kodekeep/collator

export class Collator {
    readonly #collator: Intl.Collator;

    public constructor(
        locales?: string | string[] | undefined,
        options?: Intl.CollatorOptions | undefined
    ) {
        this.#collator = new Intl.Collator(locales, options);
    }

    public compare(value: string, other: string): number {
        return this.#collator.compare(value, other);
    }

    public isEqual(value: string, other: string): boolean {
        return this.comparator(value, other) === 0;
    }

    public isGreaterThan(value: string, other: string): boolean {
        return this.comparator(value, other) === 1;
    }

    public isGreaterThanOrEqual(value: string, other: string): boolean {
        return this.isGreaterThan(value, other) || this.isEqual(value, other);
    }

    public isLessThan(value: string, other: string): boolean {
        return this.comparator(value, other) === -1;
    }

    public isLessThanOrEqual(value: string, other: string): boolean {
        return this.isLessThan(value, other) || this.isEqual(value, other);
    }

    private comparator(value: string, other: string): number {
        const a: string[] = value.split(".");
        const b: string[] = other.split(".");

        const hasSameMajor: number = this.#collator.compare(a[0]!, b[0]!);

        if (hasSameMajor) {
            return hasSameMajor;
        }

        const hasSameMinor: number = this.#collator.compare(a[1]!, b[1]!);

        if (hasSameMinor) {
            return hasSameMinor;
        }

        return this.#collator.compare(a.slice(2).join("."), b.slice(2).join("."));
    }
}