package ripv2

import (
	"crypto/sha256"
	"fmt"
	"net"
	"sync"
	"time"
)

type Routes struct {
	Routes map[string]Route
	sync.Mutex
}

type Route struct {
	Addr    net.IP
	FIB     bool
	Subnet  net.IPMask
	Nexthop net.IP
	Metric  uint32
	TTL     time.Time
}

func Init() *Routes {
	var routes Routes
	routes.Routes = make(map[string]Route, 25)
	return &routes
}

func (r *Routes) append(route Route) {
	key := route.Addr.String() + route.Subnet.String() + route.Nexthop.String() + fmt.Sprintf("%d", route.Metric)
	h := sha256.New()
	h.Write([]byte(key))
	bs := h.Sum(nil)
	r.Lock()
	defer r.Unlock()
	k, ok := r.Routes[string(bs)]
	if !ok {
		r.Routes[string(bs)] = route
		return
	}
	k.TTL = time.Now()
	r.Routes[string(bs)] = k
}

func (r *Routes) ParseRoutes(addr net.UDPAddr, rip *[]RIP) {
	var route Route
	for _, rip := range *rip {
		/* if not af_inet */
		if rip.AFI != 2 {
			continue
		}

		if rip.Addr == 0 || rip.Subnet == 0 {
			continue
		}

		route = Route{}

		route.Addr = net.IPv4(byte(rip.Addr>>24), byte(rip.Addr>>16), byte(rip.Addr>>8), byte(rip.Addr))
		route.Subnet = net.IPv4Mask(byte(rip.Subnet>>24), byte(rip.Subnet>>16), byte(rip.Subnet>>8), byte(rip.Subnet))
		if rip.Nexthop == 0 {
			route.Nexthop = addr.IP
		} else {
			route.Nexthop = net.IPv4(byte(rip.Nexthop>>24), byte(rip.Nexthop>>16), byte(rip.Nexthop>>8), byte(rip.Nexthop))
		}
		route.Metric = rip.Metric
		route.TTL = time.Now()
		r.append(route)
	}
}