package nettest

import (
	"net"
	"testing"
	"time"
)

func TestCheckSum(t *testing.T) {
	// 单字节直接累加：sum=0x01 → ^0x01 = 0xFFFE
	if got := CheckSum([]byte{0x01}); got != 0xFFFE {
		t.Errorf("CheckSum([0x01]) = %#04x, want 0xFFFE", got)
	}
	// 双字节：sum=0x0102 → ^0x0102 = 0xFEFD
	if got := CheckSum([]byte{0x01, 0x02}); got != 0xFEFD {
		t.Errorf("CheckSum([0x01,0x02]) = %#04x, want 0xFEFD", got)
	}
	// 往返性质：带正确校验和的报文再次计算应为 0
	data := []byte{0x08, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01}
	cs := CheckSum(data)
	full := append(data, byte(cs>>8), byte(cs&0xFF))
	if got := CheckSum(full); got != 0 {
		t.Errorf("正确校验和报文再计算 = %#04x, want 0", got)
	}
}

func TestPortCheck(t *testing.T) {
	l, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatal(err)
	}
	defer l.Close()
	go func() {
		for {
			c, err := l.Accept()
			if err != nil {
				return
			}
			c.Close()
		}
	}()

	port := l.Addr().(*net.TCPAddr).Port
	p := NewPing("127.0.0.1", port, 1000)
	if got := p.Test(); got < 0 {
		t.Errorf("本地端口探测应成功, got %d", got)
	}

	// 探测不存在的端口应失败
	if got := NewPing("127.0.0.1", 1, 500).Test(); got >= 0 {
		t.Errorf("不可达端口应返回 -1, got %d", got)
	}
}

func TestPingSet(t *testing.T) {
	p := NewPing("127.0.0.1", 80, 1000)
	p.Set("localhost", 443, 2000)
	if p.addr != "localhost" || p.port != 443 || p.timeout != 2000 {
		t.Errorf("Set 后字段错误: %+v", p)
	}
}

func TestNetTestFlow(t *testing.T) {
	l, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatal(err)
	}
	defer l.Close()
	go func() {
		for {
			c, err := l.Accept()
			if err != nil {
				return
			}
			c.Close()
		}
	}()
	port := l.Addr().(*net.TCPAddr).Port

	// timeout 300ms 同时作为探测间隔
	tt := NewNetTest(1, "test", "127.0.0.1", port, 300, false)
	tt.Start()
	time.Sleep(1100 * time.Millisecond)
	tt.Stop()

	r := tt.GetResult(false)
	if r.TotalCount == 0 {
		t.Fatal("应有探测记录")
	}
	if r.SuccessCount == 0 {
		t.Errorf("本地端口应全部成功: %+v", r)
	}
	if r.SuccessCount+r.FailCount != r.TotalCount {
		t.Errorf("成功+失败应等于总数: %+v", r)
	}

	// GetResult(false) 不清零
	r2 := tt.GetResult(false)
	if r2.TotalCount != r.TotalCount {
		t.Errorf("isReset=false 时统计不应清零: %d != %d", r2.TotalCount, r.TotalCount)
	}
}