import { expect } from 'chai';
import { describe, it } from 'mocha';
import { Validator, ValidationError, LazyValidator } from '../src/validation/Validator';
import { decodeJWT } from '../src/util/TokenUtil';

// Helper function to create mock JWT tokens
const createMockJWT = (payload: any): string => {
  const header = Buffer.from(JSON.stringify({ alg: "HS256", typ: "JWT" })).toString('base64');
  const encodedPayload = Buffer.from(JSON.stringify(payload)).toString('base64');
  const signature = "mock-signature";
  return `${header}.${encodedPayload}.${signature}`;
};

describe('decodeJWT', () => {
  it('should decode a valid JWT token with Bearer prefix', () => {
    const payload = { sub: "1234567890", name: "John Doe", iat: 1516239022 };
    const token = createMockJWT(payload);
    const authHeader = `Bearer ${token}`;
    
    const result = decodeJWT(authHeader);
    
    expect(result).to.deep.equal(payload);
  });

  it('should decode JWT generated by GCP for a Service Account (e.g. PubSub)', () => {
    const authHeader = "Bearer eyJhbGciOiJSUzI1NiIsImtpZCI6Ijg4NDg5MjEyMmUyOTM5ZmQxZjMxMzc1YjJiMzYzZWM4MTU3MjNiYmIiLCJ0eXAiOiJKV1QifQ.eyJhdWQiOiJ0b3RvLTg5MGQ4czkwYSIsImF6cCI6IjExNDYwMTcwNjIyMjQyODYwNDMwMyIsImVtYWlsIjoidG90by1wdWJzdWJAdG90b2V4cGVyaW1lbnRzLmlhbS5nc2VydmljZWFjY291bnQuY29tIiwiZW1haWxfdmVyaWZpZWQiOnRydWUsImV4cCI6MTc2MTgxMjQ5MSwiaWF0IjoxNzYxODA4ODkxLCJpc3MiOiJodHRwczovL2FjY291bnRzLmdvb2dsZS5jb20iLCJzdWIiOiIxMTQ2MDE3MDYyMjI0Mjg2MDQzMDMifQ.WAcnNo6Ec1OvUceBtUu_1snRSnY8Zqsp2elpjbdEOx7Ue21lI4fRuPjZna7XcbXT1ZzXyJZUkJlIIpDSjaxntIM9bBJJ2vGBVw8ZRSDq7JemWLBnyO3-ecTVtVfG8cpjRLJ3VYfZdPlX8taXt4zlvn6oVlQcLQ02CVb_ZolGUQTJ_zGjxChnBHg6zLwIDkxmCDz8r1IYdPPn0A8BvAgnkXQslMjlRS614vh7d1udc4ARL8Ix9txpQT5rSD3gpa-UhoVA1TAp26LUn1tSKsKOlpQF8IX4LsFLcSCFTPnf-W4ZVkl_79OX0ZwEsJ6Gsm78vMqQeR_ayRX77Gxa4oyXpA";

    const result = decodeJWT(authHeader);

    expect(result.iss).to.equal("https://accounts.google.com");
    expect(result.email).to.equal("toto-pubsub@totoexperiments.iam.gserviceaccount.com");
    expect(result.aud).to.equal("toto-890d8s90a");
    expect(result.exp).to.equal(1761812491);
    expect(result.iat).to.equal(1761808891);
    
  });

  it('should decode JWT token with authProvider field', () => {
    const payload = { 
      sub: "user123", 
      authProvider: "custom",
      email: "test@example.com"
    };
    const token = createMockJWT(payload);
    const authHeader = `Bearer ${token}`;
    
    const result = decodeJWT(authHeader);
    
    expect(result.authProvider).to.equal("custom");
    expect(result.email).to.equal("test@example.com");
  });

  it('should decode JWT token with Google issuer', () => {
    const payload = { 
      iss: "accounts.google.com",
      sub: "google-user-id",
      email: "user@gmail.com"
    };
    const token = createMockJWT(payload);
    const authHeader = `Bearer ${token}`;
    
    const result = decodeJWT(authHeader);
    
    expect(result.iss).to.equal("accounts.google.com");
    expect(result.email).to.equal("user@gmail.com");
  });

  it('should throw error for malformed JWT token', () => {
    const authHeader = "Bearer invalid.token";
    
    expect(() => decodeJWT(authHeader)).to.throw();
  });

  it('should throw error for JWT with invalid base64 payload', () => {
    const authHeader = "Bearer header.invalid-base64.signature";
    
    expect(() => decodeJWT(authHeader)).to.throw();
  });

  it('should throw error for JWT with missing parts', () => {
    const authHeader = "Bearer onlyonepart";
    
    expect(() => decodeJWT(authHeader)).to.throw();
  });

  // Note: This test reveals a bug in the logic - should use && instead of ||
  it('should handle the current logic bug with null/undefined check', () => {
    const authHeader = "Bearer ";
    
    // Due to the OR condition bug, this will always try to decode
    expect(() => decodeJWT(authHeader)).to.throw();
  });
});

describe('Validator', () => {
  let validator: Validator;

  beforeEach(() => {
    validator = new LazyValidator();
  });

  describe('ValidationError', () => {
    it('should create ValidationError with code and message', () => {
      const error = new ValidationError(400, "Test error");
      
      expect(error.code).to.equal(400);
      expect(error.message).to.equal("Test error");
      expect(error.subcode).to.be.undefined;
    });

    it('should create ValidationError with subcode', () => {
      const error = new ValidationError(412, "Version error", "app-version-not-compatible");
      
      expect(error.code).to.equal(412);
      expect(error.message).to.equal("Version error");
      expect(error.subcode).to.equal("app-version-not-compatible");
    });
  });

  describe('LazyValidator', () => {
    it('should create a LazyValidator instance', () => {
      const lazyValidator = new LazyValidator();
      
      expect(lazyValidator).to.be.instanceOf(Validator);
      expect(lazyValidator.props).to.deep.equal({});
    });
  });
});