/**
 * Zips two objects together by their keys, creating an object with
 * both left and right values for each key.
 */
export function zipObjects<A, B = A>(
	objLeft?: Partial<Record<string, A>> | undefined,
	objRight?: Partial<Record<string, B>> | undefined,
): Partial<Record<string, { left?: A | undefined; right?: B | undefined }>> {
	const allKeys = [...new Set(Object.keys(objLeft || {}).concat(Object.keys(objRight || {})))]

	return allKeys.reduce<Record<string, { left?: A | undefined; right?: B | undefined }>>(
		(acc, key) => {
			const left = objLeft?.[key]
			const right = objRight?.[key]
			return {
				...acc,
				[key]: { left, right },
			}
		},
		{},
	)
}

/**
 * Returns true if the object has at least one key.
 */
export function isNotEmpty<A extends object>(obj: A): boolean {
	return Boolean(Object.keys(obj).length)
}

/**
 * Converts an array to a record using the provided key function.
 */
export function toRecord<A extends object>(
	arr: ReadonlyArray<A>,
	key: (obj: A) => string,
): Record<string, A> {
	return arr.reduce<Record<string, A>>((acc, entry) => {
		const k = key(entry)
		return {
			...acc,
			[k]: entry,
		}
	}, {})
}