feat(xp): basic reducer

xp/events.go

@@ -30,6 +30,7 @@ func OnMessage(s *discordgo.Session, m *discordgo.MessageCreate) {
 		return
 	}
 	c := GetCopaing(m.Author.ID, m.GuildID)
+	onLastEventUpdate(c)
 	// add xp
 	trimmed := utils.TrimMessage(strings.ToLower(m.Content))
 	m.Member.User = m.Author
@@ -62,6 +63,7 @@ func OnVoiceUpdate(s *discordgo.Session, e *discordgo.VoiceStateUpdate) {
 	if e.Member.User.Bot {
 		return
 	}
+	onLastEventUpdate(GetCopaing(e.UserID, e.GuildID))
 	cfg := config.GetGuildConfig(e.GuildID)
 	if cfg.IsDisabled(e.ChannelID) {
 		return

xp/level.go

@@ -42,3 +42,10 @@ func onNewLevel(s *discordgo.Session, m *discordgo.Member, level uint) {
 		}
 	}
 }
+
+func onLastEventUpdate(c *Copaing) {
+	h := c.HourSinceLastEvent()
+	c.XP -= Lose(h, c.XP)
+	c.Save()
+	c.SetLastEvent()
+}

xp/member.go

@@ -2,6 +2,7 @@ package xp
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"github.com/anhgelus/gokord"
 	"github.com/anhgelus/gokord/utils"
@@ -77,7 +78,9 @@ func (c *Copaing) HourSinceLastEvent() uint {
 	}
 	u := c.GetUserBase()
 	res := client.Get(context.Background(), fmt.Sprintf("%s:%s", u.GenKey(), LastEvent))
-	if res.Err() != nil {
+	if errors.Is(res.Err(), redis.Nil) {
+		return 0
+	} else if res.Err() != nil {
 		utils.SendAlert("xp/member.go - Getting last event", res.Err().Error(), "base_key", u.GenKey())
 		return 0
 	}