import DiffMatchPatch from "diff-match-patch";

const dmp = new DiffMatchPatch();

export function createDiff(oldText: string, newText: string): string {
	const patches = dmp.patch_make(oldText, newText);
	return dmp.patch_toText(patches);
}

export function applyDiff(text: string, patchText: string): string {
	const patches = dmp.patch_fromText(patchText);
	const [result, applied] = dmp.patch_apply(patches, text);
	const failed = applied.filter((ok) => !ok);
	if (failed.length > 0) {
		throw new Error(`Failed to apply ${failed.length} patch(es)`);
	}
	return result;
}