package network

import (
	"sync"

	"github.com/luscis/openlan/pkg/libol"
	"github.com/vishvananda/netlink"
	nl "github.com/vishvananda/netlink"
)

type VRF struct {
	name  string
	table int
	link  nl.Link
	out   *libol.SubLogger
}

var tableId = 1000

func GenTable() int {
	tableId += 1
	return tableId
}

type VRFs struct {
	vrfs map[string]*VRF
	lock sync.RWMutex
}

func (s *VRFs) Get(name string) *VRF {
	s.lock.Lock()
	defer s.lock.Unlock()
	obj, _ := s.vrfs[name]
	return obj
}

func (s *VRFs) Add(name string, obj *VRF) {
	s.lock.Lock()
	defer s.lock.Unlock()
	s.vrfs[name] = obj
}

var vrfs = VRFs{
	vrfs: make(map[string]*VRF, 1024),
}

func NewVRF(name string, table int) *VRF {
	if obj := vrfs.Get(name); obj != nil {
		return obj
	}

	if table == 0 {
		table = GenTable()
	}
	obj := &VRF{
		name:  name,
		table: table,
		out:   libol.NewSubLogger(name),
	}
	vrfs.Add(name, obj)

	return obj
}

func (v *VRF) Up() error {
	if link, _ := nl.LinkByName(v.name); link != nil {
		v.link = link
		return nil
	}

	link := &nl.Vrf{
		LinkAttrs: nl.LinkAttrs{
			Name: v.name,
		},
		Table: uint32(v.table),
	}

	if err := nl.LinkAdd(link); err != nil {
		return err
	}
	if err := nl.LinkSetUp(link); err != nil {
		return err
	}

	v.link = link
	v.out.Info("VRF.Up %s", v.name)

	return nil
}

func (v *VRF) Down() error {
	if v.link == nil {
		return nil
	}

	if err := nl.LinkDel(v.link); err != nil {
		return err
	}

	v.link = nil
	v.out.Info("VRF.Down %s", v.name)

	return nil
}

func (v *VRF) AddSlave(name string) error {
	if v.link == nil {
		return libol.NewErr("VRF %s not up", v.name)
	}

	link, err := netlink.LinkByName(name)
	if link == nil {
		return err
	}

	if err := nl.LinkSetMaster(link, v.link); err != nil {
		return nil
	}

	v.out.Info("VRF.AddSlave %s", name)

	return nil
}

func (v *VRF) DelSlave(name string) error {
	link, _ := netlink.LinkByName(name)
	if link == nil {
		return nil
	}

	if err := nl.LinkSetNoMaster(link); err != nil {
		return nil
	}

	v.out.Info("VRF.DelSlave %s", name)

	return nil
}

func (v *VRF) Table() int {
	return v.table
}

func (v *VRF) Name() string {
	return v.name
}

func (v *VRF) Link() nl.Link {
	return v.link
}