.rawData) {
          if(item.item == filter){
            //console.log("MATCH"+item.item);
            item.selected = true;
            this.toggleSelection({'item': filter, selected: false});
          }
        }
      }
    }
    //console.log(this.selectData);
    this.evaluateIndeterminate();
  }


  /**
  * The function filter filters the list with the select options
  * @param filter text to search for
  */
  filter = (filter: string): Array<ItemData> => {
    this.filterString = filter;
    if (filter.length > 0) {
      return this.rawData.filter(option => {
        return option.item.toLowerCase().indexOf(filter.toLowerCase()) >= 0;
      });
    } else {
      return this.rawData.slice();
    }
  };

  displayFn = (): string => '';
  /**
  * The funtion optionClicked hanled the selection of a select option (filter option)
  * @param event selection event
  * @param data (filter)item data
  */
  optionClicked = (event: Event, data: ItemData): void => {
    event.stopPropagation();
    this.toggleSelection(data);
  };
  /**
  * The function toggleSelection handles a click on a selection item
  * if it is already selected it will be removed from the selection, if it is not yet selected it will be selected
  * it builds the base for many filter select option
  */
  toggleSelection = (data: ItemData): void => {
    ////console.log(data);
    //console.log(this.selectData);
    data.selected = !data.selected;
    if (data.selected === true) {
      this.selectData.push(data);
    } else {
      const i = this.selectData.findIndex(value => value.item === data.item);
      this.selectData.splice(i, 1);
    }
    this.selectControl.setValue(this.selectData);
    this.emitAdjustedData();
    this.evaluateIndeterminate();
  };
  /**
  * The emitAdjustedData emits the selected options the the parent component
  * its triggered when the selectbox is closed
  */

  emitAdjustedData = (): void => {
    const results: Array<string> = []
    this.selectData.forEach((data: ItemData) => {
      results.push(data.item);
    });
    this.result.emit({ key: this.key, data: results });
  };

  /**
  * The removeChip removes a option from the selection list if the user presses the remove button on the chip list
  */
  removeChip = (data: ItemData): void => {
    let dat = {item: data.item, selected: true};
    this.toggleSelection(dat);
    for (const rawItem of this.rawData) {
      if(data.item == rawItem.item){
        rawItem.selected = false;
      }
    }
  };

  public toggleAll(): void {
    this.allSelected = !this.allSelected;

    if (this.allSelected) {
      for (const item of this.rawData) {
        const filterExists = this.selectData.some(selectedItem => selectedItem.item === item.item);

        if (!filterExists) {
          item.selected = true;
          this.selectData.push(item);
        }
      }
    } else {
      for (const item of this.rawData) {
        const index = this.selectData.findIndex(selectedItem => selectedItem.item === item.item);

        if (index !== -1) {
          item.selected = false;
          this.selectData.splice(index, 1);
        }
      }
    }

    this.selectControl.setValue(this.selectData);
    this.emitAdjustedData();
    this.evaluateIndeterminate();
  }


  public showCheckBox(): void{
    this.showCheckbox = true;
    //console.log("####")
  }
  public hideCheckBox(): void{
    this.showCheckbox = false;
  }

  public evaluateIndeterminate():void{
    if(this.selectData.length == 0){
      this.indeterminate = false;
      this.allSelected = false;
    }
    if(this.selectData.length > 0 && this.selectData.length<this.rawData.length){
      this.indeterminate = true;
    }
    if(this.selectData.length == this.rawData.length){
      this.indeterminate = false;
      this.allSelected = true;
    }
  }

}