Add models and migrations

lib/nulla_web/controllers/user_html.ex

@@ -38,4 +38,42 @@ defmodule NullaWeb.UserHTML do
 
     "#{formatted} (#{relative})"
   end
+
+  def format_note_datetime(datetime) do
+    Timex.format!(datetime, "{0D} {Mfull} {YYYY}, {h24}:{m}", :strftime)
+  end
+
+  def format_note_datetime_diff(datetime) do
+    now = Timex.now()
+    diff = Timex.diff(now, datetime, :seconds)
+    
+    cond do
+      diff < 60 ->
+        "now"
+
+      diff < 3600 ->
+        minutes = div(diff, 60)
+        "#{minutes}m ago"
+
+      diff < 86400 ->
+        hours = div(diff, 3600)
+        "#{hours}h ago"
+
+      diff < 518400 ->
+        days = div(diff, 86400)
+        "#{days}d ago"
+
+      diff < 2419200 ->
+        weeks = div(diff, 604800)
+        "#{weeks}w ago"
+
+      diff < 28512000 ->
+        months = Timex.diff(now, datetime, :months)
+        "#{months}mo ago"
+
+      true ->
+        years = Timex.diff(now, datetime, :years)
+        "#{years}y ago"
+    end
+  end
 end