/**
 * Unit tests for x-connection-id pinning in src/sse/handlers/chat.js
 *
 * Covers:
 *  - the dashboard per-key test header is forwarded to getProviderCredentials
 *    as preferredConnectionId (same contract as embeddings/images/video)
 *  - a pinned request does NOT rotate to another account on failure
 *  - an unpinned request keeps rotating (regression guard)
 */

import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";

const authMocks = vi.hoisted(() => ({
  getProviderCredentials: vi.fn(),
  markAccountUnavailable: vi.fn(async () => ({ shouldFallback: true })),
  clearAccountError: vi.fn(async () => {}),
  extractApiKey: vi.fn(() => null),
  isValidApiKey: vi.fn(async () => true),
  isModelAllowedForKey: vi.fn(() => true),
}));
const tokenMocks = vi.hoisted(() => ({
  checkAndRefreshToken: vi.fn(async (_p, creds) => creds),
  updateProviderCredentials: vi.fn(async () => {}),
}));

vi.mock("@/sse/services/auth.js", () => authMocks);
vi.mock("@/sse/services/tokenRefresh.js", () => tokenMocks);
vi.mock("@/lib/localDb", () => ({
  getSettings: vi.fn(async () => ({ requireApiKey: false })),
  getComboByName: vi.fn(async () => null),
  getModelAliases: vi.fn(async () => ({})),
  getCustomModels: vi.fn(async () => []),
  getProviderNodes: vi.fn(async () => []),
  getProviderConnections: vi.fn(async () => []),
  updateProviderCredentials: vi.fn(async () => {}),
}));
vi.mock("@/sse/utils/logger.js", () => ({
  info: vi.fn(), warn: vi.fn(), error: vi.fn(), debug: vi.fn(), maskKey: (k) => k,
}));
// chatCore would perform the upstream call; stub success so the loop exits.
vi.mock("open-sse/handlers/chatCore.js", () => ({
  handleChatCore: vi.fn(async ({ credentials }) => ({
    success: true,
    response: new Response(JSON.stringify({ servedBy: credentials.connectionId }), {
      status: 200,
      headers: { "Content-Type": "application/json" },
    }),
  })),
}));
vi.mock("open-sse/services/combo.js", () => ({
  getComboModels: vi.fn(async () => null),
  resetComboRotation: vi.fn(),
  detectRequiredCapabilities: vi.fn(() => new Set()),
  augmentModelsWithCapacityAdapter: vi.fn((m) => m),
  withCapacityAdapterStripping: vi.fn((fn) => fn),
  getActiveAdapterStrategy: vi.fn(() => "fallback"),
}));

import { handleChat } from "@/sse/handlers/chat.js";

const originalFetch = global.fetch;

const makeRequest = (body, headers = {}) =>
  new Request("http://localhost/v1/chat/completions", {
    method: "POST",
    headers: { "Content-Type": "application/json", ...headers },
    body: JSON.stringify(body),
  });

const account = (id) => ({
  connectionId: id,
  connectionName: `acc-${id}`,
  accessToken: "tok",
  refreshToken: "ref",
  authType: "oauth",
});

beforeEach(() => {
  global.fetch = vi.fn();
  authMocks.getProviderCredentials.mockReset();
  authMocks.getProviderCredentials.mockImplementation(async (_p, exclude) =>
    exclude.size === 0 ? account("conn-A") : null,
  );
  authMocks.markAccountUnavailable.mockClear();
  authMocks.clearAccountError.mockClear();
  tokenMocks.checkAndRefreshToken.mockClear();
});

afterEach(() => {
  global.fetch = originalFetch;
});

describe("chat x-connection-id pinning", () => {
  it("forwards x-connection-id as preferredConnectionId", async () => {
    const res = await handleChat(
      makeRequest({ model: "prov/m1", messages: [{ role: "user", content: "hi" }] }, { "x-connection-id": "conn-B" }),
    );
    expect(res.status).toBe(200);
    expect(authMocks.getProviderCredentials).toHaveBeenCalledWith(
      "prov",
      expect.anything(),
      "m1",
      expect.objectContaining({ preferredConnectionId: "conn-B" }),
    );
  });

  it("passes null when no pin header is present", async () => {
    await handleChat(makeRequest({ model: "prov/m1", messages: [{ role: "user", content: "hi" }] }));
    expect(authMocks.getProviderCredentials).toHaveBeenCalledWith(
      "prov",
      expect.anything(),
      "m1",
      expect.objectContaining({ preferredConnectionId: null }),
    );
  });
});