/* This program uses an iterator to enumerate the keys inside a JSON object.
   For each key, it prints:
     - The key and val, if the val is a number or string.
     - The key and val size if the val is an object or array.
 */
   
#include "nlohmann/json.hpp"
#include <iostream>
using namespace std;
using nlohmann::json;

int main()
{
  json js;
  json::const_iterator jit;

  /* Read the json from standard input. */

  cin >> js;
  
  /* If it's not an object, print an error message and exit. */

  if (!js.is_object()) {
    cout << "Not a JSON object: " << js << endl;
    return 0;
  } 

  /* Otherwise, run through the keys with an iterator and print them. */

  for (jit = js.begin(); jit != js.end(); jit++) {
    printf("Key: %-10s ", jit.key().c_str());
    if (jit.value().is_string() || jit.value().is_number()) {
      cout << "Value: " << jit.value() << endl;
    } else if (jit.value().is_object() || jit.value().is_array()) {
      cout << "Size: " << jit.value().size() << endl;
    } else {
      cout << "Unknown value type.\n";
    }
  }
  return 0;
}