/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import {Component, forwardRef} from '@angular/core';
import {ControlValueAccessor, NG_VALUE_ACCESSOR} from '@angular/forms';
import {ListItem} from '@app/classes/list-item';
import {UtilsService} from '@app/services/utils.service';
import {MenuButtonComponent} from '@app/components/menu-button/menu-button.component';

@Component({
  selector: 'filter-button',
  templateUrl: '../menu-button/menu-button.component.html',
  styleUrls: ['../menu-button/menu-button.component.less'],
  providers: [
    {
      provide: NG_VALUE_ACCESSOR,
      useExisting: forwardRef(() => FilterButtonComponent),
      multi: true
    }
  ]
})
export class FilterButtonComponent extends MenuButtonComponent implements ControlValueAccessor {

  private selectedItems: ListItem[] = [];

  private onChange: (fn: any) => void;

  constructor(private utils: UtilsService) {
    super();
  }

  get selection(): ListItem[] {
    return this.selectedItems;
  }

  set selection(items: ListItem[]) {
    this.selectedItems = items;
    if (this.onChange) {
      this.onChange(items);
    }
  }

  updateSelection(updates: ListItem | ListItem[]): void {
    if (updates && (!Array.isArray(updates) || updates.length)) {
      const items: ListItem[] = Array.isArray(updates) ? updates : [updates];
      if (this.isMultipleChoice) {
        items.forEach((item: ListItem) => {
          if (this.subItems && this.subItems.length) {
            const itemToUpdate: ListItem = this.subItems.find((option: ListItem) => this.utils.isEqual(option.value, item.value));
            if (itemToUpdate) {
              itemToUpdate.isChecked = item.isChecked;
            }
          }
        });
      } else {
        const selectedItem: ListItem = items.find((item: ListItem) => item.isChecked);
        this.subItems.forEach((item: ListItem) => {
          item.isChecked = !!selectedItem && this.utils.isEqual(item.value, selectedItem.value);
        });
      }
    } else {
      this.subItems.forEach((item: ListItem) => item.isChecked = false);
    }
    const checkedItems = this.subItems.filter((option: ListItem): boolean => option.isChecked);
    this.selection = checkedItems;
    this.selectItem.emit(checkedItems.map((option: ListItem): any => option.value));
    if (this.dropdownList) {
      this.dropdownList.doItemsCheck();
    }
  }

  writeValue(items: ListItem[]) {
    let listItems: ListItem[] = [];
    if (items && items.length) {
      listItems = items.map((item: ListItem) => {
        return {
          ...item,
          isChecked: true
        };
      });
    }
    this.updateSelection(listItems);
  }

  registerOnChange(callback: any): void {
    this.onChange = callback;
  }

  registerOnTouched() {
  }

}