Added transactions streaming functions - tested completely

Author: PythonHacker24

internal/session/stream_user.go

@@ -2,13 +2,17 @@ package session
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"time"
 
+	"github.com/PythonHacker24/linux-acl-management-backend/internal/types"
 	"github.com/gorilla/websocket"
 	"github.com/redis/go-redis/v9"
 )
 
+/* ==== User Session ==== */
+
 /* send current session of a user */
 func (m *Manager) sendCurrentSession(conn *websocket.Conn, sessionID string) error {
 	ctx := context.Background()
@@ -50,10 +54,12 @@ func (m *Manager) sendCurrentSession(conn *websocket.Conn, sessionID string) err
 
 /* send data regarding current session */
 func (m *Manager) listenForSessionChanges(ctx context.Context, conn *websocket.Conn, sessionID string) {
+	/* subscribe to both keyspace and keyevent notifications */
 	keyspacePattern := fmt.Sprintf("__keyspace@0__:session:%s", sessionID)
+	keyeventPattern := fmt.Sprintf("__keyevent@0__:hset:session:%s", sessionID)
 
-	/* subscribe to Redis keyspace */
-	pubsub, err := m.redis.PSubscribe(ctx, keyspacePattern)
+	/* subscribe to Redis keyspace and keyevent */
+	pubsub, err := m.redis.PSubscribe(ctx, keyspacePattern, keyeventPattern)
 	if err != nil {
 		m.errCh <- fmt.Errorf("failed to subscribe to redis events: %w", err)
 		return
@@ -104,6 +110,109 @@ func (m *Manager) handleSessionChangeEvent(conn *websocket.Conn, sessionID strin
 		Timestamp: time.Now(),
 	}
 
-	/* send the message payload via websocket */
+	/* send the message to the client */
+	return conn.WriteJSON(message)
+}
+
+/* ==== User Transaction List ==== */
+
+/* sends list of current transactions of the user */
+func (m *Manager) sendCurrentUserTransactions(conn *websocket.Conn, username, sessionID string, limit int) error {
+	/* get session from manager */
+	m.mutex.RLock()
+	session, exists := m.sessionsMap[username]
+	m.mutex.RUnlock()
+
+	/* return if session doesn't exist */
+	if !exists {
+		return fmt.Errorf("session not found")
+	}
+
+	/* get latest transactions from Redis */
+	transactions, err := m.getTransactionResultsRedis(session, limit)
+	if err != nil {
+		return fmt.Errorf("failed to fetch transaction results from Redis: %w", err)
+	}
+
+	/* create message payload for websocket */
+	message := StreamMessage{
+		Type: "user_transactions",
+		Data: map[string]interface{}{
+			"session_id":   sessionID,
+			"transactions": transactions,
+		},
+		Timestamp: time.Now(),
+	}
+
+	return conn.WriteJSON(message)
+}
+
+/* listen for transaction changes in Redis */
+func (m *Manager) listenForTransactionsChanges(ctx context.Context, conn *websocket.Conn, sessionID string) {
+	/* subscribe to both keyspace and keyevent notifications */
+	keyspacePattern := fmt.Sprintf("__keyspace@0__:session:%s:txresults", sessionID)
+	keyeventPattern := fmt.Sprintf("__keyevent@0__:rpush:session:%s:txresults", sessionID)
+
+	/* subscribe to Redis keyspace and keyevent */
+	pubsub, err := m.redis.PSubscribe(ctx, keyspacePattern, keyeventPattern)
+	if err != nil {
+		m.errCh <- fmt.Errorf("failed to subscribe to redis events: %w", err)
+		return
+	}
+
+	defer pubsub.Close()
+
+	/* Redis update channel */
+	ch := pubsub.Channel()
+
+	/* handling transaction changes */
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case msg := <-ch:
+			/* changes in transactions stored in Redis detected; handle the event */
+			if err := m.handleTransactionChangeEvent(conn, sessionID, msg); err != nil {
+				m.errCh <- fmt.Errorf("error handling transaction change: %w", err)
+			}
+		}
+	}
+}
+
+/* handle transaction change event */
+func (m *Manager) handleTransactionChangeEvent(conn *websocket.Conn, sessionID string, msg *redis.Message) error {
+	ctx := context.Background()
+
+	/* get latest transactions */
+	key := fmt.Sprintf("session:%s:txresults", sessionID)
+	values, err := m.redis.LRange(ctx, key, -100, -1).Result()
+	if err != nil {
+		return fmt.Errorf("failed to get transaction results: %w", err)
+	}
+
+	/* convert each JSON string back into a Transaction */
+	transactions := make([]types.Transaction, 0, len(values))
+	for _, val := range values {
+		var tx types.Transaction
+		if err := json.Unmarshal([]byte(val), &tx); err != nil {
+			/* skip malformed results */
+			continue
+		}
+		transactions = append(transactions, tx)
+	}
+
+	/* prepare the message payload */
+	message := StreamMessage{
+		Type: "transaction_update",
+		Data: map[string]interface{}{
+			"session_id":   sessionID,
+			"transactions": transactions,
+			"event_type":   msg.Payload,
+			"event_source": "redis_keyspace",
+		},
+		Timestamp: time.Now(),
+	}
+
+	/* send the message to the client */
 	return conn.WriteJSON(message)
 }