package xnet

import (
	"net/netip"
	"testing"

	"github.com/soypat/lneto/ethernet"
	"github.com/soypat/lneto/tcp"
)

func BenchmarkARPExchange(b *testing.B) {
	const MTU = ethernet.MaxMTU
	const frameSize = ethernet.MaxFrameLength
	c1, c2 := new(StackAsync), new(StackAsync)
	queryAddr := netip.AddrFrom4([4]byte{192, 168, 1, 2})

	err := c1.Reset(StackConfig{
		Hostname:        "C1",
		RandSeed:        1,
		StaticAddress4:  [4]byte{192, 168, 1, 1},
		HardwareAddress: [6]byte{0xde, 0xad, 0xbe, 0xef, 0x00, 0x00},
		MTU:             MTU,
	})
	if err != nil {
		b.Fatal(err)
	}
	err = c2.Reset(StackConfig{
		Hostname:        "C2",
		RandSeed:        2,
		StaticAddress4:  queryAddr.As4(),
		HardwareAddress: [6]byte{0xc0, 0xff, 0xee, 0xc0, 0xff, 0xee},
		MTU:             MTU,
	})
	if err != nil {
		b.Fatal(err)
	}
	// Set gateways so ethernet frames are properly addressed.
	c1.SetGatewayHardwareAddr(c2.HardwareAddr())
	c2.SetGatewayHardwareAddr(c1.HardwareAddr())

	var buf [frameSize]byte

	b.ResetTimer()
	for b.Loop() {
		err = c1.StartResolveHardwareAddress6(queryAddr)
		if err != nil {
			b.Fatal(err)
		}
		n, err := c1.EgressEthernet(buf[:]) // Send Request.
		if err != nil {
			b.Fatal(err)
		} else if n == 0 {
			b.Fatal("expected send of data after first query")
		}
		err = c2.IngressEthernet(buf[:n]) // Receive request.
		if err != nil {
			b.Fatal(err)
		}
		n, err = c2.EgressEthernet(buf[:]) // Send response.
		if err != nil {
			b.Fatal(err)
		} else if n == 0 {
			b.Fatal("got no response to request")
		}
		err = c1.IngressEthernet(buf[:n]) // Receive response.
		if err != nil {
			b.Fatal(err)
		}
		_, err = c1.ResultResolveHardwareAddress6(queryAddr)
		if err != nil {
			b.Fatal("expected query result:", err)
		}
		// Discard query for next iteration.
		c1.DiscardResolveHardwareAddress6(queryAddr)
	}
}

func BenchmarkTCPHandshake(b *testing.B) {
	const MTU = ethernet.MaxMTU
	const frameSize = ethernet.MaxFrameLength
	const svPort = 8080
	client, sv := new(StackAsync), new(StackAsync)
	clconn, svconn := new(tcp.Conn), new(tcp.Conn)

	err := sv.Reset(StackConfig{
		Hostname:          "Server",
		RandSeed:          1,
		StaticAddress4:    [4]byte{10, 0, 0, 1},
		MaxActiveTCPPorts: 1,
		HardwareAddress:   [6]byte{0xbe, 0xef, 0, 0, 0, 1},
		MTU:               MTU,
	})
	if err != nil {
		b.Fatal(err)
	}
	err = client.Reset(StackConfig{
		Hostname:          "Client",
		RandSeed:          2,
		StaticAddress4:    [4]byte{10, 0, 0, 2},
		MaxActiveTCPPorts: 1,
		HardwareAddress:   [6]byte{0xbe, 0xef, 0, 0, 0, 2},
		MTU:               MTU,
	})
	if err != nil {
		b.Fatal(err)
	}
	sv.SetGatewayHardwareAddr(client.HardwareAddr())
	client.SetGatewayHardwareAddr(sv.HardwareAddr())

	buf := make([]byte, MTU*4)
	err = clconn.Configure(tcp.ConnConfig{
		RxBuf:             buf[:MTU],
		TxBuf:             buf[MTU : MTU*2],
		TxPacketQueueSize: 4,
		RWBackoff:         backoffYield,
	})
	if err != nil {
		b.Fatal(err)
	}
	err = svconn.Configure(tcp.ConnConfig{
		RxBuf:             buf[2*MTU : 3*MTU],
		TxBuf:             buf[3*MTU : 4*MTU],
		TxPacketQueueSize: 4,
		RWBackoff:         backoffYield,
	})
	if err != nil {
		b.Fatal(err)
	}

	var pktbuf [frameSize]byte

	b.ResetTimer()
	for b.Loop() {
		// Setup connections.
		err = sv.ListenTCP4(svconn, svPort)
		if err != nil {
			b.Fatal(err)
		}
		err = client.DialTCP(clconn, 1337, netip.AddrPortFrom(netip.AddrFrom4(sv.Addr4()), svPort))
		if err != nil {
			b.Fatal(err)
		}

		// SYN from client.
		n, err := client.EgressEthernet(pktbuf[:])
		if err != nil {
			b.Fatal(err)
		}
		err = sv.IngressEthernet(pktbuf[:n])
		if err != nil {
			b.Fatal(err)
		}

		// SYN-ACK from server.
		n, err = sv.EgressEthernet(pktbuf[:])
		if err != nil {
			b.Fatal(err)
		}
		err = client.IngressEthernet(pktbuf[:n])
		if err != nil {
			b.Fatal(err)
		}

		// ACK from client.
		n, err = client.EgressEthernet(pktbuf[:])
		if err != nil {
			b.Fatal(err)
		}
		err = sv.IngressEthernet(pktbuf[:n])
		if err != nil {
			b.Fatal(err)
		}

		// Abort connections for next iteration.
		clconn.Abort()
		svconn.Abort()
	}
}