<?php

$semaphore = sem_get(1);

if (false !== sem_acquire($semaphore, 1)) {

  require_once('config.php');
  require_once('library/mysql.php');
  require_once('library/api.php');
  require_once('library/hash.php');
  require_once('library/base58.php');
  require_once('library/base58check.php');
  require_once('library/crypto.php');
  require_once('library/helper.php');

  $db  = new MySQL();
  $api = new API();

  $blockLast  = $db->getLastBlock();
  $blockTotal = $api->getblockcount();

  if (!$blockTotal) {
    echo "API connection error.\n";
    exit;
  }

  $response = [];

  if (CRAWLER_DEBUG) {
    echo "scanning blockhain...\n";
  }

  for ($blockCurrent = ($blockLast + 1); $blockCurrent <= $blockLast + STEP_BLOCK_LIMIT; $blockCurrent++) {

    if ($blockCurrent > $blockTotal) {

      if (CRAWLER_DEBUG) {
        echo "database is up to date.\n";
      }

      break;
    }

    if (CRAWLER_DEBUG) {
      echo sprintf("reading block %s\n", $blockCurrent);
    }

    if (!$blockHash = $api->getblockhash($blockCurrent)) {

      if (CRAWLER_DEBUG) {
        echo "could not read the block hash. waiting for reconnect.\n";
      }

      break;
    }

    if (!$blockData = $api->getblock($blockHash)) {

      if (CRAWLER_DEBUG) {
        echo "could not read the block data. waiting for reconnect.\n";
      }

      break;
    }

    if (!$blockId = $db->getBlock($blockCurrent)) {
         $blockId = $db->addBlock($blockCurrent);

         if (CRAWLER_DEBUG) {
           echo sprintf("add block %s\n", $blockCurrent);
         }
    }

    $lostTransactions = 0;

    foreach ($blockData['tx'] as $transaction) {

      if (!$transactionRaw = $api->getrawtransaction($transaction)) {

        $lostTransactions++;

        $db->setLostTransactions($blockId, $lostTransactions);

        if (CRAWLER_DEBUG) {
          echo sprintf("could not read the transaction %s. skipped.\n", $transaction);
        }

        break;
      }

      foreach($transactionRaw['vout'] as $vout) {

        $asmArray = explode(' ', $vout['scriptPubKey']['asm']);

        if (in_array($asmArray[0], ['OP_KEVA_NAMESPACE', 'OP_KEVA_PUT', 'OP_KEVA_DELETE'])) {

          $hash = Base58Check::encode($asmArray[1], false , 0 , false);

          switch ($asmArray[0]) {

            case 'OP_KEVA_DELETE':

              $key   = filterString(decodeString($asmArray[2]));
              $value = '';

            break;

            case 'OP_KEVA_NAMESPACE':

              $key   = '_KEVA_NS_';
              $value = filterString(decodeString($asmArray[2]));

            break;

            default:

              $key   = filterString(decodeString($asmArray[2]));
              $value = filterString(decodeString($asmArray[3]));
          }

          if (!$nameSpaceId = $db->getNameSpace($hash)) {
               $nameSpaceId = $db->addNameSpace($hash);

               if (CRAWLER_DEBUG) {
                 echo sprintf("add namespace %s\n", $hash);
               }
          }

          if (!$dataId = $db->getData($transactionRaw['txid'])) {
               $dataId = $db->addData($blockId,
                                      $nameSpaceId,
                                      $transactionRaw['time'],
                                      $transactionRaw['size'],
                                      $transactionRaw['txid'],
                                      $key,
                                      $value,
                                      ($key == '_KEVA_NS_'),
                                      empty($value));

            if ($value) {

              $db->setDataKeyDeleted($nameSpaceId, $key, false);

              if (CRAWLER_DEBUG) {
                echo sprintf("add new key/value %s\n", $transactionRaw['txid']);
              }

            } else {

              $db->setDataKeyDeleted($nameSpaceId, $key, true);

              if (CRAWLER_DEBUG) {
                echo sprintf("delete key %s from namespace %s\n", $key, $hash);
              }
            }
          }

          if (CRAWLER_DEBUG) {
            $response[] = [
              'blocktotal'=> $blockTotal,
              'block'     => $blockCurrent,
              'blockhash' => $transactionRaw['blockhash'],
              'txid'      => $transactionRaw['txid'],
              'version'   => $transactionRaw['version'],
              'size'      => $transactionRaw['size'],
              'time'      => $transactionRaw['time'],
              'blocktime' => $transactionRaw['blocktime'],
              'namehash'  => $hash,
              'key'       => $key,
              'value'     => $value
            ];
          }
        }
      }
    }
  }


  // Debug
  if (CRAWLER_DEBUG) {
    echo "scanning completed.\n";
    # print_r($response);
  }

  sem_release($semaphore);

} else {
  echo "database locked by the another process...\n";
}