<?php
// $Id$

/*
 * @file
 * Visits an AST and inserts every identifier into the terms array.
 * The key will be the term, the value how many time it occurs in the AST of the query.
 */
class TqlNameToTid extends TqlNodeVisitor {

  public $terms = array();

  public $missingTerms = array();

  /*
   * Compute term-ids for all terms occuring in the AST.
   * The result is stored in $this->terns with the terms as keys and the term-ids as values.
   */
  function computeTermIDs($tqlAST, $vocabularyList) {
    $tqlAST->accept ($this);
    foreach ($this->terms as $term => &$ids) {
      $result = taxonomy_get_term_by_name($term);
      if (count($result) > 0) {
        $ids = array();
        foreach ($result as $termid) {
          if (is_null($vocabularyList) || in_array($termid->vid, $vocabularyList)) {
            array_push($ids, $termid->tid);
          }
        }
        if (count($ids) == 0) {
          // if $ids is set to null the code generator knows what to do.
          $ids = NULL;
          // add the not found term to the missing terms list (used for error reporting)
          $this->addToMissing($term);
        }
      }
      else {
        // the term was not found at all
        $this->addToMissing($term);
      }
    }
  }

  function addToMissing($term) {
    if (!in_array($term, $this->missingTerms)) {
      array_push($this->missingTerms, $term);
    }
  }

  /*
   * Visitor functions
   */

  function visitIdentifier($tqlIdentifier) {
    if (!isset($this->terms[$tqlIdentifier->value])) {
      $this->terms[$tqlIdentifier->value] = NULL;
    }
  }

  function visitUnaryOperation($tqlUnaryOperation) {
    // check for null as operand can be null in error case
    if ($tqlUnaryOperation->operand) {
      $tqlUnaryOperation->operand->accept($this);
    }
  }

  function visitBinaryOperation($tqlBinaryOperation) {
    $tqlBinaryOperation->left->accept($this);
    $tqlBinaryOperation->right->accept($this);
  }
}