package service

import (
	"context"
	"fmt"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gorm.io/gorm"

	"github.com/gochat/gochat/internal/channel"
	"github.com/gochat/gochat/internal/llm"
	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/repository"
	"github.com/gochat/gochat/internal/search"
)

// mockMessageLLMProvider implements llm.Provider for message service testing.
// (Separate name to avoid conflict with mockLLMProvider in captain_task_service_test.go)
type mockMessageLLMProvider struct {
	chatResponse *llm.ChatResponse
	chatErr      error
}

func (m *mockMessageLLMProvider) ChatCompletion(ctx context.Context, req llm.ChatRequest) (*llm.ChatResponse, error) {
	if m.chatErr != nil {
		return nil, m.chatErr
	}
	return m.chatResponse, nil
}

func (m *mockMessageLLMProvider) CreateEmbedding(ctx context.Context, req llm.EmbeddingRequest) (*llm.EmbeddingResponse, error) {
	return nil, fmt.Errorf("not implemented")
}

func (m *mockMessageLLMProvider) ChatCompletionStream(ctx context.Context, req llm.ChatRequest, onChunk func(llm.StreamChunk) error) error {
	return fmt.Errorf("not implemented")
}

// mockRetryListener implements channel.EventListener for capturing dispatched events.
type mockRetryListener struct {
	received bool
	lastData map[string]interface{}
}

func (l *mockRetryListener) Name() string {
	return "mock-retry-listener"
}

func (l *mockRetryListener) OnEvent(ctx context.Context, event *channel.ChannelEvent) error {
	l.received = true
	l.lastData = event.Data
	return nil
}

// setupMessageService creates MessageRepo + Dispatcher + mockLLM + MessageService test instances.
func setupMessageService(t *testing.T, mockLLM *mockMessageLLMProvider) (*gorm.DB, *repository.MessageRepo, *channel.Dispatcher, *MessageService) {
	t.Helper()
	db := setupServiceTestDB(t)
	repo := repository.NewMessageRepo(db)
	dispatcher := channel.NewDispatcher()
	svc := NewMessageService(repo, dispatcher, mockLLM)
	return db, repo, dispatcher, svc
}

// setupMessageServiceWithDefaultLLM creates a MessageService with a default mock LLM that returns "translated text".
func setupMessageServiceWithDefaultLLM(t *testing.T) (*gorm.DB, *repository.MessageRepo, *channel.Dispatcher, *MessageService) {
	t.Helper()
	mockLLM := &mockMessageLLMProvider{
		chatResponse: &llm.ChatResponse{
			Choices: []llm.ChatChoice{
				{Message: llm.ChatMessage{Role: "assistant", Content: "translated text"}},
			},
		},
	}
	return setupMessageService(t, mockLLM)
}

// ========== ListByConversation 测试 ==========

func TestMessageService_ListByConversation(t *testing.T) {
	db, _, _, svc := setupMessageServiceWithDefaultLLM(t)

	ctx := context.Background()
	account := createTestAccount(t, db)
	user := createTestUser(t, db, account.ID)
	inbox := createTestInbox(t, db, account.ID, "web_widget")
	contact := createTestContact(t, db, account.ID)
	conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

	// 创建多条消息
	msg1 := &model.Message{
		ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
		Content: "消息1", MessageType: "incoming", ContentType: "text", SenderType: "contact", SenderID: &contact.ID,
	}
	msg2 := &model.Message{
		ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
		Content: "消息2", MessageType: "outgoing", ContentType: "text", SenderType: "user", SenderID: &user.ID,
	}
	require.NoError(t, db.Create(msg1).Error)
	require.NoError(t, db.Create(msg2).Error)

	// 正常路径：查询会话消息列表
	messages, total, err := svc.ListByConversation(ctx, conv.ID, 0, 10)
	assert.NoError(t, err)
	assert.Equal(t, int64(2), total)
	assert.Len(t, messages, 2)

	// 正常路径：分页查询
	messages2, total2, err2 := svc.ListByConversation(ctx, conv.ID, 1, 1)
	assert.NoError(t, err2)
	assert.Equal(t, int64(2), total2)
	assert.Len(t, messages2, 1)

	// 正常路径：空会话
	messages3, total3, err3 := svc.ListByConversation(ctx, 9999, 0, 10)
	assert.NoError(t, err3)
	assert.Equal(t, int64(0), total3)
	assert.Len(t, messages3, 0)
}

// ========== GetByID 测试 ==========

func TestMessageService_GetByID(t *testing.T) {
	db, _, _, svc := setupMessageServiceWithDefaultLLM(t)

	ctx := context.Background()
	account := createTestAccount(t, db)
	inbox := createTestInbox(t, db, account.ID, "web_widget")
	contact := createTestContact(t, db, account.ID)
	conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

	msg := &model.Message{
		ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
		Content: "Hello", MessageType: "incoming", ContentType: "text", SenderType: "contact",
	}
	require.NoError(t, db.Create(msg).Error)

	// 正常路径：按ID查询
	found, err := svc.GetByID(ctx, msg.ID)
	assert.NoError(t, err)
	assert.Equal(t, "Hello", found.Content)
	assert.Equal(t, "incoming", found.MessageType)

	// 错误路径：不存在的ID
	_, err = svc.GetByID(ctx, 9999)
	assert.Error(t, err)
}

// ========== GetByAccountAndID 测试 ==========

func TestMessageService_GetByAccountAndID(t *testing.T) {
	db, _, _, svc := setupMessageServiceWithDefaultLLM(t)

	ctx := context.Background()
	account := createTestAccount(t, db)
	inbox := createTestInbox(t, db, account.ID, "web_widget")
	contact := createTestContact(t, db, account.ID)
	conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

	msg := &model.Message{
		ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
		Content: "ScopedMsg", MessageType: "outgoing", ContentType: "text", SenderType: "user",
	}
	require.NoError(t, db.Create(msg).Error)

	// 正常路径：按account和ID查询
	found, err := svc.GetByAccountAndID(ctx, account.ID, msg.ID)
	assert.NoError(t, err)
	assert.Equal(t, "ScopedMsg", found.Content)

	// 错误路径：accountID不匹配
	_, err = svc.GetByAccountAndID(ctx, 9999, msg.ID)
	assert.Error(t, err)

	// 错误路径：ID不存在
	_, err = svc.GetByAccountAndID(ctx, account.ID, 9999)
	assert.Error(t, err)
}

// ========== GetByConversationAndID 测试 ==========

func TestMessageService_GetByConversationAndID(t *testing.T) {
	db, _, _, svc := setupMessageServiceWithDefaultLLM(t)

	ctx := context.Background()
	account := createTestAccount(t, db)
	inbox := createTestInbox(t, db, account.ID, "web_widget")
	contact := createTestContact(t, db, account.ID)
	conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

	msg := &model.Message{
		ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
		Content: "ConvScopedMsg", MessageType: "incoming", ContentType: "text", SenderType: "contact",
	}
	require.NoError(t, db.Create(msg).Error)

	// 正常路径：按conversation和ID查询
	found, err := svc.GetByConversationAndID(ctx, conv.ID, msg.ID)
	assert.NoError(t, err)
	assert.Equal(t, "ConvScopedMsg", found.Content)

	// 错误路径：conversationID不匹配
	_, err = svc.GetByConversationAndID(ctx, 9999, msg.ID)
	assert.Error(t, err)

	// 错误路径：ID不存在
	_, err = svc.GetByConversationAndID(ctx, conv.ID, 9999)
	assert.Error(t, err)
}

// ========== Search 测试 ==========

func TestMessageService_Search(t *testing.T) {
	// Search底层使用ILIKE，SQLite不支持该语法
	// 在SQLite环境下Search会返回SQL错误，Service层只做委托调用，这是预期行为
	db, _, _, svc := setupMessageServiceWithDefaultLLM(t)

	ctx := context.Background()
	account := createTestAccount(t, db)
	inbox := createTestInbox(t, db, account.ID, "web_widget")
	contact := createTestContact(t, db, account.ID)
	conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

	msg1 := &model.Message{
		ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
		Content: "important meeting", MessageType: "incoming", ContentType: "text", SenderType: "contact",
	}
	msg2 := &model.Message{
		ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
		Content: "casual chat", MessageType: "incoming", ContentType: "text", SenderType: "contact",
	}
	require.NoError(t, db.Create(msg1).Error)
	require.NoError(t, db.Create(msg2).Error)

	// ILIKE不兼容SQLite，在SQLite下搜索会返回SQL语法错误
	// 这属于Repo层SQL兼容性问题，Service层本身只做委托调用
	results, total, err := svc.Search(ctx, account.ID, "meeting", 0, 10, search.SearchModeILike)
	if err != nil {
		// SQLite环境：ILIKE语法不被支持，Search返回错误属于预期行为
		t.Logf("Search在SQLite下返回错误（ILIKE不兼容）: %v", err)
	} else {
		// PostgreSQL环境：正常搜索
		assert.Equal(t, int64(1), total)
		assert.Len(t, results, 1)
		if len(results) > 0 {
			assert.Equal(t, "important meeting", results[0].Content)
		}
	}
}

// ========== Create 测试 ==========

func TestMessageService_Create(t *testing.T) {
	db, _, _, svc := setupMessageServiceWithDefaultLLM(t)

	ctx := context.Background()
	account := createTestAccount(t, db)
	user := createTestUser(t, db, account.ID)
	inbox := createTestInbox(t, db, account.ID, "web_widget")
	contact := createTestContact(t, db, account.ID)
	conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

	// 正常路径：创建消息
	req := CreateMessageRequest{
		ConversationID: conv.ID,
		Content:        "测试消息内容",
		MessageType:    "outgoing",
		ContentType:    "text",
	}
	created, err := svc.Create(ctx, account.ID, user.ID, req)
	assert.NoError(t, err)
	assert.Equal(t, conv.ID, created.ConversationID)
	assert.Equal(t, account.ID, created.AccountID)
	assert.Equal(t, "测试消息内容", created.Content)
	assert.Equal(t, "outgoing", created.MessageType)
	assert.Equal(t, "text", created.ContentType)
	assert.Equal(t, user.ID, *created.SenderID)
	assert.Equal(t, "user", created.SenderType)
	assert.False(t, created.Private)

	// 正常路径：默认ContentType为text
	reqNoContentType := CreateMessageRequest{
		ConversationID: conv.ID,
		Content:        "无ContentType",
		MessageType:    "incoming",
	}
	created2, err2 := svc.Create(ctx, account.ID, user.ID, reqNoContentType)
	assert.NoError(t, err2)
	assert.Equal(t, "text", created2.ContentType)

	// 正常路径：创建私密消息
	reqPrivate := CreateMessageRequest{
		ConversationID: conv.ID,
		Content:        "私密消息",
		MessageType:    "private_note",
		Private:        true,
	}
	created3, err3 := svc.Create(ctx, account.ID, user.ID, reqPrivate)
	assert.NoError(t, err3)
	assert.True(t, created3.Private)

	// 错误路径：验证失败 - 空Content
	reqEmpty := CreateMessageRequest{
		ConversationID: conv.ID,
		Content:        "",
		MessageType:    "outgoing",
	}
	_, err4 := svc.Create(ctx, account.ID, user.ID, reqEmpty)
	assert.Error(t, err4)

	// 错误路径：验证失败 - 无效MessageType
	reqInvalid := CreateMessageRequest{
		ConversationID: conv.ID,
		Content:        "内容",
		MessageType:    "invalid_type",
	}
	_, err5 := svc.Create(ctx, account.ID, user.ID, reqInvalid)
	assert.Error(t, err5)

	// 错误路径：验证失败 - 无效ContentType
	reqInvalidCT := CreateMessageRequest{
		ConversationID: conv.ID,
		Content:        "内容",
		MessageType:    "outgoing",
		ContentType:    "invalid_ct",
	}
	_, err6 := svc.Create(ctx, account.ID, user.ID, reqInvalidCT)
	assert.Error(t, err6)

	// 错误路径：验证失败 - 缺少ConversationID
	reqNoConvID := CreateMessageRequest{
		Content:     "内容",
		MessageType: "outgoing",
	}
	_, err7 := svc.Create(ctx, account.ID, user.ID, reqNoConvID)
	assert.Error(t, err7)
}

// ========== Update 测试 ==========

func TestMessageService_Update(t *testing.T) {
	db, _, _, svc := setupMessageServiceWithDefaultLLM(t)

	ctx := context.Background()
	account := createTestAccount(t, db)
	inbox := createTestInbox(t, db, account.ID, "web_widget")
	contact := createTestContact(t, db, account.ID)
	conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

	msg := &model.Message{
		ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
		Content: "原始内容", MessageType: "outgoing", ContentType: "text", SenderType: "user",
	}
	require.NoError(t, db.Create(msg).Error)

	// 正常路径：更新消息内容
	req := UpdateMessageRequest{Content: "更新内容"}
	updated, err := svc.Update(ctx, account.ID, msg.ID, req)
	assert.NoError(t, err)
	assert.Equal(t, "更新内容", updated.Content)

	// 正常路径：空Content字符串不触发更新（omitempty跳过验证）
	reqEmpty := UpdateMessageRequest{Content: ""}
	updated2, err2 := svc.Update(ctx, account.ID, msg.ID, reqEmpty)
	assert.NoError(t, err2)
	assert.Equal(t, "更新内容", updated2.Content) // Content保持不变

	// 错误路径：accountID不匹配
	_, err = svc.Update(ctx, 9999, msg.ID, req)
	assert.Error(t, err)

	// 错误路径：消息ID不存在
	_, err = svc.Update(ctx, account.ID, 9999, req)
	assert.Error(t, err)
}

// ========== Delete 测试 ==========

func TestMessageService_Delete(t *testing.T) {
	db, _, _, svc := setupMessageServiceWithDefaultLLM(t)

	ctx := context.Background()
	account := createTestAccount(t, db)
	inbox := createTestInbox(t, db, account.ID, "web_widget")
	contact := createTestContact(t, db, account.ID)
	conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

	msg := &model.Message{
		ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
		Content: "待删除消息", MessageType: "incoming", ContentType: "text", SenderType: "contact",
	}
	require.NoError(t, db.Create(msg).Error)

	// 正常路径：Chatwoot 删除会保留消息并标记 content_attributes.deleted
	deleted, err := svc.Delete(ctx, account.ID, msg.ID)
	assert.NoError(t, err)
	assert.Equal(t, "This message was deleted", deleted.Content)

	stored, err := svc.GetByAccountAndID(ctx, account.ID, msg.ID)
	assert.NoError(t, err)
	assert.JSONEq(t, `{"deleted":true}`, string(stored.ContentAttributes))

	// 错误路径：accountID不匹配
	msg2 := &model.Message{
		ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
		Content: "另一条消息", MessageType: "incoming", ContentType: "text", SenderType: "contact",
	}
	require.NoError(t, db.Create(msg2).Error)
	_, err = svc.Delete(ctx, 9999, msg2.ID)
	assert.Error(t, err)

	// 错误路径：ID不存在
	_, err = svc.Delete(ctx, account.ID, 9999)
	assert.Error(t, err)
}

// ========== CountByConversation 测试 ==========

func TestMessageService_CountByConversation(t *testing.T) {
	db, _, _, svc := setupMessageServiceWithDefaultLLM(t)

	ctx := context.Background()
	account := createTestAccount(t, db)
	inbox := createTestInbox(t, db, account.ID, "web_widget")
	contact := createTestContact(t, db, account.ID)
	conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

	// 创建3条消息
	for i := 0; i < 3; i++ {
		msg := &model.Message{
			ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
			Content:     fmt.Sprintf("消息%c", 'A'+i),
			MessageType: "incoming", ContentType: "text", SenderType: "contact",
		}
		require.NoError(t, db.Create(msg).Error)
	}

	// 正常路径：统计会话消息数量
	count, err := svc.CountByConversation(ctx, conv.ID)
	assert.NoError(t, err)
	assert.Equal(t, int64(3), count)

	// 正常路径：空会话
	count2, err2 := svc.CountByConversation(ctx, 9999)
	assert.NoError(t, err2)
	assert.Equal(t, int64(0), count2)
}

// ========== Translate 测试 ==========

func TestMessageService_Translate(t *testing.T) {
	ctx := context.Background()

	t.Run("success", func(t *testing.T) {
		mockLLM := &mockMessageLLMProvider{
			chatResponse: &llm.ChatResponse{
				Choices: []llm.ChatChoice{
					{Message: llm.ChatMessage{Role: "assistant", Content: "Hello"}},
				},
			},
		}
		db, _, _, svc := setupMessageService(t, mockLLM)

		account := createTestAccount(t, db)
		inbox := createTestInbox(t, db, account.ID, "web_widget")
		contact := createTestContact(t, db, account.ID)
		conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

		msg := &model.Message{
			ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
			Content: "你好", MessageType: "incoming", ContentType: "text", SenderType: "contact",
		}
		require.NoError(t, db.Create(msg).Error)

		result, err := svc.Translate(ctx, account.ID, msg.ID, TranslateMessageRequest{TargetLanguage: "en"})
		assert.NoError(t, err)
		assert.Equal(t, msg.ID, result.ID)
		assert.Equal(t, "你好", result.OriginalContent)
		assert.Equal(t, "Hello", result.TranslatedContent)
		assert.Equal(t, "en", result.TargetLanguage)
	})

	t.Run("empty_choices", func(t *testing.T) {
		mockLLM := &mockMessageLLMProvider{
			chatResponse: &llm.ChatResponse{
				Choices: []llm.ChatChoice{},
			},
		}
		db, _, _, svc := setupMessageService(t, mockLLM)

		account := createTestAccount(t, db)
		inbox := createTestInbox(t, db, account.ID, "web_widget")
		contact := createTestContact(t, db, account.ID)
		conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

		msg := &model.Message{
			ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
			Content: "你好", MessageType: "incoming", ContentType: "text", SenderType: "contact",
		}
		require.NoError(t, db.Create(msg).Error)

		result, err := svc.Translate(ctx, account.ID, msg.ID, TranslateMessageRequest{TargetLanguage: "en"})
		assert.NoError(t, err)
		assert.Equal(t, "", result.TranslatedContent)
	})

	t.Run("llm_error", func(t *testing.T) {
		mockLLM := &mockMessageLLMProvider{
			chatErr: fmt.Errorf("LLM service unavailable"),
		}
		db, _, _, svc := setupMessageService(t, mockLLM)

		account := createTestAccount(t, db)
		inbox := createTestInbox(t, db, account.ID, "web_widget")
		contact := createTestContact(t, db, account.ID)
		conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

		msg := &model.Message{
			ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
			Content: "你好", MessageType: "incoming", ContentType: "text", SenderType: "contact",
		}
		require.NoError(t, db.Create(msg).Error)

		_, err := svc.Translate(ctx, account.ID, msg.ID, TranslateMessageRequest{TargetLanguage: "en"})
		assert.Error(t, err)
	})

	t.Run("message_not_found", func(t *testing.T) {
		mockLLM := &mockMessageLLMProvider{
			chatResponse: &llm.ChatResponse{
				Choices: []llm.ChatChoice{
					{Message: llm.ChatMessage{Role: "assistant", Content: "translated"}},
				},
			},
		}
		db, _, _, svc := setupMessageService(t, mockLLM)

		account := createTestAccount(t, db)

		_, err := svc.Translate(ctx, account.ID, 9999, TranslateMessageRequest{TargetLanguage: "en"})
		assert.Error(t, err)
	})

	t.Run("validation_empty_target_language", func(t *testing.T) {
		mockLLM := &mockMessageLLMProvider{}
		db, _, _, svc := setupMessageService(t, mockLLM)

		account := createTestAccount(t, db)
		inbox := createTestInbox(t, db, account.ID, "web_widget")
		contact := createTestContact(t, db, account.ID)
		conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

		msg := &model.Message{
			ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
			Content: "你好", MessageType: "incoming", ContentType: "text", SenderType: "contact",
		}
		require.NoError(t, db.Create(msg).Error)

		_, err := svc.Translate(ctx, account.ID, msg.ID, TranslateMessageRequest{TargetLanguage: ""})
		assert.Error(t, err)
	})
}

// ========== Retry 测试 ==========

func TestMessageService_Retry(t *testing.T) {
	ctx := context.Background()

	t.Run("success", func(t *testing.T) {
		db, _, dispatcher, svc := setupMessageServiceWithDefaultLLM(t)

		account := createTestAccount(t, db)
		inbox := createTestInbox(t, db, account.ID, "web_widget")
		contact := createTestContact(t, db, account.ID)
		conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

		msg := &model.Message{
			ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
			Content: "failed message", MessageType: "outgoing", ContentType: "text", SenderType: "user",
			Status: "failed",
		}
		require.NoError(t, db.Create(msg).Error)

		// Register a listener to verify dispatch
		listener := &mockRetryListener{}
		dispatcher.Register(listener)

		retried, err := svc.Retry(ctx, account.ID, msg.ID)
		assert.NoError(t, err)
		assert.Equal(t, "retrying", retried.Status)
		assert.True(t, listener.received)
		assert.Equal(t, "retrying", listener.lastData["status"])
		assert.Equal(t, msg.ID, listener.lastData["message_id"])
	})

	t.Run("message_not_found", func(t *testing.T) {
		db, _, _, svc := setupMessageServiceWithDefaultLLM(t)

		account := createTestAccount(t, db)

		_, err := svc.Retry(ctx, account.ID, 9999)
		assert.Error(t, err)
	})

	t.Run("account_mismatch", func(t *testing.T) {
		db, _, _, svc := setupMessageServiceWithDefaultLLM(t)

		account := createTestAccount(t, db)
		inbox := createTestInbox(t, db, account.ID, "web_widget")
		contact := createTestContact(t, db, account.ID)
		conv := createTestConversation(t, db, account.ID, inbox.ID, contact.ID)

		msg := &model.Message{
			ConversationID: conv.ID, AccountID: account.ID, InboxID: inbox.ID,
			Content: "test", MessageType: "outgoing", ContentType: "text", SenderType: "user",
			Status: "failed",
		}
		require.NoError(t, db.Create(msg).Error)

		_, err := svc.Retry(ctx, 9999, msg.ID)
		assert.Error(t, err)
	})
}