import { describe, expect, it, vi } from "vitest";
import { createMs365TokenProvider, Ms365TokenError } from "./ms365-oauth";

const CONFIG = { tenantId: "wabenhain.onmicrosoft.com", clientId: "11111111-2222-3333-4444-555555555555", clientSecret: "s3cr3t~value" };

function tokenResponse(token: string, expiresIn = 3600): Response {
  return new Response(JSON.stringify({ token_type: "Bearer", expires_in: expiresIn, access_token: token }), { status: 200 });
}

describe("createMs365TokenProvider", () => {
  it("requests a client-credentials token for Exchange Online", async () => {
    const fetchImpl = vi.fn(async () => tokenResponse("tok-1"));
    const provider = createMs365TokenProvider(CONFIG, { fetchImpl });

    await expect(provider.getToken()).resolves.toBe("tok-1");

    const [url, init] = fetchImpl.mock.calls[0] as unknown as [string, RequestInit];
    expect(url).toBe("https://login.microsoftonline.com/wabenhain.onmicrosoft.com/oauth2/v2.0/token");
    expect(init.method).toBe("POST");
    const body = new URLSearchParams(String(init.body));
    expect(body.get("grant_type")).toBe("client_credentials");
    expect(body.get("scope")).toBe("https://outlook.office365.com/.default");
    expect(body.get("client_id")).toBe(CONFIG.clientId);
    expect(body.get("client_secret")).toBe(CONFIG.clientSecret);
  });

  it("reuses the cached token until shortly before it expires", async () => {
    let now = 1_000_000;
    const fetchImpl = vi.fn().mockResolvedValueOnce(tokenResponse("tok-1", 3600)).mockResolvedValueOnce(tokenResponse("tok-2", 3600));
    const provider = createMs365TokenProvider(CONFIG, { fetchImpl, now: () => now });

    expect(await provider.getToken()).toBe("tok-1");
    now += 50 * 60 * 1000; // 50 Minuten: noch gueltig
    expect(await provider.getToken()).toBe("tok-1");
    now += 6 * 60 * 1000; // 56 Minuten: innerhalb der 5-Minuten-Reserve
    expect(await provider.getToken()).toBe("tok-2");
    expect(fetchImpl).toHaveBeenCalledTimes(2);
  });

  it("fetches a fresh token when a renewal is forced", async () => {
    const fetchImpl = vi.fn().mockResolvedValueOnce(tokenResponse("tok-1")).mockResolvedValueOnce(tokenResponse("tok-2"));
    const provider = createMs365TokenProvider(CONFIG, { fetchImpl });
    await provider.getToken();
    expect(await provider.getToken(true)).toBe("tok-2");
  });

  it("shares one request between concurrent callers", async () => {
    const fetchImpl = vi.fn(async () => tokenResponse("tok-1"));
    const provider = createMs365TokenProvider(CONFIG, { fetchImpl });
    const tokens = await Promise.all([provider.getToken(), provider.getToken(), provider.getToken()]);
    expect(tokens).toEqual(["tok-1", "tok-1", "tok-1"]);
    expect(fetchImpl).toHaveBeenCalledTimes(1);
  });

  it("reports the AADSTS code and never the client secret", async () => {
    const fetchImpl = vi.fn(
      async () =>
        new Response(
          JSON.stringify({
            error: "invalid_client",
            error_description: `AADSTS7000215: Invalid client secret provided. Ensure the secret being sent is the client secret value, not the client secret ID, for a secret added to app '${CONFIG.clientId}'. Secret: ${CONFIG.clientSecret}`,
          }),
          { status: 401 }
        )
    );
    const provider = createMs365TokenProvider(CONFIG, { fetchImpl });
    const error = await provider.getToken().catch((e: unknown) => e);
    expect(error).toBeInstanceOf(Ms365TokenError);
    expect((error as Ms365TokenError).aadCode).toBe("7000215");
    expect((error as Error).message).not.toContain(CONFIG.clientSecret);
  });

  it("does not cache a failed request", async () => {
    const fetchImpl = vi.fn().mockRejectedValueOnce(new Error("fetch failed")).mockResolvedValueOnce(tokenResponse("tok-1"));
    const provider = createMs365TokenProvider(CONFIG, { fetchImpl });
    await expect(provider.getToken()).rejects.toBeInstanceOf(Ms365TokenError);
    await expect(provider.getToken()).resolves.toBe("tok-1");
  });

  it("rejects a tenant id that could change the request URL", () => {
    expect(() => createMs365TokenProvider({ ...CONFIG, tenantId: "evil.com/x?" })).toThrow(Ms365TokenError);
    expect(() => createMs365TokenProvider({ ...CONFIG, tenantId: "../common" })).toThrow(Ms365TokenError);
  });
});