// `punktfunk-host plugins …` package operations, run on the vendored bun. The host CLI forwards
// add/remove/list here (crates/punktfunk-host/src/plugins.rs) and the runner-cli exposes them as
// subcommands. Everything a plugin needs to be installed — the plugins dir, the `@punktfunk`
// registry scope in bunfig.toml, and the right bun — is handled here so the operator types one line
// instead of the old create-dir / write-bunfig / `bun add` ritual.
import * as fs from "node:fs";
import * as path from "node:path";
import { configDir } from "./config.js";

/** The `@punktfunk` package registry (Gitea's npm registry for the `unom` org). */
export const REGISTRY = "https://git.unom.io/api/packages/unom/npm/";

/** Where plugin packages install: `<config_dir>/plugins` (matches runner.ts discovery). */
export const pluginsDirDefault = (): string => path.join(configDir(), "plugins");

/**
 * Resolve a friendly plugin name to its npm package. A bare first-party name maps into the
 * `@punktfunk` scope (`playnite` → `@punktfunk/plugin-playnite`, `rom-manager` →
 * `@punktfunk/plugin-rom-manager`); a scoped name (`@…/…`), the unscoped plugin convention
 * (`punktfunk-plugin-…`), or any name with a `/` is used verbatim.
 */
export const resolvePackage = (name: string): string => {
	const n = name.trim();
	if (!n) throw new Error("empty plugin name");
	if (n.startsWith("@")) return n; // already scoped, e.g. @punktfunk/plugin-playnite
	if (n.startsWith("punktfunk-plugin-")) return n; // unscoped plugin convention, verbatim
	if (n.includes("/")) return n; // some other registry path — trust it
	return `@punktfunk/plugin-${n}`; // bare first-party name
};

/** Create the plugins dir (and parents) if needed. On Windows the ACL lockdown is the host's job. */
export const ensurePluginsDir = (dir = pluginsDirDefault()): string => {
	fs.mkdirSync(dir, { recursive: true });
	return dir;
};

/**
 * Ensure `<dir>/bunfig.toml` points the `@punktfunk` scope at the registry so `bun add` resolves
 * first-party plugins. Idempotent: a file already mapping the scope is left untouched; an existing
 * bunfig with an `[install.scopes]` table gets our line inserted under it; anything else appends a
 * fresh table.
 */
export const ensureBunfig = (dir = pluginsDirDefault()): void => {
	const file = path.join(dir, "bunfig.toml");
	const scopeLine = `"@punktfunk" = "${REGISTRY}"`;
	let existing = "";
	try {
		existing = fs.readFileSync(file, "utf8");
	} catch {
		// no bunfig yet — write a fresh one below
	}
	if (existing.includes("@punktfunk") && existing.includes(REGISTRY)) return; // already wired

	const table = `[install.scopes]\n${scopeLine}\n`;
	if (!existing.trim()) {
		fs.writeFileSync(file, table);
	} else if (/^\[install\.scopes\][^\n]*$/m.test(existing)) {
		// Insert our scope line right after the existing table header.
		fs.writeFileSync(
			file,
			existing.replace(/^\[install\.scopes\][^\n]*$/m, (m) => `${m}\n${scopeLine}`),
		);
	} else {
		const sep = existing.endsWith("\n") ? "" : "\n";
		fs.writeFileSync(file, `${existing}${sep}\n${table}`);
	}
};

export interface PkgOpts {
	/** Plugins dir. Default `<config_dir>/plugins`. */
	dir?: string;
	/** Line sink for progress. Default stdout. */
	log?: (line: string) => void;
}

/** Run `bun add`/`bun remove` in the plugins dir on the current (vendored) bun. */
const runBun = (action: "add" | "remove", pkgs: string[], opts: PkgOpts): void => {
	const dir = opts.dir ?? pluginsDirDefault();
	const log = opts.log ?? ((l: string) => console.log(l));
	ensurePluginsDir(dir);
	if (action === "add") ensureBunfig(dir);
	log(`${action === "add" ? "installing" : "removing"} ${pkgs.join(", ")} in ${dir}`);
	// `process.execPath` is the bun running this file (the vendored one under the package), so a
	// system-wide bun on PATH is not required. Inherit stdio so `bun`'s progress reaches the user.
	const res = Bun.spawnSync([process.execPath, action, ...pkgs], {
		cwd: dir,
		stdio: ["inherit", "inherit", "inherit"],
	});
	if (!res.success) {
		throw new Error(`bun ${action} exited ${res.exitCode ?? "?"} — see output above`);
	}
};

/** Install one or more plugins by friendly name or package. */
export const addPlugins = (names: string[], opts: PkgOpts = {}): void =>
	runBun("add", names.map(resolvePackage), opts);

/** Uninstall one or more plugins by friendly name or package. */
export const removePlugins = (names: string[], opts: PkgOpts = {}): void =>
	runBun("remove", names.map(resolvePackage), opts);

export interface InstalledPlugin {
	/** npm package name, e.g. `@punktfunk/plugin-playnite` or `punktfunk-plugin-foo`. */
	pkg: string;
	/** Installed version from the package's package.json, if readable. */
	version?: string;
}

/**
 * Enumerate installed plugin packages under `<dir>/node_modules` — both the scoped first-party
 * convention (`@punktfunk/plugin-*`) and the unscoped one (`punktfunk-plugin-*`). Mirrors the
 * discovery in runner.ts so `list` shows exactly what the runner would supervise.
 */
export const listInstalled = (dir = pluginsDirDefault()): InstalledPlugin[] => {
	const modules = path.join(dir, "node_modules");
	const out: InstalledPlugin[] = [];
	const versionOf = (pkgDir: string): string | undefined => {
		try {
			const m = JSON.parse(
				fs.readFileSync(path.join(pkgDir, "package.json"), "utf8"),
			) as { version?: string };
			return m.version;
		} catch {
			return undefined;
		}
	};
	let entries: string[];
	try {
		entries = fs.readdirSync(modules).sort();
	} catch {
		return out; // no plugins installed yet
	}
	for (const entry of entries) {
		if (entry.startsWith("punktfunk-plugin-")) {
			out.push({ pkg: entry, version: versionOf(path.join(modules, entry)) });
		} else if (entry === "@punktfunk") {
			let scoped: string[] = [];
			try {
				scoped = fs.readdirSync(path.join(modules, entry)).sort();
			} catch {
				scoped = [];
			}
			for (const s of scoped) {
				if (s.startsWith("plugin-")) {
					out.push({
						pkg: `${entry}/${s}`,
						version: versionOf(path.join(modules, entry, s)),
					});
				}
			}
		}
	}
	return out;
};