import { test, after } from "node:test";
import assert from "node:assert/strict";
import { spawnSync } from "node:child_process";
import { mkdtempSync, rmSync, cpSync, statSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { fileURLToPath } from "node:url";

const ROOT = fileURLToPath(new URL("../", import.meta.url));
const HOOKS = join(ROOT, ".githooks");
const SHA = "1".repeat(40);
const ZERO = "0".repeat(40);

// Run git and the hooks without inheriting GIT_DIR & co, e.g. when tests run from inside a hook.
const env = Object.fromEntries(Object.entries(process.env).filter(([k]) => !k.startsWith("GIT_")));
const run = (cmd, args, opts = {}) => spawnSync(cmd, args, { env, encoding: "utf8", ...opts });

const dirs = [];
after(() => dirs.forEach((d) => rmSync(d, { recursive: true, force: true })));

function repoOn(branch) {
  const dir = mkdtempSync(join(tmpdir(), "todo-hooks-"));
  dirs.push(dir);
  const init = run("git", ["init", "-q", "-b", branch, dir]);
  assert.equal(init.status, 0, `git init failed: ${init.stderr}`);
  return dir;
}

function prePush(...lines) {
  return run("sh", [join(HOOKS, "pre-push"), "origin", "git@example:repo.git"], {
    input: lines.map((l) => l + "\n").join(""),
  });
}

for (const [label, line] of [
  ["an update", `refs/heads/fix/x ${SHA} refs/heads/main ${SHA}`],
  ["a new ref", `refs/heads/fix/x ${SHA} refs/heads/main ${ZERO}`],
  ["a deletion", `(delete) ${ZERO} refs/heads/main ${SHA}`],
]) {
  test(`pre-push rejects ${label} of main`, () => {
    const res = prePush(line);
    assert.equal(res.status, 1);
    assert.match(res.stderr, /pushing to main is not allowed/);
  });
}

test("pre-push rejects --all style pushes that include main", () => {
  const res = prePush(`refs/heads/fix/x ${SHA} refs/heads/fix/x ${SHA}`, `refs/heads/main ${SHA} refs/heads/main ${SHA}`);
  assert.equal(res.status, 1);
});

test("pre-push allows other branches, including ones named like main", () => {
  const res = prePush(`refs/heads/fix/x ${SHA} refs/heads/fix/x ${ZERO}`, `refs/heads/maintenance ${SHA} refs/heads/maintenance ${SHA}`);
  assert.equal(res.status, 0);
});

for (const hook of ["pre-commit", "pre-merge-commit"]) {
  test(`${hook} rejects main, names itself, and allows other branches`, () => {
    const onMain = run("sh", [join(HOOKS, hook)], { cwd: repoOn("main") });
    assert.equal(onMain.status, 1);
    assert.match(onMain.stderr, new RegExp(`^${hook}: committing on main is not allowed`));
    assert.equal(run("sh", [join(HOOKS, hook)], { cwd: repoOn("fix/x") }).status, 0);
  });
}

test("install-hooks copies every hook into .git/hooks as an executable", () => {
  const repo = repoOn("fix/x");
  cpSync(join(ROOT, "scripts"), join(repo, "scripts"), { recursive: true });
  cpSync(HOOKS, join(repo, ".githooks"), { recursive: true });
  const res = run("sh", [join(repo, "scripts", "install-hooks.sh")]);
  assert.equal(res.status, 0, res.stderr);
  for (const hook of ["pre-push", "pre-commit", "pre-merge-commit"]) {
    assert.ok(statSync(join(repo, ".git", "hooks", hook)).mode & 0o100, `${hook} is not executable`);
  }
});

test("install-hooks skips cleanly outside a git checkout", () => {
  const dir = mkdtempSync(join(tmpdir(), "todo-hooks-"));
  dirs.push(dir);
  cpSync(join(ROOT, "scripts"), join(dir, "scripts"), { recursive: true });
  const res = run("sh", [join(dir, "scripts", "install-hooks.sh")], { env: { ...env, GIT_CEILING_DIRECTORIES: tmpdir() } });
  assert.equal(res.status, 0);
  assert.match(res.stderr, /not a git checkout; skipping/);
});