/*

 * Copyright 2010 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/>.

 */

$incdir = dirname(__FILE__) . DIRECTORY_SEPARATOR;

include_once $incdir . 'class.course.inc';

include_once $incdir . 'class.section.php';

include_once $incdir . 'class.page.php';

require_once $incdir . 'school.inc';

/*

 * Load a Classes -> Course converter class for the sake of the

 * Schedule::__wakeup() magic function.

 */

require_once $incdir . 'class.classes_convert.inc';

/**

 * \brief

 *   Finds possible Section combinations for a user's given Courses

 *   and stores and displays the results.

 *

 * Represents a schedule of a week. Stores the classes that are part

 * of that week and calculates all the possible permutations.

 */

class Schedule

{

  /*

   * Variables for upgrading from saved schedules created when there

   * was a class called Classes.

   */

  private $classStorage;			// array of courses

  private $nclasses;				// Integer number of classes

   *   Adds a new class to the schedule.

   *

   * \param $slot

   *   Currently, the Schedule class is not smart enough to understand

   *   CourseSlots. At a lower level, we split Courses with multiple

   *   CourseSlots into multiple Course objects with redundant

   *   information.

   */

  function addCourse($course_id, $title)

  {

    $this->courses[] = new Course($course_id, $title);

  }

  /**

   * \brief

   *   Adds a section to this semester after finding the class.

   *

   * \param $instructor

   *   The instructor of this section/section_meeting.

   *

   * \return

   *   NULL on success, a string on error which is a message for the

   *   user and a valid XHTML fragment.

   */

  {

    if (empty($letter) && (empty($time_start) || !strcmp($time_start, 'none')) && (empty($time_end) || !strcmp($time_end, 'none')) && empty($days)

	&& empty($synonym) && empty($instructor) && empty($location) && (empty($type) || !strcmp($type, 'lecture'))

	&& (empty($slot) || !strcmp($slot, 'default')))

      return;

    /* reject invalid times */

    if (!strcmp($time_start, 'none') || !strcmp($time_end, 'none')

	|| $time_start > $time_end)

      {

	return 'Invalid time specifications for ' . htmlentities($course_name) . '-' . htmlentities($letter)

	  . '. Start time: <tt>' . htmlentities($time_start) . '</tt>. End time: <tt>' . htmlentities($time_end) . '</tt>.';

      }

    foreach ($this->courses as $course)

      if (!strcmp($course_name, $course->getName()))

	{

	  $section = $course->section_get($letter);

	  if (!$section)

	    {

	      $course->section_add($section, $slot);

	    }

	  $section->meeting_add(new SectionMeeting($days, $time_start, $time_end, $location, $type, $instructor));

	  return;

	}

    error_log('Could not find class when parsing schedule from postData: ' . $course_name);

    echo 'Could not find class: ' . $course_name . "<br />\n";

  }

  /**

   * \brief

   *   Get the school associated with this schedule.

   *

   * \return

   *   The school associated with this schedule or some fallback.

   */

  public function school_get()

  {

    $school = NULL;

    if (!empty($this->school_id))

      /*

	. '        <p class="centeredtext graytext"><em>Keyboard Shortcut: Left and right arrow keys switch between schedules</em></p>' . PHP_EOL;

    }		

    echo "\n";

    if($this->nPermutations > 0)

      {

	/*

	 * Figure out if we have to deal with Saturday and then deal

	 * with it.

	 *

	 * Also, ensure that our $time array is big enough for all of

	 * these courses.

	 */

	$max_day_plusone = 5;

	$have_saturday = FALSE;

	$max_time = (int)max($time);

	$min_time = (int)min($time);

	$sort_time = FALSE;

	foreach ($this->courses as $course)

	  foreach ($course as $course_slot)

	  {

	    for ($si = 0; $si < $course_slot->sections_count(); $si ++)

		{

		  /* Saturdayness */

		  if ($meeting->getDay(5))

		    {

		      $max_day_plusone = 6;

		      $have_saturday = TRUE;

		    }

		  /* very late / very early classes */

		  while ((int)ltrim($meeting->getEndTime(), '0') > $max_time)

		    {

		      $max_time += $max_time + 30;

		      while ($max_time % 100 >= 60)

			$max_time += 40; /* + 100 - 60 */

		      $time[] = $max_time;

		    }

		  while ((int)ltrim($meeting->getStartTime(), '0') < $min_time)

		    {

		      $max_time += 30;

		      while ($min_time % 100 < 30)

			$min_time -= 40; /* + 60 - 100 */

		      $min_time -= 30;

		      $time[] = $min_time;

		      $sort_time = TRUE;

	  . '      <p class="regDialog-disclaimer graytext">' . PHP_EOL

	  . '        <em>' . PHP_EOL

	  . '          Note: The registration information above corresponds to the sections' . PHP_EOL

	  . '          displayed on the currently selected tab.' . PHP_EOL

	  . '        </em>' . PHP_EOL

	  . '      </p>' . PHP_EOL

	  . '      <p class="regDialog-disclaimer graytext">' . PHP_EOL

	  . '        <em>' . PHP_EOL

	  . '          Disclaimer: You are responsible for' . PHP_EOL

	  . '          double-checking the information you get from and input into slate_permutate' . PHP_EOL

	  . '          when registering for classes. There is no guarantee that the harvested' . PHP_EOL

	  . '          information is correct or that slate_permutate will handle' . PHP_EOL

	  . '          the information you enter correctly.' . PHP_EOL

	  . '        </em>' . PHP_EOL

	  . '      </p>' . PHP_EOL

	  . '    </div>' . PHP_EOL;

	echo '<div id="tabs">' . "\n" .

               '<div id="show-box" class="show-buttons">

                  <form action="#"><p class="nospace">

                    <label><strong>Display:</strong></label>

                    <input id="show-course-title" name="show-course-title" type="checkbox" /><label for="show-course-title">Course Title</label>

                    <input id="show-prof" name="show-prof" type="checkbox" checked="checked" /><label for="show-prof">Professor</label>

                    <input id="show-location" name="show-location" type="checkbox" /><label for="show-location">Room</label>

                    <input id="show-synonym" name="show-synonym" type="checkbox" /><label for="show-synonym">Synonym</label>

                    <span id="regCodes"><label><a href="#"><strong>Register for Classes</strong></a></label></span></p>

                  </form>

                </div> <!-- id="show-box" -->'

	     . '<div id="the-tabs"><ul>' . "\n";

	$suppressed_permutations = array();

	if (!empty($_REQUEST['print']))

	  {

	    $print = $_REQUEST['print'];

	    if ($print !== 'all')

	      {

		for ($i = $first_permutation; $i <= $last_permutation; $i ++)

		  $suppressed_permutations[$i] = TRUE;

		foreach (explode(',', $print) as $item_to_print)

		  unset($suppressed_permutations[((int)$item_to_print) - 1]);

	      }

	  }

	for($nn = $first_permutation + 1; $nn <= $last_permutation; $nn++)

	  {

	    if (!empty($suppressed_permutations[$nn - 1]))

	      continue;

	    echo  "<li><a href=\"#tabs-" . $nn . "\">&nbsp;" . $nn . "&nbsp;</a></li>\n";

	  }

	  echo '      <div id="pager-next" class="pager right"><a href="' . htmlentities($this->my_url($page + 1)) . '">Next &raquo;</a></div>' . "\n";

	echo "    </div> <!-- id=\"pagers\" -->\n";

	echo "  <div class=\"scroller\">\n"

	  . "    <div class=\"scontent\">\n";

	for($i = $first_permutation; $i < $last_permutation; $i++)

	  {

	    /*

	     * Skip suppressed permutations, such as when displaying a

	     * page for printing a particular permutation.

	     */

	    if (!empty($suppressed_permutations[$i]))

	      continue;

	    /*

	     * Store a JSON list of courses, each with only the one

	     * section rendered in this permutation. This is used for

	     * the ``Registration Numbers'' dialog which noramlly

	     * shows users course synonyms.

	     */

	    $permutation_courses = array();

	     echo  '      <div class="section" id="tabs-' . ($i+1) . "\">\n";

	    // Beginning of table

	    echo "        <table style=\"empty-cells:show;\" border=\"1\" cellspacing=\"0\">\n";

	    // Header row

	    echo "          <tr>\n"

	      . '            <td class="none permuteNum">' . ($i + 1) . "</td>\n"

	      . "            <td class=\"day\">Monday</td>\n"

	      . "            <td class=\"day\">Tuesday</td>\n"

	      . "            <td class=\"day\">Wednesday</td>\n"

	      . "            <td class=\"day\">Thursday</td>\n"

	      . "            <td class=\"day\">Friday</td>\n";

	    if ($have_saturday)

	      echo "            <td class=\"day\">Saturday</td>\n";

	    echo "          </tr>\n";

	    $last_meeting = array();

	    $rowspan = array(0, 0, 0, 0, 0, 0);

	    for($r = 0; $r < (count($time)-1); $r++)

	      {

		echo "          <tr>\n"

		  . "            <td class=\"time\">" . $this->prettyTime($time[$r]) . "</td>\n";

				    {

				      /* calculate how many rows this section should span */

				      for ($my_r = $r;

					   $my_r < (count($time)-1) && $current_meeting->getEndTime() > $time[$my_r];

					   $my_r ++)

					;

				      $rowspan[$dayLoop] = $my_r - $r;

				      $single_multi = 'single';

				      if ($rowspan[$dayLoop] > 1)

					$single_multi = 'multi';

				      $title = $course->title_get();

				      if (empty($title))

					$title = '';

				      else

					$title .= ' ';

				      $carret = '&#013;' . htmlentities("<br />");

				      echo '            <td rowspan="' . $rowspan[$dayLoop]

					. '" class="qTipCell ' . $single_multi . ' class' . $j

					. '" title="' . htmlentities($title, ENT_QUOTES) . $carret

					. 'Prof: ' . htmlentities($current_meeting->instructor_get(), ENT_QUOTES) . $carret

					. 'Room: ' . htmlentities($current_meeting->getLocation(), ENT_QUOTES) . $carret

					. '<span class="course-title block">' . htmlentities($title) . '</span>' . PHP_EOL

					. htmlentities($course->getName(), ENT_QUOTES) . '-'

					. htmlentities($section->getLetter(), ENT_QUOTES) . "\n"

					. '<span class="prof block">' . htmlentities($current_meeting->instructor_get(), ENT_QUOTES) . "</span>\n"

					. '<span class="location block">' . htmlentities($current_meeting->getLocation(), ENT_QUOTES) . "</span>\n"

					. '<span class="synonym block">' . htmlentities($section->getSynonym(), ENT_QUOTES) . "</span>\n"

					. "</td>\n";

				      /* for the ``Registration Codes'' dialogue: */

				      if (empty($permutations_courses[$j]))

					{

					  $singleton_course = new Course($course->getName(), $course->title_get());

					  $singleton_course->section_add($section, $course_slot->id_get());

					  $permutation_courses[$j] = $singleton_course->to_json_array();

					}

				      $filled = TRUE;

				    }

			    } /* $course_slot */

			}

		    }

		  if ($rowspan[$dayLoop] > 0)

		    {

		      $filled = TRUE;

		      $rowspan[$dayLoop] --;

		    }

		  /* If the cell was not filled, fill it with an empty cell. */

			if(!$filled)

			{

				echo "            <td class=\"none\">&nbsp;</td>\n";

			}

			$filled = FALSE;

		}

		// End of row

		echo "          </tr>\n";

	      }

	    // End of table

	      . '      </div> <!-- id="section' . ($i + 1) . "\" -->\n";

	  }

          echo "    </div> <!-- class=\"scontent\" -->\n"

	     . "  </div> <!-- class=\"scroller\" -->\n"

	     . "</div> <!-- id=\"my-glider\" -->\n"

	     . $footcloser; // Closes off the content div

      } else {

      echo '<html><body><p>There are no possible schedules. Please <a href="input.php?s='.$this->id.'">try again</a>.</p></body></html>';

    }

    echo '<p id="possiblestats">' . PHP_EOL

      . '  There were a total of ' . $this->possiblePermutations . ' possible permutations. Only ' . $this->nPermutations . ' permutations had no class conflicts.' . PHP_EOL

      . '</p>' . PHP_EOL;

    if ($this->created)

      echo ''

	. '<p id="created-time">' . PHP_EOL

	. '  Created <span class="cute-time">' . gmdate('c', $this->created) . '</span>.' . PHP_EOL

	. '</p>' . PHP_EOL;

    $outputPage->foot();

  }

  //--------------------------------------------------

 * 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/>.

 */

require_once dirname(__FILE__) . DIRECTORY_SEPARATOR . 'class.section_meeting.inc';

/**

 * \brief

 *   Represent a Section associated with a Course.

 */

class Section

{

  private $letter;	// Section letter

  private $prof;	// Professor, preserved for Section::__wakeup()

  /* meeting times, array of SectionMeeting */

  private $meetings;

  /* the section synonym which uniquely identifies this section/course combination */

  private $synonym;

  /**

   * \brief

   *   Construct a Section.

   *

   * \param $letter

   *   The identifier (often a letter or numeral) of this section. For

   *   CS-262-A, this would be 'a'.

   * \param $section_meetings

   *   An array of SectionMeeting objects which describe all the

   *   different types of meetings this particular section has. It

   *   will be very uncommon for a course to have more than one such

   *   meeting time for a section. For example, Calvin doesn't have

   *   this. Another example, Cedarville lists different meeting times

   *   inside of a single section. Cedarville also lists all lectures

   *   and lab meeting times directly in a section's listing.

   * \param $synonym

   *   Some schools have a unique number for each section. This field

   *   is for that number.

   */

  {

    $this->letter = $letter;

    $this->meetings = $section_meetings;

    $this->synonym = $synonym;

  }

  public function getLetter()

  {

    return $this->letter;

  }

  /**

   * \return

   *   This section's synonym -- a unique numeric identifier for this

   *   course. NULL if undefined.

   */

  public function getSynonym()

  {

    return $this->synonym;

  }

  /**

   * \brief

   *   Get an array of section meetings for this section.

   *

   * \return

   *   An array of SectionMeeting objects.

   */

  public function getMeetings()

  {

    return $this->meetings;

  }

  /**

   * \brief

   *   Check if this section conflicts with the given section.

   *

   * \param $that

   *   The other section for which I should check for conflicts.

   * \return

   *   TRUE if there is a conflict, FALSE otherwise.

   */

  public function conflictsWith(Section $that)

  {

    foreach ($this->meetings as $this_meeting)

      foreach ($that->meetings as $that_meeting)

      if ($this_meeting->conflictsWith($that_meeting))

	return TRUE;

    return FALSE;

  }

  /**

   * \brief

   *   Add another section meeting time to this section.

   *

   * Useful for process.php when it's calling

   * Schedule::addSectionMeeting() multiple times.

   */

     * these amazingly.

     */

    if (!preg_match(';([a-zA-Z0-9]+);', $section_spec, $section_matches))

      return $ret;

    $ret['section'] = strtoupper($section_matches[1]);

    return $ret;

  }

  /**

   * \brief

   *   Get arrays of information needed by the AJAX stuff.

   *

   * \return

   *   An array of arrays that should be merged with the return value

   *   of other Section::to_json_arrays() calls.

   */

  public function to_json_arrays()

  {

    $json_arrays = array();

    foreach ($this->meetings as $meeting)

      {

			    'synonym' => $this->synonym,

			    );

	$json_array += $meeting->to_json_array();

	$json_arrays[] = $json_array;

      }

    return $json_arrays;

  }

  /**

   * \brief

   *   Parse a set of JSON arrays into a Section.

   *

   * When this function was written, the JS frontend did not yet have

   * support for directly supporting sections +

   * section_meetings. Thus, multiple section meetings were simluated

   * by having multiple sections with the same section letter. Thus,

   * multiple ``sections'' of JSON are necessary to form together one

   * section.

   *

   * Thus, the caller must ensure that there is only one section in

   * the passed-in $json_arrays.

   *

   * \param $json_arrays

   *   The JSON array to be parsed into a Section.

   * \return

   *   A Section object.

   */

  public static function from_json_arrays(array $json_arrays)

  {

    $section_meetings = array();

    $letter = '';

    $synonym = NULL;

    foreach ($json_arrays as $meeting)

      {

	$letter = $meeting['section'];

	$synonym = $meeting['synonym'];

	$section_meetings[] = SectionMeeting::from_json_array($meeting);

      }

    return $section;

  }

  /* for legacy unserialization */

  private $start;

  private $tend;

  private $bdays;

  /**

   * \brief

   *   A magic function which tries to upgrade old serialized sections

   *   to the new format.

   */

  public function __wakeup()

  {

    /* upgrade to SectionMeeting stuffage */

    if (!empty($this->start))

      {

	$days = '';

	$daymap = array(0 => 'm', 1 => 't', 2 => 'w', 3 => 'h', 4 => 'f');

	foreach ($this->bdays as $day => $have_day)

	  if ($have_day)

	    $days .= $daymap[$day];

	/* the old format had a ->prof but initialied it to ``unknown prof'' */

	$this->prof = '';

	$this->meetings = array();

	$this->meeting_add(new SectionMeeting($days, $this->start, $this->tend, '', 'lecture', $this->prof));

	/*

	 * if we're reserialized in the future, make sure we don't do this same upgrade procedure again ;-).

	 */

	unset($this->start);

      }

    elseif (!empty($this->prof))

      {

	/* Move the instructor (old $this->prof) property to our SectionMeeting children */

	foreach ($this->meetings as $meeting)

	  $meeting->instructor_set($this->prof);

	unset($this->prof);

      }

  }

}

   *   Add a section_meeting, calling Semester::section_add() as

   *   necessary.

   *

   * To be used by crawlers when parsing data which only presents one

   * section_meeting at a time. I.e., when they do tabular data right.

   *

   * \param $dept

   *   The department this section_meeting's course belongs to.

   * \param $course

   *   The course number this section_meeting's section belongs to.

   * \param $title

   *   The course title of the given course the section_meeting or

   *   NULL.

   *   belongs to.

   * \param $section

   *   The letter or numbers which make up the section's name.

   * \param $synonym

   *   The section synonym or NULL.

   * \param $section_meeting

   *   The SectionMeeting to be added to a section which may or may

   *   not already be in this Semester.

   * \param $course_slot_id

   *   The name of the new CourseSlot to create if the given section

   *   does not yet exist.

   */

  {

    $dept = strtoupper($dept);

    $course = strtoupper($course);

    if (empty($this->departments[$dept][$course]))

      $course_obj = NULL;

    else

      {

	$course_obj = $this->departments[$dept][$course];

	$section_obj = $course_obj->section_get($section);

      }

    if (empty($course_obj) || empty($section_obj))

    $section_obj->meeting_add($section_meeting);

    return;

  }

  /**

   * \brief

   *   Update the time_end.

   *

   * The time_end is a unix timestamp roughly estimating the time at

   * which a semester starts. It is used when guessing what semester a

   * user is interested in.

   *

   * \param $time_end

   *   The new time_end.

   */

  public function time_end_set($time_end)

  {

    $this->time_end = $time_end;

  }

  /**

   * \brief

   *   Set the time_end only if it would make the semester end later.

     *   overflowing stuff.

     */

    function mean(array $values)

    {

      /*

       * As the influence of each element reduces with each iteration

       * in the used algorithm, shuffling the array should give a

       * better idea of what the actual mean is for larger arrays.

       */

      shuffle($values);

      $val = 0;

      $i = 0;

      foreach ($values as $value)

        {

          $val = $val * $i / ($i + 1)

            + $value / ($i + 1);

          $i ++;

        }

      return $val;

    }

  }

if (!function_exists('stddev'))

  {

    function stddev(array $values)

    {

      $mean = mean($values);

      $squares = 0;

      $i = 0;

      foreach ($values as $value)

        $squares += pow($mean - $value, 2);

      return sqrt($squares / (count($values) - 1));

    }

  }

/**

 * \brief

 *   Return the four quartile points of an array of sorted values with

 *   normal integral indexes.

 */

function sp_iqr(array $values)

{

  $count = count($values);

  if (!$count)

    return array(0, 0, 0, 0);

}

elseif ($errors_fix)

  {

    foreach ($_POST['postData'] as $course)

      if (is_array($course))

	{

	  $title = '';

	  if (!empty($course['title']))

	    $title = $course['title'];

	  if (empty($course['name']))

	    $my_hc .= '    class_last = add_class();' . PHP_EOL;

	  else

	    $my_hc .= '    class_last = add_class_n(' . json_encode($course['name']) . ', ' . json_encode($title) . ');' . PHP_EOL;

	  foreach ($course as $section)

	    if (is_array($section))

	      $my_hc .= '    add_section_n(class_last, ' . json_encode($section['letter']) . ', '

		. json_encode($section['synonym']) . ', ' . json_encode($section['start']) . ', '

		. json_encode($section['end']) . ', '