import { injectable, inject } from 'inversify';
import { ServiceIdentifiers } from '../container/ServiceIdentifiers';

import { IArrayUtils } from '../interfaces/utils/IArrayUtils';
import { IRandomGenerator } from '../interfaces/utils/IRandomGenerator';

@injectable()
export class ArrayUtils implements IArrayUtils {
    /**
     * @type {IRandomGenerator}
     */
    private readonly randomGenerator: IRandomGenerator;

    /**
     * @param randomGenerator
     */
    constructor (
        @inject(ServiceIdentifiers.IRandomGenerator) randomGenerator: IRandomGenerator
    ) {
        this.randomGenerator = randomGenerator;
    }

    /**
     * @param length
     * @return {number[]}
     */
    public arrayRange (length: number): number[] {
        const range: number[] = [];

        for (let i: number = 0; i < length; i++) {
            range.push(i);
        }

        return range;
    }

    /**
     * @param array
     * @param times
     * @returns {T[]}
     */
    public arrayRotate <T> (array: T[], times: number): T[] {
        if (!array.length) {
            throw new ReferenceError(`Cannot rotate empty array.`);
        }

        if (times <= 0) {
            return array;
        }

        const newArray: T[] = array;

        let temp: T | undefined;

        while (times--) {
            temp = newArray.pop()!;
            newArray.unshift(temp);
        }

        return newArray;
    }

    /**
     * @param array
     * @return {T[]}
     */
    public arrayShuffle <T> (array: T[]): T[] {
        const shuffledArray: T[] = [...array];

        for (let i: number = shuffledArray.length; i; i--) {
            const j: number = Math.floor(this.randomGenerator.getMathRandom() * i);

            [shuffledArray[i - 1], shuffledArray[j]] = [shuffledArray[j], shuffledArray[i - 1]];
        }

        return shuffledArray;
    }
}