Lunaris2.0/Bot/Handler/MusicPlayer/PlayCommand/readme.md

flowchart TD
    PlayHandler --> EnsureConnected
    EnsureConnected --> GetPlayer
    GetPlayer --> SearchAsync
    SearchAsync --> SearchResponse
    SearchResponse --> PlayTrack
    PlayTrack --> NowPlayingEmbed

classDiagram
    class PlayHandler {
        -MusicEmbed _musicEmbed
        -DiscordSocketClient _client
        -IAudioService _audioService
        -SocketSlashCommand _context
        -const int MaxTrackDuration
        -LavalinkTrack? _previousTrack
        -static HashSet~ulong~ SubscribedGuilds
        +PlayHandler(DiscordSocketClient client, MusicEmbed musicEmbed, IAudioService audioService)
        +Task Handle(PlayCommand command, CancellationToken cancellationToken)
        -void PlayMusic()
        -Task OnTrackEnded(object sender, TrackEndedEventArgs eventargs)
        -Task OnTrackStarted(object sender, TrackStartedEventArgs eventargs)
        -void RegisterTrackStartedEventListerner(PlayCommand command)
        -static Task ApplyFilters(CancellationToken cancellationToken, QueuedLavalinkPlayer player)
        -static Task ConfigureSponsorBlock(CancellationToken cancellationToken, QueuedLavalinkPlayer player)
    }

    class PlayCommand {
        +SocketSlashCommand Message
    }

    class TrackEndedEventArgs {
    }

    class TrackStartedEventArgs {
    }

    class QueuedLavalinkPlayer {
        +LavalinkTrack? CurrentTrack
        +Task PlayAsync(LavalinkTrack track, CancellationToken cancellationToken)
        +Task Queue.AddRangeAsync(List~TrackQueueItem~ queueTracks, CancellationToken cancellationToken)
        +Task Filters.SetFilter(NormalizationFilter normalizationFilter)
        +Task Filters.CommitAsync(CancellationToken cancellationToken)
        +Task UpdateSponsorBlockCategoriesAsync(ImmutableArray~SegmentCategory~ categories, CancellationToken cancellationToken)
    }

    class LavalinkTrack {
        +string Identifier
    }

    class NormalizationFilter {
        +NormalizationFilter(double gain, bool enabled)
    }

    class SegmentCategory {
        +static SegmentCategory Intro
        +static SegmentCategory Sponsor
        +static SegmentCategory SelfPromotion
        +static SegmentCategory Outro
        +static SegmentCategory Filler
    }

    class TrackQueueItem {
        +TrackQueueItem(LavalinkTrack track)
    }

    PlayHandler --> PlayCommand
    PlayHandler --> TrackEndedEventArgs
    PlayHandler --> TrackStartedEventArgs
    PlayHandler --> QueuedLavalinkPlayer
    PlayHandler --> LavalinkTrack
    PlayHandler --> NormalizationFilter
    PlayHandler --> SegmentCategory
    PlayHandler --> TrackQueueItem

Steps in the code

Name	Description
PlayHandler	Holds the logic for playing songs
GetPlayer	Joins voice channel, produces chat resposne
EnsureConnected	Makes sure the client is connected
SearchAsync	Searches for songs information
SearchResponse	Handling possible errors from the response of SearchAsync
PlayTrack	Plays the song

There is also OnTrackEnd, when it get called an attempt is made to play the next song in queue.

Short explaination for some of the variables used:

Variable	Type	Description
_lavaNode	LavaNode	An instance of the LavaNode class, used to interact with the LavaLink server for playing music in Discord voice channels.
_client	DiscordSocketClient	An instance of the DiscordSocketClient class, used to interact with the Discord API for sending messages, joining voice channels, etc.
_musicEmbed	MusicEmbed	An instance of a custom MusicEmbed class, used to create and send embed messages related to the music player's current status.
context	SocketSlashCommand	An instance of the SocketSlashCommand class, representing a slash command received from Discord. Used to get information about the command and to respond to it.
player	LavaPlayer	An instance of the LavaPlayer class, representing a music player connected to a specific voice channel. Used to play, pause, skip, and queue tracks.
guildMessageIds	Dictionary<ulong, List<ulong>>	A dictionary that maps guild IDs to lists of message IDs. Used to keep track of messages sent by the bot in each guild, allowing the bot to delete its old messages when it sends new ones.
songName	string	A string that represents the name or URL of a song to play. Used to search for and queue tracks.
searchResponse	SearchResponse	An instance of the SearchResponse class, representing the result of a search for tracks. Used to get the tracks that were found and queue them in the player.