feat: support multi pics (#53)

* feat: support multi pics

* Update memogram.go

---------

Co-authored-by: boojack <24653555+boojack@users.noreply.github.com>

cache.go

@@ -0,0 +1,68 @@
+package memogram
+
+import (
+	"sync"
+	"time"
+)
+
+// Cache is a simple cache implementation
+type Cache struct {
+	sync.RWMutex
+	items map[string]*CacheItem
+}
+
+type CacheItem struct {
+	Value      interface{}
+	Expiration time.Time
+}
+
+func NewCache() *Cache {
+	return &Cache{
+		items: make(map[string]*CacheItem),
+	}
+}
+
+// set adds a key value pair to the cache with a given duration
+func (c *Cache) set(key string, value interface{}, duration time.Duration) {
+	c.Lock()
+	defer c.Unlock()
+	c.items[key] = &CacheItem{
+		Value:      value,
+		Expiration: time.Now().Add(duration),
+	}
+}
+
+// get returns a value from the cache if it exists
+func (c *Cache) get(key string) (interface{}, bool) {
+	c.RLock()
+	defer c.RUnlock()
+	item, found := c.items[key]
+	if !found {
+		return nil, false
+	}
+	if time.Now().After(item.Expiration) {
+		return nil, false
+	}
+	return item.Value, true
+}
+
+// deleteExpired deletes all expired key value pairs
+func (c *Cache) deleteExpired() {
+	c.Lock()
+	defer c.Unlock()
+	for k, v := range c.items {
+		if time.Now().After(v.Expiration) {
+			delete(c.items, k)
+		}
+	}
+}
+
+// startGC starts a goroutine to clean expired key value pairs
+func (c *Cache) startGC() {
+	go func() {
+		for {
+			<-time.After(5 * time.Minute)
+			c.deleteExpired()
+		}
+	}()
+}

memogram.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"github.com/go-telegram/bot"
 	"github.com/go-telegram/bot/models"
@@ -25,6 +26,7 @@ type Service struct {
 	client *MemosClient
 	config *Config
 	store  *store.Store
+	cache  *Cache
 }
 
 func NewService() (*Service, error) {
@@ -48,7 +50,9 @@ func NewService() (*Service, error) {
 		config: config,
 		client: client,
 		store:  store,
+		cache:  NewCache(),
 	}
+	s.cache.startGC()
 
 	opts := []bot.Option{
 		bot.WithDefaultHandler(s.handler),
@@ -93,6 +97,43 @@ func (s *Service) Start(ctx context.Context) {
 	s.bot.Start(ctx)
 }
 
+func (s *Service) createMemo(ctx context.Context, content string) (*v1pb.Memo, error) {
+	memo, err := s.client.MemoService.CreateMemo(ctx, &v1pb.CreateMemoRequest{
+		Content: content,
+	})
+	if err != nil {
+		slog.Error("failed to create memo", slog.Any("err", err))
+		return nil, err
+	}
+	return memo, nil
+}
+
+func (s *Service) handleMemoCreation(ctx context.Context, m *models.Update, content string) (*v1pb.Memo, error) {
+	var memo *v1pb.Memo
+	var err error
+
+	if m.Message.MediaGroupID != "" {
+		cacheMemo, ok := s.cache.get(m.Message.MediaGroupID)
+		if !ok {
+			memo, err = s.createMemo(ctx, content)
+			if err != nil {
+				return nil, err
+			}
+
+			s.cache.set(m.Message.MediaGroupID, memo, 24*time.Hour)
+		} else {
+			memo = cacheMemo.(*v1pb.Memo)
+		}
+	} else {
+		memo, err = s.createMemo(ctx, content)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return memo, nil
+}
+
 func (s *Service) handler(ctx context.Context, b *bot.Bot, m *models.Update) {
 	if strings.HasPrefix(m.Message.Text, "/start ") {
 		s.startHandler(ctx, b, m)
@@ -166,11 +207,10 @@ func (s *Service) handler(ctx context.Context, b *bot.Bot, m *models.Update) {
 
 	accessToken, _ := s.store.GetUserAccessToken(userID)
 	ctx = metadata.NewOutgoingContext(ctx, metadata.Pairs("Authorization", fmt.Sprintf("Bearer %s", accessToken)))
-	memo, err := s.client.MemoService.CreateMemo(ctx, &v1pb.CreateMemoRequest{
-		Content: content,
-	})
+
+	var memo *v1pb.Memo
+	memo, err := s.handleMemoCreation(ctx, m, content)
 	if err != nil {
-		slog.Error("failed to create memo", slog.Any("err", err))
 		b.SendMessage(ctx, &bot.SendMessageParams{
 			ChatID: m.Message.Chat.ID,
 			Text:   "Failed to create memo",