import { interviewerNode } from './interviewer.node';
import { AIMessage } from '@langchain/core/messages';

function baseState(overrides: any = {}) {
  return {
    questions: [{ id: 'q1', questionText: 'What is JS?', keyPoints: ['point1'], dimension: 'llm' }],
    currentQuestionIndex: 0,
    shouldFollowUp: false,
    language: 'en',
    ...overrides,
  } as any;
}

describe('interviewerNode', () => {
  describe('empty questions handling', () => {
    it('should return apology message when questions array is empty', async () => {
      const state = baseState({ questions: [] });
      const result = await interviewerNode(state);
      expect(result.messages).toBeDefined();
      expect((result.messages as any)[0].content).toContain("sorry");
    });

    it('should return apology message when questions is undefined', async () => {
      const state = baseState({ questions: undefined });
      const result = await interviewerNode(state);
      expect(result.messages).toBeDefined();
      expect((result.messages as any)[0].content).toContain("sorry");
    });

    it('should return Chinese apology when language is zh', async () => {
      const state = baseState({ questions: [], language: 'zh' });
      const result = await interviewerNode(state);
      expect((result.messages as any)[0].content).toContain('抱歉');
    });

    it('should return Japanese apology when language is ja', async () => {
      const state = baseState({ questions: [], language: 'ja' });
      const result = await interviewerNode(state);
      expect((result.messages as any)[0].content).toContain('申し訳');
    });
  });

  describe('question index range checks', () => {
    it('should return shouldFollowUp: false when currentQuestionIndex >= questions.length', async () => {
      const state = baseState({ currentQuestionIndex: 5, questions: [{ id: 'q1', questionText: 'Q', keyPoints: ['k'], dimension: 'llm' }] });
      const result = await interviewerNode(state);
      expect(result.shouldFollowUp).toBe(false);
    });
  });

  describe('standard question presentation', () => {
    it('should present the current question', async () => {
      const result = await interviewerNode(baseState());
      expect(result.messages).toBeDefined();
      const msg = (result.messages as any)[0].content as string;
      expect(msg).toContain('Question 1');
      expect(msg).toContain('What is JS?');
    });

    it('should include answer instruction', async () => {
      const result = await interviewerNode(baseState());
      const msg = (result.messages as any)[0].content as string;
      expect(msg).toContain('answer');
    });

    it('should use Chinese labels when language is zh', async () => {
      const state = baseState({ language: 'zh' });
      const result = await interviewerNode(state);
      const msg = (result.messages as any)[0].content as string;
      expect(msg).toContain('问题');
      expect(msg).toContain('回答');
    });

    it('should use Japanese labels when language is ja', async () => {
      const state = baseState({ language: 'ja' });
      const result = await interviewerNode(state);
      const msg = (result.messages as any)[0].content as string;
      expect(msg).toContain('質問');
      expect(msg).toContain('回答');
    });
  });

  describe('follow-up mode', () => {
    it('should use last feedbackHistory message content as follow-up prompt', async () => {
      const state = baseState({
        shouldFollowUp: true,
        feedbackHistory: [new AIMessage('You need more details')],
      });
      const result = await interviewerNode(state);
      const msg = (result.messages as any)[0].content as string;
      expect(msg).toContain('You need more details');
    });

    it('should reset shouldFollowUp to false after processing', async () => {
      const state = baseState({
        shouldFollowUp: true,
        feedbackHistory: [new AIMessage('Feedback: More info needed')],
      });
      const result = await interviewerNode(state);
      expect(result.shouldFollowUp).toBe(false);
    });
  });
});