package peer

import (
	"net/netip"
	"time"

	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"

	"vppn/peer/control"
	"vppn/peer/wginterface"
)

type PeerState string

const (
	StateRelayed = PeerState("RELAY")
	StateProbing = PeerState("PROBE")
	StateDirect  = PeerState("DIRECT")
)

type Peer struct {
	wgPeer      wgtypes.Peer
	VPNIP       netip.Addr     // VPN IP address.
	Name        string         // Human-readable DNS label.
	IsRelay     bool           // Peer is a relay.
	IsPublic    bool           // Peer has a public IP.
	EndpointV4  netip.AddrPort // Reported IPv4 endpoint.
	EndpointV6  netip.AddrPort // Reported IPv6 endpoint.
	EndpointLAN netip.AddrPort // Discovered via multicast.
	RTT         time.Duration  // Round-trip time.
	State       PeerState      // Current routing state; updated on each devXxx call.
	Role        control.Role   // Client initiates pings; server responds.
	SignPubKey  [32]byte       // nacl/sign public key for verifying multicast beacons.
}

// PubKey is the wireguard public key.
func (p *Peer) PubKey() wgtypes.Key {
	return p.wgPeer.PublicKey
}

func (p *Peer) WGEndpoint() netip.AddrPort {
	ep := p.wgPeer.Endpoint
	if ep == nil {
		return netip.AddrPort{}
	}
	addr, ok := netip.AddrFromSlice(ep.IP)
	if !ok {
		return netip.AddrPort{}
	}
	return netip.AddrPortFrom(addr.Unmap(), uint16(ep.Port))
}

func (p *Peer) LastHandshakeTime() time.Time {
	return p.wgPeer.LastHandshakeTime
}

func (p *Peer) Up() bool {
	return time.Since(p.wgPeer.LastHandshakeTime) < wginterface.SessionTimeout
}

func (p *Peer) CanRelay() bool {
	return p.IsRelay && p.Up()
}

func (p *Peer) PreferredEndpoint() netip.AddrPort {
	if p.EndpointLAN.IsValid() {
		return p.EndpointLAN
	} else if p.EndpointV4.IsValid() {
		return p.EndpointV4
	} else {
		return p.EndpointV6
	}
}

func (p *Peer) UpdateEndpoints(v4, v6 netip.AddrPort) {
	if v4.IsValid() {
		p.EndpointV4 = v4
	}
	if v6.IsValid() {
		p.EndpointV6 = v6
	}
}