/**
 * Unit tests for the tool limit detector.
 */

import { describe, it, beforeEach } from "node:test";
import assert from "node:assert/strict";

import {
  getEffectiveToolLimit,
  setDetectedToolLimit,
  parseToolLimitFromError,
  shouldDetectLimit,
  clearDetectedLimits,
} from "../../open-sse/services/toolLimitDetector.ts";

describe("toolLimitDetector", () => {
  beforeEach(() => {
    clearDetectedLimits();
  });

  it("should return default limit when no cached value", () => {
    assert.strictEqual(getEffectiveToolLimit("openai"), 128);
  });

  it("should return cached limit when available", () => {
    setDetectedToolLimit("openai", 100);
    assert.strictEqual(getEffectiveToolLimit("openai"), 100);
  });

  it("should only update cache when limit is lower", () => {
    setDetectedToolLimit("openai", 100);
    setDetectedToolLimit("openai", 120);
    assert.strictEqual(getEffectiveToolLimit("openai"), 100);
  });

  it("should parse tool limit from OpenAI error message", () => {
    const result = parseToolLimitFromError("'tools': maximum number of items is 128");
    assert.strictEqual(result, 128);
  });

  it("should parse tool limit from alternative format", () => {
    const result = parseToolLimitFromError("Maximum number of tools allowed is 64");
    assert.strictEqual(result, 64);
  });

  it("should return null for non-tool errors", () => {
    const result = parseToolLimitFromError("Invalid API key");
    assert.strictEqual(result, null);
  });

  it("should detect tool limit errors for 400 status", () => {
    assert.strictEqual(shouldDetectLimit("Maximum number of tools is 128", 400), true);
    assert.strictEqual(shouldDetectLimit("Too many tools provided", 400), true);
    assert.strictEqual(shouldDetectLimit("Invalid API key", 400), false);
  });

  it("should not detect for non-400 errors", () => {
    assert.strictEqual(shouldDetectLimit("Maximum number of tools is 128", 500), false);
    assert.strictEqual(shouldDetectLimit("Maximum number of tools is 128", 429), false);
  });
});