package cni

import (
	"bytes"
	"net"
	"path/filepath"
	"testing"
	"time"

	current "github.com/containernetworking/cni/pkg/types/100"
)

func TestEncodeDecode_RequestRoundtrip(t *testing.T) {
	req := Request{
		Op:          OpAdd,
		ContainerID: "abc",
		Netns:       "/proc/1234/ns/net",
		IfName:      "eth0",
		Args:        "K8S_POD_NAMESPACE=mail;K8S_POD_NAME=stalwart-0",
		Path:        "/opt/cni/bin",
		StdinData:   []byte(`{"cniVersion":"1.0.0","name":"flock"}`),
	}
	var buf bytes.Buffer
	if err := EncodeRequest(&buf, req); err != nil {
		t.Fatal(err)
	}
	got, err := DecodeRequest(&buf)
	if err != nil {
		t.Fatal(err)
	}
	if got.Op != req.Op || got.ContainerID != req.ContainerID || string(got.StdinData) != string(req.StdinData) {
		t.Fatalf("roundtrip mismatch:\n got=%+v\nwant=%+v", got, req)
	}
}

func TestEncodeDecode_ResponseRoundtrip(t *testing.T) {
	resp := Response{
		Result: &current.Result{CNIVersion: current.ImplementedSpecVersion},
	}
	var buf bytes.Buffer
	if err := EncodeResponse(&buf, resp); err != nil {
		t.Fatal(err)
	}
	got, err := DecodeResponse(&buf)
	if err != nil {
		t.Fatal(err)
	}
	if got.Result == nil || got.Result.CNIVersion != current.ImplementedSpecVersion {
		t.Fatalf("response roundtrip lost CNIVersion: %+v", got)
	}
}

// TestRPC_ClientToFakeServer wires the real client to a tiny in-process
// server over a unix socket, exercising end-to-end framing.
func TestRPC_ClientToFakeServer(t *testing.T) {
	dir := t.TempDir()
	sockPath := filepath.Join(dir, "flock.sock")

	l, err := net.Listen("unix", sockPath)
	if err != nil {
		t.Fatal(err)
	}
	defer l.Close()

	// Server: read one Request, write one Response.
	done := make(chan error, 1)
	go func() {
		conn, err := l.Accept()
		if err != nil {
			done <- err
			return
		}
		defer conn.Close()
		req, err := DecodeRequest(conn)
		if err != nil {
			done <- err
			return
		}
		var resp Response
		switch req.Op {
		case OpAdd:
			resp.Result = &current.Result{CNIVersion: current.ImplementedSpecVersion}
		case OpDel, OpCheck:
			// no-op success
		default:
			resp.Error = "unknown op"
		}
		done <- EncodeResponse(conn, resp)
	}()

	// Point the client at our test socket.
	prev := rpcSocket
	rpcSocket = sockPath
	defer func() { rpcSocket = prev }()

	resp, err := call(Request{Op: OpAdd, ContainerID: "test"})
	if err != nil {
		t.Fatalf("call: %v", err)
	}
	if resp.Result == nil {
		t.Fatalf("expected result, got %+v", resp)
	}

	select {
	case err := <-done:
		if err != nil {
			t.Fatalf("server: %v", err)
		}
	case <-time.After(2 * time.Second):
		t.Fatal("server did not finish")
	}
}

func TestRPC_ServerErrorPropagatesToCNIError(t *testing.T) {
	resp := &Response{Error: "no NodeConfig for host001"}
	err := toCNIError("add", resp)
	if err == nil {
		t.Fatal("expected CNI error")
	}
	if got := err.Error(); got == "" || got == "no NodeConfig for host001" {
		// types.Error wraps the message — just make sure something non-empty
		// surfaces and that the underlying string is contained.
		t.Fatalf("unexpected error format: %q", got)
	}
}