/* eslint-disable max-lines-per-function -- Test suites naturally have many cases */
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";

describe("discord service", () => {
  const ORIGINAL_ENV = process.env;
  const mockFetch = vi.fn();

  beforeEach(() => {
    process.env = { ...ORIGINAL_ENV };
    vi.resetModules();
    vi.stubGlobal("fetch", mockFetch);
  });

  afterEach(() => {
    process.env = ORIGINAL_ENV;
    vi.unstubAllGlobals();
    mockFetch.mockReset();
  });

  describe("buildOAuthUrl", () => {
    it("throws when DISCORD_CLIENT_ID is missing", async () => {
      delete process.env["DISCORD_CLIENT_ID"];
      process.env["DISCORD_REDIRECT_URI"] = "http://localhost/callback";
      const { buildOAuthUrl } = await import("../../src/services/discord.js");
      expect(() => buildOAuthUrl()).toThrow("Discord OAuth environment variables are required");
    });

    it("throws when DISCORD_REDIRECT_URI is missing", async () => {
      process.env["DISCORD_CLIENT_ID"] = "client123";
      delete process.env["DISCORD_REDIRECT_URI"];
      const { buildOAuthUrl } = await import("../../src/services/discord.js");
      expect(() => buildOAuthUrl()).toThrow("Discord OAuth environment variables are required");
    });

    it("returns a URL with correct query params", async () => {
      process.env["DISCORD_CLIENT_ID"] = "client123";
      process.env["DISCORD_REDIRECT_URI"] = "http://localhost/callback";
      const { buildOAuthUrl } = await import("../../src/services/discord.js");
      const url = buildOAuthUrl();
      expect(url).toContain("client_id=client123");
      expect(url).toContain("response_type=code");
      expect(url).toContain("scope=identify");
    });
  });

  describe("exchangeCode", () => {
    it("throws when env vars are missing", async () => {
      delete process.env["DISCORD_CLIENT_ID"];
      const { exchangeCode } = await import("../../src/services/discord.js");
      await expect(exchangeCode("mycode")).rejects.toThrow("Discord OAuth environment variables are required");
    });

    it("throws when response is not ok", async () => {
      process.env["DISCORD_CLIENT_ID"] = "cid";
      process.env["DISCORD_CLIENT_SECRET"] = "secret";
      process.env["DISCORD_REDIRECT_URI"] = "http://localhost/cb";
      mockFetch.mockResolvedValueOnce({ ok: false, statusText: "Unauthorized" });
      const { exchangeCode } = await import("../../src/services/discord.js");
      await expect(exchangeCode("bad_code")).rejects.toThrow("Discord token exchange failed");
    });

    it("returns parsed body on success", async () => {
      process.env["DISCORD_CLIENT_ID"] = "cid";
      process.env["DISCORD_CLIENT_SECRET"] = "secret";
      process.env["DISCORD_REDIRECT_URI"] = "http://localhost/cb";
      const tokenData = { access_token: "tok", token_type: "Bearer", expires_in: 3600, refresh_token: "ref", scope: "identify" };
      mockFetch.mockResolvedValueOnce({ ok: true, json: () => Promise.resolve(tokenData) });
      const { exchangeCode } = await import("../../src/services/discord.js");
      const result = await exchangeCode("good_code");
      expect(result.access_token).toBe("tok");
    });
  });

  describe("fetchDiscordUser", () => {
    it("throws when response is not ok", async () => {
      mockFetch.mockResolvedValueOnce({ ok: false, statusText: "Forbidden" });
      const { fetchDiscordUser } = await import("../../src/services/discord.js");
      await expect(fetchDiscordUser("bad_token")).rejects.toThrow("Discord user fetch failed");
    });

    it("returns parsed user on success", async () => {
      const user = { id: "123", username: "testuser", discriminator: "0", avatar: null };
      mockFetch.mockResolvedValueOnce({ ok: true, json: () => Promise.resolve(user) });
      const { fetchDiscordUser } = await import("../../src/services/discord.js");
      const result = await fetchDiscordUser("valid_token");
      expect(result.id).toBe("123");
      expect(result.username).toBe("testuser");
    });
  });
});