class Config {
  private config: Record<string, any>;
  private cache: Record<string, any>;

  constructor(config: Record<string, any>) {
    this.config = config;
    this.cache = {};
  }

  getConfig() {
    const getConfigRecursive = (target: Record<string, any>, path: string[]) => {
      return new Proxy(target, {
        get: (currentTarget, property) => {
          const newPath = [...path, property.toString()];
          const fullPath = newPath.join('.');

          if (fullPath in this.cache) {
            console.log(`Getting ${fullPath} from cache`);
            return this.cache[fullPath];
          }

          if (typeof currentTarget[property] === 'object') {
            return getConfigRecursive(currentTarget[property], newPath);
          }

          console.log(`Getting ${fullPath} from config`);
          const value = currentTarget[property];
          this.cache[fullPath] = value;
          return value;
        },
        set: (currentTarget, property, value) => {
          const newPath = [...path, property.toString()];
          const fullPath = newPath.join('.');
          console.log(`Setting ${fullPath} in config`);
          currentTarget[property] = value;
          this.cache[fullPath] = value;
          return true;
        },
      });
    };

    return getConfigRecursive(this.config, []);
  }
}

const initialConfig = {
  apiUrl: 'https://example.com/api',
  apiKey: 'secret_key',
  nested: {
    nestedProperty: 'nested_value',
  },
};

const config = new Config(initialConfig).getConfig();

console.log(config.apiUrl); // Accessing apiUrl for the first time
console.log(config.nested.nestedProperty); // Accessing nestedProperty for the first time
console.log(config.apiUrl); // Accessing apiUrl from cache
console.log(config.nested.nestedProperty); // Accessing nestedProperty from cache
config.apiUrl = 'https://updated-api.com'; // Setting apiUrl in config
config.nested.nestedProperty = 'new_nested_value'; // Setting nestedProperty in config
console.log(config.apiUrl); // Accessing updated apiUrl from cache
console.log(config.nested.nestedProperty); // Accessing updated nestedProperty from cache