import { Command } from "effect/unstable/cli";

import type { Config } from "./config.js";
import { VERSION } from "./constants.js";
import { flags, specsArgument } from "./flags.js";
import { run } from "./run.js";

/**
 * What the tool is for, in one line, at the top of `--help`.
 *
 * The same sentence as the README's opening, because both answer the same
 * question and two versions of it would drift.
 * "Complete dependency closure" is the load-bearing part: the thing that
 * distinguishes this from `npm pack` is that it follows the graph.
 */
const DESCRIPTION =
	"Bundle npm packages and their complete dependency closure into tarballs you can carry " +
	"across an air gap and import into a registry on a restricted network.";

/** The root command. */
export const bundleCommand = Command.make("packall", { specs: specsArgument, ...flags }, (parsed) =>
	run(toConfig(parsed)),
).pipe(Command.withDescription(DESCRIPTION));

/** The runnable CLI. */
export const cli = Command.run(bundleCommand, { version: VERSION });

/**
 * Narrows the parsed arguments into `Config`.
 *
 * `Argument.variadic` widens its element type to `unknown`, so the positional
 * specs are narrowed here rather than asserted: `Argument.string` only ever
 * produces strings, and a guard that is a no-op at runtime is still cheaper
 * than a cast that stops the compiler checking the other thirty fields.
 */
const toConfig = (
	parsed: Omit<Config, "specs"> & { readonly specs: ReadonlyArray<unknown> },
): Config => ({
	...parsed,
	specs: parsed.specs.flatMap((spec) => (typeof spec === "string" ? spec : [])),
});