package biz

import (
	"context"
	"errors"
	"time"

	"github.com/go-kratos/kratos/v2/log"
)

// Socket 是Socket模型
type Socket struct {
	ID      string
	Message string
}

// SocketRepo 是Socket repo的接口
type SocketRepo interface {
	SendMessage(ctx context.Context, to []string, from []string, message []string) error
	IsOnline(ctx context.Context, userID string) (bool, error)
	UpdateUserStatus(ctx context.Context, userID string, roomID string, connected bool) error
	GetOnlineUsers(ctx context.Context, roomID string) ([]string, error)
	CleanupInactiveUsers(ctx context.Context, timeout time.Duration) error
}

// SocketUsecase 是Socket usecase的接口
type SocketUsecase interface {
	SendMessage(ctx context.Context, to []string, from []string, message []string) error
	IsOnline(ctx context.Context, userID string) (bool, error)
	UpdateUserStatus(ctx context.Context, userID string, roomID string, connected bool) error
	GetOnlineUsers(ctx context.Context, roomID string) ([]string, error)
	CleanupInactiveUsers(ctx context.Context, timeout time.Duration) error
}

// socketUsecase 是Socket usecase的实现
type socketUsecase struct {
	repo SocketRepo
	log  *log.Helper
}

// NewSocketUsecase 创建一个新的Socket usecase
func NewSocketUsecase(repo SocketRepo, logger log.Logger) SocketUsecase {
	return &socketUsecase{repo: repo, log: log.NewHelper(logger)}
}

// SendMessage 发送消息
func (su *socketUsecase) SendMessage(ctx context.Context, to []string, from []string, message []string) error {
	// 参数验证
	if len(to) == 0 {
		return errors.New("receiver list is empty")
	}
	if len(message) == 0 {
		return errors.New("message is empty")
	}

	// 检查接收者是否在线
	for _, receiver := range to {
		online, err := su.repo.IsOnline(ctx, receiver)
		if err != nil {
			su.log.WithContext(ctx).Errorf("check online status failed: %v", err)
			return err
		}
		if !online {
			su.log.WithContext(ctx).Warnf("receiver %s is offline", receiver)
		}
	}

	// 发送消息
	return su.repo.SendMessage(ctx, to, from, message)
}

// IsOnline 检查用户是否在线
func (su *socketUsecase) IsOnline(ctx context.Context, userID string) (bool, error) {
	return su.repo.IsOnline(ctx, userID)
}

// UpdateUserStatus 更新用户在线状态
func (su *socketUsecase) UpdateUserStatus(ctx context.Context, userID string, roomID string, connected bool) error {
	return su.repo.UpdateUserStatus(ctx, userID, roomID, connected)
}

// GetOnlineUsers 获取在线用户列表
func (su *socketUsecase) GetOnlineUsers(ctx context.Context, roomID string) ([]string, error) {
	return su.repo.GetOnlineUsers(ctx, roomID)
}

// CleanupInactiveUsers 清理不活跃用户
func (su *socketUsecase) CleanupInactiveUsers(ctx context.Context, timeout time.Duration) error {
	return su.repo.CleanupInactiveUsers(ctx, timeout)
}