Presence.elm

module Phoenix.Presence exposing (Presence, create, onChange, onJoins, onLeaves)

import Dict exposing (Dict)
import Json.Decode as JD exposing (Decoder, Value)


type alias Presence msg =
    PhoenixPresence msg


type alias PhoenixPresence val msg =
    { onChange : Maybe (Dict String (List Value) -> msg)
    , onJoins : Maybe (Dict String (List Value) -> msg)
    , onLeaves : Maybe (Dict String (List Value) -> msg)
    }


create : PhoenixPresence val msg
create =
    { onChange = Nothing
    , onJoins = Nothing
    , onLeaves = Nothing
    }


onChange : (Dict String (List Value) -> msg) -> PhoenixPresence msg -> PhoenixPresence msg
onChange func presence =
    { presence | onChange = Just func }


onJoins : (Dict String (List Value) -> msg) -> PhoenixPresence msg -> PhoenixPresence msg
onJoins func presence =
    { presence | onJoins = Just func }


onLeaves : (Dict String (List Value) -> msg) -> PhoenixPresence msg -> PhoenixPresence msg
onLeaves func presence =
    { presence | onLeaves = Just func }


{- And in Channel -}

withPresence : Presence msg -> Channel msg -> Channel msg
withPresence presence chan =
    { chan | presence = Just presence }