package netclient

import (
	"context"
	"testing"
	"time"

	"mc/internal/logx"
	"mc/internal/netproto"
	"mc/internal/netserver"
)

// testServer 测试服务器：登录后发一个方块变更。
type testServer struct {
	t    *testing.T
	sent chan struct{}
}

func (s *testServer) OnConnect(c *netserver.Conn) {}
func (s *testServer) OnHandshake(c *netserver.Conn, hs netproto.Handshake) uint8 {
	if hs.ProtocolVersion != 1 {
		return 1
	}
	return 0
}
func (s *testServer) OnMove(c *netserver.Conn, m netproto.PlayerMove) {
	// 收到移动后回发一个方块变更（验证客户端接收链路）
	c.Send(netproto.Frame{MsgID: netproto.MsgBlockChange, Payload: netproto.BlockChange{
		X: 1, Y: 2, Z: 3, BlockID: 5, Meta: 0,
	}.Encode()})
	s.sent <- struct{}{}
}
func (s *testServer) OnDisconnect(c *netserver.Conn) {}

// testHandler 客户端回调记录。
type testHandler struct {
	login  chan uint8
	blocks chan netproto.BlockChange
}

func newTestHandler() *testHandler {
	return &testHandler{login: make(chan uint8, 1), blocks: make(chan netproto.BlockChange, 4)}
}
func (h *testHandler) OnLogin(code uint8)                   { h.login <- code }
func (h *testHandler) OnChunk(data []byte)                  {}
func (h *testHandler) OnBlockChange(m netproto.BlockChange) { h.blocks <- m }

// TestClientRoundtrip 客户端登录 → 发移动 → 收方块变更全链路（多人同步.md §2）。
func TestClientRoundtrip(t *testing.T) {
	log, _ := logx.New("", logx.LevelError)
	sh := &testServer{t: t, sent: make(chan struct{}, 1)}
	srv := netserver.New("127.0.0.1:0", log, sh)
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	if err := srv.Listen(ctx); err != nil {
		t.Fatalf("监听失败: %v", err)
	}

	h := newTestHandler()
	c, err := Dial(srv.Addr(), netproto.Handshake{ProtocolVersion: 1, ClientID: "测试"}, h)
	if err != nil {
		t.Fatalf("拨号失败: %v", err)
	}
	defer c.Close()

	select {
	case code := <-h.login:
		if code != 0 {
			t.Fatalf("登录结果期望 0，实际 %d", code)
		}
	case <-time.After(3 * time.Second):
		t.Fatal("未收到登录结果")
	}

	// 发送移动 → 服务器回方块变更
	c.SendMove(netproto.PlayerMove{X: 1, Y: 64, Z: 2})
	select {
	case m := <-h.blocks:
		if m.X != 1 || m.Y != 2 || m.Z != 3 || m.BlockID != 5 {
			t.Fatalf("方块变更内容异常: %+v", m)
		}
	case <-time.After(3 * time.Second):
		t.Fatal("未收到方块变更")
	}
}