Refactor Chats Service (#48)

chats/handler/create_chat.go

@@ -0,0 +1,57 @@
+package handler
+
+import (
+	"context"
+	"encoding/json"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/micro/micro/v3/service/errors"
+	"github.com/micro/micro/v3/service/logger"
+	pb "github.com/micro/services/chats/proto"
+)
+
+// Create a chat between two or more users, if a chat already exists for these users, the existing
+// chat will be returned
+func (c *Chats) CreateChat(ctx context.Context, req *pb.CreateChatRequest, rsp *pb.CreateChatResponse) error {
+	// validate the request
+	if len(req.UserIds) < 2 {
+		return ErrMissingUserIDs
+	}
+
+	// sort the user ids and then marshal to json
+	sort.Strings(req.UserIds)
+	bytes, err := json.Marshal(req.UserIds)
+	if err != nil {
+		logger.Errorf("Error mashaling user ids: %v", err)
+		return errors.InternalServerError("ENCODING_ERROR", "Error encoding user ids")
+	}
+
+	// construct the chat
+	chat := Chat{
+		ID:        uuid.New().String(),
+		CreatedAt: time.Now(),
+		UserIDs:   string(bytes),
+	}
+
+	// write to the database, if we get a unique key error, the chat already exists
+	err = c.DB.Create(&chat).Error
+	if err == nil {
+		rsp.Chat = chat.Serialize()
+		return nil
+	}
+	if !strings.Contains(err.Error(), "idx_chats_user_ids") {
+		logger.Errorf("Error creating chat: %v", err)
+		return errors.InternalServerError("DATABASE_ERROR", "Error connecting to database")
+	}
+
+	var existing Chat
+	if err := c.DB.Where(&Chat{UserIDs: chat.UserIDs}).First(&existing).Error; err != nil {
+		logger.Errorf("Error reading chat: %v", err)
+		return errors.InternalServerError("DATABASE_ERROR", "Error connecting to database")
+	}
+	rsp.Chat = existing.Serialize()
+	return nil
+}