package frame

import (
	"encoding/binary"
	"net"
	"testing"
)

func TestFrameRoundtrip(t *testing.T) {
	c1, c2 := net.Pipe()
	defer c1.Close()
	defer c2.Close()

	f := NewFrame(FrameVersion, 0x10, 42)
	if err := f.SetData([]byte("hello frame")); err != nil {
		t.Fatalf("SetData: %v", err)
	}

	go func() {
		if err := WriteFrame(c1, f); err != nil {
			t.Errorf("WriteFrame: %v", err)
		}
	}()

	got, err := ReadFrame(c2)
	if err != nil {
		t.Fatalf("ReadFrame: %v", err)
	}
	if got.Version() != FrameVersion || got.Cmd() != 0x10 || got.StreamID() != 42 {
		t.Errorf("帧头不符: %s", got.String())
	}
	if string(got.Data()) != "hello frame" {
		t.Errorf("Data = %q, want hello frame", got.Data())
	}
}

func TestFramePipelineRead(t *testing.T) {
	// 连续两帧不丢数据（回归：旧实现用临时 bufio.Reader 会吞掉后续帧字节）
	c1, c2 := net.Pipe()
	defer c1.Close()
	defer c2.Close()

	go func() {
		a := NewFrame(1, 1, 1)
		if err := a.SetData([]byte("first")); err != nil {
			t.Errorf("SetData: %v", err)
		}
		b := NewFrame(1, 2, 2)
		if err := b.SetData([]byte("second")); err != nil {
			t.Errorf("SetData: %v", err)
		}
		if err := WriteFrame(c1, a); err != nil {
			t.Errorf("WriteFrame: %v", err)
		}
		if err := WriteFrame(c1, b); err != nil {
			t.Errorf("WriteFrame: %v", err)
		}
	}()

	got1, err := ReadFrame(c2)
	if err != nil || string(got1.Data()) != "first" {
		t.Fatalf("第一帧 = %q, %v", got1.Data(), err)
	}
	got2, err := ReadFrame(c2)
	if err != nil || string(got2.Data()) != "second" {
		t.Fatalf("第二帧 = %q, %v", got2.Data(), err)
	}
}

func TestSetDataOverflow(t *testing.T) {
	f := NewFrame(1, 0, 0)
	if err := f.SetData(make([]byte, 65536)); err == nil {
		t.Error("超过 65535 字节应返回错误")
	}
	if err := f.SetData(make([]byte, 65535)); err != nil {
		t.Errorf("65535 字节应成功: %v", err)
	}
}

func TestMarshalUnmarshal(t *testing.T) {
	f := NewFrame(1, 3, 9)
	type payload struct {
		Name string
		N    int
	}
	if err := f.Marshal(payload{Name: "a", N: 1}); err != nil {
		t.Fatalf("Marshal: %v", err)
	}
	var got payload
	if err := f.Unmarshal(&got); err != nil {
		t.Fatalf("Unmarshal: %v", err)
	}
	if got.Name != "a" || got.N != 1 {
		t.Errorf("Unmarshal 结果 = %+v", got)
	}
}

func TestRawHeader(t *testing.T) {
	h := RawHeader{}
	h[0] = 2
	h[1] = 7
	binary.LittleEndian.PutUint16(h[2:], 300)
	binary.LittleEndian.PutUint32(h[4:], 100000)
	if h.Version() != 2 || h.Cmd() != 7 || h.Length() != 300 || h.StreamID() != 100000 {
		t.Errorf("RawHeader 解析不符: %v %v %v %v", h.Version(), h.Cmd(), h.Length(), h.StreamID())
	}
	if len(h.Bytes()) != 8 {
		t.Errorf("Bytes 长度 = %d, want 8", len(h.Bytes()))
	}
}