import path from "node:path";
import { spawnSync } from "node:child_process";
import { fileURLToPath } from "node:url";

const scriptDir = path.dirname(fileURLToPath(import.meta.url));
const repoRoot = path.resolve(scriptDir, "..");
const gitPathspecs = [":(glob)tests/**/*.js", ":(glob)tests/**/*.ts"];

function run(command, args, options = {}) {
  const result = spawnSync(command, args, {
    cwd: repoRoot,
    encoding: "utf8",
    ...options,
  });

  if (result.error) {
    throw result.error;
  }

  return result;
}

function fail(message) {
  console.error(message);
  process.exit(1);
}

function runNpmScript(scriptName) {
  if (process.env.npm_execpath) {
    return run(process.execPath, [process.env.npm_execpath, "run", scriptName], { stdio: "inherit" });
  }

  const npmCommand = process.platform === "win32" ? "npm.cmd" : "npm";
  return run(npmCommand, ["run", scriptName], {
    shell: process.platform === "win32",
    stdio: "inherit",
  });
}

function parseLines(output) {
  return output
    .split(/\r?\n/)
    .map((line) => line.trim())
    .filter(Boolean);
}

const worktreeResult = run("git", ["rev-parse", "--show-toplevel"]);

if (worktreeResult.status !== 0) {
  fail("Pre-commit formatting must run inside the front-end-vue Git worktree.");
}

const gitRoot = path.resolve(worktreeResult.stdout.trim());

if (gitRoot !== repoRoot) {
  fail(`Expected front-end-vue to be the Git root, but git reported: ${gitRoot}`);
}

const unstagedTrackedResult = run("git", ["diff", "--name-only", "--", ...gitPathspecs]);

if (unstagedTrackedResult.status !== 0) {
  fail("Unable to inspect unstaged test-file changes before running Prettier.");
}

const untrackedResult = run("git", ["ls-files", "--others", "--exclude-standard", "--", ...gitPathspecs]);

if (untrackedResult.status !== 0) {
  fail("Unable to inspect untracked test files before running Prettier.");
}

const unsafePaths = [
  ...parseLines(unstagedTrackedResult.stdout),
  ...parseLines(untrackedResult.stdout),
];

if (unsafePaths.length > 0) {
  const formattedPaths = unsafePaths.map((filePath) => ` - ${filePath}`).join("\n");
  fail(
    [
      "Pre-commit formatting aborted because tests contain unstaged changes.",
      "Stage or discard these files before committing so the hook does not add unrelated work:",
      formattedPaths,
    ].join("\n")
  );
}

console.log("Running Prettier for frontend test files...");
const formatResult = runNpmScript("format:tests");

if (formatResult.status !== 0) {
  process.exit(formatResult.status ?? 1);
}

console.log("Restaging formatted frontend test files...");
const knownFilesResult = run("git", ["ls-files", "--cached", "--others", "--exclude-standard", "--", ...gitPathspecs]);

if (knownFilesResult.status !== 0) {
  fail("Prettier completed, but the hook could not resolve test files for restaging.");
}

const filesToStage = parseLines(knownFilesResult.stdout);

if (filesToStage.length === 0) {
  process.exit(0);
}

const addResult = run("git", ["add", "--", ...filesToStage], { stdio: "inherit" });

if (addResult.status !== 0) {
  fail("Prettier completed, but git add failed while restaging formatted test files.");
}