chore: migrate get tag suggestions

api/v2/tag_service.go

@@ -3,8 +3,11 @@ package v2
 import (
 	"context"
 	"fmt"
+	"regexp"
+	"sort"
 
 	"github.com/pkg/errors"
+	"golang.org/x/exp/slices"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 
@@ -36,7 +39,7 @@ func (s *APIV2Service) UpsertTag(ctx context.Context, request *apiv2pb.UpsertTag
 }
 
 func (s *APIV2Service) ListTags(ctx context.Context, request *apiv2pb.ListTagsRequest) (*apiv2pb.ListTagsResponse, error) {
-	username, err := ExtractUsernameFromName(request.Creator)
+	username, err := ExtractUsernameFromName(request.User)
 	if err != nil {
 		return nil, status.Errorf(codes.InvalidArgument, "invalid username: %v", err)
 	}
@@ -91,6 +94,61 @@ func (s *APIV2Service) DeleteTag(ctx context.Context, request *apiv2pb.DeleteTag
 	return &apiv2pb.DeleteTagResponse{}, nil
 }
 
+func (s *APIV2Service) GetTagSuggestions(ctx context.Context, request *apiv2pb.GetTagSuggestionsRequest) (*apiv2pb.GetTagSuggestionsResponse, error) {
+	username, err := ExtractUsernameFromName(request.User)
+	if err != nil {
+		return nil, status.Errorf(codes.InvalidArgument, "invalid username: %v", err)
+	}
+	user, err := s.Store.GetUser(ctx, &store.FindUser{
+		Username: &username,
+	})
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "failed to get user: %v", err)
+	}
+	if user == nil {
+		return nil, status.Errorf(codes.NotFound, "user not found")
+	}
+	normalRowStatus := store.Normal
+	memoFind := &store.FindMemo{
+		CreatorID:     &user.ID,
+		ContentSearch: []string{"#"},
+		RowStatus:     &normalRowStatus,
+	}
+	memoList, err := s.Store.ListMemos(ctx, memoFind)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "failed to list memos: %v", err)
+	}
+
+	tagList, err := s.Store.ListTags(ctx, &store.FindTag{
+		CreatorID: user.ID,
+	})
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "failed to list tags: %v", err)
+	}
+
+	tagNameList := []string{}
+	for _, tag := range tagList {
+		tagNameList = append(tagNameList, tag.Name)
+	}
+	tagMapSet := make(map[string]bool)
+	for _, memo := range memoList {
+		for _, tag := range findTagListFromMemoContent(memo.Content) {
+			if !slices.Contains(tagNameList, tag) {
+				tagMapSet[tag] = true
+			}
+		}
+	}
+	suggestions := []string{}
+	for tag := range tagMapSet {
+		suggestions = append(suggestions, tag)
+	}
+	sort.Strings(suggestions)
+
+	return &apiv2pb.GetTagSuggestionsResponse{
+		Tags: suggestions,
+	}, nil
+}
+
 func (s *APIV2Service) convertTagFromStore(ctx context.Context, tag *store.Tag) (*apiv2pb.Tag, error) {
 	user, err := s.Store.GetUser(ctx, &store.FindUser{
 		ID: &tag.CreatorID,
@@ -103,3 +161,21 @@ func (s *APIV2Service) convertTagFromStore(ctx context.Context, tag *store.Tag)
 		Creator: fmt.Sprintf("%s%s", UserNamePrefix, user.Username),
 	}, nil
 }
+
+var tagRegexp = regexp.MustCompile(`#([^\s#,]+)`)
+
+func findTagListFromMemoContent(memoContent string) []string {
+	tagMapSet := make(map[string]bool)
+	matches := tagRegexp.FindAllStringSubmatch(memoContent, -1)
+	for _, v := range matches {
+		tagName := v[1]
+		tagMapSet[tagName] = true
+	}
+
+	tagList := []string{}
+	for tag := range tagMapSet {
+		tagList = append(tagList, tag)
+	}
+	sort.Strings(tagList)
+	return tagList
+}