analytics/lib/plausible/timezones.ex

60 lines
1.9 KiB
Elixir

defmodule Plausible.Timezones do
@moduledoc """
API for working with timezones wrapping around external libraries where necessary.
"""
@spec valid?(String.t()) :: boolean()
def valid?(tz) do
Timex.is_valid_timezone?(tz)
end
@spec options(DateTime.t()) :: [{:key, String.t()}, {:value, String.t()}, {:offset, integer()}]
def options(now \\ DateTime.utc_now()) do
Tzdata.zone_list()
|> Enum.reduce([], fn timezone_code, acc -> build_option(timezone_code, acc, now) end)
|> Enum.sort_by(& &1[:offset], :desc)
end
@spec to_date_in_timezone(Date.t() | NaiveDateTime.t() | DateTime.t(), String.t()) :: Date.t()
def to_date_in_timezone(dt, timezone) do
to_datetime_in_timezone(dt, timezone) |> DateTime.to_date()
end
@spec to_datetime_in_timezone(Date.t() | NaiveDateTime.t() | DateTime.t(), String.t()) ::
DateTime.t()
def to_datetime_in_timezone(dt, timezone) do
dt |> to_datetime() |> DateTime.shift_zone!(timezone)
end
defp to_datetime(%NaiveDateTime{} = naive), do: DateTime.from_naive!(naive, "Etc/UTC")
defp to_datetime(%Date{} = date), do: DateTime.new!(date, ~T[00:00:00], "Etc/UTC")
defp to_datetime(%DateTime{} = already_dt), do: already_dt
defp build_option(timezone_code, acc, now) do
case Timex.Timezone.get(timezone_code, now) do
%Timex.TimezoneInfo{} = timezone_info ->
offset_in_minutes = timezone_info |> Timex.Timezone.total_offset() |> div(-60)
hhmm_formatted_offset =
timezone_info
|> Timex.TimezoneInfo.format_offset()
|> String.slice(0..-4//1)
option = [
key: "(GMT#{hhmm_formatted_offset}) #{timezone_code}",
value: timezone_code,
offset: offset_in_minutes
]
[option | acc]
error ->
Sentry.capture_message("Failed to fetch timezone",
extra: %{code: timezone_code, error: inspect(error)}
)
acc
end
end
end