# HG changeset patch
# User Nathan Phillip Brink <ohnobinki@ohnopublishing.net>
# Date 2010-10-18 19:38:35
# Node ID 54bfd4a095e6d4ab08aabe1e0fa3090486eb9be4
# Parent  21a52190eb20908de2e44046993ead1dcbb655f5

Move the conflict checking functionality into the Section class (no functional change though -- if this change causes different permutation results, I did something wrong).

diff --git a/class.schedule.php b/class.schedule.php
--- a/class.schedule.php
+++ b/class.schedule.php
@@ -132,29 +132,15 @@ class Schedule
 	    
 				for ($downCounter = $this->nclasses - 1; $downCounter > $upCounter && !$conflict; $downCounter --)
 				{
-					$start1 = $this->classStorage[$upCounter]->getSection($cs[$upCounter])->getStartTime();
-					$end1 = $this->classStorage[$upCounter]->getSection($cs[$upCounter])->getEndTime();
-					$start2 = $this->classStorage[$downCounter]->getSection($cs[$downCounter])->getStartTime();
-					$end2 = $this->classStorage[$downCounter]->getSection($cs[$downCounter])->getEndTime();
-					
-					// If the two times overlap, then check if days overlap.
-					if ((($start1 >= $start2) && ($start1 <= $end2)) || (($start2 >= $start1) && ($start2 <= $end1)))
-					{
-				
-					for($day=0; $day<5; $day++)
-						{
-							if(!$conflict
-								&& ($this->classStorage[$upCounter]->getSection($cs[$upCounter])->getDay($day)
-								&& $this->classStorage[$downCounter]->getSection($cs[$downCounter])->getDay($day)))
-							{
-								$conflict = TRUE;
-							}
-						}
-		
+				  if ($this->classStorage[$upCounter]->getSection($cs[$upCounter])
+				      ->conflictsWith($this->classStorage[$downCounter]->getSection($cs[$downCounter])))
+				    {
+				      $conflict = TRUE;
+				      break;
+				    }
 				}
 			}
-		}
-            
+	
 	// Store to storage if no conflict is found.
 	if(!$conflict)
 	  {
diff --git a/class.section.php b/class.section.php
--- a/class.section.php
+++ b/class.section.php
@@ -199,6 +199,45 @@ class Section
   {
     return $this->bdays[$i];
   }
+
+  /**
+   * \brief
+   *   Check if this section conflicts withthe 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 $that)
+  {
+    /*
+     * The two sections can't conflict if the start/end times don't
+     * overlap. Also, use >= or <= here so that one can say ``I have
+     * gym from 10 through 11 and then latin from 11 though 12''.
+     */	
+    if ($this->getStartTime() >= $that->getEndTime()
+	|| $this->getEndTime() <= $that->getStartTime())
+      {
+	return FALSE;
+      }
+
+    /*
+     * Now we know that the sections overlap in start/end times. But
+     * if they don't both meet on the same day at least once, they
+     * don't conflict.
+     */
+    for ($day = 0; $day < 5; $day ++)
+      {
+	if ($this->getDay($day) && $that->getDay($day))
+	  return TRUE;
+      }
+
+    /*
+     * The sections don't both share a day of the week.
+     */
+    return FALSE;
+  }
   
   /**
    * \brief