import { ValidationOptions } from "../ValidationOptions";
import { buildMessage, ValidateBy } from "../common/ValidateBy";

export const ARRAY_UNIQUE = "arrayUnique";

/**
 * Checks if all array's values are unique. Comparison for objects is reference-based.
 * If null or undefined is given then this function returns false.
 */
export function arrayUnique(array: unknown): boolean {
    if (!(array instanceof Array))
        return false;

    const uniqueItems = array.filter((a, b, c) => c.indexOf(a) === b);
    return array.length === uniqueItems.length;
}

/**
 * Checks if all array's values are unique. Comparison for objects is reference-based.
 * If null or undefined is given then this function returns false.
 */
export function ArrayUnique(validationOptions?: ValidationOptions): PropertyDecorator {
    return ValidateBy(
        {
            name: ARRAY_UNIQUE,
            validator: {
                validate: (value, args): boolean => arrayUnique(value),
                defaultMessage: buildMessage(
                    (eachPrefix) => eachPrefix + "All $property's elements must be unique",
                    validationOptions
                )
            }
        },
        validationOptions
    );
}