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

const DISALLOWED_PATTERNS = [
    "node:fs",
    "node:path",
    "node:url",
    "process.env",
    "Buffer",
    "document.",
    "window.",
];

// Allow ReadableStream (Web Streams API — explicitly permitted)

function walkDir(dir: string, results: string[] = []): string[] {
    for (const entry of readdirSync(dir)) {
        const full = join(dir, entry);
        if (statSync(full).isDirectory()) {
            if (
                entry !== "__benchmarks__" &&
                entry !== "node_modules" &&
                entry !== "dist"
            ) {
                walkDir(full, results);
            }
        } else if (
            full.endsWith(".ts") &&
            !full.endsWith(".test.ts") &&
            !full.endsWith(".bench.ts") &&
            !full.endsWith(".types.ts")
        ) {
            results.push(full);
        }
    }
    return results;
}

describe("no-disallowed: source files must not use banned APIs", () => {
    it("source files do not use node:fs, node:path, node:url, process.env, Buffer, document, window", {
        timeout: 10000,
    }, () => {
        const srcDir = join(import.meta.dirname, "..", "src");
        const files = walkDir(srcDir);

        const violations: string[] = [];

        for (const file of files) {
            const content = readFileSync(file, "utf-8");
            const relativePath = file.split("/src/")[1] ?? file;

            for (const pattern of DISALLOWED_PATTERNS) {
                if (content.includes(pattern)) {
                    violations.push(`${relativePath}: contains "${pattern}"`);
                }
            }
        }

        if (violations.length > 0) {
            throw new Error(
                `Disallowed patterns found in source:\n${violations.join("\n")}`
            );
        }

        // At least checked one file
        expect(files.length).toBeGreaterThan(0);
    });
});