import crypto from "node:crypto";
import { describe, expect, it } from "vitest";
import {
  buildAuthorizationUrl,
  certificateFingerprint,
  createPkce,
  decodeJwtClaims,
  fetchRootCertificate,
  findOidcProvisioner,
  generateSshKeyPair,
  normalizeCaUrl,
  normalizeFingerprint,
  parseSshCertificate,
} from "../../src/backend/client.js";
import { parseHostList } from "../../src/backend/auth-session.js";
import { CA_URL, createFakeCa, createSshCa, fakeRoot } from "./fake-ca.js";

describe("step-ca client helpers", () => {
  it("normalizes the CA url and fingerprint the way step does", () => {
    expect(normalizeCaUrl(" https://ca.internal:9000/ ")).toBe(
      "https://ca.internal:9000",
    );
    expect(() => normalizeCaUrl("http://ca.internal")).toThrow(/https/);
    const fp = "AB:cd".repeat(16).replace(/:/g, "");
    expect(normalizeFingerprint("AB:cd".repeat(16))).toBe(fp.toLowerCase());
    expect(() => normalizeFingerprint("abcd")).toThrow(/SHA-256/);
  });

  it("fingerprints a PEM certificate by the sha256 of its DER", () => {
    const root = fakeRoot();
    expect(certificateFingerprint(root.pem)).toBe(root.fingerprint);
  });

  it("builds a PKCE authorization request", () => {
    const { verifier, challenge } = createPkce();
    expect(challenge).toBe(
      crypto.createHash("sha256").update(verifier).digest("base64url"),
    );
    const url = new URL(
      buildAuthorizationUrl({
        authorizationEndpoint: "https://idp.example/auth?tenant=x",
        clientId: "cid",
        redirectUri: "https://termix.example/callback",
        state: "s",
        nonce: "n",
        codeChallenge: challenge,
      }),
    );
    expect(url.searchParams.get("tenant")).toBe("x");
    expect(url.searchParams.get("response_type")).toBe("code");
    expect(url.searchParams.get("code_challenge_method")).toBe("S256");
    expect(url.searchParams.get("scope")).toContain("openid");
  });

  it("generates an ed25519 key a CA can certify, and reads the cert back", () => {
    const { publicKeyLine, privateKeyPem } = generateSshKeyPair();
    expect(publicKeyLine).toMatch(/^ssh-ed25519 [A-Za-z0-9+/=]+$/);
    expect(privateKeyPem).toContain("BEGIN PRIVATE KEY");

    const cert = createSshCa().sign({
      publicKeyBlob: publicKeyLine.split(" ")[1],
      keyId: "alice@example",
      principals: ["alice", "ops"],
      validAfter: 1_700_000_000,
      validBefore: 1_700_057_600,
    });
    const info = parseSshCertificate(cert);
    expect(info).toMatchObject({
      keyType: "ssh-ed25519-cert-v01@openssh.com",
      publicKeyLine,
      keyId: "alice@example",
      principals: ["alice", "ops"],
    });
    expect(info.validAfter.toISOString()).toBe("2023-11-14T22:13:20.000Z");
    expect(info.validBefore.getTime() - info.validAfter.getTime()).toBe(
      16 * 3600 * 1000,
    );
    expect(() => parseSshCertificate(publicKeyLine)).toThrow(/certificate/);
    expect(() =>
      parseSshCertificate("ssh-ed25519-cert-v01@openssh.com AAAA"),
    ).toThrow(/certificate/);
  });

  it("reads the private endpoint list with commas or new lines", () => {
    expect(parseHostList("ca.internal, SSO.internal\nidp.lan")).toEqual([
      "ca.internal",
      "sso.internal",
      "idp.lan",
    ]);
    expect(parseHostList(undefined)).toEqual([]);
  });
});

describe("talking to the CA", () => {
  it("refuses a root whose fingerprint does not match", async () => {
    const ca = createFakeCa({ nonce: () => "" });
    await expect(
      fetchRootCertificate({
        fetch: ca.fetch,
        caUrl: CA_URL,
        fingerprint: "b".repeat(64),
        allowedPrivateHosts: [],
      }),
    ).rejects.toThrow();
  });

  it("finds the OIDC provisioner by name and passes the private hosts", async () => {
    const ca = createFakeCa({ nonce: () => "" });
    const target = {
      fetch: ca.fetch,
      caUrl: CA_URL,
      fingerprint: ca.root.fingerprint,
      allowedPrivateHosts: ["ca.test"],
    };
    const root = await fetchRootCertificate(target);
    const provisioner = await findOidcProvisioner(target, root, "oidc");
    expect(provisioner.clientID).toBe("termix");
    expect(ca.calls.every((call) => call.init?.allowPrivateHosts)).toBe(true);
    await expect(findOidcProvisioner(target, root, "jwk")).rejects.toThrow(
      /not found/,
    );
  });
});

describe("decodeJwtClaims", () => {
  it("reads the payload without verifying and tolerates junk", () => {
    const payload = Buffer.from(
      JSON.stringify({ email: "a@b.c", nonce: "n1" }),
    ).toString("base64url");
    expect(decodeJwtClaims(`x.${payload}.y`)).toEqual({
      email: "a@b.c",
      nonce: "n1",
    });
    expect(decodeJwtClaims("not-a-jwt")).toEqual({});
  });
});