import * as fs from "node:fs";
import * as path from "node:path";
import * as os from "node:os";
import { TesterAgent } from "../agents/tester.js";
import { AgentContext } from "../agents/base.js";
import { IntelligenceBackend, BackendRequest, BackendResult } from "../backends/types.js";
import { emptyTokenUsage } from "../backends/types.js";

class MockBackend implements IntelligenceBackend {
  readonly name = "mock";
  readonly type = "llm" as const;
  async isAvailable(): Promise<boolean> { return true; }
  async execute(request: BackendRequest): Promise<BackendResult> {
    return {
      success: true,
      output: `Mock backend executed: ${request.task.slice(0, 50)}`,
      artifacts: [],
      decisions: [],
      escalations: [],
      usage: emptyTokenUsage(),
    };
  }
}

function createTempDir(): string {
  return fs.mkdtempSync(path.join(os.tmpdir(), "ciagent-tester-test-"));
}

function cleanup(dir: string): void {
  fs.rmSync(dir, { recursive: true, force: true });
}

function makeContext(dir: string, backend?: IntelligenceBackend): AgentContext {
  return {
    project_path: dir,
    phase: 1,
    stage: "test",
    specification: "Build a REST API for task management",
    config_path: path.join(dir, ".ciagent", "config.json"),
    backend,
  };
}

describe("TesterAgent", () => {
  let dir: string;

  beforeEach(() => {
    dir = createTempDir();
  });

  afterEach(() => {
    cleanup(dir);
  });

  it("detects test files when src directory exists", async () => {
    const srcDir = path.join(dir, "src");
    fs.mkdirSync(srcDir, { recursive: true });
    fs.writeFileSync(path.join(srcDir, "app.integration.test.ts"), "test('integration', () => {});\n");

    const tester = new TesterAgent();
    const result = await tester.execute(makeContext(dir));
    expect(result.success).toBeDefined();
  });

  it("does not write test files", async () => {
    const srcDir = path.join(dir, "src");
    fs.mkdirSync(srcDir, { recursive: true });
    fs.writeFileSync(path.join(srcDir, "app.test.ts"), "test('unit', () => {});\n");

    const testFilesBefore = fs.readdirSync(srcDir).filter(f => f.endsWith(".test.ts"));
    const tester = new TesterAgent();
    await tester.execute(makeContext(dir));
    const testFilesAfter = fs.readdirSync(srcDir).filter(f => f.endsWith(".test.ts"));
    expect(testFilesAfter.length).toBe(testFilesBefore.length);
  });

  it("delegates to backend when available", async () => {
    const mockBackend = new MockBackend();
    const tester = new TesterAgent();
    const result = await tester.execute(makeContext(dir, mockBackend));
    expect(result.success).toBe(true);
    expect(result.output).toContain("Mock backend executed");
  });

  it("has correct agent name", () => {
    const tester = new TesterAgent();
    expect(tester.name).toBe("tester");
  });

  it("has correct workflow", () => {
    const tester = new TesterAgent();
    expect(tester.workflow).toBe("test");
  });
});