package user

import (
	"context"
	"fmt"

	"github.com/perfect-panel/server/internal/config"
	"github.com/perfect-panel/server/internal/model/user"
	"github.com/perfect-panel/server/internal/svc"
	"github.com/perfect-panel/server/internal/types"
	"github.com/perfect-panel/server/pkg/constant"
	"github.com/perfect-panel/server/pkg/logger"
	"github.com/perfect-panel/server/pkg/xerr"
	"github.com/pkg/errors"
	"gorm.io/gorm"
)

type UnbindDeviceLogic struct {
	logger.Logger
	ctx    context.Context
	svcCtx *svc.ServiceContext
}

// Unbind Device
func NewUnbindDeviceLogic(ctx context.Context, svcCtx *svc.ServiceContext) *UnbindDeviceLogic {
	return &UnbindDeviceLogic{
		Logger: logger.WithContext(ctx),
		ctx:    ctx,
		svcCtx: svcCtx,
	}
}

func (l *UnbindDeviceLogic) UnbindDevice(req *types.UnbindDeviceRequest) error {
	userInfo, ok := l.ctx.Value(constant.CtxKeyUser).(*user.User)
	if !ok {
		return errors.Wrapf(xerr.NewErrCode(xerr.InvalidAccess), "Invalid Access")
	}

	device, err := l.svcCtx.UserModel.FindOneDevice(l.ctx, req.Id)
	if err != nil {
		return errors.Wrapf(xerr.NewErrCode(xerr.DeviceNotExist), "find device")
	}

	isSelf := (device.UserId == userInfo.Id)

	if !isSelf {
		// Not own device — check if in the same family
		if !l.isInSameFamily(userInfo.Id, device.UserId) {
			return errors.Wrapf(xerr.NewErrCode(xerr.InvalidParams), "not in same family")
		}
	}

	targetUser, err := l.svcCtx.UserModel.FindOne(l.ctx, device.UserId)
	if err != nil {
		return errors.Wrapf(xerr.NewErrCode(xerr.DatabaseQueryError), "find target user")
	}

	// If kicking another user (not self), check if subscription transfer is needed
	if !isSelf {
		if err := l.transferSubscriptionsIfNeeded(userInfo, targetUser); err != nil {
			return err
		}
	}

	currentSessionID, _ := l.ctx.Value(constant.CtxKeySessionID).(string)
	return l.logoutUnbind(targetUser, device, currentSessionID)
}

func (l *UnbindDeviceLogic) logoutUnbind(userInfo *user.User, device *user.Device, currentSessionID string) error {
	// 1. 事务前查出 AuthMethods，用于事务后清邮箱缓存
	authMethods, _ := l.svcCtx.UserModel.FindUserAuthMethods(l.ctx, userInfo.Id)

	// 2. 事务前收集受影响的家庭成员 ID（事务会改变家庭关系，之后查不到）
	familyMemberIDs := l.collectFamilyMemberIDs(userInfo.Id)

	// 3. 事务：解绑家庭组 + 解绑非 device 的登录方式
	err := l.svcCtx.DB.Transaction(func(tx *gorm.DB) error {
		// 解绑家庭组（owner 解散整个家庭，member 退出家庭）
		exitHelper := newFamilyExitHelper(l.ctx, l.svcCtx)
		if err := exitHelper.removeUserFromActiveFamily(tx, userInfo.Id, true); err != nil {
			return err
		}

		// 解绑邮箱等非 device 类型的 auth_methods（保留 device 绑定）
		if err := tx.Where("user_id = ? AND auth_type != ?", userInfo.Id, "device").
			Delete(&user.AuthMethods{}).Error; err != nil {
			return errors.Wrapf(xerr.NewErrCode(xerr.DatabaseDeletedError), "delete non-device auth methods failed")
		}

		return nil
	})
	if err != nil {
		return err
	}

	// 4. 事务提交后立即清缓存（避免 KickDevice/clearAllSessions 触发重连时命中旧缓存）
	for _, am := range authMethods {
		if am.AuthType == "email" && am.AuthIdentifier != "" {
			cacheKey := fmt.Sprintf("cache:user:email:%s", am.AuthIdentifier)
			if delErr := l.svcCtx.Redis.Del(l.ctx, cacheKey).Err(); delErr != nil {
				l.Errorw("clear email cache failed",
					logger.Field("user_id", userInfo.Id),
					logger.Field("email", am.AuthIdentifier),
					logger.Field("error", delErr.Error()),
				)
			}
		}
	}
	if clearErr := l.svcCtx.UserModel.ClearUserCache(l.ctx, userInfo); clearErr != nil {
		l.Errorw("clear user cache failed",
			logger.Field("user_id", userInfo.Id),
			logger.Field("error", clearErr.Error()),
		)
	}

	// 5. Kick 设备（缓存已清，重连时 FindOne 会查到最新数据）
	l.svcCtx.DeviceManager.KickDevice(device.UserId, device.Identifier)

	// 6. 清除该用户所有 session（旧 token 全部失效）
	l.clearAllSessions(userInfo.Id)

	// 7. 清理受影响的家庭成员缓存（家庭解散后成员需感知变化）
	for _, memberID := range familyMemberIDs {
		if memberUser, findErr := l.svcCtx.UserModel.FindOne(l.ctx, memberID); findErr == nil {
			if clearErr := l.svcCtx.UserModel.ClearUserCache(l.ctx, memberUser); clearErr != nil {
				l.Errorw("clear family member cache failed",
					logger.Field("member_id", memberID),
					logger.Field("error", clearErr.Error()),
				)
			}
		}
	}

	return nil
}

// collectFamilyMemberIDs 收集当前用户所在家庭的其他成员 ID（需在事务前调用）
func (l *UnbindDeviceLogic) collectFamilyMemberIDs(userID int64) []int64 {
	var result struct {
		FamilyId int64
	}
	err := l.svcCtx.DB.WithContext(l.ctx).
		Model(&user.UserFamilyMember{}).
		Select("family_id").
		Where("user_id = ? AND status = ?", userID, user.FamilyMemberActive).
		First(&result).Error
	if err != nil || result.FamilyId == 0 {
		return nil
	}

	var memberIDs []int64
	l.svcCtx.DB.WithContext(l.ctx).
		Model(&user.UserFamilyMember{}).
		Where("family_id = ? AND status = ? AND user_id != ?", result.FamilyId, user.FamilyMemberActive, userID).
		Pluck("user_id", &memberIDs)

	return memberIDs
}

// clearAllSessions 清除指定用户的所有会话
func (l *UnbindDeviceLogic) clearAllSessions(userId int64) {
	sessionsKey := fmt.Sprintf("%s%v", config.UserSessionsKeyPrefix, userId)
	sessions, err := l.svcCtx.Redis.ZRange(l.ctx, sessionsKey, 0, -1).Result()
	if err != nil {
		l.Errorw("获取用户会话列表失败",
			logger.Field("user_id", userId),
			logger.Field("error", err.Error()),
		)
		return
	}

	if len(sessions) == 0 {
		return
	}

	pipe := l.svcCtx.Redis.TxPipeline()
	for _, sessionID := range sessions {
		if sessionID == "" {
			continue
		}
		pipe.Del(l.ctx, fmt.Sprintf("%v:%v", config.SessionIdKey, sessionID))
	}
	pipe.Del(l.ctx, sessionsKey)

	if _, err = pipe.Exec(l.ctx); err != nil {
		l.Errorw("清理会话缓存失败",
			logger.Field("user_id", userId),
			logger.Field("error", err.Error()),
		)
	}

	l.Infow("退出登录-清除所有Session",
		logger.Field("user_id", userId),
		logger.Field("count", len(sessions)),
	)
}

// isInSameFamily checks whether two users belong to the same active family
func (l *UnbindDeviceLogic) isInSameFamily(userID1, userID2 int64) bool {
	var relation1 struct{ FamilyId int64 }
	err := l.svcCtx.DB.WithContext(l.ctx).
		Model(&user.UserFamilyMember{}).
		Select("family_id").
		Where("user_id = ? AND status = ?", userID1, user.FamilyMemberActive).
		First(&relation1).Error
	if err != nil || relation1.FamilyId == 0 {
		return false
	}

	var count int64
	l.svcCtx.DB.WithContext(l.ctx).
		Model(&user.UserFamilyMember{}).
		Where("family_id = ? AND user_id = ? AND status = ?",
			relation1.FamilyId, userID2, user.FamilyMemberActive).
		Count(&count)
	return count > 0
}

// transferSubscriptionsIfNeeded transfers subscriptions from the kicked user to the kicker
func (l *UnbindDeviceLogic) transferSubscriptionsIfNeeded(kicker *user.User, kicked *user.User) error {
	// Query kicked user's subscriptions
	var subscribes []user.Subscribe
	if err := l.svcCtx.DB.WithContext(l.ctx).
		Model(&user.Subscribe{}).
		Where("user_id = ?", kicked.Id).
		Find(&subscribes).Error; err != nil {
		return nil // query error, skip transfer
	}
	if len(subscribes) == 0 {
		return nil // no subscriptions to transfer
	}

	// Transfer subscriptions: UPDATE user_subscribe SET user_id = kicker WHERE user_id = kicked
	if err := l.svcCtx.DB.WithContext(l.ctx).
		Model(&user.Subscribe{}).
		Where("user_id = ?", kicked.Id).
		Update("user_id", kicker.Id).Error; err != nil {
		return errors.Wrapf(xerr.NewErrCode(xerr.DatabaseUpdateError), "transfer subscriptions failed")
	}

	// Clear subscription caches for both users
	for _, sub := range subscribes {
		_ = l.svcCtx.UserModel.ClearSubscribeCache(l.ctx, &sub)
	}

	l.Infow("subscriptions transferred",
		logger.Field("from_user_id", kicked.Id),
		logger.Field("to_user_id", kicker.Id),
		logger.Field("count", len(subscribes)),
	)
	return nil
}