import {isNullOrUndefined} from 'util';
import {Pipe, PipeTransform} from '@angular/core';
import {NameValue} from '../types/name-value';


/**
 * @author Harsha A.N.S
 */
@Pipe({
  name: 'filter'
})
export class FilterParentPipe implements PipeTransform {

  transform(objects: any[], parentName: string, parentData: any, childName: string): any[] {

    // if parent is all then return all child elements
    if (typeof 'parentData' === 'string' && parentData.toString().toUpperCase() === 'ALL') {
      return this.getChildObject(objects, childName);
    }

    if (parentName === undefined
      || parentData === undefined
      || childName === undefined

    ) {
      return objects;
    }


    const filterObject = objects.filter(object => {
      return object[parentName] === parentData;

    });


    const childObject: any[] = this.getChildObject(filterObject, childName);


    return childObject;
  }


  transformMulti(objects: any[], parentNames: string[], parentData: any[], childName: string): any[] {
    let childData: any[] = JSON.parse(JSON.stringify(objects));

    const filteredChildData = parentNames.forEach((p, index) => {
      if ( !p || !parentData[index] || !childName ||   parentData[index].toUpperCase() === 'ALL') {
        return;
      }
      childData = childData.filter(x => {
        return x[p] === parentData[index];
      });
    });
  
    childData = this.getChildObject(childData, childName);
  
    return childData;

  }

  getChildObject(filterObject: any, childName: string): any[] {
    const childObject: any[] = [];
    
    filterObject.forEach(x => {
      childObject.push(x[childName]);
    });

    if (childObject[0] === null || childObject[0] === undefined) {
      return new Array(new NameValue('All', 'All'));
    }

    return this.removeDuplicates(childObject, 'name');

  }

  private removeDuplicates(originalArray, prop) {
    const newArray = [];
    const lookupObject = {};

    for (const i of Object.keys(originalArray)) {
      lookupObject[originalArray[i][prop]] = originalArray[i];
    }

    for (const i of Object.keys(lookupObject)) {
      newArray.push(lookupObject[i]);
    }
    
    return newArray;
  }


}