Pinned thread should come first when sorting

Pinned threads come on the top when we sort threads
by most recent activities but in the most activities
and most vote case it doesn't come on top. Pinned
thread should come on top in any case of sorting

TNL-90

common/static/coffee/spec/discussion/view/discussion_thread_list_view_spec.coffee

@@ -103,6 +103,7 @@ describe "DiscussionThreadListView", ->
             id: "1",
             title: "Thread1",
             votes: {up_count: '20'},
+            pinned: true,
             comments_count: 1,
             created_at: '2013-04-03T20:08:39Z',
           }),
@@ -120,6 +121,14 @@ describe "DiscussionThreadListView", ->
             comments_count: 3,
             created_at: '2013-04-03T20:06:39Z',
           }),
+          DiscussionViewSpecHelper.makeThreadWithProps({
+            id: "4",
+            title: "Thread4",
+            votes: {up_count: '25'},
+            comments_count: 0,
+            pinned: true,
+            created_at: '2013-04-03T20:05:39Z',
+          }),
         ]
 
         spyOn($, "ajax")
@@ -199,10 +208,11 @@ describe "DiscussionThreadListView", ->
         expect(@view.$(".forum-nav-filter-main-control").val()).toEqual("all")
 
     checkThreadsOrdering =  (view, sort_order, type) ->
-      expect(view.$el.find(".forum-nav-thread").children().length).toEqual(3)
+      expect(view.$el.find(".forum-nav-thread").children().length).toEqual(4)
       expect(view.$el.find(".forum-nav-thread:nth-child(1) .forum-nav-thread-title").text()).toEqual(sort_order[0])
       expect(view.$el.find(".forum-nav-thread:nth-child(2) .forum-nav-thread-title").text()).toEqual(sort_order[1])
       expect(view.$el.find(".forum-nav-thread:nth-child(3) .forum-nav-thread-title").text()).toEqual(sort_order[2])
+      expect(view.$el.find(".forum-nav-thread:nth-child(4) .forum-nav-thread-title").text()).toEqual(sort_order[3])
       expect(view.$el.find(".forum-nav-sort-control").val()).toEqual(type)
 
     describe "thread rendering should be correct", ->
@@ -211,17 +221,17 @@ describe "DiscussionThreadListView", ->
             view = makeView(discussion)
             view.render()
             checkThreadsOrdering(view, sort_order, type)
-            expect(view.$el.find(".forum-nav-thread-comments-count:visible").length).toEqual(if type == "votes" then 0 else 3)
-            expect(view.$el.find(".forum-nav-thread-votes-count:visible").length).toEqual(if type == "votes" then 3 else 0)
+            expect(view.$el.find(".forum-nav-thread-comments-count:visible").length).toEqual(if type == "votes" then 0 else 4)
+            expect(view.$el.find(".forum-nav-thread-votes-count:visible").length).toEqual(if type == "votes" then 4 else 0)
 
         it "with sort preference date", ->
-            checkRender(@threads, "date", [ "Thread1", "Thread2", "Thread3"])
+            checkRender(@threads, "date", ["Thread1", "Thread4", "Thread2", "Thread3"])
 
         it "with sort preference votes", ->
-            checkRender(@threads, "votes", [ "Thread2", "Thread1", "Thread3"])
+            checkRender(@threads, "votes", ["Thread4", "Thread1", "Thread2", "Thread3"])
 
         it "with sort preference comments", ->
-            checkRender(@threads, "comments", [ "Thread3", "Thread2", "Thread1"])
+            checkRender(@threads, "comments", ["Thread1", "Thread4", "Thread3", "Thread2"])
 
     describe "Sort change should be correct", ->
       changeSorting = (threads, selected_type, new_type, sort_order) ->
@@ -232,11 +242,11 @@ describe "DiscussionThreadListView", ->
         expect(sortControl.val()).toEqual(selected_type)
         sorted_threads = []
         if new_type == 'date'
-          sorted_threads = [threads[0], threads[1], threads[2]]
+          sorted_threads = [threads[0], threads[3], threads[1], threads[2]]
         else if new_type == 'comments'
-          sorted_threads = [threads[2], threads[1], threads[0]]
+          sorted_threads = [threads[0], threads[3], threads[2], threads[1]]
         else if new_type == 'votes'
-          sorted_threads = [threads[1], threads[0], threads[2]]
+          sorted_threads = [threads[3], threads[0], threads[1], threads[2]]
         $.ajax.andCallFake((params) =>
           params.success(
                 {"discussion_data":sorted_threads, page:1, num_pages:1}
@@ -248,13 +258,13 @@ describe "DiscussionThreadListView", ->
         checkThreadsOrdering(view, sort_order, new_type)
 
       it "with sort preference date", ->
-          changeSorting(@threads, "comments", "date", ["Thread1", "Thread2", "Thread3"])
+          changeSorting(@threads, "comments", "date", ["Thread1", "Thread4", "Thread2", "Thread3"])
 
       it "with sort preference votes", ->
-          changeSorting(@threads, "date", "votes", ["Thread2", "Thread1", "Thread3"])
+          changeSorting(@threads, "date", "votes", ["Thread4", "Thread1", "Thread2", "Thread3"])
 
       it "with sort preference comments", ->
-          changeSorting(@threads, "votes", "comments", ["Thread3", "Thread2", "Thread1"])
+          changeSorting(@threads, "votes", "comments", ["Thread1", "Thread4", "Thread3", "Thread2"])
 
     describe "search alerts", ->
 

common/static/coffee/src/discussion/discussion.coffee

@@ -67,31 +67,21 @@ if Backbone?
         error: error
 
     sortByDate: (thread) ->
-        #   
-        #The comment client asks each thread for a value by which to sort the collection
-        #and calls this sort routine regardless of the order returned from the LMS/comments service
-        #so, this takes advantage of this per-thread value and returns tomorrow's date
-        #for pinned threads, ensuring that they appear first, (which is the intent of pinned threads)
-        #
-        if thread.get('pinned')
-          #use tomorrow's date
-          today = new Date();
-          new Date(today.getTime() + (24 * 60 * 60 * 1000));
-        else
-          thread.get("created_at")
+      #
+      # The comment client asks each thread for a value by which to sort the collection
+      # and calls this sort routine regardless of the order returned from the LMS/comments service
+      # so, this takes advantage of this per-thread value and returns tomorrow's date
+      # for pinned threads, ensuring that they appear first, (which is the intent of pinned threads)
+      #
+      @pinnedThreadsSortComparatorWithDate(thread, true)
 
 
     sortByDateRecentFirst: (thread) ->
-        #
-        #Same as above
-        #but negative to flip the order (newest first)
-        #
-        if thread.get('pinned')
-          #use tomorrow's date
-          today = new Date();
-          -(new Date(today.getTime() + (24 * 60 * 60 * 1000)));
-        else
-          -(new Date(thread.get("created_at")).getTime())
+      #
+      # Same as above
+      # but negative to flip the order (newest first)
+      #
+      @pinnedThreadsSortComparatorWithDate(thread, false)
       #return String.fromCharCode.apply(String,
       #  _.map(thread.get("created_at").split(""),
       #        ((c) -> return 0xffff - c.charChodeAt()))
@@ -100,15 +90,42 @@ if Backbone?
     sortByVotes: (thread1, thread2) ->
       thread1_count = parseInt(thread1.get("votes")['up_count'])
       thread2_count = parseInt(thread2.get("votes")['up_count'])
-      if thread2_count != thread1_count
-        thread2_count - thread1_count
-      else
-        thread2.created_at_time() - thread1.created_at_time()
+      @pinnedThreadsSortComparatorWithCount(thread1, thread2, thread1_count, thread2_count)
 
     sortByComments: (thread1, thread2) ->
       thread1_count = parseInt(thread1.get("comments_count"))
       thread2_count = parseInt(thread2.get("comments_count"))
-      if thread2_count != thread1_count
-        thread2_count - thread1_count
+      @pinnedThreadsSortComparatorWithCount(thread1, thread2, thread1_count, thread2_count)
+
+    pinnedThreadsSortComparatorWithCount: (thread1, thread2, thread1_count, thread2_count) ->
+      # if threads are pinned they should be displayed on top.
+      # Unpinned will be sorted by their property count
+      if thread1.get('pinned') and not thread2.get('pinned')
+        -1
+      else if thread2.get('pinned') and not thread1.get('pinned')
+        1
+      else
+        if thread1_count > thread2_count
+          -1
+        else if thread2_count > thread1_count
+          1
+        else
+          if thread1.created_at_time() > thread2.created_at_time()
+            -1
+          else
+            1
+
+    pinnedThreadsSortComparatorWithDate: (thread, ascending)->
+      # if threads are pinned they should be displayed on top.
+      # Unpinned will be sorted by their date
+      threadCreatedTime = new Date(thread.get("created_at")).getTime()
+      if thread.get('pinned')
+        #use tomorrow's date
+        today = new Date();
+        preferredDate = new Date(today.getTime() + (24 * 60 * 60 * 1000) + threadCreatedTime);
+      else
+        preferredDate = threadCreatedTime
+      if ascending
+        preferredDate
       else
-        thread2.created_at_time() - thread1.created_at_time()
+        -(preferredDate)