import { describe, it, before, after, mock } from "node:test";
import assert from "node:assert/strict";

let tlsClient: import("../../open-sse/utils/tlsClient.ts").default;

describe("tlsClient circuit breaker — session recreation", () => {
  before(async () => {
    tlsClient = (await import("../../open-sse/utils/tlsClient.ts")).default;
    tlsClient.resetCircuit();
  });

  after(() => {
    tlsClient.resetCircuit();
  });

  // --------------------------------------------------------------------------
  // 1. Circuit opens after maxFailures consecutive failures
  // --------------------------------------------------------------------------
  it("opens circuit after maxFailures (3) consecutive failures", () => {
    tlsClient.resetCircuit();

    tlsClient.recordFailure();
    assert.equal(tlsClient.getCircuitState().circuitTripped, false);
    assert.equal(tlsClient.getCircuitState().failureCount, 1);

    tlsClient.recordFailure();
    assert.equal(tlsClient.getCircuitState().circuitTripped, false);
    assert.equal(tlsClient.getCircuitState().failureCount, 2);

    tlsClient.recordFailure();
    assert.equal(tlsClient.getCircuitState().circuitTripped, true);
    assert.equal(tlsClient.getCircuitState().failureCount, 3);
  });

  // --------------------------------------------------------------------------
  // 2. RecordSuccess resets failure count and closes circuit
  // --------------------------------------------------------------------------
  it("recordSuccess resets failure count and closes circuit", () => {
    tlsClient.resetCircuit();

    // Open the circuit
    tlsClient.recordFailure();
    tlsClient.recordFailure();
    tlsClient.recordFailure();
    assert.equal(tlsClient.getCircuitState().circuitTripped, true);
    assert.equal(tlsClient.getCircuitState().failureCount, 3);

    // Simulate success (as would happen after half-open retry)
    tlsClient.recordSuccess();
    assert.equal(tlsClient.getCircuitState().circuitTripped, false);
    assert.equal(tlsClient.getCircuitState().failureCount, 0);
  });

  // --------------------------------------------------------------------------
  // 3. Session is nulled when circuit opens (stale session cleanup)
  // --------------------------------------------------------------------------
  it("stale session is closed when circuit opens", () => {
    tlsClient.resetCircuit();
    // Force-clear the session since we can't create a real wreq-js session
    // The session property is private, so we verify via behavior:
    // After circuit opens and then recovers, getSession() should attempt to
    // create a new session rather than returning the old one.
    // We verify this by checking available flag transitions.
    assert.equal(tlsClient.getCircuitState().available, true);

    tlsClient.recordFailure();
    tlsClient.recordFailure();
    tlsClient.recordFailure();

    // Circuit open — available should be false
    assert.equal(tlsClient.getCircuitState().circuitTripped, true);
    assert.equal(tlsClient.getCircuitState().available, false);

    // After simulated cooldown period, recordSuccess closes circuit
    tlsClient.recordSuccess();
    assert.equal(tlsClient.getCircuitState().circuitTripped, false);
    assert.equal(tlsClient.getCircuitState().available, true);
  });

  // --------------------------------------------------------------------------
  // 4. checkCircuit allows half-open retry after cooldown
  // --------------------------------------------------------------------------
  it("checkCircuit returns true after cooldown period (half-open)", () => {
    tlsClient.resetCircuit();

    // Open the circuit
    tlsClient.recordFailure();
    tlsClient.recordFailure();
    tlsClient.recordFailure();
    assert.equal(tlsClient.getCircuitState().coolDownRemainingMs > 0, true);

    // Set circuitOpenUntil to the past (simulate cooldown expired)
    // We access the private circuitOpenUntil via getCircuitState
    const state = tlsClient.getCircuitState();
    if (state.coolDownRemainingMs > 0) {
      // Fast-forward by setting failureCount to 0 and circuitTripped to false
      // via recordSuccess — this simulates the half-open retry behavior
      tlsClient.recordSuccess();
      assert.equal(tlsClient.getCircuitState().circuitTripped, false);
    }
  });

  // --------------------------------------------------------------------------
  // 5. Multiple circuit open/close cycles don't degrade
  // --------------------------------------------------------------------------
  it("survives 100 circuit open/close cycles without degradation", () => {
    tlsClient.resetCircuit();

    for (let i = 0; i < 100; i++) {
      // Open: 3 failures
      tlsClient.recordFailure();
      tlsClient.recordFailure();
      tlsClient.recordFailure();
      assert.equal(tlsClient.getCircuitState().circuitTripped, true);

      // Close: success
      tlsClient.recordSuccess();
      assert.equal(tlsClient.getCircuitState().circuitTripped, false);
      assert.equal(tlsClient.getCircuitState().failureCount, 0);
    }

    assert.equal(tlsClient.getCircuitState().available, true);
  });

  // --------------------------------------------------------------------------
  // 6. Partial failures don't trip the circuit
  // --------------------------------------------------------------------------
  it("does not open circuit on 1-2 failures (below maxFailures)", () => {
    tlsClient.resetCircuit();

    tlsClient.recordFailure();
    assert.equal(tlsClient.getCircuitState().circuitTripped, false);

    tlsClient.recordSuccess(); // Recovery before reaching threshold

    assert.equal(tlsClient.getCircuitState().failureCount, 0);
    assert.equal(tlsClient.getCircuitState().circuitTripped, false);
  });

  // --------------------------------------------------------------------------
  // 7. Session exit() is safe to call multiple times
  // --------------------------------------------------------------------------
  it("exit() is safe to call when session is already null", async () => {
    tlsClient.resetCircuit();
    // Calling exit when session is null should not throw
    await tlsClient.exit();
    // Calling exit again should also be safe
    await tlsClient.exit();
    assert.equal(tlsClient.getCircuitState().available, true);
  });
});