nex/backend/internal/handler/proxy_handler_test.go

package handler

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"net/http/httptest"
	"testing"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"nex/backend/internal/conversion"
	"nex/backend/internal/conversion/anthropic"
	"nex/backend/internal/conversion/openai"
	"nex/backend/internal/domain"
	"nex/backend/internal/provider"
	appErrors "nex/backend/pkg/errors"
)

func init() {
	gin.SetMode(gin.TestMode)
}

type mockProxyProviderClient struct {
	sendFn      func(ctx context.Context, spec conversion.HTTPRequestSpec) (*conversion.HTTPResponseSpec, error)
	sendStreamFn func(ctx context.Context, spec conversion.HTTPRequestSpec) (<-chan provider.StreamEvent, error)
}

func (m *mockProxyProviderClient) Send(ctx context.Context, spec conversion.HTTPRequestSpec) (*conversion.HTTPResponseSpec, error) {
	if m.sendFn != nil {
		return m.sendFn(ctx, spec)
	}
	return &conversion.HTTPResponseSpec{
		StatusCode: 200,
		Headers:    map[string]string{"Content-Type": "application/json"},
		Body:       []byte(`{"id":"resp-1","model":"gpt-4","choices":[{"index":0,"message":{"role":"assistant","content":"hi"},"finish_reason":"stop"}],"usage":{"prompt_tokens":1,"completion_tokens":1,"total_tokens":2}}`),
	}, nil
}

func (m *mockProxyProviderClient) SendStream(ctx context.Context, spec conversion.HTTPRequestSpec) (<-chan provider.StreamEvent, error) {
	if m.sendStreamFn != nil {
		return m.sendStreamFn(ctx, spec)
	}
	ch := make(chan provider.StreamEvent, 10)
	go func() {
		defer close(ch)
		ch <- provider.StreamEvent{Data: []byte("data: {\"id\":\"1\",\"choices\":[{\"delta\":{\"content\":\"hi\"}}]}\n\n")}
		ch <- provider.StreamEvent{Data: []byte("data: [DONE]\n\n")}
		ch <- provider.StreamEvent{Done: true}
	}()
	return ch, nil
}

type mockProxyRoutingService struct {
	result *domain.RouteResult
	err    error
}

func (m *mockProxyRoutingService) Route(modelName string) (*domain.RouteResult, error) {
	return m.result, m.err
}

type mockProxyProviderService struct {
	providers []domain.Provider
	err       error
}

func (m *mockProxyProviderService) Create(p *domain.Provider) error                              { return nil }
func (m *mockProxyProviderService) Get(id string, maskKey bool) (*domain.Provider, error)        { return nil, nil }
func (m *mockProxyProviderService) List() ([]domain.Provider, error)                             { return m.providers, m.err }
func (m *mockProxyProviderService) Update(id string, updates map[string]interface{}) error        { return nil }
func (m *mockProxyProviderService) Delete(id string) error                                       { return nil }

type mockProxyStatsService struct{}

func (m *mockProxyStatsService) Record(providerID, modelName string) error                                         { return nil }
func (m *mockProxyStatsService) Get(providerID, modelName string, startDate, endDate *time.Time) ([]domain.UsageStats, error) { return nil, nil }
func (m *mockProxyStatsService) Aggregate(stats []domain.UsageStats, groupBy string) []map[string]interface{}      { return nil }

func setupProxyEngine(t *testing.T) *conversion.ConversionEngine {
	t.Helper()
	registry := conversion.NewMemoryRegistry()
	engine := conversion.NewConversionEngine(registry)
	require.NoError(t, registry.Register(openai.NewAdapter()))
	return engine
}

func newTestProxyHandler(engine *conversion.ConversionEngine, client *mockProxyProviderClient, routingSvc *mockProxyRoutingService, providerSvc *mockProxyProviderService) *ProxyHandler {
	return NewProxyHandler(
		engine,
		client,
		routingSvc,
		providerSvc,
		&mockProxyStatsService{},
	)
}

func TestProxyHandler_HandleProxy_MissingProtocol(t *testing.T) {
	engine := setupProxyEngine(t)
	h := newTestProxyHandler(engine, &mockProxyProviderClient{}, &mockProxyRoutingService{}, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Request = httptest.NewRequest("POST", "/", bytes.NewReader([]byte(`{}`)))

	h.HandleProxy(c)
	assert.Equal(t, 400, w.Code)
}

func TestProxyHandler_HandleProxy_NonStreamSuccess(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{
		result: &domain.RouteResult{
			Provider: &domain.Provider{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "openai", Enabled: true},
			Model:    &domain.Model{ID: "m1", ProviderID: "p1", ModelName: "gpt-4", Enabled: true},
		},
	}
	client := &mockProxyProviderClient{
		sendFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (*conversion.HTTPResponseSpec, error) {
			return &conversion.HTTPResponseSpec{
				StatusCode: 200,
				Headers:    map[string]string{"Content-Type": "application/json"},
				Body: []byte(`{"id":"resp-1","object":"chat.completion","model":"gpt-4","choices":[{"index":0,"message":{"role":"assistant","content":"Hello"},"finish_reason":"stop"}],"usage":{"prompt_tokens":5,"completion_tokens":3,"total_tokens":8}}`),
			}, nil
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/chat/completions"}}
	c.Request = httptest.NewRequest("POST", "/openai/v1/chat/completions", bytes.NewReader([]byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}]}`)))

	h.HandleProxy(c)
	assert.Equal(t, 200, w.Code)

	var resp map[string]any
	require.NoError(t, json.Unmarshal(w.Body.Bytes(), &resp))
	assert.Equal(t, "resp-1", resp["id"])
}

func TestProxyHandler_HandleProxy_RoutingError_WithBody(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{err: appErrors.ErrModelNotFound}
	h := newTestProxyHandler(engine, &mockProxyProviderClient{}, routingSvc, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/chat/completions"}}
	c.Request = httptest.NewRequest("POST", "/openai/v1/chat/completions", bytes.NewReader([]byte(`{"model":"unknown","messages":[{"role":"user","content":"hi"}]}`)))

	h.HandleProxy(c)
	assert.Equal(t, 404, w.Code)
}

func TestProxyHandler_HandleProxy_ConversionError(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{
		result: &domain.RouteResult{
			Provider: &domain.Provider{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "openai", Enabled: true},
			Model:    &domain.Model{ID: "m1", ProviderID: "p1", ModelName: "gpt-4", Enabled: true},
		},
	}
	client := &mockProxyProviderClient{
		sendFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (*conversion.HTTPResponseSpec, error) {
			return nil, context.DeadlineExceeded
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/chat/completions"}}
	c.Request = httptest.NewRequest("POST", "/openai/v1/chat/completions", bytes.NewReader([]byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}]}`)))

	h.HandleProxy(c)
	assert.Equal(t, 500, w.Code)
}

func TestProxyHandler_HandleProxy_ClientSendError(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{
		result: &domain.RouteResult{
			Provider: &domain.Provider{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "openai", Enabled: true},
			Model:    &domain.Model{ID: "m1", ProviderID: "p1", ModelName: "gpt-4", Enabled: true},
		},
	}
	client := &mockProxyProviderClient{
		sendFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (*conversion.HTTPResponseSpec, error) {
			return nil, context.DeadlineExceeded
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/chat/completions"}}
	c.Request = httptest.NewRequest("POST", "/openai/v1/chat/completions", bytes.NewReader([]byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}]}`)))

	h.HandleProxy(c)
	assert.Equal(t, 500, w.Code)
}

func TestProxyHandler_HandleProxy_StreamSuccess(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{
		result: &domain.RouteResult{
			Provider: &domain.Provider{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "openai", Enabled: true},
			Model:    &domain.Model{ID: "m1", ProviderID: "p1", ModelName: "gpt-4", Enabled: true},
		},
	}
	client := &mockProxyProviderClient{
		sendStreamFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (<-chan provider.StreamEvent, error) {
			ch := make(chan provider.StreamEvent, 10)
			go func() {
				defer close(ch)
				ch <- provider.StreamEvent{Data: []byte("data: {\"id\":\"1\",\"object\":\"chat.completion.chunk\",\"choices\":[{\"index\":0,\"delta\":{\"role\":\"assistant\"}}]}\n\n")}
				ch <- provider.StreamEvent{Data: []byte("data: {\"id\":\"1\",\"object\":\"chat.completion.chunk\",\"choices\":[{\"index\":0,\"delta\":{\"content\":\"Hello\"}}]}\n\n")}
				ch <- provider.StreamEvent{Data: []byte("data: [DONE]\n\n")}
				ch <- provider.StreamEvent{Done: true}
			}()
			return ch, nil
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/chat/completions"}}
	c.Request = httptest.NewRequest("POST", "/openai/v1/chat/completions", bytes.NewReader([]byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}],"stream":true}`)))

	h.HandleProxy(c)
	assert.Equal(t, 200, w.Code)
	assert.Equal(t, "text/event-stream", w.Header().Get("Content-Type"))
	assert.Contains(t, w.Body.String(), "Hello")
}

func TestProxyHandler_HandleProxy_StreamError(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{
		result: &domain.RouteResult{
			Provider: &domain.Provider{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "openai", Enabled: true},
			Model:    &domain.Model{ID: "m1", ProviderID: "p1", ModelName: "gpt-4", Enabled: true},
		},
	}
	client := &mockProxyProviderClient{
		sendStreamFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (<-chan provider.StreamEvent, error) {
			return nil, context.DeadlineExceeded
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/chat/completions"}}
	c.Request = httptest.NewRequest("POST", "/openai/v1/chat/completions", bytes.NewReader([]byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}],"stream":true}`)))

	h.HandleProxy(c)
	assert.Equal(t, 500, w.Code)
}

func TestProxyHandler_ForwardPassthrough_GET(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{err: appErrors.ErrModelNotFound}
	providerSvc := &mockProxyProviderService{
		providers: []domain.Provider{
			{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "openai"},
		},
	}
	client := &mockProxyProviderClient{
		sendFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (*conversion.HTTPResponseSpec, error) {
			return &conversion.HTTPResponseSpec{
				StatusCode: 200,
				Headers:    map[string]string{"Content-Type": "application/json"},
				Body:       []byte(`{"object":"list","data":[{"id":"gpt-4","object":"model"}]}`),
			}, nil
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, providerSvc)

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/models"}}
	c.Request = httptest.NewRequest("GET", "/openai/v1/models", nil)

	h.HandleProxy(c)
	assert.Equal(t, 200, w.Code)
}

func TestProxyHandler_ForwardPassthrough_UnsupportedProtocol(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{err: appErrors.ErrModelNotFound}
	providerSvc := &mockProxyProviderService{}
	h := newTestProxyHandler(engine, &mockProxyProviderClient{}, routingSvc, providerSvc)

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "unknown"}, {Key: "path", Value: "/models"}}
	c.Request = httptest.NewRequest("GET", "/unknown/v1/models", nil)

	h.HandleProxy(c)
	assert.Equal(t, 400, w.Code)
}

func TestProxyHandler_ForwardPassthrough_NoProviders(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{err: appErrors.ErrModelNotFound}
	providerSvc := &mockProxyProviderService{providers: []domain.Provider{}}
	h := newTestProxyHandler(engine, &mockProxyProviderClient{}, routingSvc, providerSvc)

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/models"}}
	c.Request = httptest.NewRequest("GET", "/openai/v1/models", nil)

	h.HandleProxy(c)
	assert.Equal(t, 404, w.Code)
}

func TestExtractModelName(t *testing.T) {
	tests := []struct {
		name string
		body string
		want string
	}{
		{"basic", `{"model":"gpt-4","messages":[]}`, "gpt-4"},
		{"nested", `{"stream":true,"model":"claude-3","messages":[]}`, "claude-3"},
		{"no_model", `{"messages":[]}`, ""},
		{"empty", "", ""},
		{"escaped", `{"model":"gpt\"4","messages":[]}`, `gpt\"4`},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := extractModelName([]byte(tt.body))
			assert.Equal(t, tt.want, got)
		})
	}
}

func TestExtractHeaders(t *testing.T) {
	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Request = httptest.NewRequest("POST", "/", nil)
	c.Request.Header.Set("Authorization", "Bearer test")
	c.Request.Header.Set("Content-Type", "application/json")

	headers := extractHeaders(c)
	assert.Equal(t, "Bearer test", headers["Authorization"])
	assert.Equal(t, "application/json", headers["Content-Type"])
}

func TestIsStreamRequest(t *testing.T) {
	engine := setupProxyEngine(t)
	h := newTestProxyHandler(engine, &mockProxyProviderClient{}, &mockProxyRoutingService{}, &mockProxyProviderService{})

	tests := []struct {
		name     string
		body     string
		path     string
		expected bool
	}{
		{"stream true chat", `{"model":"gpt-4","stream":true}`, "/v1/chat/completions", true},
		{"stream false chat", `{"model":"gpt-4","stream":false}`, "/v1/chat/completions", false},
		{"no stream field", `{"model":"gpt-4"}`, "/v1/chat/completions", false},
		{"stream true non-chat", `{"model":"gpt-4","stream":true}`, "/v1/models", false},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result := h.isStreamRequest([]byte(tt.body), "openai", tt.path)
			assert.Equal(t, tt.expected, result)
		})
	}
}

func TestProxyHandler_HandleProxy_ProviderProtocolDefault(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{
		result: &domain.RouteResult{
			Provider: &domain.Provider{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "", Enabled: true},
			Model:    &domain.Model{ID: "m1", ProviderID: "p1", ModelName: "gpt-4", Enabled: true},
		},
	}
	client := &mockProxyProviderClient{
		sendFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (*conversion.HTTPResponseSpec, error) {
			return &conversion.HTTPResponseSpec{
				StatusCode: 200,
				Body:       []byte(`{"id":"r1","object":"chat.completion","model":"gpt-4","choices":[{"index":0,"message":{"role":"assistant","content":"ok"},"finish_reason":"stop"}],"usage":{"prompt_tokens":1,"completion_tokens":1,"total_tokens":2}}`),
			}, nil
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/chat/completions"}}
	c.Request = httptest.NewRequest("POST", "/openai/v1/chat/completions", bytes.NewReader([]byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}]}`)))

	h.HandleProxy(c)
	assert.Equal(t, 200, w.Code)
}

func TestProxyHandler_WriteConversionError_NonConversionError(t *testing.T) {
	engine := setupProxyEngine(t)
	h := newTestProxyHandler(engine, &mockProxyProviderClient{}, &mockProxyRoutingService{}, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Request = httptest.NewRequest("POST", "/", nil)

	h.writeConversionError(c, context.DeadlineExceeded, "openai")
	assert.Equal(t, 500, w.Code)
}

func TestProxyHandler_WriteConversionError_ConversionError(t *testing.T) {
	engine := setupProxyEngine(t)
	h := newTestProxyHandler(engine, &mockProxyProviderClient{}, &mockProxyRoutingService{}, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Request = httptest.NewRequest("POST", "/", nil)

	convErr := conversion.NewConversionError(conversion.ErrorCodeInvalidInput, "bad request")
	h.writeConversionError(c, convErr, "openai")
	assert.Equal(t, 500, w.Code)
}

func TestProxyHandler_HandleProxy_EmptyBody(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{err: appErrors.ErrModelNotFound}
	providerSvc := &mockProxyProviderService{
		providers: []domain.Provider{
			{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "openai"},
		},
	}
	client := &mockProxyProviderClient{
		sendFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (*conversion.HTTPResponseSpec, error) {
			return &conversion.HTTPResponseSpec{
				StatusCode: 200,
				Body:       []byte(`{"object":"list","data":[]}`),
			}, nil
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, providerSvc)

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/models"}}
	c.Request = httptest.NewRequest("GET", "/openai/v1/models", nil)

	h.HandleProxy(c)
	assert.Equal(t, 200, w.Code)
}

func TestProxyHandler_HandleStream_MidStreamError(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{
		result: &domain.RouteResult{
			Provider: &domain.Provider{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "openai", Enabled: true},
			Model:    &domain.Model{ID: "m1", ProviderID: "p1", ModelName: "gpt-4", Enabled: true},
		},
	}
	client := &mockProxyProviderClient{
		sendStreamFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (<-chan provider.StreamEvent, error) {
			ch := make(chan provider.StreamEvent, 10)
			go func() {
				defer close(ch)
				ch <- provider.StreamEvent{Data: []byte("data: {\"id\":\"1\",\"object\":\"chat.completion.chunk\",\"choices\":[{\"index\":0,\"delta\":{\"content\":\"Hello\"}}]}\n\n")}
				ch <- provider.StreamEvent{Error: fmt.Errorf("connection reset by peer")}
			}()
			return ch, nil
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/chat/completions"}}
	c.Request = httptest.NewRequest("POST", "/openai/v1/chat/completions", bytes.NewReader([]byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}],"stream":true}`)))

	h.HandleProxy(c)
	assert.Equal(t, 200, w.Code)
	assert.Equal(t, "text/event-stream", w.Header().Get("Content-Type"))
	body := w.Body.String()
	assert.Contains(t, body, "Hello")
}

func TestProxyHandler_HandleStream_FlushOutput(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{
		result: &domain.RouteResult{
			Provider: &domain.Provider{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "openai", Enabled: true},
			Model:    &domain.Model{ID: "m1", ProviderID: "p1", ModelName: "gpt-4", Enabled: true},
		},
	}
	client := &mockProxyProviderClient{
		sendStreamFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (<-chan provider.StreamEvent, error) {
			ch := make(chan provider.StreamEvent, 10)
			go func() {
				defer close(ch)
				ch <- provider.StreamEvent{Data: []byte("data: {\"id\":\"1\",\"object\":\"chat.completion.chunk\",\"choices\":[{\"index\":0,\"delta\":{\"content\":\"Hi\"}}]}\n\n")}
				ch <- provider.StreamEvent{Data: []byte("data: [DONE]\n\n")}
				ch <- provider.StreamEvent{Done: true}
			}()
			return ch, nil
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/chat/completions"}}
	c.Request = httptest.NewRequest("POST", "/openai/v1/chat/completions", bytes.NewReader([]byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}],"stream":true}`)))

	h.HandleProxy(c)
	assert.Equal(t, 200, w.Code)
	assert.Equal(t, "text/event-stream", w.Header().Get("Content-Type"))
	assert.Equal(t, "no-cache", w.Header().Get("Cache-Control"))
	assert.Equal(t, "keep-alive", w.Header().Get("Connection"))
	body := w.Body.String()
	assert.Contains(t, body, "Hi")
	assert.Contains(t, body, "[DONE]")
}

func TestProxyHandler_HandleStream_CreateStreamConverterError(t *testing.T) {
	registry := conversion.NewMemoryRegistry()
	engine := conversion.NewConversionEngine(registry)
	err := registry.Register(openai.NewAdapter())
	require.NoError(t, err)

	routingSvc := &mockProxyRoutingService{
		result: &domain.RouteResult{
			Provider: &domain.Provider{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "nonexistent", Enabled: true},
			Model:    &domain.Model{ID: "m1", ProviderID: "p1", ModelName: "gpt-4", Enabled: true},
		},
	}
	h := newTestProxyHandler(engine, &mockProxyProviderClient{}, routingSvc, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/chat/completions"}}
	c.Request = httptest.NewRequest("POST", "/openai/v1/chat/completions", bytes.NewReader([]byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}],"stream":true}`)))

	h.HandleProxy(c)
	assert.Equal(t, 500, w.Code)
}

func TestProxyHandler_HandleStream_ConvertRequestError(t *testing.T) {
	registry := conversion.NewMemoryRegistry()
	engine := conversion.NewConversionEngine(registry)
	require.NoError(t, registry.Register(openai.NewAdapter()))

	routingSvc := &mockProxyRoutingService{
		result: &domain.RouteResult{
			Provider: &domain.Provider{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "nonexistent", Enabled: true},
			Model:    &domain.Model{ID: "m1", ProviderID: "p1", ModelName: "gpt-4", Enabled: true},
		},
	}
	h := newTestProxyHandler(engine, &mockProxyProviderClient{}, routingSvc, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/chat/completions"}}
	c.Request = httptest.NewRequest("POST", "/openai/v1/chat/completions", bytes.NewReader([]byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}],"stream":true}`)))

	h.HandleProxy(c)
	assert.Equal(t, 500, w.Code)
}

func TestProxyHandler_HandleNonStream_ConvertResponseError(t *testing.T) {
	registry := conversion.NewMemoryRegistry()
	engine := conversion.NewConversionEngine(registry)
	require.NoError(t, registry.Register(openai.NewAdapter()))
	require.NoError(t, registry.Register(anthropic.NewAdapter()))

	routingSvc := &mockProxyRoutingService{
		result: &domain.RouteResult{
			Provider: &domain.Provider{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "anthropic", Enabled: true},
			Model:    &domain.Model{ID: "m1", ProviderID: "p1", ModelName: "claude-3", Enabled: true},
		},
	}
	client := &mockProxyProviderClient{
		sendFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (*conversion.HTTPResponseSpec, error) {
			return &conversion.HTTPResponseSpec{
				StatusCode: 200,
				Headers:    map[string]string{"Content-Type": "application/json"},
				Body:       []byte(`invalid json`),
			}, nil
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/chat/completions"}}
	c.Request = httptest.NewRequest("POST", "/openai/v1/chat/completions", bytes.NewReader([]byte(`{"model":"claude-3","messages":[{"role":"user","content":"hi"}]}`)))

	h.HandleProxy(c)
	assert.Equal(t, 500, w.Code)
}

func TestProxyHandler_HandleNonStream_ResponseHeaders(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{
		result: &domain.RouteResult{
			Provider: &domain.Provider{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "openai", Enabled: true},
			Model:    &domain.Model{ID: "m1", ProviderID: "p1", ModelName: "gpt-4", Enabled: true},
		},
	}
	client := &mockProxyProviderClient{
		sendFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (*conversion.HTTPResponseSpec, error) {
			return &conversion.HTTPResponseSpec{
				StatusCode: 200,
				Headers:    map[string]string{"Content-Type": "application/json", "X-Custom": "test-value"},
				Body:       []byte(`{"id":"r1","object":"chat.completion","model":"gpt-4","choices":[{"index":0,"message":{"role":"assistant","content":"ok"},"finish_reason":"stop"}],"usage":{"prompt_tokens":1,"completion_tokens":1,"total_tokens":2}}`),
			}, nil
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/chat/completions"}}
	c.Request = httptest.NewRequest("POST", "/openai/v1/chat/completions", bytes.NewReader([]byte(`{"model":"gpt-4","messages":[{"role":"user","content":"hi"}]}`)))

	h.HandleProxy(c)
	assert.Equal(t, 200, w.Code)
	assert.Equal(t, "test-value", w.Header().Get("X-Custom"))
	assert.Equal(t, "application/json", w.Header().Get("Content-Type"))
}

func TestProxyHandler_ForwardPassthrough_CrossProtocol(t *testing.T) {
	registry := conversion.NewMemoryRegistry()
	engine := conversion.NewConversionEngine(registry)
	require.NoError(t, registry.Register(openai.NewAdapter()))

	anthropicAdapter := anthropic.NewAdapter()
	require.NoError(t, registry.Register(anthropicAdapter))

	routingSvc := &mockProxyRoutingService{err: appErrors.ErrModelNotFound}
	providerSvc := &mockProxyProviderService{
		providers: []domain.Provider{
			{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "anthropic"},
		},
	}
	client := &mockProxyProviderClient{
		sendFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (*conversion.HTTPResponseSpec, error) {
			return &conversion.HTTPResponseSpec{
				StatusCode: 200,
				Headers:    map[string]string{"Content-Type": "application/json"},
				Body:       []byte(`{"object":"list","data":[]}`),
			}, nil
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, providerSvc)

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/models"}}
	c.Request = httptest.NewRequest("GET", "/openai/v1/models", nil)

	h.HandleProxy(c)
	assert.Equal(t, 200, w.Code)
}

func TestProxyHandler_ForwardPassthrough_NoBody_NoModel(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{err: appErrors.ErrModelNotFound}
	providerSvc := &mockProxyProviderService{
		providers: []domain.Provider{
			{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "openai"},
		},
	}
	client := &mockProxyProviderClient{
		sendFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (*conversion.HTTPResponseSpec, error) {
			return &conversion.HTTPResponseSpec{
				StatusCode: 200,
				Headers:    map[string]string{"Content-Type": "application/json"},
				Body:       []byte(`{"object":"list","data":[{"id":"gpt-4","object":"model"}]}`),
			}, nil
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, providerSvc)

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/models"}}
	c.Request = httptest.NewRequest("GET", "/openai/v1/models", nil)

	h.HandleProxy(c)
	assert.Equal(t, 200, w.Code)
}

func TestIsStreamRequest_EdgeCases(t *testing.T) {
	engine := setupProxyEngine(t)
	h := newTestProxyHandler(engine, &mockProxyProviderClient{}, &mockProxyRoutingService{}, &mockProxyProviderService{})

	tests := []struct {
		name     string
		body     string
		path     string
		expected bool
	}{
		{"stream at end of JSON", `{"messages":[],"stream":true}`, "/v1/chat/completions", true},
		{"stream with spaces", `{"stream" :  true}`, "/v1/chat/completions", true},
		{"stream embedded in string value", `{"model":"stream:true"}`, "/v1/chat/completions", false},
		{"empty body", "", "/v1/chat/completions", false},
		{"stream true embeddings", `{"model":"text-emb","stream":true}`, "/v1/embeddings", false},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result := h.isStreamRequest([]byte(tt.body), "openai", tt.path)
			assert.Equal(t, tt.expected, result)
		})
	}
}

func TestProxyHandler_WriteError_RouteError(t *testing.T) {
	engine := setupProxyEngine(t)
	h := newTestProxyHandler(engine, &mockProxyProviderClient{}, &mockProxyRoutingService{}, &mockProxyProviderService{})

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Request = httptest.NewRequest("POST", "/", nil)

	h.writeError(c, fmt.Errorf("model not found"), "openai")
	assert.Equal(t, 404, w.Code)
}

func TestProxyHandler_HandleProxy_RouteEmptyBody_NoModel(t *testing.T) {
	engine := setupProxyEngine(t)
	routingSvc := &mockProxyRoutingService{err: appErrors.ErrModelNotFound}
	providerSvc := &mockProxyProviderService{
		providers: []domain.Provider{
			{ID: "p1", Name: "Test", APIKey: "sk-test", BaseURL: "https://api.test.com", Protocol: "openai"},
		},
	}
	client := &mockProxyProviderClient{
		sendFn: func(ctx context.Context, spec conversion.HTTPRequestSpec) (*conversion.HTTPResponseSpec, error) {
			return &conversion.HTTPResponseSpec{
				StatusCode: 200,
				Body:       []byte(`{"object":"list","data":[]}`),
			}, nil
		},
	}
	h := newTestProxyHandler(engine, client, routingSvc, providerSvc)

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "protocol", Value: "openai"}, {Key: "path", Value: "/models"}}
	c.Request = httptest.NewRequest("GET", "/openai/v1/models", nil)

	h.HandleProxy(c)
	assert.Equal(t, 200, w.Code)
}