Alter service to allow marking as read when a thread is fetched

api/comment_threads.rb

@@ -3,7 +3,14 @@ get "#{APIPREFIX}/threads" do # retrieve threads by course
 end
 
 get "#{APIPREFIX}/threads/:thread_id" do |thread_id|
-  CommentThread.find(thread_id).to_hash(recursive: bool_recursive, user_id: params["user_id"]).to_json
+  thread = CommentThread.find(thread_id)
+
+  if params["user_id"] and bool_mark_as_read
+    user = User.only([:id, :read_states]).find_or_create_by(external_id: params["user_id"])
+    user.mark_as_read(thread)
+  end
+
+  thread.to_hash(recursive: bool_recursive, user_id: params["user_id"]).to_json
 end
 
 put "#{APIPREFIX}/threads/:thread_id" do |thread_id|

api/users.rb

@@ -43,25 +43,6 @@ get "#{APIPREFIX}/users/:user_id/active_threads" do |user_id|
   
 end
 
-put "#{APIPREFIX}/users/:user_id/read_states" do |user_id|
-  user = User.find_or_create_by(external_id: user_id)
-  read_state = user.read_states.find_or_create_by(course_id: params["course_id"])
-  # support updating single thread data or bulk update
-  if params["last_read_time"] and params["thread_id"]
-    read_state.last_read_times = read_state.last_read_times.with_indifferent_access.merge({
-      params["thread_id"] => params["last_read_time"]
-    })
-  elsif params["last_read_times"]
-    read_state.last_read_times = read_state.last_read_times.with_indifferent_access.merge(params["last_read_times"])
-  end
-  read_state.save
-  if read_state.errors.any?
-    error 400, read_state.errors.full_messages.to_json
-  else
-    read_state.to_hash.to_json
-  end
-end
-
 put "#{APIPREFIX}/users/:user_id" do |user_id|
   user = User.find_or_create_by(external_id: user_id)
   user.update_attributes(params.slice(*%w[username email default_sort_key]))

lib/helpers.rb

@@ -51,6 +51,10 @@ helpers do
     value_to_boolean params["recursive"]
   end
 
+  def bool_mark_as_read
+    value_to_boolean params["mark_as_read"]
+  end
+
   def bool_complete
     value_to_boolean params["complete"]
   end

models/comment_thread.rb

@@ -171,7 +171,7 @@ class CommentThread < Content
     if params[:user_id]
       user = User.find_or_create_by(external_id: params[:user_id])
       read_state = user.read_states.where(course_id: self.course_id).first
-      last_read_time = Time.parse(read_state.last_read_times[self.id.to_s]) if read_state
+      last_read_time = read_state.last_read_times[self.id.to_s] if read_state
       # comments created by the user are excluded in the count
       # this is rather like a hack but it avoids the following situation:
       #   when you reply to a thread and while you are editing,

models/user.rb

@@ -102,6 +102,12 @@ class User
     subscription
   end
 
+  def mark_as_read(thread)
+    read_state = read_states.find_or_create_by(course_id: thread.course_id)
+    read_state.last_read_times[thread.id] = Time.now.utc
+    read_state.save
+  end
+
 end
 
 class ReadState