package device

import (
	"context"
	"fmt"
	"time"

	"iot-base-station/pkg/database"
	"iot-base-station/pkg/security"

	"github.com/go-redis/redis/v8"
	"go.uber.org/zap"
	"gorm.io/gorm"
)

// Manager 设备管理器
type Manager struct {
	db     *gorm.DB
	redis  *redis.Client
	logger *zap.Logger
}

// NewManager 创建设备管理器
func NewManager(db *gorm.DB, redis *redis.Client, logger *zap.Logger) *Manager {
	return &Manager{
		db:     db,
		redis:  redis,
		logger: logger,
	}
}

// CreateDevice 创建设备
func (m *Manager) CreateDevice(ctx context.Context, req *CreateDeviceRequest) (*DeviceResponse, error) {
	// 生成设备ID
	deviceID := generateDeviceID(req.Type)

	// 创建设备对象
	device := &Device{
		ID:       deviceID,
		Name:     req.Name,
		Type:     req.Type,
		Protocol: req.Protocol,
		Status:   StatusOffline,
		Metadata: req.Metadata,
		Config:   req.Config,
		Location: req.Location,
		Firmware: FirmwareInfo{
			Version:     "1.0.0",
			ReleaseDate: time.Now(),
		},
	}

	// 保存到数据库
	if err := m.db.WithContext(ctx).Create(device).Error; err != nil {
		m.logger.Error("Failed to create device", zap.Error(err))
		return nil, fmt.Errorf("failed to create device: %w", err)
	}

	// 创建设备事件
	event := &DeviceEvent{
		ID:        generateEventID(),
		DeviceID:  deviceID,
		Type:      EventConnect,
		Severity:  SeverityInfo,
		Message:   "设备已创建",
		Timestamp: time.Now(),
	}

	if err := m.db.WithContext(ctx).Create(event).Error; err != nil {
		m.logger.Error("Failed to create device event", zap.Error(err))
	}

	m.logger.Info("Device created", zap.String("device_id", deviceID))

	return &device.ToResponse(), nil
}

// ListDevices 获取设备列表
func (m *Manager) ListDevices(ctx context.Context, page, pageSize int, deviceType string) ([]DeviceResponse, int64, error) {
	var devices []Device
	var total int64

	query := m.db.WithContext(ctx).Model(&Device{})

	// 按类型筛选
	if deviceType != "" {
		query = query.Where("type = ?", deviceType)
	}

	// 获取总数
	if err := query.Count(&total).Error; err != nil {
		m.logger.Error("Failed to count devices", zap.Error(err))
		return nil, 0, fmt.Errorf("failed to count devices: %w", err)
	}

	// 分页查询
	offset := (page - 1) * pageSize
	if err := query.Offset(offset).Limit(pageSize).Find(&devices).Error; err != nil {
		m.logger.Error("Failed to list devices", zap.Error(err))
		return nil, 0, fmt.Errorf("failed to list devices: %w", err)
	}

	// 转换为响应格式
	responses := make([]DeviceResponse, len(devices))
	for i, device := range devices {
		responses[i] = device.ToResponse()
	}

	return responses, total, nil
}

// GetDevice 获取设备详情
func (m *Manager) GetDevice(ctx context.Context, deviceID string) (*DeviceResponse, error) {
	var device Device

	if err := m.db.WithContext(ctx).Where("id = ?", deviceID).First(&device).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, fmt.Errorf("device not found")
		}
		m.logger.Error("Failed to get device", zap.Error(err))
		return nil, fmt.Errorf("failed to get device: %w", err)
	}

	return &device.ToResponse(), nil
}

// UpdateDevice 更新设备信息
func (m *Manager) UpdateDevice(ctx context.Context, deviceID string, req *UpdateDeviceRequest) (*DeviceResponse, error) {
	var device Device

	// 查询设备
	if err := m.db.WithContext(ctx).Where("id = ?", deviceID).First(&device).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, fmt.Errorf("device not found")
		}
		m.logger.Error("Failed to get device", zap.Error(err))
		return nil, fmt.Errorf("failed to get device: %w", err)
	}

	// 更新字段
	if req.Name != "" {
		device.Name = req.Name
	}
	if req.Metadata != nil {
		device.Metadata = req.Metadata
	}
	if req.Config.ReportInterval > 0 {
		device.Config.ReportInterval = req.Config.ReportInterval
	}
	if req.Config.Threshold != nil {
		device.Config.Threshold = req.Config.Threshold
	}
	if req.Location.Address != "" {
		device.Location = req.Location
	}

	// 保存更新
	if err := m.db.WithContext(ctx).Save(&device).Error; err != nil {
		m.logger.Error("Failed to update device", zap.Error(err))
		return nil, fmt.Errorf("failed to update device: %w", err)
	}

	// 创建配置更新事件
	event := &DeviceEvent{
		ID:        generateEventID(),
		DeviceID:  deviceID,
		Type:      EventConfig,
		Severity:  SeverityInfo,
		Message:   "设备配置已更新",
		Timestamp: time.Now(),
	}

	if err := m.db.WithContext(ctx).Create(event).Error; err != nil {
		m.logger.Error("Failed to create device event", zap.Error(err))
	}

	m.logger.Info("Device updated", zap.String("device_id", deviceID))

	return &device.ToResponse(), nil
}

// DeleteDevice 删除设备
func (m *Manager) DeleteDevice(ctx context.Context, deviceID string) error {
	// 软删除设备
	if err := m.db.WithContext(ctx).Delete(&Device{}, "id = ?", deviceID).Error; err != nil {
		m.logger.Error("Failed to delete device", zap.Error(err))
		return fmt.Errorf("failed to delete device: %w", err)
	}

	m.logger.Info("Device deleted", zap.String("device_id", deviceID))

	return nil
}

// UpdateDeviceConfig 更新设备配置
func (m *Manager) UpdateDeviceConfig(ctx context.Context, deviceID string, req *UpdateDeviceConfigRequest) error {
	var device Device

	// 查询设备
	if err := m.db.WithContext(ctx).Where("id = ?", deviceID).First(&device).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return fmt.Errorf("device not found")
		}
		m.logger.Error("Failed to get device", zap.Error(err))
		return fmt.Errorf("failed to get device: %w", err)
	}

	// 更新配置
	device.Config = req.Config

	// 保存更新
	if err := m.db.WithContext(ctx).Save(&device).Error; err != nil {
		m.logger.Error("Failed to update device config", zap.Error(err))
		return fmt.Errorf("failed to update device config: %w", err)
	}

	// 创建配置更新事件
	event := &DeviceEvent{
		ID:        generateEventID(),
		DeviceID:  deviceID,
		Type:      EventConfig,
		Severity:  SeverityInfo,
		Message:   "设备配置已更新",
		Timestamp: time.Now(),
	}

	if err := m.db.WithContext(ctx).Create(event).Error; err != nil {
		m.logger.Error("Failed to create device event", zap.Error(err))
	}

	m.logger.Info("Device config updated", zap.String("device_id", deviceID))

	return nil
}

// UpdateFirmware 更新设备固件
func (m *Manager) UpdateFirmware(ctx context.Context, deviceID string, req *UpdateFirmwareRequest) error {
	var device Device

	// 查询设备
	if err := m.db.WithContext(ctx).Where("id = ?", deviceID).First(&device).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return fmt.Errorf("device not found")
		}
		m.logger.Error("Failed to get device", zap.Error(err))
		return fmt.Errorf("failed to get device: %w", err)
	}

	// 更新固件信息
	device.Firmware = FirmwareInfo{
		Version:     req.Version,
		URL:         req.URL,
		Description: req.Description,
		ReleaseDate: time.Now(),
	}

	// 更新设备状态为更新中
	device.Status = StatusUpdating

	// 保存更新
	if err := m.db.WithContext(ctx).Save(&device).Error; err != nil {
		m.logger.Error("Failed to update device firmware", zap.Error(err))
		return fmt.Errorf("failed to update device firmware: %w", err)
	}

	// 创建固件更新事件
	event := &DeviceEvent{
		ID:        generateEventID(),
		DeviceID:  deviceID,
		Type:      EventFirmware,
		Severity:  SeverityInfo,
		Message:   fmt.Sprintf("固件更新开始，版本: %s", req.Version),
		Timestamp: time.Now(),
	}

	if err := m.db.WithContext(ctx).Create(event).Error; err != nil {
		m.logger.Error("Failed to create device event", zap.Error(err))
	}

	m.logger.Info("Device firmware update started", 
		zap.String("device_id", deviceID),
		zap.String("version", req.Version))

	// TODO: 实际的固件更新逻辑
	// 这里应该通过协议适配器发送固件更新命令

	return nil
}

// StartStatusCheck 启动设备状态检查
func (m *Manager) StartStatusCheck() {
	ticker := time.NewTicker(5 * time.Minute)
	defer ticker.Stop()

	for {
		select {
		case <-ticker.C:
			m.checkDeviceStatus()
		}
	}
}

// checkDeviceStatus 检查设备状态
func (m *Manager) checkDeviceStatus() {
	ctx := context.Background()
	var devices []Device

	// 查询所有在线设备
	if err := m.db.WithContext(ctx).Where("status = ?", StatusOnline).Find(&devices).Error; err != nil {
		m.logger.Error("Failed to get online devices", zap.Error(err))
		return
	}

	// 检查每个设备的最后在线时间
	now := time.Now()
	for _, device := range devices {
		if device.LastSeen != nil && now.Sub(*device.LastSeen) > 10*time.Minute {
			// 设备离线
			device.Status = StatusOffline
			m.db.WithContext(ctx).Save(&device)

			// 创建离线事件
			event := &DeviceEvent{
				ID:        generateEventID(),
				DeviceID:  device.ID,
				Type:      EventDisconnect,
				Severity:  SeverityWarning,
				Message:   "设备离线",
				Timestamp: now,
			}

			m.db.WithContext(ctx).Create(event)

			m.logger.Info("Device went offline", zap.String("device_id", device.ID))
		}
	}
}

// generateDeviceID 生成设备ID
func generateDeviceID(deviceType string) string {
	return fmt.Sprintf("%s_%d", deviceType, time.Now().UnixNano())
}

// generateEventID 生成事件ID
func generateEventID() string {
	return fmt.Sprintf("event_%d", time.Now().UnixNano())
}