import { describe, expect, it } from "vitest";
import { nextHealthState } from "../src/services/health/state-machine.js";

const thresholds = {
  degradedFailures: 1,
  downFailures: 2,
  successRecoveries: 2,
  latencyWarnMs: 1000,
};

describe("health state machine", () => {
  it("first success from unknown is healthy immediately", () => {
    const next = nextHealthState(true, 20, null, thresholds);
    expect(next.legacy).toBe("up");
    expect(next.node).toBe("healthy");
  });

  it("recovery from down goes checking until consecutive successes", () => {
    const first = nextHealthState(
      true,
      10,
      { status: "down", consecutive_failures: 3, consecutive_successes: 0 },
      thresholds,
    );
    expect(first.node).toBe("checking");
    expect(first.legacy).toBe("unknown");
    const second = nextHealthState(
      true,
      10,
      {
        status: "checking",
        consecutive_failures: 0,
        consecutive_successes: first.successes,
      },
      thresholds,
    );
    expect(second.node).toBe("healthy");
    expect(second.legacy).toBe("up");
  });

  it("two failures mark unhealthy", () => {
    const first = nextHealthState(
      false,
      5,
      { status: "up", consecutive_failures: 0, consecutive_successes: 1 },
      thresholds,
    );
    expect(first.node).toBe("degraded");
    const second = nextHealthState(
      false,
      5,
      {
        status: "degraded",
        consecutive_failures: first.failures,
        consecutive_successes: 0,
      },
      thresholds,
    );
    expect(second.node).toBe("unhealthy");
    expect(second.legacy).toBe("down");
  });
});