package services

import (
	"strings"
	"testing"
	"time"

	"cs-ai-agent/internal/models"
	"cs-ai-agent/internal/pkg/enums"
	"cs-ai-agent/internal/pkg/openidentity"

	"github.com/glebarez/sqlite"
	"github.com/mlogclub/simple/sqls"
	"gorm.io/gorm"
	"gorm.io/gorm/schema"
)

func TestAllowAIMessageOnPendingHandoff(t *testing.T) {
	conversation := &models.Conversation{
		Status:            enums.IMConversationStatusPending,
		CurrentAssigneeID: 0,
		HandoffAt:         ptrTime(time.Now()),
	}
	if !MessageService.allowAIMessageOnPendingHandoff(conversation) {
		t.Fatalf("expected pending handoff conversation to allow ai handoff notice")
	}

	conversation.Status = enums.IMConversationStatusAIServing
	if MessageService.allowAIMessageOnPendingHandoff(conversation) {
		t.Fatalf("expected ai serving conversation not to use pending handoff allowance")
	}
}

func ptrTime(v time.Time) *time.Time {
	return &v
}

func setupMessageWelcomeTestDB(t *testing.T) *gorm.DB {
	t.Helper()

	dbName := "message_welcome_test_" + strings.NewReplacer("/", "_").Replace(t.Name())
	db, err := gorm.Open(sqlite.Open("file:"+dbName+"?mode=memory&cache=shared"), &gorm.Config{
		NamingStrategy: schema.NamingStrategy{
			TablePrefix:   "t_",
			SingularTable: true,
		},
	})
	if err != nil {
		t.Fatalf("open sqlite db: %v", err)
	}
	sqlDB, err := db.DB()
	if err != nil {
		t.Fatalf("get sqlite db: %v", err)
	}
	t.Cleanup(func() {
		if err := sqlDB.Close(); err != nil {
			t.Fatalf("close sqlite db: %v", err)
		}
	})
	if err := db.AutoMigrate(
		&models.AIAgent{},
		&models.Channel{},
		&models.ChannelMessageOutbox{},
		&models.Customer{},
		&models.CustomerIdentity{},
		&models.Conversation{},
		&models.ConversationParticipant{},
		&models.ConversationReadState{},
		&models.ConversationEventLog{},
		&models.Message{},
	); err != nil {
		t.Fatalf("auto migrate: %v", err)
	}
	sqls.SetDB(db)
	return db
}

func createWelcomeTestAIAgent(t *testing.T, db *gorm.DB, welcomeMessage string) *models.AIAgent {
	t.Helper()

	now := time.Now()
	aiAgent := &models.AIAgent{
		Name:           "welcome-test-agent",
		Status:         enums.StatusOk,
		ServiceMode:    enums.IMConversationServiceModeAIOnly,
		WelcomeMessage: welcomeMessage,
		AuditFields: models.AuditFields{
			CreatedAt: now,
			UpdatedAt: now,
		},
	}
	if err := db.Create(aiAgent).Error; err != nil {
		t.Fatalf("create ai agent: %v", err)
	}
	return aiAgent
}

func welcomeTestExternalUser(id string) openidentity.ExternalUser {
	return openidentity.ExternalUser{
		ExternalSource: enums.ExternalSourceUser,
		ExternalID:     id,
		ExternalName:   "访客" + id,
	}
}

func TestConversationCreateCreatesAIWelcomeMessage(t *testing.T) {
	db := setupMessageWelcomeTestDB(t)
	aiAgent := createWelcomeTestAIAgent(t, db, "  您好，请问有什么可以帮您？  ")

	conversation, err := ConversationService.Create(welcomeTestExternalUser("welcome-1"), 11, aiAgent.ID)
	if err != nil {
		t.Fatalf("create conversation: %v", err)
	}
	if conversation == nil {
		t.Fatalf("expected conversation")
	}

	var messages []models.Message
	if err := db.Find(&messages).Error; err != nil {
		t.Fatalf("find messages: %v", err)
	}
	if len(messages) != 1 {
		t.Fatalf("expected exactly one welcome message, got %d", len(messages))
	}
	message := messages[0]
	if message.ConversationID != conversation.ID {
		t.Fatalf("expected conversation_id %d, got %d", conversation.ID, message.ConversationID)
	}
	if message.SenderType != enums.IMSenderTypeAI {
		t.Fatalf("expected sender type ai, got %q", message.SenderType)
	}
	if message.SenderID != aiAgent.ID {
		t.Fatalf("expected sender id %d, got %d", aiAgent.ID, message.SenderID)
	}
	if message.MessageType != enums.IMMessageTypeText {
		t.Fatalf("expected message type text, got %q", message.MessageType)
	}
	if message.Content != "您好，请问有什么可以帮您？" {
		t.Fatalf("expected trimmed welcome content, got %q", message.Content)
	}
	if message.SeqNo != 1 {
		t.Fatalf("expected seq no 1, got %d", message.SeqNo)
	}
	if message.SendStatus != enums.IMMessageStatusSent {
		t.Fatalf("expected sent status, got %d", message.SendStatus)
	}

	var updated models.Conversation
	if err := db.First(&updated, conversation.ID).Error; err != nil {
		t.Fatalf("find conversation: %v", err)
	}
	if updated.LastMessageID != message.ID {
		t.Fatalf("expected last message id %d, got %d", message.ID, updated.LastMessageID)
	}
	if updated.LastMessageSummary != "您好，请问有什么可以帮您？" {
		t.Fatalf("expected last message summary, got %q", updated.LastMessageSummary)
	}
	if updated.CustomerUnreadCount != 1 {
		t.Fatalf("expected customer unread count 1, got %d", updated.CustomerUnreadCount)
	}
	if updated.AgentUnreadCount != 0 {
		t.Fatalf("expected agent unread count 0, got %d", updated.AgentUnreadCount)
	}
}

func TestSendCustomerMessageStoresRequestIDOnMessageAndEvent(t *testing.T) {
	db := setupMessageWelcomeTestDB(t)
	aiAgent := createWelcomeTestAIAgent(t, db, "")
	external := welcomeTestExternalUser("trace-user")
	conversation, err := ConversationService.Create(external, 11, aiAgent.ID)
	if err != nil {
		t.Fatalf("create conversation: %v", err)
	}

	message, err := MessageService.SendCustomerMessageWithRequestID(
		conversation.ID,
		"client-msg-trace",
		enums.IMMessageTypeText,
		"hello",
		"",
		external,
		"trace-123",
	)
	if err != nil {
		t.Fatalf("SendCustomerMessageWithRequestID() error = %v", err)
	}
	if message.RequestID != "trace-123" {
		t.Fatalf("message.RequestID=%q want %q", message.RequestID, "trace-123")
	}

	var event models.ConversationEventLog
	if err := db.Where("conversation_id = ?", conversation.ID).Order("id DESC").First(&event).Error; err != nil {
		t.Fatalf("find event: %v", err)
	}
	if event.RequestID != "trace-123" {
		t.Fatalf("event.RequestID=%q want %q", event.RequestID, "trace-123")
	}
}

func TestConversationCreateDoesNotDuplicateWelcomeMessageForExistingConversation(t *testing.T) {
	db := setupMessageWelcomeTestDB(t)
	aiAgent := createWelcomeTestAIAgent(t, db, "欢迎咨询")
	external := welcomeTestExternalUser("u-2")

	first, err := ConversationService.Create(external, 11, aiAgent.ID)
	if err != nil {
		t.Fatalf("create first conversation: %v", err)
	}
	second, err := ConversationService.Create(external, 11, aiAgent.ID)
	if err != nil {
		t.Fatalf("create second conversation: %v", err)
	}
	if first.ID != second.ID {
		t.Fatalf("expected existing conversation id %d, got %d", first.ID, second.ID)
	}

	var count int64
	if err := db.Model(&models.Message{}).Where("conversation_id = ?", first.ID).Count(&count).Error; err != nil {
		t.Fatalf("count messages: %v", err)
	}
	if count != 1 {
		t.Fatalf("expected exactly one welcome message, got %d", count)
	}
}

func TestConversationCreateSkipsBlankWelcomeMessage(t *testing.T) {
	db := setupMessageWelcomeTestDB(t)
	aiAgent := createWelcomeTestAIAgent(t, db, "   ")

	conversation, err := ConversationService.Create(welcomeTestExternalUser("blank-welcome-1"), 11, aiAgent.ID)
	if err != nil {
		t.Fatalf("create conversation: %v", err)
	}
	if conversation == nil {
		t.Fatalf("expected conversation")
	}

	var count int64
	if err := db.Model(&models.Message{}).Where("conversation_id = ?", conversation.ID).Count(&count).Error; err != nil {
		t.Fatalf("count messages: %v", err)
	}
	if count != 0 {
		t.Fatalf("expected no welcome messages, got %d", count)
	}

	var updated models.Conversation
	if err := db.First(&updated, conversation.ID).Error; err != nil {
		t.Fatalf("find conversation: %v", err)
	}
	if updated.LastMessageID != 0 {
		t.Fatalf("expected last message id 0, got %d", updated.LastMessageID)
	}
	if updated.CustomerUnreadCount != 0 {
		t.Fatalf("expected customer unread count 0, got %d", updated.CustomerUnreadCount)
	}
}

func TestConversationCreateWelcomeMessageDoesNotTriggerAIReplyHook(t *testing.T) {
	db := setupMessageWelcomeTestDB(t)
	aiAgent := createWelcomeTestAIAgent(t, db, "欢迎咨询")

	previousHook := TriggerAIReplyAsyncHook
	called := false
	TriggerAIReplyAsyncHook = func(conversation models.Conversation, message models.Message) {
		called = true
	}
	t.Cleanup(func() {
		TriggerAIReplyAsyncHook = previousHook
	})

	if _, err := ConversationService.Create(welcomeTestExternalUser("hook-welcome-1"), 11, aiAgent.ID); err != nil {
		t.Fatalf("create conversation: %v", err)
	}
	if called {
		t.Fatalf("expected welcome message not to trigger ai reply hook")
	}
}