package response

import (
	"context"
	"errors"
	"testing"

	codecimpl "github.com/noahlann/nnet/internal/codec"
	protocolpkg "github.com/noahlann/nnet/pkg/protocol"
	unpackerpkg "github.com/noahlann/nnet/pkg/unpacker"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestResponse(t *testing.T) {
	mockConn := &mockConnectionWriter{}
	codecRegistry := codecimpl.NewRegistry()
	_ = codecRegistry.Register("json", codecimpl.NewJSONCodec())
	resp := New(mockConn, nil, codecRegistry, "json")

	// 测试WriteString
	err := resp.WriteString("hello")
	require.NoError(t, err, "Expected no error when writing string")
	assert.Equal(t, 1, len(mockConn.written), "Expected data to be written")
}

func TestResponseWriteBytes(t *testing.T) {
	mockConn := &mockConnectionWriter{}
	codecRegistry := codecimpl.NewRegistry()
	resp := New(mockConn, nil, codecRegistry, "json")

	data := []byte("test data")
	err := resp.WriteBytes(data)
	require.NoError(t, err, "Expected no error when writing bytes")
	assert.Equal(t, 1, len(mockConn.written), "Expected data to be written")
	assert.Equal(t, data, mockConn.written[0], "Expected written data to match")
}

func TestResponseWrite(t *testing.T) {
	mockConn := &mockConnectionWriter{}
	codecRegistry := codecimpl.NewRegistry()
	_ = codecRegistry.Register("json", codecimpl.NewJSONCodec())
	resp := New(mockConn, nil, codecRegistry, "json")

	type TestStruct struct {
		Name  string `json:"name"`
		Value int    `json:"value"`
	}

	data := TestStruct{
		Name:  "test",
		Value: 42,
	}

	err := resp.WriteWithCodec(data, "json")
	require.NoError(t, err, "Expected no error when writing struct")
	assert.Equal(t, 1, len(mockConn.written), "Expected data to be written")
}

func TestResponseWriteWithCodec(t *testing.T) {
	mockConn := &mockConnectionWriter{}
	codecRegistry := codecimpl.NewRegistry()
	_ = codecRegistry.Register("json", codecimpl.NewJSONCodec())
	resp := New(mockConn, nil, codecRegistry, "json")

	type TestStruct struct {
		Name string `json:"name"`
	}

	data := TestStruct{
		Name: "test",
	}

	err := resp.WriteWithCodec(data, "json")
	require.NoError(t, err, "Expected no error when writing with codec")
	assert.Equal(t, 1, len(mockConn.written), "Expected data to be written")
}

func TestResponseWriteWithInvalidCodec(t *testing.T) {
	mockConn := &mockConnectionWriter{}
	codecRegistry := codecimpl.NewRegistry()
	resp := New(mockConn, nil, codecRegistry, "json")

	err := resp.WriteWithCodec("test", "nonexistent")
	assert.Error(t, err, "Expected error for nonexistent codec")
}

func TestResponseHeader(t *testing.T) {
	mockConn := &mockConnectionWriter{}
	codecRegistry := codecimpl.NewRegistry()
	resp := New(mockConn, nil, codecRegistry, "json")

	// 测试Header（初始可能为nil，取决于协议）
	header := resp.Header()
	// Header可能为nil（无帧头协议），这是正常的
	_ = header
}

func TestResponseSetHeader(t *testing.T) {
	mockConn := &mockConnectionWriter{}
	codecRegistry := codecimpl.NewRegistry()
	resp := New(mockConn, nil, codecRegistry, "json").(*responseImpl)

	// 设置Header
	newHeader := NewFrameHeader()
	newHeader.Set("message_id", uint64(123))
	newHeader.Set("type", "response")
	resp.SetHeader(newHeader)

	// 验证Header
	header := resp.Header()
	assert.NotNil(t, header, "Expected header to be non-nil")
	assert.Equal(t, uint64(123), header.Get("message_id"), "Expected message ID to match")
	assert.Equal(t, "response", header.Get("type"), "Expected type to match")
}

func TestResponseWriteError(t *testing.T) {
	mockConn := &mockConnectionWriter{
		writeError: errors.New("write error"),
	}
	codecRegistry := codecimpl.NewRegistry()
	resp := New(mockConn, nil, codecRegistry, "json")

	err := resp.WriteString("test")
	assert.Error(t, err, "Expected error when write fails")
}

func TestResponseWriteWithProtocol(t *testing.T) {
	mockConn := &mockConnectionWriter{}
	mockProtocol := &mockProtocol{}
	codecRegistry := codecimpl.NewRegistry()
	resp := New(mockConn, mockProtocol, codecRegistry, "json")

	err := resp.WriteString("test")
	require.NoError(t, err, "Expected no error when writing with protocol")
	assert.Equal(t, 1, len(mockConn.written), "Expected data to be written")
}

// mockConnectionWriter 模拟连接写入器
type mockConnectionWriter struct {
	written   [][]byte
	writeError error
}

func (m *mockConnectionWriter) Write(data []byte) error {
	if m.writeError != nil {
		return m.writeError
	}
	m.written = append(m.written, data)
	return nil
}

// mockProtocol 模拟协议
type mockProtocol struct{}

func (m *mockProtocol) Name() string {
	return "test"
}

func (m *mockProtocol) Version() string {
	return "1.0"
}

func (m *mockProtocol) HasHeader() bool {
	return false
}

func (m *mockProtocol) Encode(data []byte, header protocolpkg.FrameHeader) ([]byte, error) {
	return data, nil
}

func (m *mockProtocol) Decode(data []byte) (protocolpkg.FrameHeader, []byte, error) {
	return nil, data, nil
}

func (m *mockProtocol) Handle(ctx context.Context, data []byte) ([]byte, error) {
	return data, nil
}

func (m *mockProtocol) Unpacker() unpackerpkg.Unpacker {
	return nil
}