package services

import (
	"context"
	"platform/pkg/orm"
	"platform/web/models"
)

type NodeServiceErr string

func (e NodeServiceErr) Error() string {
	return string(e)
}

var Node = &nodeService{}

type nodeService struct{}

func (s *nodeService) Filter(ctx context.Context, userId int32, count int, config ...NodeFilterConfig) ([]*models.Node, error) {
	_config := NodeFilterConfig{}
	if len(config) > 0 {
		_config = config[0]
	}

	// 筛选符合条件且未分配给用户过的节点
	// 静态条件：省，市，运营商
	// 排序方式，1.分配给该用户的次数 2.分配给全部用户的次数 3.todo 节点的健康状态
	var nodes []*FilteredNode
	orm.DB.Raw(filterSqlRaw, userId, _config.Isp, _config.Prov, _config.City).
		Limit(count).
		Find(&nodes)

	// todo 异步任务关闭代理

	// todo 异步任务缩容

	return nil, nil
}

type NodeFilterConfig struct {
	Isp  string `json:"isp"`
	Prov string `json:"prov"`
	City string `json:"city"`
}

type NodeFilterAsyncTask struct {
	Config NodeFilterConfig `json:"config"`
	Count  int              `json:"count"`
}

// 筛选节点的SQL语句，暂时用不到
// 筛选已连接的符合条件且未分配给用户过的节点
//
//	静态条件：省，市，运营商
//	排序方式，1.分配给该用户的次数 2.分配给全部用户的次数
const filterSqlRaw = `
select
    n.id as id,
    n.name as name,
    n.host as host,
    n.fwd_port as fwd_port,
    count(c.*) as total,
    count(c.*) filter ( where c.user_id = ? ) as assigned
from
    node n
    left join public.channel c
    on n.id = c.node_id and c.expiration > now() and c.deleted_at is null
where
    n.isp = ? and
    n.prov = ? and
    n.city = ?
group by
    n.id
order by
    assigned, total
`

type FilteredNode struct {
	Id       int32  `json:"id"`
	Name     string `json:"name"`
	Host     string `json:"host"`
	FwdPort  int32  `json:"fwd_port"`
	Total    int32  `json:"total"`
	Assigned int32  `json:"assigned"`
}