import * as fs from "node:fs";
import { join } from "node:path";
import { describe, expect, it } from "@suaveplan/testing/runner";

const PKG_ROOT = join(import.meta.dirname ?? __dirname, "..");
const DIST = join(PKG_ROOT, "dist");

function walk(dir: string, out: string[] = []): string[] {
    for (const name of fs.readdirSync(dir)) {
        const p = join(dir, name);
        const st = fs.statSync(p);
        if (st.isDirectory()) walk(p, out);
        else if (p.endsWith(".js")) out.push(p);
    }
    return out;
}

describe("purity", () => {
    it("dist references no Node globals", { timeout: 5000 }, () => {
        const files = walk(DIST);
        expect(files.length).toBeGreaterThan(0);
        const banned = [/\bnode:fs\b/, /\bnode:path\b/, /\bnode:crypto\b/];
        const hits: string[] = [];
        for (const file of files) {
            const content = fs.readFileSync(file, "utf8");
            for (const rx of banned) {
                if (rx.test(content)) hits.push(`${file}:${rx}`);
            }
        }
        expect(hits).toEqual([]);
    });

    it("dependency set is limited to the declared workspace, standardized-audio-context, and zod", {
        timeout: 5000,
    }, () => {
        const pkg = JSON.parse(
            fs.readFileSync(join(PKG_ROOT, "package.json"), "utf8")
        ) as { dependencies: Record<string, string> };
        const allowed = new Set([
            "@suaveplan/audio-core",
            "@suaveplan/audio-fx-plugin-base",
            "@suaveplan/audio-timeline",
            "@suaveplan/audio-transport",
            "@suaveplan/error",
            "@suaveplan/events",
            "@opentelemetry/api",
            "standardized-audio-context",
            "tslib",
            "zod",
        ]);
        for (const dep of Object.keys(pkg.dependencies)) {
            expect(allowed).toContain(dep);
        }
    });

    it("importing the package mutates no global state", {
        timeout: 5000,
    }, async () => {
        const before = new Set(Object.keys(globalThis));
        await import("../src/index.js");
        const after = new Set(Object.keys(globalThis));
        for (const k of after) {
            if (before.has(k)) continue;
            expect(k).not.toMatch(/audio.engine.browser/i);
        }
    });
});