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

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

    static orderByComparator = (a: any, b: any): number => {
        if ((isNaN(parseFloat(a)) || !isFinite(a)) || (isNaN(parseFloat(b)) || !isFinite(b))) {
            if (a.toLowerCase() < b.toLowerCase()) {
                return -1;
            }
            if (a.toLowerCase() > b.toLowerCase()) {
                return 1;
            }
        } else {
            if (parseFloat(a) < parseFloat(b)) {
                return -1;
            }
            if (parseFloat(a) > parseFloat(b)) {
                return 1;
            }
        }
        return 0;
    }

    transform(input: any, config: any): any {
        if (!config) {
            config = '+';
        }
        if (!Array.isArray(input)) {
            return input;
        }

        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 ? input.sort() : input.sort().reverse();
            }
            else {
                let property: string = propertyToCheck.substr(0, 1) === '+' || propertyToCheck.substr(0, 1) === '-'
                    ? propertyToCheck.substr(1)
                    : propertyToCheck;
                return input.sort((a: any, b: any) => {
                    return !desc
                        ? OrderBy.orderByComparator(a[property], b[property])
                        : -OrderBy.orderByComparator(a[property], b[property]);
                });
            }
        } else {
            //Loop over property of the array in order and sort
            return input.sort((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 comparison = !desc
                        ? OrderBy.orderByComparator(a[property], b[property])
                        : -OrderBy.orderByComparator(a[property], b[property]);
                    //Don't return 0 yet in case of needing to sort by next property
                    if (comparison !== 0) {
                        return comparison;
                    }
                }
                return 0;
            });
        }
    }
}