From 1da6ceb136eebdfbe048e9835f939b4bcd84232f Mon Sep 17 00:00:00 2001
From: Luther Wen Xu <lutherchanpublic+git@gmail.com>
Date: Fri, 18 Oct 2019 12:20:11 +0800
Subject: [PATCH] go: discord: Rely less on state and more on events

---
 GoBot/discord/backend/members.go   | 12 +++++-----
 GoBot/discord/backend/plugin.go    | 35 ++++++++++++++----------------
 GoBot/discord/discord.go           |  2 +-
 GoBot/discord/modules/minecraft.go |  6 +++--
 4 files changed, 28 insertions(+), 27 deletions(-)

diff --git a/GoBot/discord/backend/members.go b/GoBot/discord/backend/members.go
index 754b6e2..1e1c182 100644
--- a/GoBot/discord/backend/members.go
+++ b/GoBot/discord/backend/members.go
@@ -13,12 +13,14 @@ import (
 var ErrMemberNotFound = errors.New("discord/backend: the requested member was not found")
 
 func GetAllMembers(s *discordgo.Session) ([]*discordgo.Member, error) {
-	for _, guild := range s.State.Guilds {
-		if guild.ID == config.GuildID {
-			return guild.Members, nil
-		}
+	guild, err := s.State.Guild(config.GuildID)
+	if err != nil {
+		guild, err = s.Guild(config.GuildID)
 	}
-	return nil, ErrMemberNotFound
+	if err != nil {
+		return nil, err
+	}
+	return guild.Members, nil
 }
 
 func GetMemberFromUserFriendlyName(s *discordgo.Session, user string) (*discordgo.Member, error) {
diff --git a/GoBot/discord/backend/plugin.go b/GoBot/discord/backend/plugin.go
index 760f680..6d47d1e 100644
--- a/GoBot/discord/backend/plugin.go
+++ b/GoBot/discord/backend/plugin.go
@@ -9,28 +9,25 @@ import (
 	"TerraOceanBot/server"
 )
 
-func UpdateVoiceChannelState(s *discordgo.Session) {
-	for _, guild := range s.State.Guilds {
-		if guild.ID != config.GuildID {
+func UpdateVoiceChannelState(s *discordgo.Session, guild *discordgo.GuildCreate) {
+	if guild.ID != config.GuildID {
+		return
+	}
+	for _, vs := range guild.VoiceStates {
+		if vs.ChannelID != config.VoiceChannel {
+			continue
+		}
+		if vs.Deaf || vs.SelfDeaf {
 			continue
 		}
-		for _, vs := range guild.VoiceStates {
-			if vs.ChannelID != config.VoiceChannel {
-				continue
-			}
-			if vs.Deaf || vs.SelfDeaf {
-				continue
-			}
-			username, err := db.GetMinecraftUsername(vs.UserID)
-			if err == db.ErrNotFound {
-				continue
-			}
-			if err != nil {
-				message.AuditError(s, "", err)
-				continue
-			}
-			server.ConnectUser(username)
+		username, err := db.GetMinecraftUsername(vs.UserID)
+		if err == db.ErrNotFound {
+			continue
+		}
+		if err != nil {
+			continue
 		}
+		server.ConnectUser(username)
 	}
 }
 
diff --git a/GoBot/discord/discord.go b/GoBot/discord/discord.go
index 1451931..057e9e2 100644
--- a/GoBot/discord/discord.go
+++ b/GoBot/discord/discord.go
@@ -20,6 +20,7 @@ func StartBot(token string, kill chan bool) {
 	dg.AddHandler(ProcessVoiceStateUpdate)
 	dg.AddHandler(modules.CheckForReact)
 	dg.AddHandler(modules.CheckForVote)
+	dg.AddHandler(backend.UpdateVoiceChannelState)
 	dg.State.TrackMembers = true
 	dg.State.TrackVoice = true
 
@@ -30,7 +31,6 @@ func StartBot(token string, kill chan bool) {
 	fmt.Println("Bot is now running. Press CTRL-C to exit.")
 	modules.GenerateHelpEmbed()
 	go modules.ListenToVoteFinishes(dg)
-	go backend.UpdateVoiceChannelState(dg)
 
 	<-kill
 
diff --git a/GoBot/discord/modules/minecraft.go b/GoBot/discord/modules/minecraft.go
index 68c96e8..6548577 100644
--- a/GoBot/discord/modules/minecraft.go
+++ b/GoBot/discord/modules/minecraft.go
@@ -4,7 +4,6 @@ import (
 	"github.com/bwmarrin/discordgo"
 
 	"TerraOceanBot/db"
-	"TerraOceanBot/discord/backend"
 	"TerraOceanBot/discord/config"
 	"TerraOceanBot/discord/message"
 	"TerraOceanBot/server"
@@ -77,11 +76,14 @@ func processUsernameUpdate(s *discordgo.Session, discordID, channelID, newUserna
 		return
 	}
 
-	backend.UpdateVoiceChannelState(s)
 	if oldErr == nil {
 		server.WhitelistRemove(oldUsername)
 		server.DisconnectUser(oldUsername)
 	}
+	if err == nil {
+		server.WhitelistAdd(newUsername)
+		server.ConnectUser(newUsername)
+	}
 
 	message.InitNewEmbed(
 		config.SetMCUsernameSuccessTitle,