<?php
/**
* @file
*
*/

/**
*functions for the node tab.
*/

/**
* Implementation of hook_menu() for the node tab.
*/
function graphviz_noderef_menu() {
  $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;
}

/**
* options form for the node tab.
*/
function graphviz_noderef_page_form($form_state) {
  $options = drupal_map_assoc(range(0, 5));
//   $form['title'] = array(
//     '#type' => 'textfield',
//     '#title' => t('Graph title'),
//     '#default_value' => isset($_POST['title']) ? $_POST['title'] : "" ,
//     '#maxlength' => 64,
//     '#description' => t('title of the graph'),
//   );
  $form['recursion_depth'] = array(
    '#type' => 'select',
    '#title' => t('Recursion depth'),
    '#default_value' => isset($_POST['recursion_depth']) ? $_POST['recursion_depth'] : 1 ,
    '#options' => $options,
    '#description' => t('depth to continue searching. 0 only returns nodes 1 step away, 5 returns nodes up to 6 steps away'),
  );
  $options = array('dot' => 'dot','neato' => 'neato','fdp' => 'fdp','twopi' => 'twopi','circo' => 'circo');
  $form['command'] = array(
    '#type' => 'select',
    '#title' => t('Command'),
    '#default_value' => isset($_POST['command']) ? $_POST['command'] : "dot" ,
    '#options' => $options,
    '#description' => t('which graphviz command to use to render the graph.'),
  );
  $options = array('png'=> t("png"),'jpg' => t("jpg"),'gif' => t("gif"),'svg'=> t("svg"));
  $form['formats'] = array(
    '#type' => 'checkboxes',
    '#title' => t('Output Formats'),
    '#default_value' => isset($_POST['formats']) ? $_POST['formats'] : array('png') ,
    '#options' => $options,
    '#description' => t('Select which graphics output formats to render to.')
  );
  $form['imagemap'] = array(
    '#type' => 'checkbox',
    '#title' => t('Imagemap'),
    '#default_value' => isset($_POST['imagemap']) ? $_POST['imagemap'] : true ,
  );
  $form['graphoptions'] = array(
    '#type' => 'textfield',
    '#title' => t('Graph options'),
    '#default_value' => isset($_POST['graphoptions']) ? $_POST['graphoptions'] : "label=\"\", labelloc=\"t\", overlap=false, splines=true, sep=0.2" ,
    '#description' => t('Display options for the entire graph.'),
  );
  $form['nodeoptions'] = array(
    '#type' => 'textfield',
    '#title' => t('Graph title'),
    '#default_value' => isset($_POST['nodeoptions']) ? $_POST['nodeoptions'] : "fontsize=8.0, style=filled, fillcolor=\"#ffeedd\"" ,
    '#description' => t('Display options for nodes.'),
  );
  $form['edgeoptions'] = array(
    '#type' => 'textfield',
    '#title' => t('Graph title'),
    '#default_value' => isset($_POST['edgeoptions']) ? $_POST['edgeoptions'] : "color=\"lightblue\", penwidth=3, fontsize=8.0" ,
    '#description' => t('Display options for edges.'),
  );
  $form['submit'] = array('#type' => 'submit', '#value' => t('Save'));
  $form['#redirect'] = FALSE;
  return $form;
}

/**
* Page callback for node/%node/graph (See graphviz_noderef_menu()).
*/
function graphviz_noderef_page($node) {
$output = drupal_get_form('graphviz_noderef_page_form');

  $recursion_depth = isset($_POST['recursion_depth']) ? $_POST['recursion_depth'] : 1;
  $command = isset($_POST['command']) ? $_POST['command'] : "dot";
  $formats = isset($_POST['formats']) ? $_POST['formats'] : array('png');
  $imagemap = isset($_POST['imagemap']) ? "TRUE" : "FALSE" ;
//   $title= isset($_POST['title']) ? $_POST['title'] : "";
  $graph =isset($_POST['graphoptions']) ? $_POST['graphoptions'] : "label=\"\", labelloc=\"t\", overlap=false, splines=true, sep=0.2";
  $nodes =isset($_POST['nodeoptions']) ? $_POST['nodeoptions'] : "fontsize=8.0, style=filled, fillcolor=\"#ffeedd\"";
  $edges =isset($_POST['edgeoptions']) ? $_POST['edgeoptions'] : "color=\"lightblue\", penwidth=3, fontsize=8.0";
  $headers = array('command'=>$command,'formats'=>$formats,'imagemap'=>$imagemap, 'graph'=>$graph,'nodes'=>$nodes,'edges'=>$edges);

  $output .= graphviz_noderef_render($node, $recursion_depth, $headers);
  return $output;
}

/**
* Render the map!.
*/
function graphviz_noderef_render($node, $recursion_depth = 1, array $headers) {
  $tree = graphviz_noderef_get_ref_array((int)$node->nid,(int)$recursion_depth);
  $tree[2][(int)$node->nid]['target'] = true;
  $dot = graphviz_noderef_data_to_dot($tree[0], $tree[2], $headers);
  $output =  graphviz_filter_process($dot);
//   $output =  "<pre>$dot</pre>" . $output ;
  return $output;
}

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

function graphviz_noderef_data_to_dot(array $ref_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
  $output .= graphviz_noderef_refs_to_dot($ref_array, $style);

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

  return $output;
}

/**
* ouptut the actual node-network data in dot format.
**/
function graphviz_noderef_refs_to_dot(array $ref_array, array $style = array()){
 //convert links array to dot format links
  $link_array = array();
  foreach ($ref_array as $link){
    if ($link['type'] == "nodereference") {
      $from = $link['nid'];
      $to = $link['ref'];
      $field_name = $link['field'];
    }
    elseif ($link['type'] == "nodereferrer"){
      $from = $link['ref'];
      $to = $link['nid'];
      $field_name =  $link['referrer'];
    }
    $action = str_replace(array("field_","_"),array(""," "), $field_name);
    $link_array[] .= "\t$from -> $to [ label = \"$action\" ];\n";
  }
  $output = join(array_unique($link_array));
  return $output;
}

/**
* print headers that tell graphviz_filter_process how to render the graph.
**/
function graphviz_noderef_headers_to_dot(array $options = array() ) {
  $defaults = array('command' => "dot", 'formats' => "png", 'imagemap' => true);
  $headers = array_merge($defaults,$options);
  
  foreach ($headers as $key => $value) {
    switch ($key) {
      case 'command':
	$command = $value;
	break;
      case 'formats':
	$formats = join($value);
	break;
      case 'imagemap':
	$imagemap = ($value == true) ? "true" : "false" ;
	break;
      case 'graph':
	$graph = $value;
	break;
      case 'nodes':
	$nodes = $value;
	break;
      case 'edges':
	$edges = $value;
	break;
    }
  }
  $output = <<<EOS
/*
* @command = $command
* @formats = $formats
* @imagemap = $imagemap
*/
digraph NodeRefMap {
\tgraph [ $graph ];
\tnode [ $nodes ];
\tedge [ $edges ];
EOS;
  return $output;
}

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

function graphviz_noderef_get_ref_array($nid, $recursion_depth = 2, array $checked_nodes = array()) {
// this function causes segfault when recursing from computed fields (perhaps other areas too?), probably stack overflow. Might be able to reduce stack by reducing arrays sent back?
//   ob_flush();
//   static $runCount=1; print $runCount++;
//   ob_flush();

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

  $node = node_load($nid);
  $node_data = array();
  //get all custom fields of type referrer/reference from node.
  list($node_ref_links, $nids_to_check) = graphviz_noderef_get_node_refs($node);

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

  //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'], $checked_nodes ) ) {
	//dprint_r( "Node ". $node_ref['ref'] . " has already been checked.");
      } else {
	//append results
// 	$recursion_results = array(array(),array());
	$recursion_results = graphviz_noderef_get_ref_array($node_ref['ref'], $recursion_depth, $checked_nodes);
	$return_array = array_merge($return_array,$node_ref_links, $recursion_results[0]);
	$checked_nodes = $checked_nodes + $recursion_results[1];
	$node_data = $node_data + $recursion_results[2] ;
      }
    }
  } else {
    //if we've finished recursing, we still need to check the last nodes for title, url, etc.
    $return_array = array_merge($return_array,$node_ref_links);
    foreach ($nids_to_check as $nid) {
      if ( !in_array($nid, array_keys($node_data) ) ) {
	$node = node_load($nid);
	$node_data["$nid"] = array ( 'title' => $node->title, 'type' => $node->type, 'depth' => $recursion_depth );
	$node_data["$nid"]['count'] = 1;
      }
    }
  }
  return array( $return_array, $checked_nodes, $node_data );
}

/**
* Get all the references to/from given node.
* returns array of references and array of nids
*
* @param $node 
*   Node object produced by node_load()
*/
function graphviz_noderef_get_node_refs($node){
  
  //initialise arrays
  $references = array();
  $referrers = array();
  $fields = array();
  $nids_to_check = array();
  $fields = graphviz_noderef_get_ref_fields();

//loop over all possible reference/referrer fields, and add any that exist to apporopriate array
  foreach($fields as $field) {
    $field_name = $field['name'];
    if (isset($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' => $node->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) {
	  $nids_to_check[] = $referrer['nid'];
	  foreach ($referrer['referrers'] as $referrername) {
	    $referrers[] = array('nid' => $node->nid, 'type' => $field['type'], 'field' => $field_name, 'ref' => (int)$referrer['nid'], 'referrer' => $referrername);
	  }
	}
      }
      else {
      return "Error: \$field['name'] is bad: " . $field['name'];
      }
    }
  }

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

/**
* Get all nodereferer and nodereference fields
*/
function graphviz_noderef_get_ref_fields(){
  $fields = array();
  $result_fields = db_query( "SELECT field_name, type FROM {content_node_field} WHERE type = '%s' OR  type = '%s' " , "nodereference", "nodereferrer");
  while ($row = db_fetch_object($result_fields)) {
    $fields[] = array('name' => $row->{"field_name"}, 'type' =>$row->{"type"});
  }
  return $fields;
}