use antigravity to rewrite all your code to migrate from flat files to relational database. YOLO

server/step_manager.go

@@ -1,9 +1,8 @@
 package main
 
 import (
-	"encoding/json"
+	"database/sql"
 	"fmt"
-	"os"
 	"sync"
 	"time"
 )
@@ -29,70 +28,80 @@ type StepManager struct {
 }
 
 func NewStepManager(userID string) *StepManager {
-	now := time.Now()
-	interval := 15 * time.Minute
-
-	// Default state (will be used if load fails or file missing)
-	defaultState := TripState{
-		StartDate:  now.Format("2006-01-02"),
-		StartTime:  now,
-		DailyCache: make(map[string]int),
-	}
-
 	sm := &StepManager{
 		userID:       userID,
-		tripState:    defaultState,
-		syncInterval: interval,
-		lastSyncTime: now.Add(-interval),
-		nextSyncTime: now,
+		syncInterval: 15 * time.Minute,
 	}
-
-	if err := sm.LoadTripState(); err != nil {
-		fmt.Printf("Warning: Failed to load trip state: %v. Using new trip defaults.\n", err)
-	} else {
-		// Initialize total steps from the loaded state to avoid interpolating from 0
-		initialTotal := sm.RecalculateTotalFromState()
-		sm.previousTotalSteps = initialTotal
-		sm.targetTotalSteps = initialTotal
-		fmt.Printf("Initialized step counts from cache: %d\n", initialTotal)
-	}
-
+	sm.LoadTripState()
 	return sm
 }
 
 func (sm *StepManager) LoadTripState() error {
-	tripPath := fmt.Sprintf("data/users/%s/trip.json", sm.userID)
-	data, err := os.ReadFile(tripPath)
+	var startTime time.Time
+	err := db.QueryRow(`
+		SELECT start_date, start_time, start_day_initial_steps, previous_total_steps, target_total_steps, last_sync_time, next_sync_time
+		FROM trips WHERE user_id = ?
+	`, sm.userID).Scan(
+		&sm.tripState.StartDate, &startTime, &sm.tripState.StartDayInitialSteps,
+		&sm.previousTotalSteps, &sm.targetTotalSteps, &sm.lastSyncTime, &sm.nextSyncTime,
+	)
 	if err != nil {
-		if os.IsNotExist(err) {
+		if err == sql.ErrNoRows {
 			return nil // Normal for first run
 		}
 		return err
 	}
+	sm.tripState.StartTime = startTime
 
-	var loadedState TripState
-	if err := json.Unmarshal(data, &loadedState); err != nil {
-		return fmt.Errorf("failed to parse trip.json: %w", err)
+	// Load daily cache from DB
+	rows, err := db.Query("SELECT date, steps FROM daily_steps WHERE user_id = ?", sm.userID)
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	sm.tripState.DailyCache = make(map[string]int)
+	for rows.Next() {
+		var date string
+		var steps int
+		if err := rows.Scan(&date, &steps); err != nil {
+			return err
+		}
+		sm.tripState.DailyCache[date] = steps
 	}
 
-	// Only update if valid
-	sm.tripState = loadedState
-	if sm.tripState.DailyCache == nil {
-		sm.tripState.DailyCache = make(map[string]int)
-	}
-	fmt.Printf("Loaded trip state: StartDate=%s, InitialSteps=%d\n", sm.tripState.StartDate, sm.tripState.StartDayInitialSteps)
 	return nil
 }
 
 func (sm *StepManager) SaveTripState() {
-	userDir := fmt.Sprintf("data/users/%s", sm.userID)
-	if err := os.MkdirAll(userDir, 0755); err != nil {
-		fmt.Printf("Error creating user directory: %v\n", err)
-		return
+	_, err := db.Exec(`
+		INSERT INTO trips (user_id, start_date, start_time, start_day_initial_steps, previous_total_steps, target_total_steps, last_sync_time, next_sync_time)
+		VALUES (?, ?, ?, ?, ?, ?, ?, ?)
+		ON DUPLICATE KEY UPDATE
+			start_date = VALUES(start_date),
+			start_time = VALUES(start_time),
+			start_day_initial_steps = VALUES(start_day_initial_steps),
+			previous_total_steps = VALUES(previous_total_steps),
+			target_total_steps = VALUES(target_total_steps),
+			last_sync_time = VALUES(last_sync_time),
+			next_sync_time = VALUES(next_sync_time)
+	`, sm.userID, sm.tripState.StartDate, sm.tripState.StartTime, sm.tripState.StartDayInitialSteps,
+		sm.previousTotalSteps, sm.targetTotalSteps, sm.lastSyncTime, sm.nextSyncTime)
+	if err != nil {
+		fmt.Printf("Error saving trip state: %v\n", err)
+	}
+
+	// Save daily cache
+	for date, steps := range sm.tripState.DailyCache {
+		_, err := db.Exec(`
+			INSERT INTO daily_steps (user_id, date, steps)
+			VALUES (?, ?, ?)
+			ON DUPLICATE KEY UPDATE steps = VALUES(steps)
+		`, sm.userID, date, steps)
+		if err != nil {
+			fmt.Printf("Error saving daily steps for %s: %v\n", date, err)
+		}
 	}
-	tripPath := fmt.Sprintf("%s/trip.json", userDir)
-	data, _ := json.MarshalIndent(sm.tripState, "", "  ")
-	os.WriteFile(tripPath, data, 0644)
 }
 
 func (sm *StepManager) StartNewTrip() {
@@ -233,9 +242,12 @@ func (sm *StepManager) GetStatus() map[string]interface{} {
 	sm.mu.Lock()
 	defer sm.mu.Unlock()
 
+	// Reload from DB to get latest sync results from other instances
+	sm.LoadTripState()
+
 	// Auto-trigger sync if needed
 	if time.Now().After(sm.nextSyncTime) {
-		go sm.Sync() // Async sync
+		sm.Sync() // Sync and save to DB
 	}
 
 	currentSmoothed := sm.calculateSmoothedTokenAt(time.Now())