#!/usr/bin/env node
// Cut a release: bump package.json, close the CHANGELOG [Unreleased] section,
// commit, and create an annotated git tag. The tag is the immutable version
// anchor consumers pin (WHYNOT-WP-0003). Publishing is a separate step (T02).
//
//   make release VERSION=0.3.0       # or: node scripts/release.mjs 0.3.0
//
// Guards (refuses, never half-applies):
//   - VERSION must be semver `x.y.z`
//   - working tree must be clean (untracked files are allowed)
//   - tag `vX.Y.Z` must not already exist
//   - CHANGELOG `## [Unreleased]` must exist and be non-empty
//   - CHANGELOG must not already have a `## [X.Y.Z]` section
//
// Exit codes (match adapters/ADAPTER_CONTRACT.md): 0 ok · 2 usage/config · 3 guard fail.

import { execSync } from "node:child_process";
import { readFileSync, writeFileSync } from "node:fs";

const CHANGELOG = "CHANGELOG.md";
const PKG = "package.json";

function die(code, msg) {
  console.error(`release: ${msg}`);
  process.exit(code);
}
function git(args) {
  return execSync(`git ${args}`, { encoding: "utf8" }).trim();
}

const raw = (process.argv[2] || "").replace(/^v/, "");
if (!/^\d+\.\d+\.\d+$/.test(raw)) {
  die(2, `usage: node scripts/release.mjs <x.y.z>  (got "${process.argv[2] ?? ""}")`);
}
const version = raw;
const tag = `v${version}`;

// Working tree must be clean (ignore untracked `??` lines, e.g. pnpm-lock.yaml).
const dirty = git("status --porcelain")
  .split("\n")
  .filter((l) => l && !l.startsWith("??"));
if (dirty.length) {
  die(2, `working tree not clean — commit or stash first:\n${dirty.join("\n")}`);
}

// Tag must not exist.
try {
  git(`rev-parse --verify --quiet refs/tags/${tag}`);
  die(3, `tag ${tag} already exists`);
} catch {
  /* not found — good */
}

const changelog = readFileSync(CHANGELOG, "utf8");
if (changelog.includes(`## [${version}]`)) {
  die(3, `CHANGELOG already has a [${version}] section`);
}

// Isolate the [Unreleased] body (between its header and the next `## [`).
const unreleased = changelog.match(/## \[Unreleased\]\s*\n([\s\S]*?)(?=\n## \[|$)/);
if (!unreleased) die(3, `CHANGELOG has no "## [Unreleased]" section`);
if (!unreleased[1].trim()) {
  die(3, `CHANGELOG [Unreleased] is empty — nothing to release`);
}

const today = new Date().toISOString().slice(0, 10);

// Cut: keep a fresh empty [Unreleased] above, relabel the old one to [version] — date.
const newChangelog = changelog.replace(
  "## [Unreleased]\n",
  `## [Unreleased]\n\n## [${version}] — ${today}\n`,
);

// Bump package.json with a targeted replace so the hand-aligned formatting survives.
const pkg = readFileSync(PKG, "utf8");
const bumped = pkg.replace(/("version":\s*)"[^"]+"/, `$1"${version}"`);
if (bumped === pkg) die(2, `could not find "version" in ${PKG}`);

writeFileSync(CHANGELOG, newChangelog);
writeFileSync(PKG, bumped);

git(`add ${PKG} ${CHANGELOG}`);
execSync(`git commit -m "release: ${tag}"`, { stdio: "inherit" });
execSync(`git tag -a ${tag} -m "${tag}"`, { stdio: "inherit" });

console.log(`\n✓ released ${tag}`);
console.log(`  next:  git push --follow-tags origin main`);
console.log(`  then:  publish (WHYNOT-WP-0003 T02)`);