import { execFile } from "node:child_process";
import { existsSync } from "node:fs";
import { createRequire } from "node:module";
import { mkdtemp, readFile, rm, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import { dirname, join } from "node:path";
import { promisify } from "node:util";
import { afterEach, expect, test } from "vitest";

const execFileAsync = promisify(execFile);
const require = createRequire(import.meta.url);
const repoRoot = join(import.meta.dirname, "../../..");
const cliEntry = join(repoRoot, "packages/cli/src/main.ts");
const tsxLoader = join(dirname(require.resolve("tsx/package.json")), "dist/loader.mjs");
const helperPackage = require.resolve("@scriptc/llvm-darwin-arm64/package.json");
const helper = join(dirname(helperPackage), "bin", "scriptc-llvm-codegen");
const runtimePackage = require.resolve("@scriptc/runtime-wasm32-wasi/package.json");
const runtimeManifest = join(dirname(runtimePackage), "runtime-pack.json");
const supported = existsSync(helper) && existsSync(runtimeManifest);
const dirs: string[] = [];

afterEach(async () => {
  await Promise.all(dirs.splice(0).map((path) => rm(path, { recursive: true, force: true })));
});

test.runIf(supported)(
  "WASI helper object plus runtime pack builds and runs without SCRIPTC_CC",
  async () => {
    const dir = await mkdtemp(join(tmpdir(), "scriptc-wasi-runtime-pack-"));
    dirs.push(dir);
    const output = join(dir, "hello.wasm");
    const zigCache = join(dir, "zig-cache");
    await expect(
      execFileAsync(
        process.execPath,
        [
          "--import",
          tsxLoader,
          cliEntry,
          "run",
          join(repoRoot, "tests/corpus/001-hello.ts"),
          "-o",
          output,
        ],
        {
          env: {
            ...process.env,
            SCRIPTC_TARGET: "wasm32-wasi",
            SCRIPTC_NO_CACHE: "1",
            ZIG_GLOBAL_CACHE_DIR: join(zigCache, "global"),
            ZIG_LOCAL_CACHE_DIR: join(zigCache, "local"),
          },
          encoding: "utf8",
        },
      ),
    ).resolves.toMatchObject({ stdout: "hello world\n" });
  },
);

test.runIf(supported)("switching WASI and native builds retains both executables", async () => {
  const dir = await mkdtemp(join(tmpdir(), "scriptc-wasi-native-output-"));
  dirs.push(dir);
  const entry = join(dir, "hello.ts");
  const outDir = join(dir, ".scriptc");
  const nativeEnv = { ...process.env };
  delete nativeEnv.SCRIPTC_TARGET;
  const wasiEnv = { ...nativeEnv, SCRIPTC_TARGET: "wasm32-wasi" };
  const build = (args: string[], env: NodeJS.ProcessEnv) =>
    execFileAsync(process.execPath, ["--import", tsxLoader, cliEntry, "build", entry, ...args], {
      env,
      maxBuffer: 4 * 1024 * 1024,
    });
  await writeFile(entry, 'console.log("hello");\n');

  await build([], wasiEnv);
  const llvm = await readFile(join(outDir, "hello.ll"));
  const wasm = await readFile(join(outDir, "hello.wasm"));
  await build(["--backend=llvm", "--keep-llvm"], nativeEnv);
  const native = await readFile(join(outDir, process.platform === "win32" ? "hello.exe" : "hello"));
  const nativeLlvm = await readFile(join(outDir, "hello.ll"));
  expect(nativeLlvm.equals(llvm)).toBe(false);
  expect(await readFile(join(outDir, "hello.wasm"))).toEqual(wasm);

  await build([], wasiEnv);
  expect(await readFile(join(outDir, "hello.ll"))).toEqual(llvm);
  expect(
    await readFile(join(outDir, process.platform === "win32" ? "hello.exe" : "hello")),
  ).toEqual(native);
});