adds api calls for getting, setting, removing

- using Ecto queries, the api can now get newest
  message or get the last message
- delete all messages of a sender id
- add a message (auto adding a time stamp)

lib/bump/messages.ex

@@ -1,8 +1,15 @@
 defmodule Bump.Messages do
   alias Bump.Repo
+  alias Bump.Messages.Message
   import Ecto.Query
 
-  def get_newest_message(_sender) do
+  def get_newest_message(sender) do
+    query = from m in "messages",
+            where: m.sender == ^sender,
+            order_by: [desc: m.timestamp],
+            limit: 1,
+            select: m.data
+    Repo.one(query)
   end
 
   def get_all_messages_since(sender, minutes) do
@@ -18,10 +25,21 @@ defmodule Bump.Messages do
     Repo.all(query)
   end
 
-  def remove_sender(_sender) do
+  def remove_sender(sender) do
+    query = from m in "messages",
+      where: m.sender == ^sender,
+      select: m.id
+    Repo.delete_all(query)
   end
 
-  def add_message(_sender, _message) do
+  def add_message(sender, message) do
+    time = 
+      DateTime.utc_now 
+      |> DateTime.truncate(:second)
+
+    Repo.insert(%Message{sender: sender, data: message, timestamp: time})
+
   end
 
+
 end

lib/bump/messages/message.ex

@@ -5,8 +5,7 @@ defmodule Bump.Messages.Message do
   schema "messages" do
     field :sender, :string
     field :data, :string, default: ""
-    field :timestamp, :utc_datetime, default: DateTime.utc_now |> DateTime.truncate(:second)
-
+    field :timestamp, :utc_datetime
     timestamps()
   end