feat: adding redis to save sessions

sessions/sessions_manager.go

@@ -1,27 +1,69 @@
 package sessions
 
 import (
+	"context"
+	"fmt"
 	"log"
+	"math/rand"
+
+	"github.com/redis/go-redis/v9"
 )
 
 type SessionData struct {
-	sessionId int64
-	roomId int64
-	personId int64
+	SessionId int64 `redis:"session_id"`
+	RoomId    int64 `redis:"room_id"`
+	PersonId  int64 `redis:"person_id"`
 }
 
 type SessionManagement interface {
-    Get(sessionId int64) SessionData
-	Save(roomId int64, personId int64) int64
+	Get(sessionId int64) SessionData
+	Save(roomId int64, personId int64) (int64, error)
 }
 
-type DummySM struct {}
+var ctx = context.Background()
 
-func (d DummySM)Get(sessionId int64) SessionData {
+const sessionPrefix = "session"
+
+func sessionIdToKey(sessionId int64) string {
+	return fmt.Sprintf("%s:%d", sessionPrefix, sessionId)
+}
+
+type RedisSM struct {
+	Rdb *redis.Client
+}
+
+func (redisSM RedisSM) Get(sessionId int64) SessionData {
+	var foundSession SessionData
+	err := redisSM.Rdb.HGetAll(ctx, sessionIdToKey(sessionId)).Scan(foundSession)
+	if err != nil {
+		log.Printf("> error reading %d", sessionId)
+		return SessionData{}
+	}
+	log.Printf("> successfully found %d %+v", sessionId, foundSession)
+	return foundSession
+}
+func (redisSM RedisSM) Save(roomId int64, personId int64) (int64, error) {
+	randId := rand.Int63()
+	newSession := SessionData{
+		SessionId: randId,
+		RoomId:    roomId,
+		PersonId:  personId,
+	}
+	err := redisSM.Rdb.HSet(ctx, sessionIdToKey(randId), newSession).Err()
+	if err != nil {
+		log.Printf("> error! saving session %+v %s", newSession, err)
+		return 0, fmt.Errorf("error saving new session: %+v with %s", newSession, err)
+	}
+	return randId, nil
+}
+
+type DummySM struct{}
+
+func (d DummySM) Get(sessionId int64) SessionData {
 	log.Printf("get dummy session by %d", sessionId)
 	return SessionData{}
 }
-func (d DummySM)Save(roomId int64, personId int64) int64 {
+func (d DummySM) Save(roomId int64, personId int64) (int64, error) {
 	log.Printf("save dummy session with %d %d", roomId, personId)
-	return 1
+	return 1, nil
 }