<?php

/**
* @file
*
*/

function graphviz_noderef_menu() {
  // This is the minimum information you can provide for a menu item.
  $items['node/%node/graph'] = array(
    'title' => 'Nodereference graph',
    'page callback' => 'graphviz_noderef_page',
    'page arguments' => array(1),
    'access arguments' => array('access Graphviz Noderef display'),
    'type' => MENU_LOCAL_TASK,
  );
  return $items;
}

function graphviz_noderef_page($node) {
  $tree = graphviz_noderef_get_ref_array((int)$node->nid, 0);
  $dot = graphviz_noderef_ref_array_to_dot($tree[0], $tree[1]);
  $output =  graphviz_filter_process($dot);
  return $output;
}

/**
* Custom functions for gathering and formatting data.
*
**/

function graphviz_noderef_ref_array_to_dot(array $flat_array, array $parameters = array(), array $headers = array(), array $style = array()) {
  
  //initialize output
  $output = "";

  //print headers
  $output .= graphviz_noderef_headers_to_dot($headers);

  //convert the parameters to dot format.
  $output .= graphviz_noderef_params_to_dot($parameters);

  //convert links array to dot format links
  $link_array = array();
  foreach ($flat_array as $link){
    $nid =  $link['nid'];
    $ref = $link['ref'];
    if ($link['type'] == "nodereference") {
      $action = str_replace(array("field_","_"),array(""," "), $link['field']);
      $link_array[] .= "\t$nid -> $ref [ label = \"$action\" ];\n";
    }
    elseif ($link['type'] == "nodereferrer"){
      $action = str_replace(array("field_","_"),array(""," "), $link['referrer']);
      $link_array[] .= "\t$ref -> $nid [ label = \"$action\" ];\n";
    }
  }
  $output .= join(array_unique($link_array));

  //print end
  $output .="};";

  return $output;

}

function graphviz_noderef_headers_to_dot(array $options = array() ) {
  $defaults = array('command' => "dot", 'formats' => "png", 'imagemap' => true);
  $headers = array_merge($options,$defaults);
  
  $output = "/*\n";
  foreach ($headers as $key => $value) {
    switch ($key) {
      case 'command':
	$output .= "* @command = $value\n";
	break;
      case 'formats':
	$output .= "* @formats = $value\n";
	break;
      case 'imagemap':
	$output .= "* @imagemap = " . ( ($value == true) ? "true" : "false" ) . "\n";
	break;
    }
  }
  $output .= "*/\ndigraph NodeRefMap {\n";
  $output .= "\tgraph [];\n";
  $output .= "\tnode [ fontsize=10.0];\n";
  $output .= "\tedge [ color=\"lightgrey\", penwidth=3, fontsize=9.0];\n";
  return $output;
}

function graphviz_noderef_params_to_dot(array $parameters = array()) {
  $output = "";
  foreach ($parameters as $nid => $data) {
    $shape = ($data['type'] == "organisation") ? "box" : "ellipse";
    $url = "node/". $nid;
    $output .= "\t$nid [ shape = \"$shape\" label = \"". $data['title'] . "\" URL = \"/drupal6/node/". $nid."\" ];\n";
  }
  return $output;
}

function graphviz_noderef_get_ref_array($nid, $recursion_depth = 2, array $checked_nodes = array()) {
  
  // don't be stupid - first two arguments must be int >= 1
  if ( !is_int($nid) ) {
    return "Error: your nid argument is not an integer";}
  if ($nid <= 0 ) {
    return "Error: your nid argument is $nid";}
  if ( !is_int($recursion_depth) ) {
    return "Error: Your recursion depth is not an integer.";}
  if ( $recursion_depth < 0 ) {
    return "Error: Your recursion depth is less than 0";}
  if ( in_array( $nid , array_keys($checked_nodes) ) ) {
    return "Node $nid has already been checked";
  }

  $node = node_load($nid);
  //initialise arrays
  $references = array();
  $referrers = array();
  $fields = array();
  $nids_to_check = array();

  //get all custom fields of type referrer/reference
  $result_fields = db_query( "SELECT field_name, type FROM {content_node_field} WHERE type = '%s' OR  type = '%s' " , "nodereference", "nodereferrer");
  while ($row = db_fetch_object($result_fields)) {
    $fields[] = array('name' => $row->{"field_name"}, 'type' =>$row->{"type"});
  }

  //loop over all possible reference/referrer fields, and add any that exist to apporopriate array
  foreach($fields as $field) {
    $field_name = $field['name'];
    if (is_array($node->$field_name) && count($node->$field_name) > 0){
      if ($field['type'] == "nodereference") {
	foreach ($node->$field_name as $reference){
	  if  ( (int)($reference['nid']) != 0 ) {
	    $references[] = array('nid' => $nid, 'type' => $field['type'], 'field' => $field_name, 'ref'  => (int)($reference['nid']) );
	    $nids_to_check[] = $reference['nid'];
	  }
	}
      } 
      elseif ($field['type'] == "nodereferrer"){
	$ref_field = $node->$field_name;
	foreach ($ref_field[0]['items'] as $referrer) {
	  $referrers[] = array('nid' => $nid, 
				'type' => $field['type'],
				'field' => $field_name,
				'ref' => (int)$referrer['nid'],
				'referrer' => $referrer['referrer']);
	  $nids_to_check[] = $referrer['nid'];
	}
      }
      else {
      return "Error: \$field['name'] is bad: " . $field['name'];
      }
    }
  }
  

  //stick $references and referrers in array together
  $node_ref_links = array_merge($references, $referrers);
//   dprint_r($node_ref_links);

  //add checked node to array to pass
  if ( !in_array($nid, array_keys($checked_nodes))){
    $checked_nodes["$nid"] = array ( 'title' => $node->title, 'type' => $node->type, 'name' => $node->title, 'depth' => $recursion_depth );
    $checked_nodes["$nid"]['count'] = 1;
  } else {
    $checked_nodes["$nid"]['count'] += 1;
  }
  //reduce recursion depth
  $recursion_depth -= 1;

  //initialise $return_array
  $return_array = array();

  //RECURSE - need to check checked_nodes!
  //only if recursion level still high enough
  if ($recursion_depth >= 0 ) {
    foreach ($node_ref_links as $node_ref) {
      //make sure that node hasn't already been checked.
      if ( in_array( $node_ref['ref'], array_keys($checked_nodes) ) ) {
	//dprint_r( "Node ". $node_ref['ref'] . " has already been checked.");
      } else {
	//append results
	$recursion_results = graphviz_noderef_get_ref_array($node_ref['ref'], $recursion_depth, $checked_nodes);
	$return_array = array_merge($node_ref_links, $recursion_results[0]);
	$checked_nodes = $checked_nodes + $recursion_results[1] ;
      }
    }
  } else {
    //if we've finished recursing, we still need to check the last nodes for title, url, etc.
    $return_array = $node_ref_links;
    foreach ($nids_to_check as $nid) {
      if ( !in_array($nid, array_keys($checked_nodes) ) ) {
	$node = node_load($nid);
	$checked_nodes["$nid"] = array ( 'title' => $node->title,
	  'type' => $node->type,
	  'name' => $node->title,
	  'depth' => $recursion_depth );
	$checked_nodes["$nid"]['count'] = 1;
      }
    }
  }
  
  return array( $return_array, $checked_nodes );
}