module Playlists.Encoding exposing (decoder, encode, encodePlaylistTrack, playlistTrackDecoder)

import Json.Decode as Decode
import Json.Decode.Ext as Decode
import Json.Encode as Encode
import Json.Encode.Ext exposing (..)
import Playlists exposing (..)
import Time.Ext as Time



-- ENCODE


encode : Playlist -> Encode.Value
encode playlist =
    Encode.object
        [ ( "autoGenerated"
          , case playlist.autoGenerated of
                Just { level } ->
                    Encode.object
                        [ ( "level", Encode.int level ) ]

                Nothing ->
                    Encode.null
          )
        , ( "collection", Encode.bool playlist.collection )
        , ( "name", Encode.string playlist.name )
        , ( "public", Encode.bool playlist.public )
        , ( "tracks", Encode.list encodePlaylistTrack playlist.tracks )
        ]


encodePlaylistTrack : PlaylistTrack -> Encode.Value
encodePlaylistTrack playlistTrack =
    Encode.object
        [ ( "album", encodeMaybe playlistTrack.album Encode.string )
        , ( "artist", encodeMaybe playlistTrack.artist Encode.string )
        , ( "title", Encode.string playlistTrack.title )

        --
        , ( "insertAt", Time.encode playlistTrack.insertedAt )
        ]



-- DECODE


decoder : Decode.Decoder Playlist
decoder =
    Decode.map5 Playlist
        (Decode.field "autoGenerated" <| Decode.maybe <| Decode.map (\l -> { level = l }) <| Decode.field "level" Decode.int)
        (Decode.optionalField "collection" Decode.bool False)
        (Decode.field "name" Decode.string)
        (Decode.optionalField "public" Decode.bool False)
        (Decode.field "tracks" <| Decode.list playlistTrackDecoder)


playlistTrackDecoder : Decode.Decoder PlaylistTrack
playlistTrackDecoder =
    Decode.map4 PlaylistTrack
        (Decode.maybe <| Decode.field "album" Decode.string)
        (Decode.maybe <| Decode.field "artist" Decode.string)
        (Decode.field "title" Decode.string)
        (Decode.optionalField "insertedAt" Time.decoder Time.default)