import { describe, expect, test } from "bun:test"

import fs from "fs/promises"

import path from "path"

import { which } from "../../src/util/which"

import { tmpdir } from "../fixture/fixture"

async function cmd(dir: string, name: string, exec = true) {

const ext = process.platform === "win32" ? ".cmd" : ""

const file = path.join(dir, name + ext)

const body = process.platform === "win32" ? "@echo off\r\n" : "#!/bin/sh\n"

await fs.writeFile(file, body)

if (process.platform !== "win32") {

await fs.chmod(file, exec ? 0o755 : 0o644)

}

return file

}

function env(PATH: string): NodeJS.ProcessEnv {

return {

PATH,

PATHEXT: process.env["PATHEXT"],

}

}

function envPath(Path: string): NodeJS.ProcessEnv {

return {

Path,

PathExt: process.env["PathExt"] ?? process.env["PATHEXT"],

}

}

function same(a: string | null, b: string) {

if (process.platform === "win32") {

expect(a?.toLowerCase()).toBe(b.toLowerCase())

return

}

expect(a).toBe(b)

}

describe("util.which", () => {

test("returns null when command is missing", () => {

expect(which("opencode-missing-command-for-test")).toBeNull()

})

test("finds a command from PATH override", async () => {

await using tmp = await tmpdir()

const bin = path.join(tmp.path, "bin")

await fs.mkdir(bin)

const file = await cmd(bin, "tool")

same(which("tool", env(bin)), file)

})

test("uses first PATH match", async () => {

await using tmp = await tmpdir()

const a = path.join(tmp.path, "a")

const b = path.join(tmp.path, "b")

await fs.mkdir(a)

await fs.mkdir(b)

const first = await cmd(a, "dupe")

await cmd(b, "dupe")

same(which("dupe", env([a, b].join(path.delimiter))), first)

})

test("returns null for non-executable file on unix", async () => {

if (process.platform === "win32") return

await using tmp = await tmpdir()

const bin = path.join(tmp.path, "bin")

await fs.mkdir(bin)

await cmd(bin, "noexec", false)

expect(which("noexec", env(bin))).toBeNull()

})

test("uses PATHEXT on windows", async () => {

if (process.platform !== "win32") return

await using tmp = await tmpdir()

const bin = path.join(tmp.path, "bin")

await fs.mkdir(bin)

const file = path.join(bin, "pathext.CMD")

await fs.writeFile(file, "@echo off\r\n")

expect(which("pathext", { PATH: bin, PATHEXT: ".CMD" })).toBe(file)

})

test("uses Windows Path casing fallback", async () => {

if (process.platform !== "win32") return

await using tmp = await tmpdir()

const bin = path.join(tmp.path, "bin")

await fs.mkdir(bin)

const file = await cmd(bin, "mixed")

same(which("mixed", envPath(bin)), file)

})

})