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

const PKG_DIR = join(__dirname, "..");

describe("purity", () => {
    it("importing the package adds no Suaveplan-specific globals", {
        timeout: 5000,
    }, async () => {
        const banned = ["__suaveplan_audio_loudness__", "LoudnessMeter"];
        await import("../src/index.js");
        for (const k of banned)
            expect(Object.hasOwn(globalThis, k)).toBe(false);
    });

    it("dependency set is limited to the declared workspace and zod", {
        timeout: 5000,
    }, () => {
        const pkg = JSON.parse(
            readFileSync(join(PKG_DIR, "package.json"), "utf8")
        );
        const allowed = new Set([
            "@suaveplan/audio-core",
            "@suaveplan/error",
            "@suaveplan/opentelemetry",
            "@suaveplan/types",
            "@opentelemetry/api",
            "tslib",
            "zod",
        ]);
        for (const dep of Object.keys(pkg.dependencies ?? {}))
            expect(allowed.has(dep)).toBe(true);
    });

    it("source references no browser or Node globals", {
        timeout: 5000,
    }, () => {
        // Static-scan the source tree (dist is build output; not checked here).
        const srcGlobs = [
            "src/meter/loudness-meter.ts",
            "src/algorithms/lufs.ts",
            "src/algorithms/true-peak.ts",
            "src/algorithms/loudness-range.ts",
            "src/filters/k-weighting.ts",
            "src/error-codes/error-codes.ts",
            "src/index.ts",
        ];
        // Only match identifier-use occurrences (e.g. `window.fetch`,
        // `document.body`, `process.env`, `Buffer.from`), not the
        // English-prose words "window" or "document" inside doc-comments
        // and identifiers like `sourceLength`.
        const banned = [
            /\bwindow\.\w/,
            /\bwindow\[/,
            /\bdocument\.\w/,
            /\bdocument\[/,
            /\bnavigator\.\w/,
            /\bAudioContext\b/,
            /\bAudioBuffer\b/,
            /\bAnalyserNode\b/,
            /\brequire\(["']node:fs["']\)/,
            /from\s+["']node:fs["']/,
            /from\s+["']node:path["']/,
            /\bprocess\.env/,
            /\bprocess\.argv/,
            /\bBuffer\.\w+/,
        ];
        for (const rel of srcGlobs) {
            const src = readFileSync(join(PKG_DIR, rel), "utf8");
            for (const re of banned) expect(re.test(src)).toBe(false);
        }
    });
});