import { v4 } from 'uuid';

export namespace Utilities {
    export function guid() {
        return v4();
    }

    export function preciseAssignHelper(target: any, source: any) {
        Array.from(new Set([...Object.keys(target), ...Object.keys(source)])).forEach(property => {
            const targetValue = target[property];
            const sourceValue = source[property];
            if (sourceValue) {
                if (typeof sourceValue === 'object' && typeof targetValue === 'object') {
                    preciseAssignHelper(targetValue, sourceValue);
                } else {
                    target[property] = sourceValue;
                }
            }
        });
    }

    /**
     * At any arbitrary layer of nesting within the configuration objects, any single value that
     * is not specified by the configuration is given the default counterpart. If, within an object,
     * one peer is given by configuration and two are not, the one is preserved while the two are given
     * the default value.
     * @returns the composition of all of the assigned objects, much like Object.assign(), but with more
     * granularity in the overwriting of nested objects
     */
    export function preciseAssign(target: any, ...sources: any[]): any {
        sources.forEach(source => {
            preciseAssignHelper(target, source);
        });
        return target;
    }
}