//go:build (darwin || dragonfly || freebsd || linux || netbsd || openbsd) && gc_opt

package gnet

import (
	"net"
	"testing"

	"golang.org/x/sys/unix"

	goPool "github.com/panjf2000/gnet/v2/pkg/pool/goroutine"
)

var testVastConns = false

func TestConnMatrix(t *testing.T) {
	t.Run("1k-connections", func(t *testing.T) {
		testConnMatrix(t, 1000)
	})
	t.Run("10k-connections", func(t *testing.T) {
		testConnMatrix(t, 10000)
	})
	t.Run("100k-connections", func(t *testing.T) {
		if !testVastConns {
			t.Skip("skipped because testVastConns is set to false")
		}
		testConnMatrix(t, 100000)
	})
	t.Run("1m-connections", func(t *testing.T) {
		if !testVastConns {
			t.Skip("skipped because testVastConns is set to false")
		}
		testConnMatrix(t, 1000000)
	})
}

const (
	actionAdd = iota + 1
	actionDel
)

type handleConn struct {
	c      *conn
	action int
}

func testConnMatrix(t *testing.T, n int) {
	handleConns := make(chan *handleConn, 1024)
	connections := connMatrix{}
	connections.init()
	el := eventloop{engine: &engine{opts: &Options{}}}

	done := make(chan struct{})
	go func() {
		for i := 0; i < n+n/2; i++ {
			v := <-handleConns
			switch v.action {
			case actionAdd:
				connections.addConn(v.c, 0)
			case actionDel:
				connections.delConn(v.c)
			}
		}
		close(done)
	}()

	pool := goPool.Default()
	for i := 0; i < n; i++ {
		c := newTCPConn(i, &el, &unix.SockaddrInet4{}, &net.TCPAddr{}, &net.TCPAddr{})
		handleConns <- &handleConn{c, actionAdd}
		if i%2 == 0 {
			pool.Submit(func() {
				handleConns <- &handleConn{c, actionDel}
			})
		}
	}
	m := n / 2

	<-done
	if count := connections.loadCount(); count != int32(n)/2 {
		t.Fatalf("unexpected conn count %d, expected %d", count, int32(n)/2)
	}

	for i := 0; i < len(connections.table); i++ {
		if connections.connCounts[i] == 0 {
			continue
		}

		for j := 0; j < len(connections.table[i]) && m > 0; j++ {
			m--
			c := connections.table[i][j]
			if c == nil {
				t.Fatalf("unexpected nil connection at row %d, column %d", i, j)
			}
			if c.fd != c.gfd.Fd() {
				t.Fatalf("unexpected fd %d, expected fd %d", c.gfd.Fd(), c.fd)
			}
			if i != c.gfd.ConnMatrixRow() || j != c.gfd.ConnMatrixColumn() {
				t.Fatalf("unexpected row %d, column %d, expected row %d, column %d",
					c.gfd.ConnMatrixRow(), c.gfd.ConnMatrixColumn(), i, j)
			}
			gfd, ok := connections.fd2gfd[c.fd]
			if !ok {
				t.Fatalf("missing gfd for fd %d", c.fd)
			}
			if gfd != c.gfd {
				t.Fatalf("expected gfd: %v, but got gfd: %v", c.gfd, gfd)
			}
		}
	}

	t.Log("connMatrix remains compact after many additions and deletions, test done!")
}