feat: integrate music commands with Lavalink support

- Added new music commands: play, queue, and volume.
- Implemented music management using disgolink for Lavalink integration.
- Updated bot initialization to include Lavalink host and password.
- Enhanced interaction handling for music commands, requiring DJ role for usage.
- Introduced now playing message with interactive buttons for controlling playback.
- Updated dependencies in go.mod for disgolink and snowflake.

internal/commands/music/public/permissions.go

@@ -0,0 +1,36 @@
+package public
+
+import "github.com/bwmarrin/discordgo"
+
+func memberHasDJRole(s *discordgo.Session, guildID string, m *discordgo.Member) bool {
+	if s == nil || guildID == "" || m == nil {
+		return false
+	}
+	if len(m.Roles) == 0 {
+		return false
+	}
+
+	roles, err := s.GuildRoles(guildID)
+	if err != nil {
+		return false
+	}
+
+	djRoleID := ""
+	for _, r := range roles {
+		if r != nil && r.Name == "DJ" {
+			djRoleID = r.ID
+			break
+		}
+	}
+	if djRoleID == "" {
+		return false
+	}
+
+	for _, rid := range m.Roles {
+		if rid == djRoleID {
+			return true
+		}
+	}
+	return false
+}
+

internal/commands/music/public/play.go

@@ -0,0 +1,130 @@
+package public
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+	"velox-bot/internal/music"
+
+	"github.com/bwmarrin/discordgo"
+)
+
+var Play = &discordgo.ApplicationCommand{
+	Name:        "play",
+	Description: "Play a song via Lavalink",
+	Options: []*discordgo.ApplicationCommandOption{
+		{
+			Type:        discordgo.ApplicationCommandOptionString,
+			Name:        "query",
+			Description: "Song name or URL",
+			Required:    true,
+		},
+	},
+}
+
+func PlayHandler(s *discordgo.Session, i *discordgo.InteractionCreate) {
+	data := i.ApplicationCommandData()
+	if len(data.Options) == 0 {
+		return
+	}
+	query := data.Options[0].StringValue()
+
+	// Always acknowledge quickly to avoid "application did not respond".
+	_ = s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
+		Type: discordgo.InteractionResponseDeferredChannelMessageWithSource,
+		Data: &discordgo.InteractionResponseData{
+			Content: "Searching...",
+		},
+	})
+
+	if !memberHasDJRole(s, i.GuildID, i.Member) {
+		_, _ = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
+			Content: ptr("You need the **DJ** role to use music commands."),
+		})
+		return
+	}
+
+	// If user provided plain text, turn it into a YouTube search
+	if !strings.HasPrefix(query, "http://") && !strings.HasPrefix(query, "https://") && !strings.HasPrefix(query, "ytsearch:") {
+		query = "ytsearch:" + query
+	} else {
+		query = normalizeYouTubeRadioURL(query)
+	}
+
+	vs, err := findUserVoiceState(s, i.GuildID, i.Member.User.ID)
+	if err != nil {
+		_, _ = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
+			Content: ptr(fmt.Sprintf("Error: %v", err)),
+		})
+		return
+	}
+
+	entry, started, err := music.EnqueueAndPlay(i.GuildID, vs.ChannelID, i.ChannelID, query, i.Member.User.Username)
+	if err != nil {
+		_, _ = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
+			Content: ptr(fmt.Sprintf("Error: %v", err)),
+		})
+		return
+	}
+
+	title := entry.Track.Info.Title
+	author := entry.Track.Info.Author
+	length := entry.Track.Info.Length
+
+	if started {
+		// manager will post now-playing message & manage invalidating old buttons
+		_, _ = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
+			Content: ptr(fmt.Sprintf("Starting: **%s** by **%s** `[%ds]`", title, author, length/1000)),
+		})
+	} else {
+		_, _ = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
+			Content: ptr(fmt.Sprintf("Added to queue: **%s** by **%s** `[%ds]`", title, author, length/1000)),
+		})
+	}
+}
+
+func ptr[T any](v T) *T { return new(v) }
+
+// normalizeYouTubeRadioURL strips auto-generated "radio/mix" params like:
+// https://www.youtube.com/watch?v=ID&list=RDID&start_radio=1 -> https://www.youtube.com/watch?v=ID
+// It intentionally does NOT strip normal playlist URLs.
+func normalizeYouTubeRadioURL(raw string) string {
+	u, err := url.Parse(raw)
+	if err != nil || u == nil {
+		return raw
+	}
+
+	host := strings.ToLower(u.Host)
+	if !strings.Contains(host, "youtube.com") || u.Path != "/watch" {
+		return raw
+	}
+
+	q := u.Query()
+	v := q.Get("v")
+	if v == "" {
+		return raw
+	}
+
+	list := q.Get("list")
+	_, hasStartRadio := q["start_radio"]
+	if !hasStartRadio && !strings.HasPrefix(list, "RD") {
+		return raw
+	}
+
+	u.RawQuery = url.Values{"v": []string{v}}.Encode()
+	u.Fragment = ""
+	return u.String()
+}
+
+func findUserVoiceState(s *discordgo.Session, guildID, userID string) (*discordgo.VoiceState, error) {
+	g, err := s.State.Guild(guildID)
+	if err != nil {
+		return nil, fmt.Errorf("cannot find guild voice state")
+	}
+	for _, vs := range g.VoiceStates {
+		if vs.UserID == userID {
+			return vs, nil
+		}
+	}
+	return nil, fmt.Errorf("you must be in a voice channel")
+}

internal/commands/music/public/queue.go

@@ -0,0 +1,77 @@
+package public
+
+import (
+	"fmt"
+	"strings"
+	"velox-bot/internal/music"
+
+	"github.com/bwmarrin/discordgo"
+)
+
+var Queue = &discordgo.ApplicationCommand{
+	Name:        "queue",
+	Description: "Show the current music queue",
+}
+
+func QueueHandler(s *discordgo.Session, i *discordgo.InteractionCreate) {
+	if !memberHasDJRole(s, i.GuildID, i.Member) {
+		_ = s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
+			Type: discordgo.InteractionResponseChannelMessageWithSource,
+			Data: &discordgo.InteractionResponseData{
+				Content: "You need the **DJ** role to use music commands.",
+				Flags:   discordgo.MessageFlagsEphemeral,
+			},
+		})
+		return
+	}
+
+	current, rest := music.GetQueue(i.GuildID)
+
+	if current == nil {
+		_ = s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
+			Type: discordgo.InteractionResponseChannelMessageWithSource,
+			Data: &discordgo.InteractionResponseData{
+				Content: "The queue is currently empty.",
+				Flags:   discordgo.MessageFlagsEphemeral,
+			},
+		})
+		return
+	}
+
+	nowPlaying := fmt.Sprintf("%s — %s", current.Track.Info.Title, current.Track.Info.Author)
+
+	var descBuilder strings.Builder
+	if len(rest) > 0 {
+		limit := len(rest)
+		if limit > 10 {
+			limit = 10
+		}
+		for idx, entry := range rest[:limit] {
+			fmt.Fprintf(&descBuilder, "%d. %s — %s (requested by %s)\n", idx+1, entry.Track.Info.Title, entry.Track.Info.Author, entry.RequestedBy)
+		}
+		if len(rest) > limit {
+			fmt.Fprintf(&descBuilder, "...and %d more.", len(rest)-limit)
+		}
+	} else {
+		descBuilder.WriteString("Nothing else in the queue.")
+	}
+
+	_ = s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
+		Type: discordgo.InteractionResponseChannelMessageWithSource,
+		Data: &discordgo.InteractionResponseData{
+			Embeds: []*discordgo.MessageEmbed{
+				{
+					Title:       "Music Queue",
+					Description: descBuilder.String(),
+					Fields: []*discordgo.MessageEmbedField{
+						{
+							Name:  "Now Playing",
+							Value: nowPlaying,
+						},
+					},
+				},
+			},
+		},
+	})
+}
+

internal/commands/music/public/volume.go

@@ -0,0 +1,63 @@
+package public
+
+import (
+	"fmt"
+	"velox-bot/internal/music"
+
+	"github.com/bwmarrin/discordgo"
+)
+
+var Volume = &discordgo.ApplicationCommand{
+	Name:        "volume",
+	Description: "Set playback volume (0-150)",
+	Options: []*discordgo.ApplicationCommandOption{
+		{
+			Type:        discordgo.ApplicationCommandOptionInteger,
+			Name:        "value",
+			Description: "Volume percent (0-150)",
+			Required:    true,
+			MinValue:    ptrFloat(0),
+			MaxValue:    150,
+		},
+	},
+}
+
+func VolumeHandler(s *discordgo.Session, i *discordgo.InteractionCreate) {
+	_ = s.InteractionRespond(i.Interaction, &discordgo.InteractionResponse{
+		Type: discordgo.InteractionResponseDeferredChannelMessageWithSource,
+		Data: &discordgo.InteractionResponseData{
+			Content: "Updating volume...",
+			Flags:   discordgo.MessageFlagsEphemeral,
+		},
+	})
+
+	if !memberHasDJRole(s, i.GuildID, i.Member) {
+		_, _ = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
+			Content: ptr("You need the **DJ** role to use music commands."),
+		})
+		return
+	}
+
+	data := i.ApplicationCommandData()
+	if len(data.Options) == 0 {
+		_, _ = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
+			Content: ptr("Missing volume value."),
+		})
+		return
+	}
+
+	vol := int(data.Options[0].IntValue())
+	if err := music.SetVolume(i.GuildID, vol); err != nil {
+		_, _ = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
+			Content: ptr(fmt.Sprintf("Error: %v", err)),
+		})
+		return
+	}
+
+	_, _ = s.InteractionResponseEdit(i.Interaction, &discordgo.WebhookEdit{
+		Content: ptr(fmt.Sprintf("Volume set to **%d%%**.", vol)),
+	})
+}
+
+func ptrFloat(v float64) *float64 { return &v }
+

internal/commands/music/registry.go

@@ -0,0 +1,20 @@
+package music
+
+import (
+	"velox-bot/internal/commands/music/public"
+
+	"github.com/bwmarrin/discordgo"
+)
+
+var (
+	Play  *discordgo.ApplicationCommand = public.Play
+	Queue *discordgo.ApplicationCommand = public.Queue
+	Volume *discordgo.ApplicationCommand = public.Volume
+)
+
+func PlayHandler(s *discordgo.Session, i *discordgo.InteractionCreate) { public.PlayHandler(s, i) }
+func QueueHandler(s *discordgo.Session, i *discordgo.InteractionCreate) {
+	public.QueueHandler(s, i)
+}
+func VolumeHandler(s *discordgo.Session, i *discordgo.InteractionCreate) { public.VolumeHandler(s, i) }
+