import { sep } from "node:path";

const graphemeSegmenter = new Intl.Segmenter(undefined, { granularity: "grapheme" });

export function graphemes(value: string): string[] {
	return [...graphemeSegmenter.segment(value)].map(({ segment }) => segment);
}

export function firstGrapheme(value: string): string {
	return graphemes(value)[0] ?? "";
}

export function truncateLeadingGraphemes(value: string, length: number, symbol: string): string {
	if (length <= 0) return value;
	const parts = graphemes(value);
	if (parts.length <= length) return value;
	return `${parts.slice(0, length).join("")}${firstGrapheme(symbol)}`;
}

export function toSlashPath(value: string): string {
	return sep === "\\" ? value.replaceAll("\\", "/") : value;
}

export function truncatePathComponents(
	value: string,
	length: number,
): { value: string; truncated: boolean } {
	if (length <= 0) return { value, truncated: false };
	const normalized = toSlashPath(value);
	const components = normalized.split("/").filter((component) => component.length > 0);
	if (components.length <= length) return { value: normalized, truncated: false };
	return { value: components.slice(-length).join("/"), truncated: true };
}

export function useNativePathSeparator(value: string): string {
	return sep === "/" ? value : value.replaceAll("/", sep);
}