<?php
/*
 +--------------------------------------------------------------------+
 | Copyright CiviCRM LLC. All rights reserved.                        |
 |                                                                    |
 | This work is published under the GNU AGPLv3 license with some      |
 | permitted exceptions and without any warranty. For full license    |
 | and copyright information, see https://civicrm.org/licensing       |
 +--------------------------------------------------------------------+
 */

/**
 *
 * @package CRM
 * @copyright CiviCRM LLC https://civicrm.org/licensing
 */
class CRM_Import_DataSource_CSV extends CRM_Import_DataSource {
  const
    NUM_ROWS_TO_INSERT = 100;

  /**
   * Provides information about the data source.
   *
   * @return array
   *   collection of info about this data source
   */
  public function getInfo() {
    return ['title' => ts('Comma-Separated Values (CSV)')];
  }

  /**
   * Set variables up before form is built.
   *
   * @param CRM_Core_Form $form
   */
  public function preProcess(&$form) {
  }

  /**
   * This is function is called by the form object to get the DataSource's form snippet.
   *
   * It should add all fields necessary to get the data
   * uploaded to the temporary table in the DB.
   *
   * @param CRM_Core_Form $form
   *
   * @throws \CRM_Core_Exception
   */
  public function buildQuickForm(&$form) {
    $form->add('hidden', 'hidden_dataSource', 'CRM_Import_DataSource_CSV');

    $config = CRM_Core_Config::singleton();

    $uploadFileSize = CRM_Utils_Number::formatUnitSize($config->maxFileSize . 'm', TRUE);
    //Fetch uploadFileSize from php_ini when $config->maxFileSize is set to "no limit".
    if (empty($uploadFileSize)) {
      $uploadFileSize = CRM_Utils_Number::formatUnitSize(ini_get('upload_max_filesize'), TRUE);
    }
    $uploadSize = round(($uploadFileSize / (1024 * 1024)), 2);
    $form->assign('uploadSize', $uploadSize);
    $form->add('File', 'uploadFile', ts('Import Data File'), NULL, TRUE);
    $form->setMaxFileSize($uploadFileSize);
    $form->addRule('uploadFile', ts('File size should be less than %1 MBytes (%2 bytes)', [
      1 => $uploadSize,
      2 => $uploadFileSize,
    ]), 'maxfilesize', $uploadFileSize);
    $form->addRule('uploadFile', ts('Input file must be in CSV format'), 'utf8File');
    $form->addRule('uploadFile', ts('A valid file must be uploaded.'), 'uploadedfile');

    $form->addElement('checkbox', 'skipColumnHeader', ts('First row contains column headers'));
  }

  /**
   * Process the form submission.
   *
   * @param array $params
   * @param string $db
   * @param \CRM_Core_Form $form
   *
   * @throws \CRM_Core_Exception
   */
  public function postProcess(&$params, &$db, &$form) {
    $file = $params['uploadFile']['name'];
    $result = self::_CsvToTable($db,
      $file,
      CRM_Utils_Array::value('skipColumnHeader', $params, FALSE),
      CRM_Utils_Array::value('import_table_name', $params),
      CRM_Utils_Array::value('fieldSeparator', $params, ',')
    );

    $form->set('originalColHeader', CRM_Utils_Array::value('original_col_header', $result));

    $table = $result['import_table_name'];
    $importJob = new CRM_Contact_Import_ImportJob($table);
    $form->set('importTableName', $importJob->getTableName());
  }

  /**
   * Create a table that matches the CSV file and populate it with the file's contents
   *
   * @param object $db
   *   Handle to the database connection.
   * @param string $file
   *   File name to load.
   * @param bool $headers
   *   Whether the first row contains headers.
   * @param string $tableName
   *   Name of table from which data imported.
   * @param string $fieldSeparator
   *   Character that separates the various columns in the file.
   *
   * @return array
   *   name of the created table
   * @throws \CRM_Core_Exception
   */
  private static function _CsvToTable(
    &$db,
    $file,
    $headers = FALSE,
    $tableName = NULL,
    $fieldSeparator = ','
  ) {
    $result = [];
    $fd = fopen($file, 'r');
    if (!$fd) {
      throw new CRM_Core_Exception("Could not read $file");
    }
    if (filesize($file) == 0) {
      throw new CRM_Core_Exception("$file is empty. Please upload a valid file.");
    }

    // support tab separated
    if (strtolower($fieldSeparator) === 'tab' ||
      strtolower($fieldSeparator) === '\t'
    ) {
      $fieldSeparator = "\t";
    }

    $firstrow = fgetcsv($fd, 0, $fieldSeparator);

    // create the column names from the CSV header or as col_0, col_1, etc.
    if ($headers) {
      //need to get original headers.
      $result['original_col_header'] = $firstrow;

      $strtolower = function_exists('mb_strtolower') ? 'mb_strtolower' : 'strtolower';
      $columns = array_map($strtolower, $firstrow);
      $columns = str_replace(' ', '_', $columns);
      $columns = preg_replace('/[^a-z_]/', '', $columns);

      // need to take care of null as well as duplicate col names.
      $duplicateColName = FALSE;
      if (count($columns) != count(array_unique($columns))) {
        $duplicateColName = TRUE;
      }

      // need to truncate values per mysql field name length limits
      // mysql allows 64, but we need to account for appending colKey
      // CRM-9079
      foreach ($columns as $colKey => & $colName) {
        if (strlen($colName) > 58) {
          $colName = substr($colName, 0, 58);
        }
      }

      if (in_array('', $columns) || $duplicateColName) {
        foreach ($columns as $colKey => & $colName) {
          if (!$colName) {
            $colName = "col_$colKey";
          }
          elseif ($duplicateColName) {
            $colName .= "_$colKey";
          }
        }
      }

      // CRM-4881: we need to quote column names, as they may be MySQL reserved words
      foreach ($columns as & $column) {
        $column = "`$column`";
      }
    }
    else {
      $columns = [];
      foreach ($firstrow as $i => $_) {
        $columns[] = "col_$i";
      }
    }

    if ($tableName) {
      CRM_Core_DAO::executeQuery("DROP TABLE IF EXISTS $tableName");
    }
    $table = CRM_Utils_SQL_TempTable::build()->setDurable();
    $tableName = $table->getName();
    CRM_Core_DAO::executeQuery("DROP TABLE IF EXISTS $tableName");
    $table->createWithColumns(implode(' text, ', $columns) . ' text');

    $numColumns = count($columns);

    // the proper approach, but some MySQL installs do not have this enabled
    // $load = "LOAD DATA LOCAL INFILE '$file' INTO TABLE $table FIELDS TERMINATED BY '$fieldSeparator' OPTIONALLY ENCLOSED BY '\"'";
    // if ($headers) {   $load .= ' IGNORE 1 LINES'; }
    // $db->query($load);

    // parse the CSV line by line and build one big INSERT (while MySQL-escaping the CSV contents)
    if (!$headers) {
      rewind($fd);
    }

    $sql = NULL;
    $first = TRUE;
    $count = 0;
    while ($row = fgetcsv($fd, 0, $fieldSeparator)) {
      // skip rows that dont match column count, else we get a sql error
      if (count($row) != $numColumns) {
        continue;
      }

      if (!$first) {
        $sql .= ', ';
      }

      $first = FALSE;

      // CRM-17859 Trim non-breaking spaces from columns.
      $row = array_map(
        function($string) {
          return trim($string, chr(0xC2) . chr(0xA0));
        }, $row);
      $row = array_map(['CRM_Core_DAO', 'escapeString'], $row);
      $sql .= "('" . implode("', '", $row) . "')";
      $count++;

      if ($count >= self::NUM_ROWS_TO_INSERT && !empty($sql)) {
        CRM_Core_DAO::executeQuery("INSERT IGNORE INTO $tableName VALUES $sql");

        $sql = NULL;
        $first = TRUE;
        $count = 0;
      }
    }

    if (!empty($sql)) {
      CRM_Core_DAO::executeQuery("INSERT IGNORE INTO $tableName VALUES $sql");
    }

    fclose($fd);

    //get the import tmp table name.
    $result['import_table_name'] = $tableName;

    return $result;
  }

}
