package node

import (
	"fmt"
	"lux/proto"
	"net/netip"

	ipnet "net"
)

type LuxNodeSync struct {
	Synced    map[proto.LuxID]struct{}
	Neighbors map[proto.LuxID]*ipnet.UDPAddr
	SyncState LuxNodeState
}

func NewLuxNodeSync() LuxNodeSync {
	return LuxNodeSync{
		Synced:    make(map[proto.LuxID]struct{}),
		Neighbors: make(map[proto.LuxID]*ipnet.UDPAddr),
		SyncState: LuxNodeState{},
	}
}

func (sync *LuxNodeSync) Read(rd *proto.LuxBuffer) error {
	// read synced list
	syncNum, err := rd.ReadUint16()
	if err != nil {
		return err
	}
	for i := 0; i < int(syncNum); i++ {
		id := proto.LuxID{}
		if err := id.Read(rd); err != nil {
			return err
		}

		sync.Synced[id] = struct{}{}
	}

	// read neighbors
	neighborNum, err := rd.ReadUint16()
	if err != nil {
		return err
	}
	for i := 0; i < int(neighborNum); i++ {
		id := proto.LuxID{}
		if err := id.Read(rd); err != nil {
			return err
		}

		ipOctets, err := rd.ReadVarBlock()
		if err != nil {
			return err
		}
		portNum, err := rd.ReadUint16()
		if err != nil {
			return err
		}

		// TODO: move this to proto
		var addrPort netip.AddrPort
		switch len(ipOctets) {
		case ipnet.IPv4len:
			addrPort = netip.AddrPortFrom(netip.AddrFrom4([4]byte(ipOctets)), portNum)
		case ipnet.IPv6len:
			addrPort = netip.AddrPortFrom(netip.AddrFrom16([16]byte(ipOctets)), portNum)
		default:
			return fmt.Errorf("received wrong sized neighbor ip len %d", len(ipOctets))
		}

		sync.Neighbors[id] = ipnet.UDPAddrFromAddrPort(addrPort)
	}

	// read sync state
	err = sync.SyncState.Read(rd)
	if err != nil {
		return err
	}

	return nil
}