<?php

$source = file_get_contents("readfile.json");
$target = sprintf("<?php\n\nreturn = %s", JSONToPHPArrayConverter::convert($source));

file_put_contents("output.php", $target);

class JSONToPHPArrayConverter
{
  /**
   * @param string $json
   * @return string
   * @throws \Exception - When string cannot be decoded to a PHP array due to invalid JSON
   */
  public static function convert($json)
  {
    $array = json_decode($json, true);

    if (is_null($array)) {
      throw new \Exception('Invalid JSON');
    }

    return self::arrayToPHPSyntax($array);
  }

  /**
   * @param array $array
   * @return string
   */
  private static function arrayToPHPSyntax(array $array)
  {
    $string = '[' . PHP_EOL;

    foreach ($array as $key => $value) {
      if (is_string($key)) {
        $string .= '  ' . var_export($key, true) . ' => ';
      }

      if (is_array($value)) {
        $string .= self::indent(self::arrayToPHPSyntax($value)) . ',' . PHP_EOL;
        continue;
      }

      $string .= var_export($value, true) . ',' . PHP_EOL;
    }

    $string .= ']';

    return $string;
  }

  /**
   * @param string $string
   * @return string
   */
  private static function indent($string)
  {
    $lines = explode(PHP_EOL, $string);

    $stringIndented = $lines[0] . PHP_EOL;
    $lineCount = count($lines);
    for ($i = 1; $i < $lineCount - 1; $i++) {
      $stringIndented .= '  ' . $lines[ $i ] . PHP_EOL;
    }
    $stringIndented .= '  ' . $lines[ $lineCount - 1 ];

    return $stringIndented;
  }
}