import { IDeepMerge, IObject, isObject } from './isObject';

/**
 * @description Method to perform a deep merge of objects
 * @param {Object} target - The targeted object that needs to be merged with the supplied @sources
 * @param {Array<Object>} sources - The source(s) that will be used to update the @target object
 * @return {Object} The final merged object
 */

// merge objects keep the original object values
export const deepMerge: IDeepMerge = (target: IObject, ...sources: IObject[]): IObject => {
	if (!sources.length) {
		return target;
	}

	const source = sources.shift();

	if (isObject(target) && isObject(source)) {
		for (const key in source) {
			if (isObject(source[key])) {
				if (!target[key]) {
					Object.assign(target, { [key]: {} });
				}

				deepMerge(target[key], source[key]);
			} else {
				Object.assign(target, { [key]: source[key] });
			}
		}
	}

	return deepMerge(target, ...sources);
};