import { describe, expect, it, vi, beforeEach } from "vitest";
import { noteImportContention, emitResilience } from "@/lib/resilience-metrics";
import { extractMailMeta } from "@/services/imap/snapshot";
import { computeRawHash, sha256 } from "@/utils/hash";

vi.mock("@/lib/logger", () => ({
  logger: {
    info: vi.fn(),
    warn: vi.fn(),
    error: vi.fn(),
    debug: vi.fn(),
  },
}));

import { logger } from "@/lib/logger";

describe("resilience metrics helpers", () => {
  beforeEach(() => {
    vi.clearAllMocks();
  });

  it("emitResilience writes stable metric name", () => {
    emitResilience("idempotency.hash_collision", "error", { a: 1 });
    expect(logger.error).toHaveBeenCalledWith(
      expect.objectContaining({ metric: "idempotency.hash_collision", a: 1 }),
      "idempotency.hash_collision",
    );
  });

  it("noteImportContention fires on 4th hit", () => {
    const id = `mail-${Date.now()}`;
    for (let i = 0; i < 3; i++) noteImportContention(id);
    expect(logger.warn).not.toHaveBeenCalled();
    noteImportContention(id);
    expect(logger.warn).toHaveBeenCalledWith(
      expect.objectContaining({
        metric: "import.contention",
        mailId: id,
        count: 4,
      }),
      "import.contention",
    );
  });

  it("subject missing marked when empty subject", () => {
    const meta = extractMailMeta({ subject: "   " } as never);
    expect(meta.subject).toBe("(无主题)");
    expect(meta.subjectMissing).toBe(true);
  });

  it("hash collision salt differs from base raw_hash", () => {
    const base = computeRawHash({
      date: "2026-01-01T00:00:00.000Z",
      from: "a@b.com",
      subject: "x",
      filenames: ["a.xlsx"],
    });
    const forked = sha256(`${base}|acc|INBOX|99`);
    expect(forked).not.toEqual(base);
  });
});