defmodule Excalt.XML.Builder do
  @moduledoc nil

  import Saxy.XML

  def calendar_list do
    el =
      Saxy.XML.element(
        "D:propfind",
        [
          "xmlns:D": "DAV:",
          "xmlns:C": "urn:ietf:params:xml:ns:caldav"
        ],
        Saxy.XML.element("D:prop", [], [
          Saxy.XML.element("C:calendar-description", [], ""),
          Saxy.XML.element("C:supported-calendar-component-set", [], ""),
          Saxy.XML.element("D:displayname", [], ""),
          Saxy.XML.element("C:calendar-timezone", [], "")
        ])
      )

    Saxy.encode!(el, [])
  end

  def event_list(from, to) do
    el =
      Saxy.XML.element(
        "C:calendar-query",
        [
          "xmlns:D": "DAV:",
          "xmlns:C": "urn:ietf:params:xml:ns:caldav"
        ],
        [
          Saxy.XML.element(
            "D:prop",
            [],
            [
              Saxy.XML.element("D:getetag", [], ""),
              Saxy.XML.element("C:calendar-data", [], "")
            ]
          ),
          Saxy.XML.element("C:filter", [], [
            Saxy.XML.element("C:comp-filter", [name: "VCALENDAR"], [
              Saxy.XML.element("C:comp-filter", [name: "VEVENT"], [
                Saxy.XML.element(
                  "C:time-range",
                  [start: format_datetime(from), end: format_datetime(to)],
                  ""
                )
              ])
            ])
          ])
        ]
      )

    Saxy.encode!(el, [])
  end

  def todo_list do
    el =
      Saxy.XML.element(
        "C:calendar-query",
        [
          "xmlns:D": "DAV:",
          "xmlns:C": "urn:ietf:params:xml:ns:caldav"
        ],
        [
          Saxy.XML.element(
            "D:prop",
            [],
            [
              Saxy.XML.element("D:getetag", [], ""),
              Saxy.XML.element("C:calendar-data", [], "")
            ]
          ),
          Saxy.XML.element("C:filter", [], [
            Saxy.XML.element("C:comp-filter", [name: "VCALENDAR"], [
              Saxy.XML.element("C:comp-filter", [name: "VTODO"], [])
            ])
          ])
        ]
      )

    Saxy.encode!(el, [])
  end

  defp format_datetime(datetime) do
    DateTime.shift_zone!(datetime, "Etc/UTC")
    |> DateTime.truncate(:second)
    |> DateTime.to_iso8601(:basic)
  end
end