refactor: complete core features

bot/utils.go

@@ -1,15 +1,20 @@
 package bot
 
 import (
+	"context"
 	"fmt"
 
+	"github.com/celestix/gotgproto"
 	"github.com/celestix/gotgproto/dispatcher"
-	"github.com/celestix/gotgproto/types"
+	tgTypes "github.com/celestix/gotgproto/types"
 	"github.com/gotd/td/tg"
+	"github.com/krau/SaveAny-Bot/common"
+	"github.com/krau/SaveAny-Bot/logger"
 	"github.com/krau/SaveAny-Bot/storage"
+	"github.com/krau/SaveAny-Bot/types"
 )
 
-func supportedMediaFilter(m *types.Message) (bool, error) {
+func supportedMediaFilter(m *tgTypes.Message) (bool, error) {
 	if not := m.Media == nil; not {
 		return false, dispatcher.EndGroups
 	}
@@ -69,3 +74,69 @@ func getAddTaskMarkup(messageID int) *tg.ReplyInlineMarkup {
 		},
 	}
 }
+
+func FileFromMedia(media tg.MessageMediaClass) (*types.File, error) {
+	switch media := media.(type) {
+	case *tg.MessageMediaDocument:
+		document, ok := media.Document.AsNotEmpty()
+		if !ok {
+			return nil, fmt.Errorf("unexpected type %T", media)
+		}
+		var fileName string
+		for _, attribute := range document.Attributes {
+			if name, ok := attribute.(*tg.DocumentAttributeFilename); ok {
+				fileName = name.FileName
+				break
+			}
+		}
+		return &types.File{
+			Location: document.AsInputDocumentFileLocation(),
+			FileSize: document.Size,
+			FileName: fileName,
+			MimeType: document.MimeType,
+			ID:       document.ID,
+		}, nil
+	}
+	return nil, fmt.Errorf("unexpected type %T", media)
+}
+
+func FileFromMessage(ctx context.Context, client *gotgproto.Client, chatID int64, messageID int) (*types.File, error) {
+	key := fmt.Sprintf("file:%d:%d", chatID, messageID)
+	logger.L.Debugf("Getting file: %s", key)
+	var cachedFile types.File
+	err := common.Cache.Get(key, &cachedFile)
+	if err == nil {
+		return &cachedFile, nil
+	}
+
+	message, err := GetTGMessage(ctx, client, messageID)
+	if err != nil {
+		return nil, err
+	}
+	file, err := FileFromMedia(message.Media)
+	if err != nil {
+		return nil, err
+	}
+	if err := common.Cache.Set(key, file, 3600); err != nil {
+		logger.L.Errorf("Failed to cache file: %s", err)
+	}
+	return file, nil
+}
+
+func GetTGMessage(ctx context.Context, client *gotgproto.Client, messageID int) (*tg.Message, error) {
+	logger.L.Debugf("Fetching message: %d", messageID)
+	res, err := client.API().MessagesGetMessages(ctx, []tg.InputMessageClass{
+		&tg.InputMessageID{
+			ID: messageID,
+		},
+	})
+	if err != nil {
+		return nil, err
+	}
+	messages := res.(*tg.MessagesMessages)
+	msg := messages.Messages[0]
+	if _, ok := msg.(*tg.Message); !ok {
+		return nil, fmt.Errorf("unexpected type %T, this file may be deleted", msg)
+	}
+	return msg.(*tg.Message), nil
+}