import {
  describe,
  it,
  expect,
  vi,
  beforeEach,
  afterEach,
  beforeAll,
} from "vitest";
import nock from "nock";
import { BigNumber } from "bignumber.js";
import { Bot } from "../src/bot.js";

vi.mock("console", () => ({
  log: vi.fn(),
  error: vi.fn(),
}));

vi.mock("../src/db.js", () => ({
  insertIntoDB: vi.fn(),
  initDB: vi.fn(),
}));

describe("Test Suite", () => {
  const PAIR = "BTC-USD";
  const INTERVAL = 100;
  const THRESHOLD = 0.01;

  let bot;

  beforeAll(() => {
    // Ensure BigNumber config matches what we expect
    BigNumber.config({
      DECIMAL_PLACES: 10,
      ROUNDING_MODE: BigNumber.ROUND_HALF_UP,
    });
  });

  beforeEach(() => {
    bot = new Bot(PAIR, INTERVAL, THRESHOLD);
    vi.useFakeTimers();
  });

  afterEach(() => {
    bot.stop();
    vi.runAllTimers();
    vi.useRealTimers();
    nock.cleanAll();
    vi.restoreAllMocks();
  });

  describe("Initialization and first fetch", () => {
    it("should set lastPrice on first successful API call", async () => {
      nock("https://api.uphold.com")
        .get(`/v0/ticker/${PAIR}`)
        .reply(200, { ask: "60000.50", bid: "59990.00", currency: "USD" });

      await bot.check();

      expect(bot.lastPrice).toBeDefined();
      expect(bot.lastPrice.toFixed(2)).toBe("60000.50");
    });
  });

  describe("Price change detection", () => {
    beforeEach(async () => {
      // Establish baseline
      nock("https://api.uphold.com")
        .get(`/v0/ticker/${PAIR}`)
        .reply(200, { ask: "50000.00" });
      await bot.check();
      nock.cleanAll();
    });

    it("should NOT alert when change is below threshold", async () => {
      const alertSpy = vi.spyOn(bot, "alert");
      nock("https://api.uphold.com")
        .get(`/v0/ticker/${PAIR}`)
        .reply(200, { ask: "50004.99" }); // +0.00998%

      await bot.check();

      expect(alertSpy).not.toHaveBeenCalled();
    });

    it("should alert when price moves exactly 0.01% (threshold)", async () => {
      const alertSpy = vi.spyOn(bot, "alert");
      nock("https://api.uphold.com")
        .get(`/v0/ticker/${PAIR}`)
        .reply(200, { ask: "50005.00" });

      await bot.check();

      // Check specifically for arguments passed to alert
      expect(alertSpy).toHaveBeenCalledWith("UP", "50005.00", 0.01);
    });

    it("should alert on downward move", async () => {
      const alertSpy = vi.spyOn(bot, "alert");
      nock("https://api.uphold.com")
        .get(`/v0/ticker/${PAIR}`)
        .reply(200, { ask: "49500.00" }); // -1%

      await bot.check();

      expect(alertSpy).toHaveBeenCalledWith("DOWN", "49500.00", -1);
    });
  });

  describe("Alert method", () => {
    it("should log correct message for price increase", () => {
      bot.lastPrice = new BigNumber("50000");
      const consoleSpy = vi.spyOn(console, "log");

      bot.alert("UP", "50500.00", 1);

      expect(consoleSpy).toHaveBeenCalledWith(expect.stringContaining("UP"));
      expect(consoleSpy).toHaveBeenCalledWith(expect.stringContaining("1.00%"));
    });
  });

  describe("Polling mechanism", () => {
    it("should repeatedly call check()", async () => {
      const checkSpy = vi.spyOn(bot, "check").mockResolvedValue();

      bot.start();

      vi.advanceTimersByTime(INTERVAL * 3);
      await Promise.resolve();

      expect(checkSpy).toHaveBeenCalledTimes(4);
    });
  });

  describe("Error handling", () => {
    it("should bubble up errors when check() is called directly", async () => {
      nock("https://api.uphold.com")
        .get(`/v0/ticker/${PAIR}`)
        .replyWithError("Connection Error");

      await expect(bot.check()).rejects.toThrow("Connection Error");
    });

    it("should reject invalid data formats", async () => {
      nock("https://api.uphold.com")
        .get(`/v0/ticker/${PAIR}`)
        .reply(200, { bid: "100" });
      await expect(bot.check()).rejects.toThrow("Invalid data format");
    });
  });
});