Add basic support for parsing VALARM

lib/magical/alarm.ex

@@ -0,0 +1,24 @@
+defmodule Magical.Alarm do
+  @moduledoc """
+  A representation of a iCalendar VALARM
+  """
+
+  defstruct uid: nil,
+  acknowledged: nil,
+  action: nil,
+  description: nil,
+  trigger: nil,
+  x_wr_alarm_uid: nil,
+  x_apple_default_alarm: nil
+
+
+  @type t :: %__MODULE__{
+    uid: String.t(),
+    acknowledged: DateTime.t(),
+    action: String.t(),
+    description: String.t(),
+    trigger: Duration.t() | DateTime.t(),
+    x_wr_alarm_uid: String.t(),
+    x_apple_default_alarm: boolean() | nil
+  }
+end

lib/magical/event.ex

@@ -31,7 +31,8 @@ defmodule Magical.Event do
             rstatus: nil,
             related: nil,
             resources: nil,
-            rdate: nil
+            rdate: nil,
+            alarm: nil
 
   @type t :: %__MODULE__{
           uid: String.t(),
@@ -62,6 +63,7 @@ defmodule Magical.Event do
           rstatus: String.t(),
           related: String.t(),
           resources: String.t(),
-          rdate: String.t()
+          rdate: String.t(),
+          alarm: Magical.Alarm.t()
         }
 end

lib/magical/parser/alarm_parser.ex

@@ -0,0 +1,53 @@
+defmodule Magical.Parser.AlarmParser do
+  @moduledoc false
+
+  alias Magical.Alarm
+  alias Magical.Parser.DateParser
+  alias Magical.Parser.TextParser
+  alias Magical.Parser.DurationParser
+
+  def parse(lines) do
+    Enum.reduce(lines, %Alarm{}, &parse_alarm/2)
+  end
+
+  defp parse_alarm({"uid", uid, _args}, alarm) do
+    Map.put(alarm, :uid, TextParser.parse(uid))
+  end
+
+  defp parse_alarm({"x-wr-alarmuid", uid, _args}, alarm) do
+    Map.put(alarm, :x_wr_alarm_uid, TextParser.parse(uid))
+  end
+
+  defp parse_alarm({"acknowledged", datetime, args}, alarm) do
+    Map.put(alarm, :acknowledged, DateParser.parse(datetime, args))
+  end
+
+  defp parse_alarm({"action", action, _args}, alarm) do
+    Map.put(alarm, :action, TextParser.parse(action))
+  end
+
+  defp parse_alarm({"description", description, _args}, alarm) do
+    Map.put(alarm, :action, TextParser.parse(description))
+  end
+
+  defp parse_alarm({"trigger", trigger, args}, alarm) do
+    Map.put(alarm, :trigger, DurationParser.parse(trigger, args))
+  end
+
+  defp parse_alarm({"x-apple-default-alarm", "TRUE", _args}, alarm) do
+    Map.put(alarm, :x_apple_default_alarm, true)
+  end
+
+  defp parse_alarm({"x-apple-default-alarm", "FALSE", _args}, alarm) do
+    Map.put(alarm, :x_apple_default_alarm, false)
+  end
+
+  defp parse_alarm({"x-apple-default-alarm", _, _args}, alarm) do
+    Map.put(alarm, :x_apple_default_alarm, nil)
+  end
+
+  defp parse_alarm({"end", "VALARM", _args}, alarm) do
+    alarm
+  end
+
+end

lib/magical/parser/duration_parser.ex

@@ -0,0 +1,21 @@
+defmodule Magical.Parser.DurationParser do
+  @moduledoc """
+  Responsible for parsing durations or delegating to
+  datetime parsing.
+  """
+
+  alias Magical.Parser.DateParser
+
+  def parse("P" <> _rest = duration_string, _args) do
+    Duration.from_iso8601!(duration_string)
+  end
+
+  def parse("-P" <> _rest = duration_string, _args) do
+    Duration.from_iso8601!(duration_string)
+  end
+
+  def parse(datetime_string, args) do
+    DateParser.parse(datetime_string, args)
+  end
+
+end

lib/magical/parser/event_parser.ex

@@ -1,9 +1,10 @@
 defmodule Magical.Parser.EventParser do
   @moduledoc false
 
-  alias Magical.Parser.TextParser
   alias Magical.Event
+  alias Magical.Parser.TextParser
   alias Magical.Parser.DateParser
+  alias Magical.Parser.AlarmParser
 
   def parse(lines) do
     Enum.reduce(lines, %Event{}, &parse_event/2)
@@ -27,6 +28,9 @@ defmodule Magical.Parser.EventParser do
   defp parse_event({"created", created, _}, event),
     do: Map.put(event, :created, DateParser.parse(created, %{}))
 
+  defp parse_event([{"begin", "VALARM", _} | alarm], event),
+    do: Map.put(event, :alarm, AlarmParser.parse(alarm))
+
   defp parse_event({field, value, _}, event) do
     keys =
       Magical.Event.__struct__()