add fetching message history

http.go

@@ -14,6 +14,7 @@ import (
 
 	"go-socket/Enums/ConnectionState"
 
+	"github.com/google/uuid"
 	"golang.org/x/crypto/bcrypt"
 )
 
@@ -297,23 +298,101 @@ func HttpHandleUserMessage(response http.ResponseWriter, request *http.Request)
 		return
 	}
 	message := &Message{
+		Id:             uuid.New(),
 		Content:        msgContent,
 		CreatedAt:      time.Now(),
 		Sender:         user.Id,
-		Receiver:       target.Id,
+		Receiver:       conn.Id,
 		IsGroupMessage: false,
 	}
 
+	WsMessageSendToUser(target, message)
+
 	err = DbMessageSave(ctx, message)
 	if err != nil {
 		http.Error(response, "internal server error", http.StatusInternalServerError)
 		return
 	}
 
-	WsSendToUser(target, message)
 	response.WriteHeader(http.StatusAccepted)
 }
 
+func HttpHandleUserGetMessages(response http.ResponseWriter, request *http.Request) {
+	if !isMethodAllowed(&response, request) {
+		return
+	}
+	ctx := request.Context()
+	user, err := getUserByToken(ctx, request.FormValue("token"))
+	if err != nil {
+		http.Error(response, "invalid token", http.StatusUnauthorized)
+		return
+	}
+
+	connectionId, err := ConvertStringUuid(request.FormValue("connectionid"))
+	if err != nil {
+		http.Error(response, "invalid connectionid", http.StatusBadRequest)
+		return
+	}
+
+	before, err := ConvertStringTimestamp(request.FormValue("before"))
+	if err != nil {
+		before = time.Now()
+	}
+
+	messagesCap, err := ConvertStringUint32(request.FormValue("messages"))
+	if err != nil {
+		messagesCap = MaxDirectMsgCache
+	}
+
+	conn, ok := CacheGetConnection(user, connectionId)
+	if !ok {
+		http.Error(response, "invalid connectionid", http.StatusBadRequest)
+		return
+	}
+
+	buffer, bufferSize := conn.GetSortedMessagesBuff()
+
+	var validBufCount uint32
+	for validBufCount < bufferSize && buffer[validBufCount].CreatedAt.Before(before) {
+		validBufCount++
+	}
+
+	var messages []*Message
+
+	if validBufCount >= messagesCap {
+		start := validBufCount - messagesCap
+		messages = make([]*Message, messagesCap)
+		for i := uint32(0); i < messagesCap; i++ {
+			messages[i] = buffer[start+i]
+		}
+	} else {
+		remaining := messagesCap - validBufCount
+		cutoff := before
+		if validBufCount > 0 {
+			cutoff = buffer[0].CreatedAt
+		}
+		dbMessages, err := DbConnectionGetMessagesBefore(ctx, cutoff, connectionId, remaining)
+		if err != nil {
+			http.Error(response, "internal server error", http.StatusInternalServerError)
+			return
+		}
+		messages = make([]*Message, 0, uint32(len(dbMessages))+validBufCount)
+		messages = append(messages, dbMessages...)
+		for i := uint32(0); i < validBufCount; i++ {
+			messages = append(messages, buffer[i])
+		}
+	}
+
+	json, err := json2.Marshal(messages)
+	if err != nil {
+		http.Error(response, "internal server error", http.StatusInternalServerError)
+		return
+	}
+
+	response.WriteHeader(http.StatusOK)
+	response.Write(json)
+}
+
 func HttpHandleUserNewConnection(response http.ResponseWriter, request *http.Request) {
 	if !isMethodAllowed(&response, request) {
 		return