<?php

/*

 * Copyright 2011 Nathan Gelderloos, Ethan Zonca, Nathan Phillip Brink

 *

 * This file is part of SlatePermutate.

 *

 * SlatePermutate is free software: you can redistribute it and/or modify

 * it under the terms of the GNU Affero General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * SlatePermutate is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU Affero General Public License for more details.

 *

 * You should have received a copy of the GNU Affero General Public License

 * along with SlatePermutate.  If not, see <http://www.gnu.org/licenses/>.

 */

/** Filter out whitepace items */

function umich_arrayfilter_callback($item){

    if(ltrim($item) == ''){

      return false;

    }

    else{

      return true;

    }

}

/** Parse html at URL into array, first row is row headers */

function umich_table_parse($url) {

  $arr = array();

  $dom = new DOMDocument;

  $html = file_get_contents($url);

  if(!$html){

    return 1;

  }

  $dom->loadHTML($html);

  $dom->preserveWhiteSpace = false;

  $tables = $dom->getElementsByTagName('table');

  $rows = $tables->item(3)->getElementsByTagName('tr'); // Get first table on page 

  foreach ($rows as $rownum => $row) {

    if($rownum > 5) {

      $cols = $row->getElementsByTagName('td');

      foreach($cols as $colnum => $col){

        $arr[$rownum][$colnum] = $col->nodeValue;

      }

    }

  }

  foreach($arr as &$item) {

    $item = array_filter($item, "umich_arrayfilter_callback");

  }

  $arr = array_values($arr); // Reindex array

  // Strip navigation and trailing garbage

  $arr[count($arr)-3] = NULL;

  $arr[count($arr)-2] = NULL;

  $arr[count($arr)-1] = NULL;

  $arr = array_filter($arr);

  return $arr;

}

/** Crawls uMich course listings. $season is "f" or "s", year is 2-digit year */

function umich_crawl($semester)

{

  $year = substr($semester->year_get(), 2);

  $season = strtolower(substr($semester->season_get(), 0, 1));

  /* Current academic departments. Update as needed. */

  $departments = array('AAPTIS','ACABS','AERO','AEROSP','AMCULT','ANTHRARC','ANTHRBIO','ANTHRCUL','AOSS','APPPHYS','ARCH','ARMENIAN','ARTDES','ASIAN','ASIANLAN','ASTRO','AUTO','BCS','BIOINF','BIOLCHEM','BIOLOGY','BIOMEDE','BIOPHYS','CAAS','CEE','CHE','CHEM','CIC','CICS','CJS','CLARCH','CLCIV','CMPLXSYS','COMM','COMP','COMPLIT','CSP','CZECH','DANCE','DUTCH','ECON','EDCURINS','EDUC','EEB','EECS','ELI','ENGLISH','ENGR','ENSCEN','ENVIRON','ESENG','FRENCH','GEOG','GEOSCI','GERMAN','GREEK','GTBOOKS','HBEHED','HISTART','HISTORY','HJCS','HMP','HONORS','INTMED','IOE','ITALIAN','JAZZ','JUDAIC','KINESLGY','LACS','LATIN','LHC','LHSP','LING','MACROMOL','MATH','MATSCIE','MCDB','MECHENG','MEDADM','MEDCHEM','MEMS','MENAS','MFG','MICROBIOL','MILSCI','MKT','MODGREEK','MOVESCI','MUSEUMS','MUSICOL','MUSMETH','MUSTHTRE','NAVARCH','NAVSCI','NERS','NEUROSCI','NRE','NURS','OMS','ORGSTUDY','PAT','PATH','PHARMACY','PHIL','PHRMACOL','PHYSICS','PHYSIOL','POLISH','POLSCI','PORTUG','PSYCH','PUBHLTH','PUBPOL','RCARTS','RCCORE','RCHUMS','RCIDIV','RCLANG','RCNSCI','RCSSCI','REEES','RELIGION','ROMLANG','ROMLING','RUSSIAN','SAC','SAS','SCAND','SEAS','SI','SLAVIC','SOC','SPANISH','STATS','STDABRD','SWC','TCHNCLCM','THEORY','THTREMUS','UC','UKRAINE','UP','WOMENSTD','YIDDISH');

  $basepath = "http://www.lsa.umich.edu/cg/cg_results.aspx";

  $yearsyn = 1800 + $year; // Weird year synonym name where 2000 == 1800

  $basepath .= "?termArray={$season}_{$year}_${yearsyn}&cgtype=ug";

  $season = strtolower($season);

  $tables = array();

  foreach($departments as $department) {

   $tables[$department] = umich_table_parse($basepath . '&department=' . $department . '&allsections=true&show=1000');

  }

  return $tables;

}