initial commit

.gitignore

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+/_build
+/cover
+/deps
+erl_crash.dump
+*.ez

README.md

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+# ExIcal
+
+**TODO: Add description**
+
+## Installation
+
+If [available in Hex](https://hex.pm/docs/publish), the package can be installed as:
+
+  1. Add ex_ical to your list of dependencies in `mix.exs`:
+
+        def deps do
+          [{:ex_ical, "~> 0.0.1"}]
+        end
+
+  2. Ensure ex_ical is started before your application:
+
+        def application do
+          [applications: [:ex_ical]]
+        end
+

config/config.exs

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+# This file is responsible for configuring your application
+# and its dependencies with the aid of the Mix.Config module.
+use Mix.Config
+
+# This configuration is loaded before any dependency and is restricted
+# to this project. If another project depends on this project, this
+# file won't be loaded nor affect the parent project. For this reason,
+# if you want to provide default values for your application for
+# 3rd-party users, it should be done in your "mix.exs" file.
+
+# You can configure for your application as:
+#
+#     config :ex_ical, key: :value
+#
+# And access this configuration in your application as:
+#
+#     Application.get_env(:ex_ical, :key)
+#
+# Or configure a 3rd-party app:
+#
+#     config :logger, level: :info
+#
+
+# It is also possible to import configuration files, relative to this
+# directory. For example, you can emulate configuration per environment
+# by uncommenting the line below and defining dev.exs, test.exs and such.
+# Configuration from the imported file will override the ones defined
+# here (which is why it is important to import them last).
+#
+#     import_config "#{Mix.env}.exs"

lib/ex_ical.ex

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+defmodule ExIcal do
+  use Timex
+
+  # --- parse ---
+
+  def parse(data) do
+    data |> String.split("\n") |> Enum.reduce([], fn(line, events) ->
+      parse_line(String.strip(line), events)
+    end)
+  end
+
+  defp parse_line("BEGIN:VEVENT" <> _, events),          do: [%{}] ++ events
+  defp parse_line("DTSTART" <> start, events)            when length(events) > 0, do: events |> put_to_map(:start, process_date(start))
+  defp parse_line("DTEND" <> endd, events)               when length(events) > 0, do: events |> put_to_map(:end, process_date(endd))
+  defp parse_line("DTSTAMP" <> stamp, events)            when length(events) > 0, do: events |> put_to_map(:stamp, process_date(stamp))
+  defp parse_line("SUMMARY:" <> summary, events)         when length(events) > 0, do: events |> put_to_map(:summary, summary)
+  defp parse_line("DESCRIPTION:" <> description, events) when length(events) > 0, do: events |> put_to_map(:description, description)
+  defp parse_line("RRULE:" <> rrule, events)             when length(events) > 0, do: events |> put_to_map(:rrule, process_rrule(rrule))
+  defp parse_line(_, events), do: events
+
+  defp put_to_map(events, key, value) do
+    [ event | other ] = events
+    event = event |> Map.put(key, value)
+    [event] ++ other
+  end
+
+  defp process_date(":" <> date), do: parse_date(date)
+  defp process_date(";" <> date) do
+    [timezone, date] = date |> String.split(":")
+    timezone = case timezone do
+      "TZID=" <> timezone -> timezone
+      _ -> "UTC"
+    end
+    parse_date(date, timezone)
+  end
+
+  defp process_rrule(rrule) do
+    rrule |> String.split(";") |> Enum.reduce(%{}, fn(rule, hash) ->
+      [key, value] = rule |> String.split("=")
+      case key |> String.downcase |> String.to_atom do
+        :until -> hash |> Map.put(:until, parse_date(value))
+        key -> hash |> Map.put(key, value)
+      end
+    end)
+  end
+
+  # --- date parse ---
+  def parse_date(<< year :: binary-size(4), month :: binary-size(2), day :: binary-size(2), "T",
+                        hour :: binary-size(2), minutes :: binary-size(2), seconds :: binary-size(2), "Z" >>) do
+      %DateTime{year: year |> String.to_integer, month: month |> String.to_integer, day: day |> String.to_integer,
+                hour: hour |> String.to_integer, minute: minutes |> String.to_integer, second: seconds |> String.to_integer, timezone: %TimezoneInfo{abbreviation: "UTC"}}
+  end
+
+  def parse_date(<< year :: binary-size(4), month :: binary-size(2), day :: binary-size(2), "Z" >>) do
+      %DateTime{year: year |> String.to_integer, month: month |> String.to_integer, day: day |> String.to_integer, timezone: %TimezoneInfo{abbreviation: "UTC"}}
+  end
+
+  def parse_date(<< year :: binary-size(4), month :: binary-size(2), day :: binary-size(2), "T",
+                        hour :: binary-size(2), minutes :: binary-size(2), seconds :: binary-size(2) >>, timezone) do
+      %DateTime{year: year |> String.to_integer, month: month |> String.to_integer, day: day |> String.to_integer,
+                hour: hour |> String.to_integer, minute: minutes |> String.to_integer, second: seconds |> String.to_integer, timezone: %TimezoneInfo{abbreviation: timezone}}
+  end
+
+  def parse_date(<< year :: binary-size(4), month :: binary-size(2), day :: binary-size(2) >>, timezone) do
+      %DateTime{year: year |> String.to_integer, month: month |> String.to_integer, day: day |> String.to_integer, timezone: %TimezoneInfo{abbreviation: timezone}}
+  end
+
+  # --- get_events ---
+
+  def get_events(events, start_date, end_date) do
+    (events ++ add_recurring_events(events, end_date)) |> Enum.filter(fn(event) ->
+      #Date.after?(event[:start], start_date) && Date.before?(event[:start], end_date) && Date.after?(event[:end], start_date) && Date.before?(event[:end], end_date)
+      true
+    end)
+  end
+
+  defp add_recurring_events(events, end_date) do
+    events |> Enum.reduce([], fn(event, revents) ->
+      case event[:rrule] do
+        nil ->
+          revents
+        _ ->
+          until = event[:rrule][:until] || end_date
+          revents ++ (event |> add_recurring_events_for(event[:rrule][:freq], until))
+      end
+    end)
+  end
+
+  defp add_recurring_events_for(event, "WEEKLY", until) do
+    days = (event[:rrule][:interval] || "1") |> String.to_integer
+
+    new_event = event
+    new_event = new_event |> Map.put(:start, Date.shift(event[:start], days: days * 7))
+    new_event = new_event |> Map.put(:end, Date.shift(event[:end], days: days * 7))
+
+    case Date.compare(new_event[:start], until) do
+     -1 -> [new_event] ++ add_recurring_events_for(new_event, "WEEKLY", until)
+      0 -> [new_event] ++ add_recurring_events_for(new_event, "WEEKLY", until)
+      1 -> [new_event]
+    end
+  end
+
+  defp add_recurring_events_for(event, "DAILY", until) do
+    days = (event[:rrule][:interval] || "1") |> String.to_integer
+
+    new_event = event
+    new_event = new_event |> Map.put(:start, Date.shift(event[:start], days: days))
+    new_event = new_event |> Map.put(:end, Date.shift(event[:end], days: days))
+
+    case Date.compare(new_event[:start], until) do
+     -1 -> [new_event] ++ add_recurring_events_for(new_event, "WEEKLY", until)
+      0 -> [new_event] ++ add_recurring_events_for(new_event, "WEEKLY", until)
+      1 -> [new_event]
+    end
+  end
+end

mix.exs

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+defmodule ExIcal.Mixfile do
+  use Mix.Project
+
+  def project do
+    [app: :ex_ical,
+     version: "0.0.1",
+     elixir: "~> 1.2",
+     build_embedded: Mix.env == :prod,
+     start_permanent: Mix.env == :prod,
+     deps: deps]
+  end
+
+  # Configuration for the OTP application
+  #
+  # Type "mix help compile.app" for more information
+  def application do
+    [applications: []]
+  end
+
+  defp deps do
+    [
+      {:timex, "~> 1.0"}
+    ]
+  end
+end

mix.lock

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+%{"certifi": {:hex, :certifi, "0.4.0"},
+  "combine": {:hex, :combine, "0.7.0"},
+  "hackney": {:hex, :hackney, "1.5.3"},
+  "idna": {:hex, :idna, "1.2.0"},
+  "metrics": {:hex, :metrics, "1.0.1"},
+  "mimerl": {:hex, :mimerl, "1.0.2"},
+  "ssl_verify_hostname": {:hex, :ssl_verify_hostname, "1.0.6"},
+  "timex": {:hex, :timex, "1.0.2"},
+  "tzdata": {:hex, :tzdata, "0.5.6"}}

test/ex_ical_test.exs

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+defmodule ExIcalTest do
+  use ExUnit.Case
+  doctest ExIcal
+
+  test "parse empty data" do
+    assert ExIcal.parse("") == []
+  end
+
+  test "event" do
+    ical = """
+      BEGIN:VCALENDAR
+      CALSCALE:GREGORIAN
+      VERSION:2.0
+      BEGIN:VEVENT
+      DESCRIPTION:Let's go see Star Wars.
+      DTEND:20151224T084500Z
+      DTSTART:20151224T083000Z
+      SUMMARY:Film with Amy and Adam
+      END:VEVENT
+      END:VCALENDAR
+    """
+
+    event = ExIcal.parse(ical) |> List.first
+
+    assert event[:description] == "Let's go see Star Wars."
+    assert event[:summary] == "Film with Amy and Adam"
+    assert event[:start] == ExIcal.parse_date("20151224T083000Z")
+    assert event[:end] == ExIcal.parse_date("20151224T084500Z")
+  end
+
+end

test/test_helper.exs

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+ExUnit.start()