Mining/pkg/mining/manager.go

package mining

import (
	"bytes"
	"context"
	"net"
	"regexp"
	"strconv"
	"sync"
	"time"

	"forge.lthn.ai/Snider/Mining/pkg/database"
	"forge.lthn.ai/Snider/Mining/pkg/logging"
)

// equalFold("xmrig", "XMRig") returns true.
// equalFold("tt-miner", "TT-Miner") returns true.
func equalFold(left, right string) bool {
	return bytes.EqualFold([]byte(left), []byte(right))
}

// hasPrefix("xmrig-rx0", "xmrig") returns true.
// hasPrefix("ttminer-rtx", "xmrig") returns false.
func hasPrefix(input, prefix string) bool {
	return len(input) >= len(prefix) && input[:len(prefix)] == prefix
}

// containsStr("peer not found", "not found") returns true.
// containsStr("connection ok", "not found") returns false.
func containsStr(haystack, needle string) bool {
	if len(needle) == 0 {
		return true
	}
	if len(haystack) < len(needle) {
		return false
	}
	for i := 0; i <= len(haystack)-len(needle); i++ {
		if haystack[i:i+len(needle)] == needle {
			return true
		}
	}
	return false
}

// safeName := instanceNameRegex.ReplaceAllString("my algo!", "_") // `my_algo_`
var instanceNameRegex = regexp.MustCompile(`[^a-zA-Z0-9_/-]`)

// var managerInterface ManagerInterface = mining.NewManager()
// miner, err := managerInterface.StartMiner(ctx, "xmrig", &mining.Config{Algo: "rx/0"})
// defer managerInterface.Stop()
type ManagerInterface interface {
	StartMiner(ctx context.Context, minerType string, config *Config) (Miner, error)
	StopMiner(ctx context.Context, name string) error
	GetMiner(name string) (Miner, error)
	ListMiners() []Miner
	ListAvailableMiners() []AvailableMiner
	GetMinerHashrateHistory(name string) ([]HashratePoint, error)
	UninstallMiner(ctx context.Context, minerType string) error
	Stop()
}

// manager := mining.NewManager()
// defer manager.Stop()
// miner, err := manager.StartMiner(ctx, "xmrig", &mining.Config{Algo: "rx/0"})
type Manager struct {
	miners            map[string]Miner
	mutex             sync.RWMutex
	stopChan          chan struct{}
	stopOnce          sync.Once
	waitGroup         sync.WaitGroup
	databaseEnabled   bool
	databaseRetention int
	eventHub          *EventHub
	eventHubMutex     sync.RWMutex
}

// manager.SetEventHub(eventHub)
func (manager *Manager) SetEventHub(eventHub *EventHub) {
	manager.eventHubMutex.Lock()
	defer manager.eventHubMutex.Unlock()
	manager.eventHub = eventHub
}

// manager.emitEvent(EventMinerStarted, MinerEventData{Name: instanceName})
// manager.emitEvent(EventMinerError, MinerEventData{Name: instanceName, Error: err.Error()})
func (manager *Manager) emitEvent(eventType EventType, data interface{}) {
	manager.eventHubMutex.RLock()
	eventHub := manager.eventHub
	manager.eventHubMutex.RUnlock()

	if eventHub != nil {
		eventHub.Broadcast(NewEvent(eventType, data))
	}
}

var _ ManagerInterface = (*Manager)(nil)

// manager := mining.NewManager()
// defer manager.Stop() // stops miner goroutines and the hourly database cleanup loop
func NewManager() *Manager {
	manager := &Manager{
		miners:    make(map[string]Miner),
		stopChan:  make(chan struct{}),
		waitGroup: sync.WaitGroup{},
	}
	manager.syncMinersConfig()
	manager.initDatabase()
	manager.autostartMiners()
	manager.startStatsCollection()
	return manager
}

// manager := mining.NewManagerForSimulation()
// manager.StartMiner(ctx, "xmrig", &Config{Algo: "rx/0"})
func NewManagerForSimulation() *Manager {
	manager := &Manager{
		miners:    make(map[string]Miner),
		stopChan:  make(chan struct{}),
		waitGroup: sync.WaitGroup{},
	}
	manager.startStatsCollection()
	return manager
}

// manager.initDatabase() reads `~/.config/lethean-desktop/miners.json` and enables database persistence when `Database.Enabled` is true.
func (manager *Manager) initDatabase() {
	minersConfig, err := LoadMinersConfig()
	if err != nil {
		logging.Warn("could not load config for database init", logging.Fields{"error": err})
		return
	}

	manager.databaseEnabled = minersConfig.Database.Enabled
	manager.databaseRetention = minersConfig.Database.RetentionDays
	if manager.databaseRetention == 0 {
		manager.databaseRetention = 30
	}

	if !manager.databaseEnabled {
		logging.Debug("database persistence is disabled")
		return
	}

	databaseConfig := database.Config{
		Enabled:       true,
		RetentionDays: manager.databaseRetention,
	}

	if err := database.Initialize(databaseConfig); err != nil {
		logging.Warn("failed to initialize database", logging.Fields{"error": err})
		manager.databaseEnabled = false
		return
	}

	logging.Info("database persistence enabled", logging.Fields{"retention_days": manager.databaseRetention})

	// manager.startDBCleanup() calls database.Cleanup(30) at startup and every hour after NewManager enables persistence.
	manager.startDBCleanup()
}

// manager.startDBCleanup() calls database.Cleanup(manager.databaseRetention) at startup and every hour.
func (manager *Manager) startDBCleanup() {
	manager.waitGroup.Add(1)
	go func() {
		defer manager.waitGroup.Done()
		defer func() {
			if r := recover(); r != nil {
				logging.Error("panic in database cleanup goroutine", logging.Fields{"panic": r})
			}
		}()
		cleanupTicker := time.NewTicker(time.Hour)
		defer cleanupTicker.Stop()

		if err := database.Cleanup(manager.databaseRetention); err != nil {
			logging.Warn("database cleanup failed", logging.Fields{"error": err})
		}

		for {
			select {
			case <-cleanupTicker.C:
				if err := database.Cleanup(manager.databaseRetention); err != nil {
					logging.Warn("database cleanup failed", logging.Fields{"error": err})
				}
			case <-manager.stopChan:
				return
			}
		}
	}()
}

// manager.syncMinersConfig() appends `MinerAutostartConfig{MinerType: "xmrig", Autostart: false}` to miners.json when a miner is missing.
func (manager *Manager) syncMinersConfig() {
	minersConfig, err := LoadMinersConfig()
	if err != nil {
		logging.Warn("could not load miners config for sync", logging.Fields{"error": err})
		return
	}

	availableMiners := manager.ListAvailableMiners()
	configUpdated := false

	for _, availableMiner := range availableMiners {
		minerExists := false
		for _, configuredMiner := range minersConfig.Miners {
			if equalFold(configuredMiner.MinerType, availableMiner.Name) {
				minerExists = true
				break
			}
		}
		if !minerExists {
			minersConfig.Miners = append(minersConfig.Miners, MinerAutostartConfig{
				MinerType: availableMiner.Name,
				Autostart: false,
				Config:    nil, // keep the new miner disabled until the user saves a profile
			})
			configUpdated = true
			logging.Info("added default config for missing miner", logging.Fields{"miner": availableMiner.Name})
		}
	}

	if configUpdated {
		if err := SaveMinersConfig(minersConfig); err != nil {
			logging.Warn("failed to save updated miners config", logging.Fields{"error": err})
		}
	}
}

// manager.autostartMiners() starts entries with `Autostart: true` from `context.Background()`.
func (manager *Manager) autostartMiners() {
	minersConfig, err := LoadMinersConfig()
	if err != nil {
		logging.Warn("could not load miners config for autostart", logging.Fields{"error": err})
		return
	}

	for _, minerConfig := range minersConfig.Miners {
		if minerConfig.Autostart && minerConfig.Config != nil {
			logging.Info("autostarting miner", logging.Fields{"type": minerConfig.MinerType})
			if _, err := manager.StartMiner(context.Background(), minerConfig.MinerType, minerConfig.Config); err != nil {
				logging.Error("failed to autostart miner", logging.Fields{"type": minerConfig.MinerType, "error": err})
			}
		}
	}
}

// port, err := findAvailablePort()
// if err != nil { return 0, err }
// config.HTTPPort = port
func findAvailablePort() (int, error) {
	addr, err := net.ResolveTCPAddr("tcp", "localhost:0")
	if err != nil {
		return 0, err
	}
	listener, err := net.ListenTCP("tcp", addr)
	if err != nil {
		return 0, err
	}
	defer listener.Close()
	return listener.Addr().(*net.TCPAddr).Port, nil
}

// ctx, cancel := context.WithCancel(context.Background())
// cancel()
// _, err := manager.StartMiner(ctx, "xmrig", &Config{Algo: "rx/0"}) // returns context.Canceled before locking
func (manager *Manager) StartMiner(ctx context.Context, minerType string, config *Config) (Miner, error) {
	// ctx, cancel := context.WithCancel(context.Background()); cancel(); manager.StartMiner(ctx, "xmrig", &Config{Algo: "rx/0"}) returns context.Canceled before locking.
	select {
	case <-ctx.Done():
		return nil, ctx.Err()
	default:
	}

	manager.mutex.Lock()
	defer manager.mutex.Unlock()

	if config == nil {
		config = &Config{}
	}

	miner, err := CreateMiner(minerType)
	if err != nil {
		return nil, err
	}

	instanceName := miner.GetName()
	if config.Algo != "" {
		// sanitizedAlgo := instanceNameRegex.ReplaceAllString("rx/0", "_") // "rx_0"
		sanitizedAlgo := instanceNameRegex.ReplaceAllString(config.Algo, "_")
		instanceName = instanceName + "-" + sanitizedAlgo
	} else {
		instanceName = instanceName + "-" + strconv.FormatInt(time.Now().UnixNano()%1000, 10)
	}

	if _, exists := manager.miners[instanceName]; exists {
		return nil, ErrMinerExists(instanceName)
	}

	// config.HTTPPort = 3333 keeps the miner API on a user-supplied port between 1024 and 65535.
	if config.HTTPPort != 0 {
		if config.HTTPPort < 1024 || config.HTTPPort > 65535 {
			return nil, ErrInvalidConfig("HTTPPort must be between 1024 and 65535, got " + strconv.Itoa(config.HTTPPort))
		}
	}

	apiPort, err := findAvailablePort()
	if err != nil {
		return nil, ErrInternal("failed to find an available port for the miner API").WithCause(err)
	}
	if config.HTTPPort == 0 {
		config.HTTPPort = apiPort
	}

	if xmrigMiner, ok := miner.(*XMRigMiner); ok {
		xmrigMiner.Name = instanceName
		if xmrigMiner.API != nil {
			xmrigMiner.API.ListenPort = apiPort
		}
	}
	if ttMiner, ok := miner.(*TTMiner); ok {
		ttMiner.Name = instanceName
		if ttMiner.API != nil {
			ttMiner.API.ListenPort = apiPort
		}
	}

	// manager.emitEvent(EventMinerStarting, MinerEventData{Name: "xmrig-rx_0"}) fires before miner.Start(config).
	manager.emitEvent(EventMinerStarting, MinerEventData{
		Name: instanceName,
	})

	if err := miner.Start(config); err != nil {
		// manager.emitEvent(EventMinerError, MinerEventData{Name: "xmrig-rx_0", Error: err.Error()}) reports the failure before returning it.
		manager.emitEvent(EventMinerError, MinerEventData{
			Name:  instanceName,
			Error: err.Error(),
		})
		return nil, err
	}

	manager.miners[instanceName] = miner

	if err := manager.updateMinerConfig(minerType, true, config); err != nil {
		logging.Warn("failed to save miner config for autostart", logging.Fields{"error": err})
	}

	logMessage := "CryptoCurrency Miner started: " + miner.GetName() + " (Binary: " + miner.GetBinaryPath() + ")"
	logToSyslog(logMessage)

	// manager.emitEvent(EventMinerStarted, MinerEventData{Name: "xmrig-rx_0"}) marks the miner as running for websocket clients.
	manager.emitEvent(EventMinerStarted, MinerEventData{
		Name: instanceName,
	})

	RecordMinerStart()
	return miner, nil
}

// manager.UninstallMiner(ctx, "xmrig") stops all xmrig instances and removes the matching config entry.
// manager.UninstallMiner(ctx, "ttminer") stops all ttminer instances and removes the matching config entry.
func (manager *Manager) UninstallMiner(ctx context.Context, minerType string) error {
	// ctx, cancel := context.WithCancel(context.Background()); cancel(); manager.UninstallMiner(ctx, "xmrig") returns context.Canceled before locking.
	select {
	case <-ctx.Done():
		return ctx.Err()
	default:
	}

	manager.mutex.Lock()
	// manager.UninstallMiner(ctx, "xmrig") collects every running xmrig instance before removing it from the map.
	minersToDelete := make([]string, 0)
	minersToStop := make([]Miner, 0)
	for name, runningMiner := range manager.miners {
		if xmrigInstance, ok := runningMiner.(*XMRigMiner); ok && equalFold(xmrigInstance.ExecutableName, minerType) {
			minersToStop = append(minersToStop, runningMiner)
			minersToDelete = append(minersToDelete, name)
		}
		if ttInstance, ok := runningMiner.(*TTMiner); ok && equalFold(ttInstance.ExecutableName, minerType) {
			minersToStop = append(minersToStop, runningMiner)
			minersToDelete = append(minersToDelete, name)
		}
	}
	// delete(manager.miners, "xmrig-rx_0") happens before stopping miners so Stop can block without holding the lock.
	for _, name := range minersToDelete {
		delete(manager.miners, name)
	}
	manager.mutex.Unlock()

	// miner.Stop() runs outside the lock so one slow uninstall does not block other manager calls.
	for i, miner := range minersToStop {
		if err := miner.Stop(); err != nil {
			logging.Warn("failed to stop running miner during uninstall", logging.Fields{"miner": minersToDelete[i], "error": err})
		}
	}

	miner, err := CreateMiner(minerType)
	if err != nil {
		return err
	}

	if err := miner.Uninstall(); err != nil {
		return ErrInternal("failed to uninstall miner files").WithCause(err)
	}

	return UpdateMinersConfig(func(minersConfig *MinersConfig) error {
		var updatedMiners []MinerAutostartConfig
		for _, minerConfig := range minersConfig.Miners {
			if !equalFold(minerConfig.MinerType, minerType) {
				updatedMiners = append(updatedMiners, minerConfig)
			}
		}
		minersConfig.Miners = updatedMiners
		return nil
	})
}

// manager.updateMinerConfig("xmrig", true, config) // saves Autostart=true and the last-used config back to miners.json
func (manager *Manager) updateMinerConfig(minerType string, autostart bool, config *Config) error {
	return UpdateMinersConfig(func(minersConfig *MinersConfig) error {
		minerFound := false
		for i, minerConfig := range minersConfig.Miners {
			if equalFold(minerConfig.MinerType, minerType) {
				minersConfig.Miners[i].Autostart = autostart
				minersConfig.Miners[i].Config = config
				minerFound = true
				break
			}
		}

		if !minerFound {
			minersConfig.Miners = append(minersConfig.Miners, MinerAutostartConfig{
				MinerType: minerType,
				Autostart: autostart,
				Config:    config,
			})
		}
		return nil
	})
}

// manager.StopMiner(ctx, "xmrig/monero") stops the matching miner instance and removes it from the manager map.
// manager.StopMiner(ctx, "ttminer/rtx4090") still removes the entry when the miner has already stopped.
func (manager *Manager) StopMiner(ctx context.Context, name string) error {
	// ctx, cancel := context.WithCancel(context.Background()); cancel(); manager.StopMiner(ctx, "xmrig-rx_0") returns context.Canceled before locking.
	select {
	case <-ctx.Done():
		return ctx.Err()
	default:
	}

	manager.mutex.Lock()
	defer manager.mutex.Unlock()

	miner, exists := manager.miners[name]
	if !exists {
		for minerKey := range manager.miners {
			if hasPrefix(minerKey, name) {
				miner = manager.miners[minerKey]
				name = minerKey
				exists = true
				break
			}
		}
	}

	if !exists {
		return ErrMinerNotFound(name)
	}

	// manager.emitEvent(EventMinerStopping, MinerEventData{Name: "xmrig-rx_0"}) tells websocket clients shutdown has started.
	manager.emitEvent(EventMinerStopping, MinerEventData{
		Name: name,
	})

	// stopErr := miner.Stop() may fail after an external kill, but cleanup continues so the manager state stays accurate.
	stopErr := miner.Stop()

	// delete(manager.miners, "xmrig-rx_0") removes stale entries even when the process has already exited.
	delete(manager.miners, name)

	// manager.emitEvent(EventMinerStopped, MinerEventData{Name: "xmrig-rx_0", Reason: "stopped"}) confirms the final stop reason.
	reason := "stopped"
	if stopErr != nil && stopErr.Error() != "miner is not running" {
		reason = stopErr.Error()
	}
	manager.emitEvent(EventMinerStopped, MinerEventData{
		Name:   name,
		Reason: reason,
	})

	// stopErr = errors.New("permission denied") still returns the stop failure after the manager removes the stale entry.
	if stopErr != nil && stopErr.Error() != "miner is not running" {
		return stopErr
	}

	RecordMinerStop()
	return nil
}

// miner, err := manager.GetMiner("xmrig-randomx") // returns ErrMinerNotFound when the name is missing
// if err != nil { /* miner not found */ }
func (manager *Manager) GetMiner(name string) (Miner, error) {
	manager.mutex.RLock()
	defer manager.mutex.RUnlock()
	miner, exists := manager.miners[name]
	if !exists {
		return nil, ErrMinerNotFound(name)
	}
	return miner, nil
}

// miners := manager.ListMiners()
// for _, miner := range miners { logging.Info(miner.GetName()) }
func (manager *Manager) ListMiners() []Miner {
	manager.mutex.RLock()
	defer manager.mutex.RUnlock()
	miners := make([]Miner, 0, len(manager.miners))
	for _, miner := range manager.miners {
		miners = append(miners, miner)
	}
	return miners
}

// simulatedMiner := NewSimulatedMiner(SimulatedMinerConfig{Name: "sim-rx0"})
// if err := manager.RegisterMiner(simulatedMiner); err != nil { return err }
func (manager *Manager) RegisterMiner(miner Miner) error {
	name := miner.GetName()

	manager.mutex.Lock()
	if _, exists := manager.miners[name]; exists {
		manager.mutex.Unlock()
		return ErrMinerExists(name)
	}
	manager.miners[name] = miner
	manager.mutex.Unlock()

	logging.Info("registered miner", logging.Fields{"name": name})

	// Emit miner started event (outside lock)
	manager.emitEvent(EventMinerStarted, map[string]interface{}{
		"name": name,
	})

	return nil
}

// for _, availableMiner := range manager.ListAvailableMiners() { logging.Info(availableMiner.Name, nil) }
func (manager *Manager) ListAvailableMiners() []AvailableMiner {
	return []AvailableMiner{
		{
			Name:        "xmrig",
			Description: "XMRig is a high performance, open source, cross platform RandomX, KawPow, CryptoNight and AstroBWT CPU/GPU miner and RandomX benchmark.",
		},
		{
			Name:        "tt-miner",
			Description: "TT-Miner is a high performance NVIDIA GPU miner for various algorithms including Ethash, KawPow, ProgPow, and more. Requires CUDA.",
		},
	}
}

// manager.startStatsCollection() // NewManager() uses this to poll each running miner every HighResolutionInterval
func (manager *Manager) startStatsCollection() {
	manager.waitGroup.Add(1)
	go func() {
		defer manager.waitGroup.Done()
		defer func() {
			if r := recover(); r != nil {
				logging.Error("panic in stats collection goroutine", logging.Fields{"panic": r})
			}
		}()
		ticker := time.NewTicker(HighResolutionInterval)
		defer ticker.Stop()

		for {
			select {
			case <-ticker.C:
				manager.collectMinerStats()
			case <-manager.stopChan:
				return
			}
		}
	}()
}

// ctx, cancel := context.WithTimeout(ctx, statsCollectionTimeout)
const statsCollectionTimeout = 5 * time.Second

// manager.collectMinerStats() // the stats ticker calls this to poll all running miners in parallel
func (manager *Manager) collectMinerStats() {
	// Take a snapshot of miners under read lock - minimize lock duration
	manager.mutex.RLock()
	if len(manager.miners) == 0 {
		manager.mutex.RUnlock()
		return
	}

	type minerInfo struct {
		miner     Miner
		minerType string
	}
	miners := make([]minerInfo, 0, len(manager.miners))
	for _, miner := range manager.miners {
		// Use the miner's GetType() method for proper type identification
		miners = append(miners, minerInfo{miner: miner, minerType: miner.GetType()})
	}
	databaseEnabled := manager.databaseEnabled // Copy to avoid holding lock
	manager.mutex.RUnlock()

	now := time.Now()

	// Collect stats from all miners in parallel
	var collectionWaitGroup sync.WaitGroup
	for _, entry := range miners {
		collectionWaitGroup.Add(1)
		go func(miner Miner, minerType string) {
			defer collectionWaitGroup.Done()
			defer func() {
				if r := recover(); r != nil {
					logging.Error("panic in single miner stats collection", logging.Fields{
						"panic": r,
						"miner": miner.GetName(),
					})
				}
			}()
			manager.collectSingleMinerStats(miner, minerType, now, databaseEnabled)
		}(entry.miner, entry.minerType)
	}
	collectionWaitGroup.Wait()
}

// for attempt := 0; attempt <= statsRetryCount; attempt++ { ... }
const statsRetryCount = 2

// time.Sleep(statsRetryDelay) // between retry attempts
const statsRetryDelay = 500 * time.Millisecond

// manager.collectSingleMinerStats(miner, "xmrig", time.Now(), true) // retries up to statsRetryCount times; persists to DB if databaseEnabled
func (manager *Manager) collectSingleMinerStats(miner Miner, minerType string, now time.Time, databaseEnabled bool) {
	minerName := miner.GetName()

	var stats *PerformanceMetrics
	var lastErr error

	// Retry loop for transient failures
	for attempt := 0; attempt <= statsRetryCount; attempt++ {
		// Use context with timeout to prevent hanging on unresponsive miner APIs
		ctx, cancel := context.WithTimeout(context.Background(), statsCollectionTimeout)
		stats, lastErr = miner.GetStats(ctx)
		cancel() // Release context immediately

		if lastErr == nil {
			break // Success
		}

		// Log retry attempts at debug level
		if attempt < statsRetryCount {
			logging.Debug("retrying stats collection", logging.Fields{
				"miner":   minerName,
				"attempt": attempt + 1,
				"error":   lastErr.Error(),
			})
			time.Sleep(statsRetryDelay)
		}
	}

	if lastErr != nil {
		logging.Error("failed to get miner stats after retries", logging.Fields{
			"miner":   minerName,
			"error":   lastErr.Error(),
			"retries": statsRetryCount,
		})
		RecordStatsCollection(true, true)
		return
	}

	// Record stats collection (retried if we did any retries)
	RecordStatsCollection(stats != nil && lastErr == nil, false)

	point := HashratePoint{
		Timestamp: now,
		Hashrate:  stats.Hashrate,
	}

	// Add to in-memory history (rolling window)
	// Note: AddHashratePoint and ReduceHashrateHistory must be thread-safe
	miner.AddHashratePoint(point)
	miner.ReduceHashrateHistory(now)

	// Persist to database if enabled
	if databaseEnabled {
		databasePoint := database.HashratePoint{
			Timestamp: point.Timestamp,
			Hashrate:  point.Hashrate,
		}
		// database.InsertHashratePoint(ctx, "xmrig-rx_0", databasePoint, database.ResolutionHigh) // persists a single sample
		databaseWriteContext, databaseCancel := context.WithTimeout(context.Background(), statsCollectionTimeout)
		if err := database.InsertHashratePoint(databaseWriteContext, minerName, minerType, databasePoint, database.ResolutionHigh); err != nil {
			logging.Warn("failed to persist hashrate", logging.Fields{"miner": minerName, "error": err})
		}
		databaseCancel()
	}

	// Emit stats event for real-time WebSocket updates
	manager.emitEvent(EventMinerStats, MinerStatsData{
		Name:        minerName,
		Hashrate:    stats.Hashrate,
		Shares:      stats.Shares,
		Rejected:    stats.Rejected,
		Uptime:      stats.Uptime,
		Algorithm:   stats.Algorithm,
		DiffCurrent: stats.DiffCurrent,
	})
}

// points, err := manager.GetMinerHashrateHistory("xmrig")
// for _, point := range points { logging.Info("hashrate", logging.Fields{"time": point.Timestamp, "rate": point.Hashrate}) }
func (manager *Manager) GetMinerHashrateHistory(name string) ([]HashratePoint, error) {
	manager.mutex.RLock()
	defer manager.mutex.RUnlock()
	miner, exists := manager.miners[name]
	if !exists {
		return nil, ErrMinerNotFound(name)
	}
	return miner.GetHashrateHistory(), nil
}

// ctx, cancel := context.WithTimeout(context.Background(), ShutdownTimeout)
const ShutdownTimeout = 10 * time.Second

// defer manager.Stop() // stops miners, waits for goroutines, and closes the database during shutdown
func (manager *Manager) Stop() {
	manager.stopOnce.Do(func() {
		// Stop all running miners first
		manager.mutex.Lock()
		for name, miner := range manager.miners {
			if err := miner.Stop(); err != nil {
				logging.Warn("failed to stop miner", logging.Fields{"miner": name, "error": err})
			}
		}
		manager.mutex.Unlock()

		close(manager.stopChan)

		// Wait for goroutines with timeout
		done := make(chan struct{})
		go func() {
			manager.waitGroup.Wait()
			close(done)
		}()

		select {
		case <-done:
			logging.Info("all goroutines stopped gracefully")
		case <-time.After(ShutdownTimeout):
			logging.Warn("shutdown timeout - some goroutines may not have stopped")
		}

		// Close the database
		if manager.databaseEnabled {
			if err := database.Close(); err != nil {
				logging.Warn("failed to close database", logging.Fields{"error": err})
			}
		}
	})
}

// stats, err := manager.GetMinerHistoricalStats("xmrig")
// if err == nil { logging.Info("stats", logging.Fields{"average": stats.AverageRate}) }
func (manager *Manager) GetMinerHistoricalStats(minerName string) (*database.HashrateStats, error) {
	if !manager.databaseEnabled {
		return nil, ErrDatabaseError("database persistence is disabled")
	}
	return database.GetHashrateStats(minerName)
}

// points, err := manager.GetMinerHistoricalHashrate("xmrig", time.Now().Add(-1*time.Hour), time.Now())
func (manager *Manager) GetMinerHistoricalHashrate(minerName string, since, until time.Time) ([]HashratePoint, error) {
	if !manager.databaseEnabled {
		return nil, ErrDatabaseError("database persistence is disabled")
	}

	databasePoints, err := database.GetHashrateHistory(minerName, database.ResolutionHigh, since, until)
	if err != nil {
		return nil, err
	}

	// Convert database points to mining points
	points := make([]HashratePoint, len(databasePoints))
	for i, databasePoint := range databasePoints {
		points[i] = HashratePoint{
			Timestamp: databasePoint.Timestamp,
			Hashrate:  databasePoint.Hashrate,
		}
	}
	return points, nil
}

// allStats, err := manager.GetAllMinerHistoricalStats()
// for _, stats := range allStats { logging.Info("stats", logging.Fields{"miner": stats.MinerName, "average": stats.AverageRate}) }
func (manager *Manager) GetAllMinerHistoricalStats() ([]database.HashrateStats, error) {
	if !manager.databaseEnabled {
		return nil, ErrDatabaseError("database persistence is disabled")
	}
	return database.GetAllMinerStats()
}

// if manager.IsDatabaseEnabled() { /* persist stats */ }
func (manager *Manager) IsDatabaseEnabled() bool {
	return manager.databaseEnabled
}