// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
// This module is browser compatible.

import { isWindows } from "./_os.ts";
import { relative as posixRelative } from "./posix/relative.ts";
import { relative as windowsRelative } from "./windows/relative.ts";

/**
 * Return the relative path from `from` to `to` based on current working
 * directory.
 *
 * @example Usage
 * ```ts
 * import { relative } from "@std/path/relative";
 * import { assertEquals } from "@std/assert";
 *
 * if (Deno.build.os === "windows") {
 *   const path = relative("C:\\foobar\\test\\aaa", "C:\\foobar\\impl\\bbb");
 *   assertEquals(path, "..\\..\\impl\\bbb");
 * } else {
 *   const path = relative("/data/foobar/test/aaa", "/data/foobar/impl/bbb");
 *   assertEquals(path, "../../impl/bbb");
 * }
 * ```
 *
 * @param from Path in current working directory.
 * @param to Path in current working directory.
 * @returns The relative path from `from` to `to`.
 */
export function relative(from: string, to: string): string {
  return isWindows ? windowsRelative(from, to) : posixRelative(from, to);
}