package v1

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

	"github.com/gin-gonic/gin"
	"github.com/gochat/gochat/internal/llm"
	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/repository"
	"github.com/gochat/gochat/internal/service"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
)

type mockRespHandlerLLM struct {
	response *llm.ChatResponse
	err      error
}

func (m *mockRespHandlerLLM) ChatCompletion(_ context.Context, _ llm.ChatRequest) (*llm.ChatResponse, error) {
	return m.response, m.err
}
func (m *mockRespHandlerLLM) CreateEmbedding(_ context.Context, _ llm.EmbeddingRequest) (*llm.EmbeddingResponse, error) {
	return nil, nil
}
func (m *mockRespHandlerLLM) ChatCompletionStream(_ context.Context, _ llm.ChatRequest, _ func(llm.StreamChunk) error) error {
	return nil
}

func setupAssistantResponseHandlerTest(t *testing.T, mockLLM llm.Provider) (*CaptainAssistantResponseHandler, *gorm.DB) {
	t.Helper()
	gin.SetMode(gin.TestMode)
	dbName := fmt.Sprintf("file:%s?mode=memory&cache=private", t.Name())
	db, err := gorm.Open(sqlite.Open(dbName), &gorm.Config{})
	require.NoError(t, err)
	require.NoError(t, db.AutoMigrate(
		&model.CaptainPreference{},
		&model.CaptainAssistant{},
		&model.Conversation{},
		&model.Message{},
		&model.Inbox{},
		&model.Contact{},
	))
	assistantRepo := repository.NewCaptainAssistantRepo(db)
	responseRepo := repository.NewCaptainAssistantResponseRepo(db)
	convRepo := repository.NewConversationRepo(db)
	msgRepo := repository.NewMessageRepo(db)
	prefRepo := repository.NewCaptainPreferenceRepo(db)
	svc := service.NewCaptainAssistantResponseService(assistantRepo, responseRepo, convRepo, msgRepo, prefRepo, mockLLM)
	handler := NewCaptainAssistantResponseHandler(svc)
	return handler, db
}

func seedAssistantResponseData(t *testing.T, db *gorm.DB) (*model.Conversation, *model.CaptainAssistant) {
	t.Helper()
	inbox := &model.Inbox{AccountID: 1, Name: "Inbox", ChannelType: "web_widget"}
	require.NoError(t, db.Create(inbox).Error)
	conv := &model.Conversation{AccountID: 1, InboxID: inbox.ID, Status: "open"}
	require.NoError(t, db.Create(conv).Error)
	msg := &model.Message{ConversationID: conv.ID, AccountID: 1, InboxID: inbox.ID, SenderType: "contact", Content: "reset password?", ContentType: "text", MessageType: "incoming"}
	require.NoError(t, db.Create(msg).Error)

	cfg := &model.AssistantConfig{Instructions: "Be helpful", Temperature: 0.7}
	cfgJSON, _ := json.Marshal(cfg)
	assistant := &model.CaptainAssistant{AccountID: 1, Name: "Bot", Config: cfgJSON, Status: model.AssistantStatusActive}
	require.NoError(t, db.Create(assistant).Error)
	return conv, assistant
}

func TestCaptainAssistantResponseHandler_ProcessResponse(t *testing.T) {
	mockLLM := &mockRespHandlerLLM{
		response: &llm.ChatResponse{
			Choices: []llm.ChatChoice{
				{Message: llm.ChatMessage{Role: "assistant", Content: "You can reset your password in Settings."}},
			},
		},
	}
	handler, db := setupAssistantResponseHandlerTest(t, mockLLM)
	conv, assistant := seedAssistantResponseData(t, db)

	body := map[string]interface{}{
		"conversation_id": conv.ID,
		"assistant_id":    assistant.ID,
		"send_message":    false,
	}
	bodyBytes, _ := json.Marshal(body)

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "id", Value: "1"}}
	c.Request = httptest.NewRequest(http.MethodPost, "/api/v1/accounts/1/captain/assistant_responses/process", bytes.NewReader(bodyBytes))
	c.Request.Header.Set("Content-Type", "application/json")

	handler.ProcessResponse(c)

	assert.Equal(t, http.StatusOK, w.Code)

	var resp handlerTestResponse
	require.NoError(t, json.Unmarshal(w.Body.Bytes(), &resp))
	assert.True(t, resp.Success)
}

func TestCaptainAssistantResponseHandler_ProcessResponse_InvalidAccountID(t *testing.T) {
	mockLLM := &mockRespHandlerLLM{}
	handler, _ := setupAssistantResponseHandlerTest(t, mockLLM)

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "id", Value: "invalid"}}
	c.Request = httptest.NewRequest(http.MethodPost, "/api/v1/accounts/invalid/captain/assistant_responses/process", nil)
	c.Request.Header.Set("Content-Type", "application/json")

	handler.ProcessResponse(c)

	assert.Equal(t, http.StatusBadRequest, w.Code)
}

func TestCaptainAssistantResponseHandler_ProcessResponse_LLMError(t *testing.T) {
	mockLLM := &mockRespHandlerLLM{err: fmt.Errorf("LLM unavailable")}
	handler, db := setupAssistantResponseHandlerTest(t, mockLLM)
	conv, assistant := seedAssistantResponseData(t, db)

	body := map[string]interface{}{
		"conversation_id": conv.ID,
		"assistant_id":    assistant.ID,
		"send_message":    false,
	}
	bodyBytes, _ := json.Marshal(body)

	w := httptest.NewRecorder()
	c, _ := gin.CreateTestContext(w)
	c.Params = gin.Params{{Key: "id", Value: "1"}}
	c.Request = httptest.NewRequest(http.MethodPost, "/api/v1/accounts/1/captain/assistant_responses/process", bytes.NewReader(bodyBytes))
	c.Request.Header.Set("Content-Type", "application/json")

	handler.ProcessResponse(c)

	assert.Equal(t, http.StatusUnprocessableEntity, w.Code)
}