From f218a6b7cd91fdc6333f0942eead358ca6d03a26 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=20Jurmanovi=C4=87?= <fjurma12@outlook.com>
Date: Tue, 3 Jun 2025 20:57:09 +0200
Subject: [PATCH] add log position tracking

---
 local/repository/state_history.go      | 18 +++++++++
 local/service/server.go                | 10 +++--
 local/utl/tracking/log_tailer.go       | 19 ++++++++-
 local/utl/tracking/position_tracker.go | 54 ++++++++++++++++++++++++++
 4 files changed, 95 insertions(+), 6 deletions(-)
 create mode 100644 local/utl/tracking/position_tracker.go

diff --git a/local/repository/state_history.go b/local/repository/state_history.go
index cbd5e09..13e7095 100644
--- a/local/repository/state_history.go
+++ b/local/repository/state_history.go
@@ -26,3 +26,21 @@ func (r *StateHistoryRepository) GetAll(ctx context.Context, filter *model.State
 func (r *StateHistoryRepository) Insert(ctx context.Context, model *model.StateHistory) error {
 	return r.BaseRepository.Insert(ctx, model)
 }
+
+// GetLastSessionID gets the last session ID for a server
+func (r *StateHistoryRepository) GetLastSessionID(ctx context.Context, serverID uint) (uint, error) {
+	var lastSession model.StateHistory
+	result := r.BaseRepository.db.WithContext(ctx).
+		Where("server_id = ?", serverID).
+		Order("session_id DESC").
+		First(&lastSession)
+
+	if result.Error != nil {
+		if result.Error == gorm.ErrRecordNotFound {
+			return 0, nil // Return 0 if no sessions found
+		}
+		return 0, result.Error
+	}
+
+	return lastSession.SessionID, nil
+}
diff --git a/local/service/server.go b/local/service/server.go
index 0518426..bcd19e1 100644
--- a/local/service/server.go
+++ b/local/service/server.go
@@ -118,10 +118,12 @@ func (s *ServerService) shouldInsertStateHistory(serverID uint) bool {
 }
 
 func (s *ServerService) getNextSessionID(serverID uint) uint {
-	currentID, _ := s.sessionIDs.LoadOrStore(serverID, uint(0))
-	nextID := currentID.(uint) + 1
-	s.sessionIDs.Store(serverID, nextID)
-	return nextID
+	lastID, err := s.stateHistoryRepo.GetLastSessionID(context.Background(), serverID)
+	if err != nil {
+		logging.Error("Failed to get last session ID for server %d: %v", serverID, err)
+		return 1 // Return 1 as fallback
+	}
+	return lastID + 1
 }
 
 func (s *ServerService) insertStateHistory(serverID uint, state *model.ServerState) {
diff --git a/local/utl/tracking/log_tailer.go b/local/utl/tracking/log_tailer.go
index 422119c..fad0304 100644
--- a/local/utl/tracking/log_tailer.go
+++ b/local/utl/tracking/log_tailer.go
@@ -11,6 +11,7 @@ type LogTailer struct {
 	handleLine  func(string)
 	stopChan    chan struct{}
 	isRunning   bool
+	tracker     *PositionTracker
 }
 
 func NewLogTailer(filePath string, handleLine func(string)) *LogTailer {
@@ -18,6 +19,7 @@ func NewLogTailer(filePath string, handleLine func(string)) *LogTailer {
 		filePath:   filePath,
 		handleLine: handleLine,
 		stopChan:   make(chan struct{}),
+		tracker:    NewPositionTracker(filePath),
 	}
 }
 
@@ -28,7 +30,13 @@ func (t *LogTailer) Start() {
 	t.isRunning = true
 
 	go func() {
-		var lastSize int64 = 0
+		// Load last position from tracker
+		pos, err := t.tracker.LoadPosition()
+		if err != nil {
+			pos = &LogPosition{} // Start from beginning if error
+		}
+		lastSize := pos.LastPosition
+
 		for {
 			select {
 			case <-t.stopChan:
@@ -56,8 +64,15 @@ func (t *LogTailer) Start() {
 
 					scanner := bufio.NewScanner(file)
 					for scanner.Scan() {
-						t.handleLine(scanner.Text())
+						line := scanner.Text()
+						t.handleLine(line)
 						lastSize, _ = file.Seek(0, 1) // Get current position
+						
+						// Save position periodically
+						t.tracker.SavePosition(&LogPosition{
+							LastPosition: lastSize,
+							LastRead:     line,
+						})
 					}
 
 					file.Close()
diff --git a/local/utl/tracking/position_tracker.go b/local/utl/tracking/position_tracker.go
new file mode 100644
index 0000000..3dc1075
--- /dev/null
+++ b/local/utl/tracking/position_tracker.go
@@ -0,0 +1,54 @@
+package tracking
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+)
+
+type LogPosition struct {
+	LastPosition int64    `json:"last_position"`
+	LastRead     string   `json:"last_read"`
+}
+
+type PositionTracker struct {
+	positionFile string
+}
+
+func NewPositionTracker(logPath string) *PositionTracker {
+	// Create position file in same directory as log file
+	dir := filepath.Dir(logPath)
+	base := filepath.Base(logPath)
+	positionFile := filepath.Join(dir, "."+base+".position")
+	
+	return &PositionTracker{
+		positionFile: positionFile,
+	}
+}
+
+func (t *PositionTracker) LoadPosition() (*LogPosition, error) {
+	data, err := os.ReadFile(t.positionFile)
+	if err != nil {
+		if os.IsNotExist(err) {
+			// Return empty position if file doesn't exist
+			return &LogPosition{}, nil
+		}
+		return nil, err
+	}
+
+	var pos LogPosition
+	if err := json.Unmarshal(data, &pos); err != nil {
+		return nil, err
+	}
+
+	return &pos, nil
+}
+
+func (t *PositionTracker) SavePosition(pos *LogPosition) error {
+	data, err := json.Marshal(pos)
+	if err != nil {
+		return err
+	}
+
+	return os.WriteFile(t.positionFile, data, 0644)
+} 
\ No newline at end of file