/*
 * Example use
 *		Basic Array of single type: *ngFor="let todo of todoService.todos | orderBy : '-'"
 *		Multidimensional Array Sort on single column: *ngFor="let todo of todoService.todos | orderBy : ['-status']"
 *		Multidimensional Array Sort on multiple columns: *ngFor="let todo of todoService.todos | orderBy : ['status', '-title']"
 */

import {Pipe, PipeTransform} from "@angular/core";

@Pipe({name: 'orderBy', pure: false})
export class OrderByPipe implements PipeTransform {

    value: string[] = [];

    static _orderByComparator(a: any, b: any): number {

        if (a === null || typeof a === 'undefined') a = 0;
        if (b === null || typeof b === 'undefined') b = 0;

        if ((isNaN(parseFloat(a)) || !isFinite(a)) || (isNaN(parseFloat(b)) || !isFinite(b))) {
            //Isn't a number so lowercase the string to properly compare
            if (a.toLowerCase() < b.toLowerCase()) return -1;
            if (a.toLowerCase() > b.toLowerCase()) return 1;
        }
        else {
            //Parse strings as numbers to compare properly
            if (parseFloat(a) < parseFloat(b)) return -1;
            if (parseFloat(a) > parseFloat(b)) return 1;
        }

        return 0; //equal each other
    }

    transform(input: any, config: string = '+'): any {

        //invalid input given
        if (!input) return input;

        //make a copy of the input's reference
        this.value = [...input];
        let value = this.value;

        if (!Array.isArray(value)) return value;

        if (!Array.isArray(config) || (Array.isArray(config) && config.length == 1)) {
            let propertyToCheck: string = !Array.isArray(config) ? config : config[0];
            let desc = propertyToCheck.substr(0, 1) == '-';

            //Basic array
            if (!propertyToCheck || propertyToCheck == '-' || propertyToCheck == '+') {
                return !desc ? value.sort() : value.sort().reverse();
            }
            else {
                let property: string = propertyToCheck.substr(0, 1) == '+' || propertyToCheck.substr(0, 1) == '-'
                    ? propertyToCheck.substr(1)
                    : propertyToCheck;

                return value.sort(function (a: any, b: any) {
                    let aValue = a[property];
                    let bValue = b[property];

                    let propertySplit = property.split('.');

                    if (typeof aValue === 'undefined' && typeof bValue === 'undefined' && propertySplit.length > 1) {
                        aValue = a;
                        bValue = b;
                        for (let j = 0; j < propertySplit.length; j++) {
                            aValue = aValue[propertySplit[j]];
                            bValue = bValue[propertySplit[j]];
                        }
                    }

                    return !desc
                        ? OrderByPipe._orderByComparator(aValue, bValue)
                        : -OrderByPipe._orderByComparator(aValue, bValue);
                });
            }
        }
        else {
            //Loop over property of the array in order and sort
            return value.sort(function (a: any, b: any) {
                for (let i: number = 0; i < config.length; i++) {
                    let desc = config[i].substr(0, 1) == '-';
                    let property = config[i].substr(0, 1) == '+' || config[i].substr(0, 1) == '-'
                        ? config[i].substr(1)
                        : config[i];

                    let aValue = a[property];
                    let bValue = b[property];

                    let propertySplit = property.split('.');

                    if (typeof aValue === 'undefined' && typeof bValue === 'undefined' && propertySplit.length > 1) {
                        aValue = a;
                        bValue = b;
                        for (let j = 0; j < propertySplit.length; j++) {
                            aValue = aValue[propertySplit[j]];
                            bValue = bValue[propertySplit[j]];
                        }
                    }

                    let comparison = !desc
                        ? OrderByPipe._orderByComparator(aValue, bValue)
                        : -OrderByPipe._orderByComparator(aValue, bValue);

                    //Don't return 0 yet in case of needing to sort by next property
                    if (comparison != 0) return comparison;
                }

                return 0; //equal each other
            });
        }
    }
}

export let ORDERBY_PROVIDERS = [
    OrderByPipe
];