package service

import (
	"errors"
	"time"

	"gorm.io/gorm"

	"laic-backend/cache"
	"laic-backend/common"
	"laic-backend/logger"
	"laic-backend/model"
	"laic-backend/tool"
	"laic-backend/vo"
)

type DockService struct{}

var DefaultDockService = &DockService{}

// withUserFilter admin 不过滤，普通用户按 user_id 过滤（GORM scope）
func withUserFilter(userID int64, isAdmin bool) func(*gorm.DB) *gorm.DB {
	if isAdmin {
		return func(db *gorm.DB) *gorm.DB { return db }
	}
	return func(db *gorm.DB) *gorm.DB { return db.Where("user_id = ?", userID) }
}

// withDockFilter admin 不过滤，普通用户按所属机巢过滤（用于无 user_id 的 dock 关联表，如 alarm / command_log）
func withDockFilter(userID int64, isAdmin bool) func(*gorm.DB) *gorm.DB {
	if isAdmin {
		return func(db *gorm.DB) *gorm.DB { return db }
	}
	return func(db *gorm.DB) *gorm.DB {
		return db.Where("dock_id IN (SELECT dock_id FROM dock WHERE user_id = ?)", userID)
	}
}

// GetPage 机巢分页列表
func (s *DockService) GetPage(userID int64, isAdmin bool, req *vo.DockPageReq) (*common.PageResponse[model.Dock], *common.BusiError) {
	db := common.DB.Model(&model.Dock{}).Scopes(withUserFilter(userID, isAdmin))
	if req.Status != "" {
		db = db.Where("status = ?", req.Status)
	}
	if req.RegisterStatus != "" {
		db = db.Where("register_status = ?", req.RegisterStatus)
	}
	if req.Keyword != "" {
		kw := "%" + req.Keyword + "%"
		db = db.Where("name LIKE ? OR dock_id LIKE ? OR code LIKE ?", kw, kw, kw)
	}

	var total int64
	if err := db.Count(&total).Error; err != nil {
		logger.ERROR("统计机巢失败", err)
		return nil, common.ErrInternal
	}
	var list []model.Dock
	if err := db.Scopes(req.Paginate).Order("id DESC").Find(&list).Error; err != nil {
		logger.ERROR("查询机巢列表失败", err)
		return nil, common.ErrInternal
	}
	return common.Page(req.Pagination, total, list), nil
}

// GetDetail 机巢详情（含实时状态）
func (s *DockService) GetDetail(userID int64, isAdmin bool, id int64) (*vo.DockVO, *common.BusiError) {
	var dock model.Dock
	if err := common.DB.Scopes(withUserFilter(userID, isAdmin)).First(&dock, id).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, common.ErrDockNotFound
		}
		return nil, common.ErrInternal
	}
	online, realtime := s.realtime(dock.DockID)
	return &vo.DockVO{Dock: &dock, Online: online, Realtime: realtime}, nil
}

// GetStatus 机巢纯实时状态
func (s *DockService) GetStatus(userID int64, isAdmin bool, id int64) (*vo.DockStatusVO, *common.BusiError) {
	var dock model.Dock
	if err := common.DB.Scopes(withUserFilter(userID, isAdmin)).Select("dock_id").First(&dock, id).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, common.ErrDockNotFound
		}
		return nil, common.ErrInternal
	}
	online, realtime := s.realtime(dock.DockID)
	return &vo.DockStatusVO{DockID: dock.DockID, Online: online, Realtime: realtime}, nil
}

// Create 手动登记机巢（归属当前用户；admin 可指定 userID）
func (s *DockService) Create(userID int64, isAdmin bool, req *vo.DockCreateReq) (*model.Dock, *common.BusiError) {
	owner := userID
	if isAdmin && req.UserID != 0 {
		owner = req.UserID
	}

	id, err := tool.NextID()
	if err != nil {
		return nil, common.ErrInternal
	}
	now := time.Now()
	dock := &model.Dock{
		ID:             id,
		UserID:         owner,
		DockID:         req.DockID,
		Name:           req.Name,
		Code:           req.Code,
		SN:             req.SN,
		Iccid:          req.Iccid,
		Location:       req.Location,
		Longitude:      req.Longitude,
		Latitude:       req.Latitude,
		Altitude:       req.Altitude,
		Status:         "offline",
		RegisterStatus: "registered",
		DockIDSource:   "manual",
		ProtocolVer:    "1.0",
		CreatedAt:      now,
		UpdatedAt:      now,
	}
	if err := common.DB.Create(dock).Error; err != nil {
		if code, _ := common.ParseError(err); code == 1062 {
			return nil, common.ErrDockExists
		}
		logger.ERROR("登记机巢失败", err)
		return nil, common.ErrInternal
	}
	return dock, nil
}

// Update 更新/认领机巢
func (s *DockService) Update(userID int64, isAdmin bool, id int64, req *vo.DockUpdateReq) (*model.Dock, *common.BusiError) {
	var dock model.Dock
	if err := common.DB.Scopes(withUserFilter(userID, isAdmin)).First(&dock, id).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, common.ErrDockNotFound
		}
		return nil, common.ErrInternal
	}

	updates := map[string]any{"updated_at": time.Now()}
	if req.Name != "" {
		updates["name"] = req.Name
	}
	if req.Code != "" {
		updates["code"] = req.Code
	}
	if req.Location != nil {
		updates["location"] = *req.Location
	}
	if req.Longitude != nil {
		updates["longitude"] = *req.Longitude
	}
	if req.Latitude != nil {
		updates["latitude"] = *req.Latitude
	}
	if req.Altitude != nil {
		updates["altitude"] = *req.Altitude
	}

	if isAdmin && req.UserID != 0 {
		updates["user_id"] = req.UserID
	}
	if req.RegisterAs == "registered" {
		updates["register_status"] = "registered"
		if isAdmin && req.UserID != 0 {
			updates["user_id"] = req.UserID
		} else {
			updates["user_id"] = userID // 普通用户认领 → 归属自己
		}
	}

	if err := common.DB.Transaction(func(tx *gorm.DB) error {
		if err := tx.Model(&dock).Updates(updates).Error; err != nil {
			return err
		}
		if owner, ok := updates["user_id"]; ok {
			if err := tx.Model(&model.Drone{}).Where("dock_id = ?", dock.DockID).Update("user_id", owner).Error; err != nil {
				return err
			}
		}
		return nil
	}); err != nil {
		logger.ERROR("更新机巢失败", err)
		return nil, common.ErrInternal
	}
	common.DB.First(&dock, id)
	return &dock, nil
}

// Delete 硬删除机巢及其关联设备数据
func (s *DockService) Delete(userID int64, isAdmin bool, id int64) *common.BusiError {
	var dock model.Dock
	if err := common.DB.Scopes(withUserFilter(userID, isAdmin)).First(&dock, id).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return common.ErrDockNotFound
		}
		logger.ERROR("查询待删除机巢失败", err)
		return common.ErrInternal
	}

	var taskIDs []string
	var droneSNs []string
	var simCardIDs []int64
	if err := common.DB.Transaction(func(tx *gorm.DB) error {
		if err := tx.Model(&model.TaskPlan{}).Where("dock_id = ?", dock.DockID).Pluck("id", &taskIDs).Error; err != nil {
			return err
		}
		if err := tx.Model(&model.Drone{}).Where("dock_id = ?", dock.DockID).Pluck("drone_sn", &droneSNs).Error; err != nil {
			return err
		}
		if err := tx.Model(&model.SimCard{}).Where("dock_id = ?", dock.DockID).Pluck("id", &simCardIDs).Error; err != nil {
			return err
		}

		if len(droneSNs) > 0 {
			var videoIDs []int64
			if err := tx.Model(&model.Video{}).Where("drone_sn IN ?", droneSNs).Pluck("id", &videoIDs).Error; err != nil {
				return err
			}
			if len(videoIDs) > 0 {
				if err := tx.Where("video_id IN ?", videoIDs).Delete(&model.DownloadLog{}).Error; err != nil {
					return err
				}
				if err := tx.Where("id IN ?", videoIDs).Delete(&model.Video{}).Error; err != nil {
					return err
				}
			}
		}
		if len(simCardIDs) > 0 {
			if err := tx.Where("sim_card_id IN ?", simCardIDs).Delete(&model.SimUsageRecord{}).Error; err != nil {
				return err
			}
			if err := tx.Where("sim_card_id IN ?", simCardIDs).Delete(&model.SimRechargeLog{}).Error; err != nil {
				return err
			}
			if err := tx.Where("id IN ?", simCardIDs).Delete(&model.SimCard{}).Error; err != nil {
				return err
			}
		}
		for _, item := range []any{
			&model.Alarm{}, &model.DeviceCommandLog{}, &model.WorkflowState{},
			&model.TaskExecution{}, &model.TaskPlan{}, &model.LiveSession{}, &model.Drone{},
		} {
			if err := tx.Where("dock_id = ?", dock.DockID).Delete(item).Error; err != nil {
				return err
			}
		}
		return tx.Delete(&dock).Error
	}); err != nil {
		logger.ERROR("硬删除机巢失败", err)
		return common.ErrInternal
	}

	for _, taskID := range taskIDs {
		DefaultScheduler.RemoveTask(taskID)
	}
	_ = common.SetRemove(cache.OnlineDockSetKey, dock.DockID)
	_ = common.Delete(cache.DockHeartbeatKeyOf(dock.DockID))
	_ = common.Delete(cache.DockStatusKeyOf(dock.DockID))
	return nil
}

// realtime 读取机巢实时状态（Redis Hash + 在线集合）
func (s *DockService) realtime(dockID string) (bool, map[string]string) {
	realtime, err := common.HashGetAll(cache.DockStatusKeyOf(dockID))
	if err != nil {
		realtime = map[string]string{}
	}
	online, _ := common.SetMemberExists(cache.OnlineDockSetKey, dockID)
	return online, realtime
}

// EnsureFromOnline 设备自发现：不存在则登记为 pending，存在则更新在线状态与软件版本
func (s *DockService) EnsureFromOnline(dockID string, st statusOnline) {
	online := st.Status == "online"
	status := "offline"
	if online {
		status = "online"
	}

	var dock model.Dock
	err := common.DB.Where("dock_id = ?", dockID).First(&dock).Error
	if errors.Is(err, gorm.ErrRecordNotFound) {
		id, e := tool.NextID()
		if e != nil {
			logger.ERROR("生成机巢 ID 失败", e)
			return
		}
		now := time.Now()
		dock = model.Dock{
			ID:             id,
			UserID:         0, // 待认领
			DockID:         dockID,
			Name:           st.Name,
			Code:           dockID,
			SN:             dockID,
			Location:       st.Location,
			Latitude:       st.Latitude,
			Longitude:      st.Longitude,
			RegisterStatus: "pending",
			DockIDSource:   "auto",
			SoftwareVer:    st.SoftwareVersion,
			ProtocolVer:    st.ProtocolVersion,
			Status:         status,
			CreatedAt:      now,
			UpdatedAt:      now,
		}
		if err := common.DB.Create(&dock).Error; err != nil {
			logger.ERROR("登记机巢失败", err)
			return
		}
	} else if err == nil {
		updates := map[string]any{"status": status, "updated_at": time.Now()}
		if st.SoftwareVersion != "" {
			updates["software_ver"] = st.SoftwareVersion
		}
		if st.ProtocolVersion != "" {
			updates["protocol_ver"] = st.ProtocolVersion
		}
		if dock.Name == "" && st.Name != "" {
			updates["name"] = st.Name
		}
		if dock.Location == "" && st.Location != "" {
			updates["location"] = st.Location
		}
		if dock.Latitude == 0 && st.Latitude != 0 {
			updates["latitude"] = st.Latitude
		}
		if dock.Longitude == 0 && st.Longitude != 0 {
			updates["longitude"] = st.Longitude
		}
		if err := common.DB.Model(&dock).Updates(updates).Error; err != nil {
			logger.ERROR("更新机巢在线状态失败", err)
		}
	}

	// 在线集合
	if online {
		_ = common.SetAdd(cache.OnlineDockSetKey, dockID)
		refreshDeviceHeartbeat(cache.DockHeartbeatKeyOf(dockID))
	} else {
		_ = common.SetRemove(cache.OnlineDockSetKey, dockID)
		_ = common.Delete(cache.DockHeartbeatKeyOf(dockID))
	}

	broadcast("dock.status", map[string]any{
		"dockId":      dockID,
		"online":      online,
		"softwareVer": st.SoftwareVersion,
		"protocolVer": st.ProtocolVersion,
	})
}