package service

import (
	"context"
	"errors"
	"fmt"
	"testing"
	"time"

	"github.com/gochat/gochat/internal/channel"
	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/repository"
	"github.com/gochat/gochat/internal/worker"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
)

func setupCaptainConversationWorkerTest(t *testing.T) (*gorm.DB, *CaptainConversationService, *MessageService, *model.Account, *model.Inbox, *model.Conversation, *model.CaptainAssistant) {
	t.Helper()
	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.Account{}, &model.Inbox{}, &model.Contact{}, &model.Conversation{}, &model.Message{}, &model.Attachment{}, &model.CaptainAssistant{}, &model.CaptainInbox{}, &model.BackgroundJob{}))
	t.Cleanup(func() {
		sqlDB, _ := db.DB()
		sqlDB.Close()
	})
	account := &model.Account{Name: "Captain Org", Active: true}
	require.NoError(t, db.Create(account).Error)
	inbox := &model.Inbox{AccountID: account.ID, Name: "Web", ChannelType: "web_widget", ChannelID: 1}
	require.NoError(t, db.Create(inbox).Error)
	contact := &model.Contact{AccountID: account.ID, Name: "Customer", Email: "customer@example.com"}
	require.NoError(t, db.Create(contact).Error)
	conversation := &model.Conversation{AccountID: account.ID, InboxID: inbox.ID, ContactID: contact.ID, Status: string(model.ConversationStatusPending), ChannelType: inbox.ChannelType, Channel: inbox.ChannelType}
	require.NoError(t, db.Create(conversation).Error)
	assistant := &model.CaptainAssistant{AccountID: account.ID, Name: "Fin", Config: []byte(`{"handoff_message":"Let me connect you."}`), Status: model.AssistantStatusActive}
	require.NoError(t, db.Create(assistant).Error)
	require.NoError(t, db.Create(&model.CaptainInbox{AccountID: account.ID, AssistantID: assistant.ID, InboxID: inbox.ID}).Error)
	conversationSvc := NewCaptainConversationService(db, nil)
	messageSvc := NewMessageService(repository.NewMessageRepo(db), channel.NewDispatcher(), nil)
	return db, conversationSvc, messageSvc, account, inbox, conversation, assistant
}

func TestCaptainConversationResponseJobQueuesFromIncomingMessage(t *testing.T) {
	db, conversationSvc, messageSvc, account, _, conversation, assistant := setupCaptainConversationWorkerTest(t)
	conversationSvc.SetResponseBackend(&fakeCaptainConversationBackend{response: &CaptainConversationResponse{Content: "Welcome to Captain", AgentName: "Fin"}})
	wp := worker.NewWorkerPool(db)
	conversationSvc.SetWorkerPool(wp)
	messageSvc.SetWorkerPool(wp)

	incoming, err := messageSvc.Create(context.Background(), account.ID, 99, CreateMessageRequest{ConversationID: conversation.ID, Content: "Hello", MessageType: string(model.MessageTypeIncoming), ContentType: string(model.MessageContentTypeText)})
	require.NoError(t, err)
	require.NotZero(t, incoming.ID)

	var count int64
	require.NoError(t, db.Model(&model.BackgroundJob{}).Where("job_type = ? AND status = ?", TaskTypeCaptainConversationResponseBuilder, model.BackgroundJobStatusQueued).Count(&count).Error)
	assert.Equal(t, int64(1), count)

	processed, err := wp.ProcessOne(context.Background())
	require.NoError(t, err)
	assert.True(t, processed)

	var outgoing model.Message
	require.NoError(t, db.Where("conversation_id = ? AND message_type = ?", conversation.ID, model.MessageTypeOutgoing).First(&outgoing).Error)
	assert.Equal(t, assistant.ID, *outgoing.SenderID)
	assert.Equal(t, "CaptainAssistant", outgoing.SenderType)
	assert.Equal(t, "Welcome to Captain", outgoing.Content)

	require.NoError(t, db.Model(&model.BackgroundJob{}).Where("job_type = ?", TaskTypeMessageSendReply).Count(&count).Error)
	assert.Equal(t, int64(1), count)
}

func TestCaptainConversationResponseJobHandoffOpensConversation(t *testing.T) {
	db, conversationSvc, _, account, _, conversation, _ := setupCaptainConversationWorkerTest(t)
	conversationSvc.SetResponseBackend(&fakeCaptainConversationBackend{response: &CaptainConversationResponse{Action: "handoff"}})
	wp := worker.NewWorkerPool(db)
	conversationSvc.SetWorkerPool(wp)

	_, err := wp.Enqueue(context.Background(), TaskTypeCaptainConversationResponseBuilder, captainConversationResponseBuilderJob{AccountID: account.ID, ConversationID: conversation.ID, AssistantID: 1, MessageID: 1}, worker.WithMaxAttempts(3))
	require.NoError(t, err)
	processed, err := wp.ProcessOne(context.Background())
	require.NoError(t, err)
	assert.True(t, processed)

	var updated model.Conversation
	require.NoError(t, db.First(&updated, conversation.ID).Error)
	assert.Equal(t, string(model.ConversationStatusOpen), updated.Status)
	var outgoing model.Message
	require.NoError(t, db.Where("conversation_id = ? AND message_type = ?", conversation.ID, model.MessageTypeOutgoing).First(&outgoing).Error)
	assert.Equal(t, "Let me connect you.", outgoing.Content)
}

func TestCaptainConversationResponseJobRetriesWhenProviderDisabled(t *testing.T) {
	db, conversationSvc, _, account, _, conversation, _ := setupCaptainConversationWorkerTest(t)
	now := time.Date(2026, 6, 6, 4, 30, 0, 0, time.UTC)
	wp := worker.NewWorkerPoolWithOptions(db, worker.WithNow(func() time.Time { return now }), worker.WithBackoff(func(attempt int) time.Duration { return time.Minute }))
	conversationSvc.SetWorkerPool(wp)

	_, err := wp.Enqueue(context.Background(), TaskTypeCaptainConversationResponseBuilder, captainConversationResponseBuilderJob{AccountID: account.ID, ConversationID: conversation.ID, AssistantID: 1, MessageID: 1}, worker.WithMaxAttempts(3))
	require.NoError(t, err)
	processed, err := wp.ProcessOne(context.Background())
	require.Error(t, err)
	assert.True(t, processed)

	var job model.BackgroundJob
	require.NoError(t, db.Where("job_type = ?", TaskTypeCaptainConversationResponseBuilder).First(&job).Error)
	assert.Equal(t, model.BackgroundJobStatusRetrying, job.Status)
	assert.Contains(t, job.LastError, "captain conversation response generation disabled")
}

func TestCaptainConversationResponseSkipsNonPendingConversation(t *testing.T) {
	db, conversationSvc, messageSvc, account, _, conversation, _ := setupCaptainConversationWorkerTest(t)
	require.NoError(t, db.Model(&model.Conversation{}).Where("id = ?", conversation.ID).Update("status", string(model.ConversationStatusOpen)).Error)
	wp := worker.NewWorkerPool(db)
	conversationSvc.SetWorkerPool(wp)
	messageSvc.SetWorkerPool(wp)

	_, err := messageSvc.Create(context.Background(), account.ID, 99, CreateMessageRequest{ConversationID: conversation.ID, Content: "Hello", MessageType: string(model.MessageTypeIncoming), ContentType: string(model.MessageContentTypeText)})
	require.NoError(t, err)
	var count int64
	require.NoError(t, db.Model(&model.BackgroundJob{}).Where("job_type = ?", TaskTypeCaptainConversationResponseBuilder).Count(&count).Error)
	assert.Equal(t, int64(0), count)
}

type fakeCaptainConversationBackend struct {
	response *CaptainConversationResponse
	err      error
}

func (b *fakeCaptainConversationBackend) GenerateCaptainConversationResponse(ctx context.Context, req CaptainConversationResponseRequest) (*CaptainConversationResponse, error) {
	if b.err != nil {
		return nil, b.err
	}
	if b.response == nil {
		return nil, errors.New("missing response")
	}
	return b.response, nil
}