/**
 * Spec-conformance tests for `openspec/specs/crypto-cipher/spec.md`.
 *
 * Pins structural scenarios that the per-primitive unit suites do not
 * cover directly: every AEAD has both `noble.ts` and `native.ts`,
 * every `*.select.ts` carries the GENERATED banner, every
 * `*.native.ts` is currently a `PrimitiveNotImplemented` stub
 * (runtime reflection of the dangerous-tier flip gate), the package
 * is in a consistent pre/post-Phase-0.5 vendoring state, and no
 * primitive source file consumes a CSPRNG (nonce-is-caller-supplied).
 */
import { existsSync, readdirSync, readFileSync, statSync } from "node:fs";
import { join } from "node:path";
import { describe, expect, it } from "@suaveplan/testing/runner";

const ROOT = join(__dirname, "..");
const SRC = join(ROOT, "src");
const PRIMITIVES = join(SRC, "primitives");

const AEAD_IDS = [
    "aes-256-gcm",
    "chacha20-poly1305",
    "xchacha20-poly1305",
] as const;

function* walk(dir: string): Generator<string> {
    for (const entry of readdirSync(dir)) {
        const full = join(dir, entry);
        const st = statSync(full);
        if (
            st.isDirectory() &&
            !full.includes("node_modules") &&
            !full.includes("dist")
        ) {
            yield* walk(full);
        } else if (full.endsWith(".ts") && !full.endsWith(".test.ts")) {
            yield full;
        }
    }
}

describe("crypto-cipher — universal AEAD primitive surface", () => {
    it("every AEAD id has its primitive directory", { timeout: 5000 }, () => {
        for (const id of AEAD_IDS) {
            expect(existsSync(join(PRIMITIVES, id))).toBe(true);
        }
    });
});

describe("crypto-cipher — per-primitive replaceability layout", () => {
    for (const id of AEAD_IDS) {
        it(`${id} has both noble.ts and native.ts impl files`, {
            timeout: 5000,
        }, () => {
            expect(
                existsSync(
                    join(
                        PRIMITIVES,
                        id,
                        "impl",
                        `${id}.noble`,
                        `${id}.noble.ts`
                    )
                )
            ).toBe(true);
            expect(
                existsSync(
                    join(
                        PRIMITIVES,
                        id,
                        "impl",
                        `${id}.native`,
                        `${id}.native.ts`
                    )
                )
            ).toBe(true);
        });

        it(`${id}.select.ts carries the GENERATED banner`, {
            timeout: 5000,
        }, () => {
            const sel = join(PRIMITIVES, id, `${id}.select`, `${id}.select.ts`);
            expect(existsSync(sel)).toBe(true);
            const c = readFileSync(sel, "utf8");
            expect(c).toMatch(/GENERATED/);
            expect(c).toMatch(/DO NOT EDIT/);
        });
    }
});

describe("crypto-cipher — vendored noble source (Phase 0.5)", () => {
    it("is a Phase-0.5 forward gate; current state is pre-0.5 (noble dep + no vendored/)", {
        timeout: 5000,
    }, () => {
        const pkg = JSON.parse(
            readFileSync(join(ROOT, "package.json"), "utf8")
        );
        const noblePresent =
            "@noble/ciphers" in (pkg.dependencies ?? {}) ||
            "@noble/ciphers" in (pkg.peerDependencies ?? {});
        const vendoredPresent = existsSync(join(SRC, "vendored"));
        const upstreamFile = existsSync(join(ROOT, "NOBLE_UPSTREAM.md"));
        const pre05 = noblePresent && !vendoredPresent && !upstreamFile;
        const post05 = !noblePresent && vendoredPresent && upstreamFile;
        expect(pre05 || post05).toBe(true);
    });
});

describe("crypto-cipher — constant-time and dangerous-tier reflection", () => {
    for (const id of AEAD_IDS) {
        it(`${id}.native.ts is currently a PrimitiveNotImplemented stub`, {
            timeout: 5000,
        }, () => {
            const src = readFileSync(
                join(PRIMITIVES, id, "impl", `${id}.native`, `${id}.native.ts`),
                "utf8"
            );
            expect(src).toMatch(/PrimitiveNotImplemented/);
        });
    }

    it("every native is a stub today, so no AEAD has been flipped without an audit", {
        timeout: 5000,
    }, () => {
        const offenders: string[] = [];
        for (const id of AEAD_IDS) {
            const src = readFileSync(
                join(PRIMITIVES, id, "impl", `${id}.native`, `${id}.native.ts`),
                "utf8"
            );
            if (!/PrimitiveNotImplemented/.test(src)) offenders.push(id);
        }
        expect(offenders).toEqual([]);
    });
});

describe("crypto-cipher — nonce is caller-supplied", () => {
    it("no primitive source file consumes a CSPRNG (no Math.random / crypto.getRandomValues / randomBytes)", {
        timeout: 5000,
    }, () => {
        const banned = [
            /\bMath\.random\b/,
            /\bcrypto\.getRandomValues\b/,
            /\brandomBytes\b/,
        ];
        const hits: string[] = [];
        for (const file of walk(SRC)) {
            const c = readFileSync(file, "utf8");
            for (const re of banned) {
                if (re.test(c)) hits.push(`${file}: ${re}`);
            }
        }
        expect(hits).toEqual([]);
    });
});