<?php
// $Id: gmap_tracks.module,v 1.3 2008-09-30 21:19:08 bdragon Exp $

/**
 * @file
 * Track overlays for GMap.
 */

/**
 * Implementation of hook_gmap().
 */
function gmap_tracks_gmap($op, &$map = NULL) {
  switch ($op) {
    case 'macro_multiple':
      return array('track');
    case 'parse_macro':
      if (isset($map['track']) && is_array($map['track'])) {
        foreach ($map['track'] as $track) {
          $t = array();
          $cp = strpos($track, ':');
          if ($cp != false) {
            $stylestr = substr($track, 0, $cp);
            $t['style'] = _gmap_parse_style($stylestr);
            $t['filename'] = substr($track, $cp+1);
            $map['tracks'][] = $t;
          }
        }
      }
      unset ($map['track']);
      break;

    case 'pre_theme_map':
      if (!empty($map['tracks'])) {
        // Ensure the shapeloader is loaded.
        drupal_add_js(drupal_get_path('module', 'gmap') .'/js/shapeloader_static.js');
        drupal_add_js(drupal_get_path('module', 'gmap') .'/js/gmap_shapes.js');

        // Convert tracks to shapes.
        foreach ($map['tracks'] as $track) {
          $s = array('type' => 'line');
          $s['style'] = $track['style'];
          $s['points'] = _gmap_tracks_parse($track['filename']);
          $map['shapes'][] = $s;
        }
        unset ($map['tracks']);
      }
      break;
  }
}

/**
 * Parse a plt file into coordinates.
 */
function _gmap_tracks_parse($track) {
  $points = array();
  $file = file_create_path($track);
  if ($file === FALSE) {
    drupal_set_message(t('Invalid path to track file!'));
  }
  else if (!file_exists($file)) {
    drupal_set_message(t('Track file not found!'));
  }
  else {
    // @@@ Oversimplified OziExplorer PLT parser.
    // @@@ This needs improvement for various file types.
    if ($handle = fopen($file, 'r')) {
      while (!feof($handle)) {
        $line = fgets($handle, 4096);
        $line = explode(',', $line);
        if (count($line) == 7) {
          $points[] = array(
            (float)trim($line[0]), // latitude
            (float)trim($line[1]), // longitude
          );
        }
      }
      fclose($handle);
    }
  }
  return $points;
}