import { createSign, generateKeyPairSync } from "node:crypto";
import { expect, test } from "vitest";
import { createOidcProtocol, OidcProtocolError } from "../src/auth/oidc-client.js";

const issuer = "https://issuer.example.test";
const clientId = "thothii";
const callbackUrl = "https://thothii.example.test/api/auth/oidc/callback";
const verifier = "v".repeat(43);
const nonce = "n".repeat(43);
const state = "s".repeat(43);

const keys = generateKeyPairSync("rsa", { modulusLength: 2048 });
const jwk = { ...keys.publicKey.export({ format: "jwk" }), kid: "test-key", use: "sig", alg: "RS256" };

function token(claims: Record<string, unknown>, invalidSignature = false): string {
  const encode = (value: unknown) => Buffer.from(JSON.stringify(value)).toString("base64url");
  const input = `${encode({ alg: "RS256", kid: "test-key", typ: "JWT" })}.${encode(claims)}`;
  const signer = createSign("RSA-SHA256");
  signer.update(input);
  signer.end();
  const signature = signer.sign(keys.privateKey).toString("base64url");
  const corruptedSignature = signature.startsWith("A") ? `B${signature.slice(1)}` : `A${signature.slice(1)}`;
  return `${input}.${invalidSignature ? corruptedSignature : signature}`;
}

function protocol(options: {
  claims?: Record<string, unknown>;
  discoveryIssuer?: string;
  invalidSignature?: boolean;
  seen?: URL[];
} = {}) {
  const now = Math.floor(Date.now() / 1000);
  const claims = {
    iss: issuer,
    sub: "user-123",
    aud: clientId,
    exp: now + 300,
    iat: now,
    nonce,
    name: "Ada Lovelace",
    groups: ["TOT Users", "Unmapped group"],
    ...options.claims,
  };
  const fetch = async (input: RequestInfo | URL) => {
    const url = new URL(input instanceof Request ? input.url : typeof input === "string" ? input : input.toString());
    options.seen?.push(url);
    if (url.pathname.includes(".well-known/")) {
      return Response.json({
        issuer: options.discoveryIssuer ?? issuer,
        authorization_endpoint: `${issuer}/authorize`,
        token_endpoint: `${issuer}/token`,
        jwks_uri: `${issuer}/jwks`,
        response_types_supported: ["code"],
        grant_types_supported: ["authorization_code"],
        subject_types_supported: ["public"],
        id_token_signing_alg_values_supported: ["RS256"],
      });
    }
    if (url.pathname === "/jwks") return Response.json({ keys: [jwk] });
    if (url.pathname === "/token") {
      return Response.json({
        token_type: "Bearer",
        access_token: "access-token-must-not-be-persisted",
        refresh_token: "refresh-token-must-not-be-persisted",
        id_token: token(claims, options.invalidSignature),
      });
    }
    return new Response(null, { status: 404 });
  };
  return createOidcProtocol({
    issuer,
    clientId,
    clientSecret: "client-secret-must-not-be-persisted",
    callbackUrl,
    scopes: ["openid", "profile"],
    groupsClaim: "groups",
    fetch,
  });
}

async function callback(subject = protocol()) {
  return subject.callback({
    currentUrl: new URL(`${callbackUrl}?code=good&state=${state}`), state, nonce, codeVerifier: verifier,
  });
}

test("uses HTTPS discovery, Authorization Code, and PKCE S256 without external network", async () => {
  const seen: URL[] = [];
  const subject = protocol({ seen });
  const authorization = await subject.authorizationUrl({ state, nonce, codeVerifier: verifier });

  expect(authorization.origin).toBe(issuer);
  expect(authorization.pathname).toBe("/authorize");
  expect(Object.fromEntries(authorization.searchParams)).toMatchObject({
    response_type: "code", client_id: clientId, redirect_uri: callbackUrl, state, nonce,
    code_challenge_method: "S256", scope: "openid profile",
  });
  expect(authorization.searchParams.get("code_challenge")).not.toBe(verifier);
  await expect(callback(subject)).resolves.toEqual({
    issuer, subject: "user-123", displayName: "Ada Lovelace",
    groups: ["TOT Users", "Unmapped group"], tokenExpiresAt: expect.any(Date),
  });
  expect(seen.map((url) => url.origin)).toEqual([issuer, issuer, issuer]);
});

test("rejects non-HTTPS issuer configuration and a discovery issuer mismatch", async () => {
  expect(() => createOidcProtocol({
    issuer: "http://issuer.example.test", clientId, clientSecret: "secret", callbackUrl,
    scopes: ["openid"], groupsClaim: "groups",
  })).toThrow(OidcProtocolError);
  await expect(protocol({ discoveryIssuer: "https://other.example.test" }).authorizationUrl({ state, nonce, codeVerifier: verifier }))
    .rejects.toThrow(OidcProtocolError);
});

test.each([
  ["state", new URL(`${callbackUrl}?code=good&state=wrong`), {}],
  ["nonce", new URL(`${callbackUrl}?code=good&state=${state}`), { nonce: "wrong" }],
  ["audience", new URL(`${callbackUrl}?code=good&state=${state}`), { aud: "someone-else" }],
  ["issuer", new URL(`${callbackUrl}?code=good&state=${state}`), { iss: "https://other.example.test" }],
  ["expiry", new URL(`${callbackUrl}?code=good&state=${state}`), { exp: Math.floor(Date.now() / 1000) - 1 }],
  ["subject", new URL(`${callbackUrl}?code=good&state=${state}`), { sub: undefined }],
])("rejects invalid %s claims or callback bindings", async (_label, currentUrl, claims) => {
  const subject = protocol({ claims });
  await expect(subject.callback({ currentUrl, state, nonce, codeVerifier: verifier })).rejects.toThrow(OidcProtocolError);
});

test("rejects invalid ID-token signatures", async () => {
  await expect(callback(protocol({ invalidSignature: true }))).rejects.toThrow(OidcProtocolError);
});

test.each([
  ["absent", { groups: undefined }],
  ["non-array", { groups: "TOT Users" }],
  ["empty", { groups: [""] }],
  ["duplicate", { groups: ["TOT Users", "TOT Users"] }],
  ["control", { groups: ["TOT\u0000Users"] }],
  ["oversized", { groups: ["x".repeat(257)] }],
  ["distributed", { _claim_names: { groups: "source" }, _claim_sources: { source: { endpoint: "https://issuer.example.test/claims" } } }],
  ["overage", { hasgroups: true }],
])("rejects %s mandatory groups claims", async (_label, claims) => {
  await expect(callback(protocol({ claims }))).rejects.toThrow(OidcProtocolError);
});