<?php
namespace LibRIS;

/**
 * Class for writing RIS data.
 *
 * General usage:
 * @code
 * <?php
 * use \LibRIS\RISWriter;
 *
 * $writer = new RISWriter();
 *
 * // Write an associative array of records to a string.
 * $str = $writer->writeRecords($records);
 * ?>
 * @endcode
 */
class RISWriter {

  public function __construct() {}

  /**
   * Write a series of records to a single RIS string.
   *
   * @param array $records
   *  An array in the format generated by RISReader::parseFile()
   * @retval string
   *  The record as a string.
   */
  public function writeRecords($records) {
    $buffer = array();
    foreach ($records as $record) {
      $buffer[] = $this->writeRecord($record);
    }
    return implode(RISReader::RIS_EOL, $buffer);
  }

  /**
   * Write a single record as an RIS string.
   *
   * The record should be an associative array of tags to values.
   *
   * @param array $tags
   *  An associative array of key => array(value1, value2,...).
   * @retval string
   *  The record as a string.
   */
  public function writeRecord($tags) {
    $buffer = array();
    $fmt = '%s  - %s';

	 $buffer[] = sprintf($fmt, 'TY', $tags['TY'][0]);
	 unset($tags['TY']);

    foreach ($tags as $tag => $values) {
      foreach ($values as $value) {
        $buffer[] = sprintf($fmt, $tag, $value);
      }
    }
    $buffer[] = 'ER  - ';

    return implode(RISReader::RIS_EOL, $buffer);
  }

}