SwiftyLink

SwiftyLink is a fully-fledged Lavalink client written in Swift 5. It supports querying songs from multiple platforms, and gives you full access to everything Lavalink has to offer through its REST API.

Library support

SwiftyLink supports SwiftDiscord's vapor3 branch out of the box. If you would like to add custom library support, your library MUST be able to do these things:

It must be able to intercept RAW VOICE_SERVER_UPDATE and VOICE_STATE_UPDATE payloads from Discord's dispatch handling.
It must be able to send payloads through a shard's websocket connection
It must be able to send the intercepted payloads to this library using the sendUpdate() method.

Installation

SwiftyLink is built as a Swift Package - specifically a library. This makes the package easy to install and integrate into all of your existing work.

Just add the git link as a dependency in your Packages.swift file, then make your project depend on it.

Connecting to Lavalink

First, initialize your Lavalink node.

import Discord
import Dispatch
import SwiftyLink

class Bot: DiscordClientDelegate {
    private var client: DiscordClient!
    public var manager: SwiftyNode?

    init() {
        client = DiscordClient(token: "Bot mytoken", delegate: self)
        client.connect()
        self.manager = SwiftyNode(
                        password: "youshallnotpass", 
                        port: "2333", 
                        ID: "\(client.user.id)", 
                        shards: "1", 
                        host: "127.0.0.1", 
                        client: client
    )}

    func client(_ client: DiscordClient, didCreateMessage message: DiscordMessage) {
        if message.content == "?ping" {
            message.channel?.send("pong")
        }
    }
}

let bot = Bot()
dispatchMain()

Next, you must send Lavalink raw VOICE_STATE_UPDATE/VOICE_SERVER_UPDATE payloads intercepted from Discord.

func client(_ client: DiscordClient, didRecieveVoiceServerUpdate voiceServer: DiscordVoiceServerInformation) {
        
    let server = client.ws.voiceServerData!
    let state = client.ws.voiceStateData!
        
    let userID = UserID(state["user_id"] as! String)
        
    let sJson = serverJSON(
                     token: server["token"] as! String, 
                     guild_id: server["guild_id"] as! String, 
                     endpoint: server["endpoint"] as! String
                    )
        
    let s = voiceUpdateJSON(
                op: "voiceUpdate", 
                sessionId: (client.guilds[voiceServer.guildId]!.voiceStates[userID!])!.sessionId, 
                guildId: server["guild_id"] as! String,
                event: sJson
               )
        
    let encoder = JSONEncoder()
    encoder.outputFormatting = .prettyPrinted
        
    let JSONData = try! encoder.encode(s)
        
    let JSON = String(data: JSONData, encoding: .utf8)!
        
    self.manager!.sendUpdate(msg: URLSessionWebSocketTask.Message.string(JSON))
        
   }

After that, you can connect to your nodes in the ready event.

func client(_ client: DiscordClient, didReceiveReady readyData: [String : Any]) {
        self.manager?.connect()
    }

Usage

To join a voice channel, send SwiftyLink a createPlayer() method. Afterwards, you may use the player?.connect() method to connect to the voice channel.

The player?.connect() method accepts two additional parameters. The deaf parameter determines if the client will be deafened upon joining, whilst the mute parameter determines if the client will be muted upon joining.

func client(_ client: DiscordClient, didCreateMessage message: DiscordMessage) {
        if message.content == "?join" {
            let player = self.manager?.createPlayer(guild: "\(message.channel!.guild!.id)")
        
            player?.connect(channel: "\(message.guildMember!.voice!.channelId)", deaf: true, mute: false)
        }
    }

To play a song, use the player?.play() method. The argument is either the base64 Lavalink string or the YouTube identifier.

if message.content == "?play" {
        let player = self.manager?.createPlayer(guild: "\(message.channel!.guild!.id)")
        player?.play("ytsearch:Emperor'sNewClothes")
    }

To pause or the player, use player?.pause(). The boolean argument accepts true for pausing, and false for unpausing.

if message.content == "?pause" {
        let player = self.manager?.createPlayer(guild: "\(message.channel!.guild!.id)")
        player?.pause(true)
    }

if message.content == "?resume" {
        let player = self.manager?.createPlayer(guild: "\(message.channel!.guild!.id)")
        player?.pause(false)
    }

To stop the player, utilize the player?.stop() method.

if message.content == "?stop" {
        let player = self.manager?.createPlayer(guild: "\(message.channel!.guild!.id)")
        player?.stop()
    }

Documentation and Support

Docs are coming soon!! I swear!!!

For support inquires, you can find me in the Discord API server.

It's worth mentioning that due to the rough state of the project, some events are not handled - leaving them to be ignored. For the most part, this is fine - however i'm aiming to handle every event AND leave exposed methods so interacting with them is very easy. This should be done by the mid-version codebase reinforcement.

I have a few items i'd like to complete.

Remove the SwiftDiscord dependency (all it does is it talks to the API)
Fix some runtime errors
Safely unwrap each optional instead of force unwrapping it. This makes the syntax cleaner and allows for more efficient debugging, as force unwrapping a nil operator (which is done frequently) will cause a hard crash.
Clean up the syntax

I am aiming for all of this to be completed by the mid-version codebase reinforcement.

Contributing

I am a software developer, therefore I understand how important open source software is to the community. I also understand the burden of contributing to open source software. The Contributing guidelines are simple and straightforward, easy for a beginner to understand. Following the guidelines are a MUST for contributing, as well as the PR and issue templates.

License

Licensed under the MIT license.

Disclaimer

Made it this far, huh? Seems to me you really want to use this in a project. Before you do -

This is pre-release software. Bugs are prevalent.
Meant for experienced lavalink users for now. Methods aren't exposed and some events require picking and prying at to work at all.

Because this is pre-release software, I am not responsible for this breaking anything. It's unlikely, but anything can happen. That is ALL ON YOU.

Credits

nuclearace - SwiftDiscord.

fwcd - SwiftDiscord fork that allowed me to expand.

freyacodes - Lavalink that made this all possible.

TotallyNotNero / SwiftyLink