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

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

import { TIdentifierNamesGeneratorFactory } from '../../types/container/generators/TIdentifierNamesGeneratorFactory';
import { IIdentifierNamesGenerator } from '../../interfaces/generators/identifier-names-generators/IIdentifierNamesGenerator';
import { IOptions } from '../../interfaces/options/IOptions';

import { ArrayStorage } from '../ArrayStorage';

@injectable()
export class StringArrayStorage extends ArrayStorage <string> {
    /**
     * @type {number}
     */
    private static readonly stringArrayNameLength: number = 7;

    /**
     * @type {number}
     */
    public hashEntropy: number = 0;

    /**
     * @type {IArrayUtils}
     */
    private readonly arrayUtils: IArrayUtils;

    /**
     * @type {IIdentifierNamesGenerator}
     */
    private readonly identifierNamesGenerator: IIdentifierNamesGenerator;

    /**
     * @param {TIdentifierNamesGeneratorFactory} identifierNamesGeneratorFactory
     * @param {IArrayUtils} arrayUtils
     * @param {IRandomGenerator} randomGenerator
     * @param {IOptions} options
     */
    constructor (
        @inject(ServiceIdentifiers.Factory__IIdentifierNamesGenerator)
        identifierNamesGeneratorFactory: TIdentifierNamesGeneratorFactory,
        @inject(ServiceIdentifiers.IArrayUtils) arrayUtils: IArrayUtils,
        @inject(ServiceIdentifiers.IRandomGenerator) randomGenerator: IRandomGenerator,
        @inject(ServiceIdentifiers.IOptions) options: IOptions
    ) {
        super(randomGenerator, options);

        this.identifierNamesGenerator = identifierNamesGeneratorFactory(options);
        this.arrayUtils = arrayUtils;
    }

    @postConstruct()
    public initialize (): void {
        super.initialize();

        const baseStringArrayName: string = this.identifierNamesGenerator
            .generate()
            .slice(0, StringArrayStorage.stringArrayNameLength);
        const baseStringArrayCallsWrapperName: string = this.identifierNamesGenerator
            .generate()
            .slice(0, StringArrayStorage.stringArrayNameLength);
        const stringArrayName: string = `${this.options.identifiersPrefix}${baseStringArrayName}`;
        const stringArrayCallsWrapperName: string = `${this.options.identifiersPrefix}${baseStringArrayCallsWrapperName}`;

        this.storageId = `${stringArrayName}|${stringArrayCallsWrapperName}`;

        this.hashEntropy = Math.floor(Math.random() * 255);
    }

    /**
     * @param {number} rotationValue
     */
    public rotateArray (rotationValue: number): void {
        this.storage = this.arrayUtils.rotate(this.storage, rotationValue);
    }

    public hash (): number {
        const toHash: string = this.storage.join(",");
        let hash: number = 0;
        for (let i: number = 0; i < toHash.length; i++) { // hash function from here: https://stackoverflow.com/questions/6122571/simple-non-secure-hash-function-for-javascript
            const c: number = toHash.charCodeAt(i) ^ this.hashEntropy;
            hash = ((hash << 5) - hash) + c;
            hash = hash & hash; // convert to 32bit integer
        }

        return hash;
    }

    /**
     * @returns {string}
     */
    public toString (): string {
        return this.storage.map((value: string) => {
            return `'${value}'`;
        }).toString();
    }
}