✨ Member reading anchor

pkg/internal/services/reading_anchor.go

@@ -0,0 +1,40 @@
+package services
+
+import (
+	"git.solsynth.dev/hypernet/messaging/pkg/internal/database"
+	"git.solsynth.dev/hypernet/messaging/pkg/internal/models"
+	"github.com/rs/zerolog/log"
+	"github.com/samber/lo"
+	"gorm.io/gorm"
+)
+
+var readingAnchorQueue = make(map[uint]uint)
+
+func SetReadingAnchor(memberId uint, eventId uint) {
+	if val, ok := readingAnchorQueue[memberId]; ok {
+		readingAnchorQueue[memberId] = max(eventId, val)
+	} else {
+		readingAnchorQueue[memberId] = eventId
+	}
+}
+
+func FlushReadingAnchor() {
+	if len(readingAnchorQueue) == 0 {
+		return
+	}
+	idSet := lo.Uniq(lo.Map(lo.Keys(readingAnchorQueue), func(item uint, _ int) uint {
+		return item
+	}))
+	var pairs []map[string]any
+	for k, v := range readingAnchorQueue {
+		pairs = append(pairs, map[string]any{
+			"id":             k,
+			"reading_anchor": gorm.Expr("GREATEST(reading_anchor, ?)", v),
+		})
+	}
+	if err := database.C.Model(&models.ChannelMember{}).
+		Where("id IN ?", idSet).
+		Updates(pairs).Error; err != nil {
+		log.Error().Err(err).Msg("An error occurred when flushing reading anchor...")
+	}
+}