// Cut a ChronVer release: compute the next version, prepend a changelog section
// for the pending commits, and write the version to package.json.
//
//   deno task release            # e.g. 2026.07.16, then 2026.07.16.1 same day
//   deno task release --break    # append a -break suffix (breaking change)
//   deno task release --feature  # append a -feature suffix (feature branch)
//
// This only edits CHANGELOG.md and package.json. Review the generated changelog
// (it is a draft — curate it), then commit both with jj. Suggested description:
// `release <version>`. The version then rides along into `deno task image`.
import { nextVersion } from "./version.ts";
import { pendingCommits, renderSection } from "./changelog.ts";

const PKG = new URL("../package.json", import.meta.url);
const CHANGELOG = new URL("../CHANGELOG.md", import.meta.url);

const PREAMBLE = `# Changelog

All notable changes to Quantum are documented here. Versions follow
[ChronVer](https://chronver.org); the format follows
[Keep a Changelog](https://keepachangelog.com).
`;

const suffix = Deno.args.includes("--break")
	? "break"
	: Deno.args.includes("--feature")
	? "feature"
	: "";

const version = await nextVersion(suffix);

// Build the new section from commits since the last release.
const section = renderSection(version, await pendingCommits());

// Prepend it: keep the preamble, then the new section, then the prior sections.
let prior = "";
try {
	const existing = await Deno.readTextFile(CHANGELOG);
	const firstHeading = existing.indexOf("## ");
	prior = firstHeading === -1 ? "" : existing.slice(firstHeading);
} catch {
	// No CHANGELOG.md yet — first release creates it.
}
const changelog = `${PREAMBLE}\n${section}\n${prior}`.trimEnd() + "\n";
await Deno.writeTextFile(CHANGELOG, changelog);

// Bump package.json (source of truth), preserving tab indentation.
const pkg = JSON.parse(await Deno.readTextFile(PKG));
const previous = pkg.version;
pkg.version = version;
await Deno.writeTextFile(PKG, JSON.stringify(pkg, null, "\t") + "\n");

console.log(`Released ${version} (was ${previous}).`);
console.log("Updated CHANGELOG.md and package.json.");
console.log("Next: review/curate CHANGELOG.md, then commit both");
console.log(
	`      (e.g. \`jj describe -m "release ${version}"\`), then \`deno task image\`.`,
);