46 lines
1.0 KiB
Elixir
46 lines
1.0 KiB
Elixir
defmodule Mobilizon.Service.TimezoneDetector do
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@moduledoc """
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Detect the timezone from a point
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"""
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@type detectable :: Geo.Point.t() | Geo.PointZ.t() | {float() | float()}
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@doc """
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Detect the most appropriate timezone from a value, a geographic set of coordinates and a fallback
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"""
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@spec detect(String.t() | nil, detectable() | nil, String.t()) :: String.t()
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def detect(tz, nil, fallback), do: detect(tz, fallback)
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def detect(nil, geo, fallback) do
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case TzWorld.timezone_at(geo) do
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{:ok, timezone} ->
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timezone
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{:error, :time_zone_not_found} ->
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fallback
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{:error, :enoent} ->
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fallback
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end
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end
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def detect(timezone, geo, fallback) do
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if Tzdata.zone_exists?(timezone) do
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timezone
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else
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detect(nil, geo, fallback)
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end
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end
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@spec detect(String.t() | nil, String.t()) :: String.t()
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def detect(nil, fallback), do: fallback
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def detect(timezone, fallback) do
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if Tzdata.zone_exists?(timezone) do
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timezone
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else
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fallback
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end
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end
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end
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