package service

import (
	"context"
	"crypto/hmac"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"errors"
	"fmt"
	"strconv"
	"strings"
	"time"

	"github.com/gochat/gochat/internal/automation"
	"github.com/gochat/gochat/internal/model"
	channelmodel "github.com/gochat/gochat/internal/model/channel"
	"github.com/gochat/gochat/internal/repository"
	"github.com/gochat/gochat/internal/search"
	ws "github.com/gochat/gochat/internal/ws"
	applogger "github.com/gochat/gochat/pkg/logger"
	"gorm.io/datatypes"
)

// TypingIndicator is the interface for broadcasting typing events.
// Decoupled from the concrete ws.TypingTracker to avoid circular imports.
type TypingIndicator interface {
	SetTypingOn(ctx context.Context, accountID, conversationID uint, performer *ws.Performer) error
	SetTypingOff(ctx context.Context, accountID, conversationID uint, performer *ws.Performer) error
}

// WidgetService implements business logic for the Web Widget channel.
// Reference: Chatwoot app/controllers/api/v1/widget_messages_controller.rb
// + app/services/web_widget/send_on_web_widget_service.rb
// + app/javascript/widget/sdk.js (frontend SDK)
//
// The Widget is a public-facing API — no agent JWT required.
// Contact identity is established via widget_token (pubsub_token in Chatwoot),
// which is issued on widget init/auth and carried in subsequent requests.
type WidgetService struct {
	inboxRepo          *repository.InboxRepo
	contactRepo        *repository.ContactRepo
	contactInboxRepo   *repository.ContactInboxRepo
	conversationRepo   *repository.ConversationRepo
	messageRepo        *repository.MessageRepo
	typingIndicator    TypingIndicator
	themeConfigRepo    *repository.WidgetThemeConfigRepo
	preChatFormRepo    *repository.PreChatFormRepo
	fileUploadRepo     *repository.WidgetFileUploadRepo
	offlineMessageRepo *repository.WidgetOfflineMessageRepo
	inboxMemberRepo    *repository.InboxMemberRepo
	tagRepo            *repository.TagRepo
	campaignRepo       *repository.CampaignRepo
}

// NewWidgetService creates a new Widget service.
func NewWidgetService(
	inboxRepo *repository.InboxRepo,
	contactRepo *repository.ContactRepo,
	contactInboxRepo *repository.ContactInboxRepo,
	conversationRepo *repository.ConversationRepo,
	messageRepo *repository.MessageRepo,
	typingIndicator TypingIndicator,
	themeConfigRepo *repository.WidgetThemeConfigRepo,
	preChatFormRepo *repository.PreChatFormRepo,
	fileUploadRepo *repository.WidgetFileUploadRepo,
	offlineMessageRepo *repository.WidgetOfflineMessageRepo,
	inboxMemberRepo *repository.InboxMemberRepo,
	tagRepo *repository.TagRepo,
	campaignRepo *repository.CampaignRepo,
) *WidgetService {
	return &WidgetService{
		inboxRepo:          inboxRepo,
		contactRepo:        contactRepo,
		contactInboxRepo:   contactInboxRepo,
		conversationRepo:   conversationRepo,
		messageRepo:        messageRepo,
		typingIndicator:    typingIndicator,
		themeConfigRepo:    themeConfigRepo,
		preChatFormRepo:    preChatFormRepo,
		fileUploadRepo:     fileUploadRepo,
		offlineMessageRepo: offlineMessageRepo,
		inboxMemberRepo:    inboxMemberRepo,
		tagRepo:            tagRepo,
		campaignRepo:       campaignRepo,
	}
}

// --- DTOs ---

// WidgetInitRequest is the DTO for the /widget/init endpoint.
// Reference: Chatwoot widget SDK init — website_token identifies the inbox,
// contact attributes are optional (anonymous visitor if not provided).
type WidgetInitRequest struct {
	WebsiteToken string `json:"website_token" validate:"required"`
	ContactName  string `json:"contact_name,omitempty"`
	ContactEmail string `json:"contact_email,omitempty"`
	ContactPhone string `json:"contact_phone,omitempty"`
	Identifier   string `json:"identifier,omitempty"`
	HMACVerified bool   `json:"hmac_verified,omitempty"` // true if client validated HMAC
}

// WidgetInitResponse is returned after successful widget init/auth.
// Contains widget_token for subsequent requests + inbox config for UI rendering.
type WidgetInitResponse struct {
	WidgetToken    string          `json:"widget_token"` // pubsub_token for WebSocket + auth
	ContactID      uint            `json:"contact_id"`
	ContactInboxID uint            `json:"contact_inbox_id"`
	InboxID        uint            `json:"inbox_id"`
	InboxName      string          `json:"inbox_name"`
	AccountID      uint            `json:"account_id"`
	WidgetConfig   WebWidgetConfig `json:"widget_config"`
	Contact        *model.Contact  `json:"-"`
}

// WidgetSendMessageRequest is the DTO for the /widget/messages endpoint.
// Reference: Chatwoot WidgetMessagesController#create
type WidgetSendMessageRequest struct {
	WidgetToken    string `json:"widget_token" validate:"required"`
	Content        string `json:"content" validate:"required"`
	ContentType    string `json:"content_type,omitempty"`    // default: text
	ConversationID *uint  `json:"conversation_id,omitempty"` // nil → create new conversation
	AttachmentIDs  []string
}

// WidgetSendMessageResponse is returned after sending a message.
type WidgetSendMessageResponse struct {
	ConversationID uint               `json:"conversation_id"`
	Message        model.Message      `json:"message"`
	Attachments    []model.Attachment `json:"attachments,omitempty"`
}

type WidgetContactUpdate struct {
	Name                 string
	Email                string
	PhoneNumber          string
	Identifier           string
	AvatarURL            string
	CustomAttributes     map[string]any
	AdditionalAttributes map[string]any
}

type WidgetSetUserRequest struct {
	WebsiteToken         string
	WidgetToken          string
	Identifier           string
	IdentifierHash       string
	Email                string
	Name                 string
	AvatarURL            string
	PhoneNumber          string
	CustomAttributes     map[string]any
	AdditionalAttributes map[string]any
}

type WidgetSetUserResponse struct {
	Contact         *model.Contact
	WidgetAuthToken string
}

type WidgetMessageUpdate struct {
	MessageID       uint
	WidgetToken     string
	ContactEmail    string
	ContactName     string
	SubmittedValues []map[string]any
}

type PublicContactRequest struct {
	SourceID         string
	Identifier       string
	IdentifierHash   string
	Email            string
	Name             string
	AvatarURL        string
	PhoneNumber      string
	CustomAttributes map[string]any
}

type PublicContactResponse struct {
	ContactInbox *model.ContactInbox
	Contact      *model.Contact
}

type PublicConversationRequest struct {
	CustomAttributes map[string]any
}

type PublicMessageRequest struct {
	Content         string
	EchoID          string
	SubmittedValues []map[string]any
}

type WidgetInboxMember struct {
	ID                 uint   `json:"id"`
	Name               string `json:"name"`
	AvatarURL          string `json:"avatar_url"`
	AvailabilityStatus string `json:"availability_status"`
}

type WidgetCampaign struct {
	ID                             uint           `json:"id"`
	TriggerRules                   map[string]any `json:"trigger_rules"`
	TriggerOnlyDuringBusinessHours bool           `json:"trigger_only_during_business_hours"`
	Message                        string         `json:"message"`
	Sender                         any            `json:"sender"`
}

// WidgetGetCableTokenResponse returns the pubsub_token for WebSocket connection.
// Reference: Chatwoot widget SDK — fetches token for ActionCable subscription
type WidgetGetCableTokenResponse struct {
	PubsubToken string `json:"pubsub_token"`
	ContactID   uint   `json:"contact_id"`
	InboxID     uint   `json:"inbox_id"`
	AccountID   uint   `json:"account_id"`
}

// --- Service methods ---

// Init authenticates/creates a contact for the widget and returns a widget_token.
// Reference: Chatwoot widget SDK init flow — website_token → inbox lookup →
// contact creation/identification → pubsub_token generation → UI config delivery
//
// Flow:
//  1. Resolve inbox by website_token (from channel_config JSON)
//  2. Find or create contact (by email/phone/identifier, or anonymous)
//  3. Find or create ContactInbox (join table with pubsub_token)
//  4. Return widget_token (= pubsub_token) + config
func (s *WidgetService) Init(ctx context.Context, req WidgetInitRequest) (*WidgetInitResponse, error) {
	if req.WebsiteToken == "" {
		return nil, errors.New("website_token is required")
	}

	// Step 1: Find inbox by website_token in channel_config
	inbox, err := s.findInboxByWebsiteToken(ctx, req.WebsiteToken)
	if err != nil {
		return nil, fmt.Errorf("invalid website_token: %w", err)
	}
	if !inbox.Enabled {
		return nil, errors.New("inbox is disabled")
	}

	// Parse widget config
	widgetConfig, err := ParseWebWidgetConfig(inbox.ChannelConfig)
	if err != nil {
		return nil, fmt.Errorf("invalid widget config: %w", err)
	}

	// Step 2: Find or create contact
	contact, err := s.findOrCreateWidgetContact(ctx, inbox.AccountID, req)
	if err != nil {
		return nil, fmt.Errorf("failed to identify contact: %w", err)
	}

	// Step 3: Find or create ContactInbox
	contactInbox, err := s.findOrCreateContactInbox(ctx, contact.ID, inbox.ID)
	if err != nil {
		return nil, fmt.Errorf("failed to create contact inbox: %w", err)
	}
	if req.HMACVerified && !contactInbox.HMACVerified {
		contactInbox.HMACVerified = true
		if err := s.contactInboxRepo.Update(ctx, contactInbox); err != nil {
			return nil, fmt.Errorf("failed to update contact inbox: %w", err)
		}
	}

	applogger.L().Infof("Widget init: contact=%d inbox=%d contactInbox=%d token=%s",
		contact.ID, inbox.ID, contactInbox.ID, contactInbox.PubsubToken)

	return &WidgetInitResponse{
		WidgetToken:    contactInbox.PubsubToken,
		ContactID:      contact.ID,
		ContactInboxID: contactInbox.ID,
		InboxID:        inbox.ID,
		InboxName:      inbox.Name,
		AccountID:      inbox.AccountID,
		WidgetConfig:   *widgetConfig,
		Contact:        contact,
	}, nil
}

// SendMessage sends a message from a widget contact.
// Reference: Chatwoot WidgetMessagesController#create
// If no conversation_id is provided, creates a new conversation.
func (s *WidgetService) SendMessage(ctx context.Context, req WidgetSendMessageRequest) (*WidgetSendMessageResponse, error) {
	if req.WidgetToken == "" {
		return nil, errors.New("widget_token is required")
	}
	if req.Content == "" && len(req.AttachmentIDs) == 0 {
		return nil, errors.New("content is required")
	}

	// Resolve contact by pubsub_token
	contactInbox, err := s.contactInboxRepo.FindByPubsubToken(ctx, req.WidgetToken)
	if err != nil {
		return nil, fmt.Errorf("invalid widget_token: %w", err)
	}

	contentType := req.ContentType
	if contentType == "" {
		contentType = "text"
	}

	// Resolve conversation
	var conversation *model.Conversation
	if req.ConversationID != nil {
		conversation, err = s.conversationRepo.FindByID(ctx, *req.ConversationID)
		if err != nil {
			return nil, fmt.Errorf("conversation not found: %w", err)
		}
		// Verify conversation belongs to this contact
		if conversation.ContactID != contactInbox.ContactID {
			return nil, errors.New("conversation does not belong to this contact")
		}
	} else {
		// Create new conversation
		conversation, err = s.createWidgetConversation(ctx, contactInbox)
		if err != nil {
			return nil, fmt.Errorf("failed to create conversation: %w", err)
		}
	}

	// Create message
	msg := model.Message{
		ConversationID: conversation.ID,
		AccountID:      conversation.AccountID,
		InboxID:        conversation.InboxID,
		SenderID:       &contactInbox.ContactID,
		SenderType:     "Contact",
		Content:        req.Content,
		ContentType:    contentType,
		MessageType:    "incoming",
		Status:         "sent",
	}

	if err := s.messageRepo.Create(ctx, &msg); err != nil {
		return nil, fmt.Errorf("failed to create message: %w", err)
	}

	attachments, err := s.attachWidgetUploads(ctx, &msg, req.AttachmentIDs)
	if err != nil {
		return nil, err
	}

	applogger.L().Infof("Widget message: contact=%d conversation=%d message=%d",
		contactInbox.ContactID, conversation.ID, msg.ID)

	return &WidgetSendMessageResponse{
		ConversationID: conversation.ID,
		Message:        msg,
		Attachments:    attachments,
	}, nil
}

// GetConversations returns conversations for a widget contact.
// Reference: Chatwoot widget SDK — fetches conversation list
func (s *WidgetService) GetConversations(ctx context.Context, widgetToken string) ([]model.Conversation, error) {
	contactInbox, err := s.contactInboxRepo.FindByPubsubToken(ctx, widgetToken)
	if err != nil {
		return nil, fmt.Errorf("invalid widget_token: %w", err)
	}

	conversations, _, err := s.conversationRepo.FindByContact(
		ctx, contactInbox.Contact.AccountID, contactInbox.ContactID, 0, 50)
	if err != nil {
		return nil, err
	}
	return conversations, nil
}

func (s *WidgetService) GetLatestConversation(ctx context.Context, widgetToken string) (*model.Conversation, error) {
	contactInbox, err := s.contactInboxRepo.FindByPubsubToken(ctx, widgetToken)
	if err != nil {
		return nil, fmt.Errorf("invalid widget_token: %w", err)
	}
	conversations, _, err := s.conversationRepo.FindByContact(
		ctx, contactInbox.Contact.AccountID, contactInbox.ContactID, 0, 1)
	if err != nil {
		return nil, err
	}
	if len(conversations) == 0 {
		return nil, errors.New("conversation not found")
	}
	return &conversations[0], nil
}

func (s *WidgetService) GetConversation(ctx context.Context, widgetToken string, conversationID uint) (*model.Conversation, error) {
	contactInbox, err := s.contactInboxRepo.FindByPubsubToken(ctx, widgetToken)
	if err != nil {
		return nil, fmt.Errorf("invalid widget_token: %w", err)
	}
	conversation, err := s.conversationRepo.FindByID(ctx, conversationID)
	if err != nil {
		return nil, err
	}
	if conversation.ContactID != contactInbox.ContactID {
		return nil, errors.New("conversation does not belong to this contact")
	}
	return conversation, nil
}

func (s *WidgetService) GetLatestConversationMessages(ctx context.Context, widgetToken string, offset, limit int) ([]model.Message, int64, *model.Conversation, error) {
	conversation, err := s.GetLatestConversation(ctx, widgetToken)
	if err != nil {
		if err.Error() == "conversation not found" {
			return []model.Message{}, 0, nil, nil
		}
		return nil, 0, nil, err
	}
	messages, total, err := s.messageRepo.FindByConversation(ctx, conversation.ID, offset, limit)
	return messages, total, conversation, err
}

func (s *WidgetService) GetInboxMembersByWebsiteToken(ctx context.Context, websiteToken string) ([]WidgetInboxMember, error) {
	inbox, err := s.GetInboxByWebsiteToken(ctx, websiteToken)
	if err != nil {
		return nil, err
	}
	if s.inboxMemberRepo == nil {
		return []WidgetInboxMember{}, nil
	}
	members, err := s.inboxMemberRepo.FindByInbox(ctx, inbox.ID)
	if err != nil {
		return nil, err
	}
	payload := make([]WidgetInboxMember, 0, len(members))
	for _, member := range members {
		if member.User.ID == 0 {
			continue
		}
		name := member.User.Name
		if name == "" {
			name = member.User.Email
		}
		availability := member.AvailabilityStatus
		if availability == "" {
			availability = "offline"
		}
		payload = append(payload, WidgetInboxMember{
			ID:                 member.User.ID,
			Name:               name,
			AvatarURL:          member.User.AvatarURL,
			AvailabilityStatus: availability,
		})
	}
	return payload, nil
}

func (s *WidgetService) GetCampaignsByWebsiteToken(ctx context.Context, websiteToken string) ([]WidgetCampaign, error) {
	inbox, err := s.GetInboxByWebsiteToken(ctx, websiteToken)
	if err != nil {
		return nil, err
	}
	if s.campaignRepo == nil {
		return []WidgetCampaign{}, nil
	}
	campaigns, err := s.campaignRepo.ListByInbox(ctx, inbox.AccountID, inbox.ID)
	if err != nil {
		return nil, err
	}
	payload := make([]WidgetCampaign, 0, len(campaigns))
	for _, campaign := range campaigns {
		if !campaign.Enabled {
			continue
		}
		id := campaign.DisplayID
		if id == 0 {
			id = campaign.ID
		}
		payload = append(payload, WidgetCampaign{
			ID:                             id,
			TriggerRules:                   jsonMapBytes([]byte(campaign.TriggerRules)),
			TriggerOnlyDuringBusinessHours: campaign.TriggerOnlyDuringBusinessHours,
			Message:                        campaign.Message,
			Sender:                         nil,
		})
	}
	return payload, nil
}

func (s *WidgetService) TrackEvent(ctx context.Context, websiteToken, widgetToken, name string, eventInfo map[string]any) error {
	if websiteToken == "" {
		return errors.New("website_token is required")
	}
	if name == "" {
		return errors.New("event name is required")
	}
	inbox, err := s.GetInboxByWebsiteToken(ctx, websiteToken)
	if err != nil {
		return err
	}
	if widgetToken == "" {
		return errors.New("widget_token required")
	}
	contactInbox, err := s.contactInboxRepo.FindByPubsubToken(ctx, widgetToken)
	if err != nil {
		return fmt.Errorf("invalid widget_token: %w", err)
	}
	if contactInbox.InboxID != inbox.ID {
		return errors.New("widget_token does not belong to this inbox")
	}
	_ = eventInfo
	return nil
}

func (s *WidgetService) AddLabelToLatestConversation(ctx context.Context, widgetToken, label string) error {
	label = strings.TrimSpace(label)
	if label == "" {
		return nil
	}
	conversation, err := s.GetLatestConversation(ctx, widgetToken)
	if err != nil {
		return err
	}
	if s.tagRepo != nil {
		if _, err := s.tagRepo.FindByNameAndAccountID(ctx, conversation.AccountID, label); err != nil {
			return nil
		}
	}
	labels := splitWidgetLabels(conversation.Labels)
	for _, existing := range labels {
		if existing == label {
			return nil
		}
	}
	labels = append(labels, label)
	return s.conversationRepo.UpdateLabels(ctx, conversation.ID, strings.Join(labels, ","))
}

func (s *WidgetService) RemoveLabelFromLatestConversation(ctx context.Context, widgetToken, label string) error {
	label = strings.TrimSpace(label)
	if label == "" {
		return nil
	}
	conversation, err := s.GetLatestConversation(ctx, widgetToken)
	if err != nil {
		return err
	}
	labels := splitWidgetLabels(conversation.Labels)
	filtered := labels[:0]
	for _, existing := range labels {
		if existing != label {
			filtered = append(filtered, existing)
		}
	}
	return s.conversationRepo.UpdateLabels(ctx, conversation.ID, strings.Join(filtered, ","))
}

func (s *WidgetService) updateContactFields(ctx context.Context, contact *model.Contact, req WidgetContactUpdate) (*model.Contact, error) {
	if req.Name != "" {
		contact.Name = req.Name
	}
	if req.Email != "" {
		contact.Email = req.Email
	}
	if req.PhoneNumber != "" {
		contact.PhoneNumber = req.PhoneNumber
	}
	if req.Identifier != "" {
		contact.Identifier = req.Identifier
	}
	if req.AvatarURL != "" {
		contact.AvatarURL = req.AvatarURL
	}
	if len(req.CustomAttributes) > 0 {
		merged := jsonMap(contact.CustomAttributes)
		for k, v := range req.CustomAttributes {
			merged[k] = v
		}
		contact.CustomAttributes = mustJSON(merged)
	}
	if len(req.AdditionalAttributes) > 0 {
		merged := jsonMap(contact.AdditionalAttributes)
		for k, v := range req.AdditionalAttributes {
			merged[k] = v
		}
		contact.AdditionalAttributes = mustJSON(merged)
	}
	if err := s.contactRepo.Update(ctx, contact); err != nil {
		return nil, err
	}
	return contact, nil
}

func (s *WidgetService) PublicGetInbox(ctx context.Context, inboxIdentifier string) (*model.Inbox, bool, error) {
	inbox, channelAPI, err := s.resolvePublicInbox(ctx, inboxIdentifier)
	if err != nil {
		return nil, false, err
	}
	return inbox, channelAPI.HMACToken != "", nil
}

func (s *WidgetService) PublicCreateContact(ctx context.Context, inboxIdentifier string, req PublicContactRequest) (*PublicContactResponse, error) {
	inbox, channelAPI, err := s.resolvePublicInbox(ctx, inboxIdentifier)
	if err != nil {
		return nil, err
	}
	if err := validatePublicHMAC(channelAPI.HMACToken, req.Identifier, req.IdentifierHash); err != nil {
		return nil, err
	}
	if req.SourceID == "" {
		req.SourceID, err = generateToken(16)
		if err != nil {
			return nil, err
		}
	}
	if existingInbox, err := s.contactInboxRepo.FindBySourceID(ctx, inbox.ID, req.SourceID); err == nil {
		contact, err := s.contactRepo.FindByID(ctx, existingInbox.ContactID)
		if err != nil {
			return nil, err
		}
		existingInbox.Contact = *contact
		return &PublicContactResponse{ContactInbox: existingInbox, Contact: contact}, nil
	}
	contact, err := s.findPublicContact(ctx, inbox.AccountID, req)
	if err != nil {
		return nil, err
	}
	pubsubToken, err := generateToken(32)
	if err != nil {
		return nil, err
	}
	hmacToken, err := generateToken(32)
	if err != nil {
		return nil, err
	}
	contactInbox := &model.ContactInbox{
		ContactID:    contact.ID,
		InboxID:      inbox.ID,
		SourceID:     req.SourceID,
		PubsubToken:  pubsubToken,
		HMACToken:    hmacToken,
		HMACVerified: req.IdentifierHash != "",
	}
	if err := s.contactInboxRepo.Create(ctx, contactInbox); err != nil {
		return nil, err
	}
	return &PublicContactResponse{ContactInbox: contactInbox, Contact: contact}, nil
}

func (s *WidgetService) PublicGetContact(ctx context.Context, inboxIdentifier, sourceID string) (*PublicContactResponse, error) {
	_, contactInbox, err := s.resolvePublicContactInbox(ctx, inboxIdentifier, sourceID)
	if err != nil {
		return nil, err
	}
	return &PublicContactResponse{ContactInbox: contactInbox, Contact: &contactInbox.Contact}, nil
}

func (s *WidgetService) PublicUpdateContact(ctx context.Context, inboxIdentifier, sourceID string, req PublicContactRequest) (*PublicContactResponse, error) {
	channelAPI, contactInbox, err := s.resolvePublicContactInbox(ctx, inboxIdentifier, sourceID)
	if err != nil {
		return nil, err
	}
	if err := validatePublicHMAC(channelAPI.HMACToken, req.Identifier, req.IdentifierHash); err != nil {
		return nil, err
	}
	contact, err := s.updateContactFields(ctx, &contactInbox.Contact, WidgetContactUpdate{
		Name:             req.Name,
		Email:            strings.ToLower(req.Email),
		PhoneNumber:      req.PhoneNumber,
		Identifier:       req.Identifier,
		AvatarURL:        req.AvatarURL,
		CustomAttributes: req.CustomAttributes,
	})
	if err != nil {
		return nil, err
	}
	if req.IdentifierHash != "" && !contactInbox.HMACVerified {
		contactInbox.HMACVerified = true
		if err := s.contactInboxRepo.Update(ctx, contactInbox); err != nil {
			return nil, err
		}
	}
	return &PublicContactResponse{ContactInbox: contactInbox, Contact: contact}, nil
}

func (s *WidgetService) PublicListConversations(ctx context.Context, inboxIdentifier, sourceID string) ([]model.Conversation, error) {
	_, contactInbox, err := s.resolvePublicContactInbox(ctx, inboxIdentifier, sourceID)
	if err != nil {
		return nil, err
	}
	conversations, _, err := s.conversationRepo.FindByContact(ctx, contactInbox.Contact.AccountID, contactInbox.ContactID, 0, 100)
	if err != nil {
		return nil, err
	}
	return filterPublicConversations(conversations, contactInbox), nil
}

func (s *WidgetService) PublicCreateConversation(ctx context.Context, inboxIdentifier, sourceID string, req PublicConversationRequest) (*model.Conversation, error) {
	_, contactInbox, err := s.resolvePublicContactInbox(ctx, inboxIdentifier, sourceID)
	if err != nil {
		return nil, err
	}
	conversation, err := s.createWidgetConversation(ctx, contactInbox)
	if err != nil {
		return nil, err
	}
	if len(req.CustomAttributes) > 0 {
		conversation.CustomAttributes = mustJSON(req.CustomAttributes)
		if err := s.conversationRepo.Update(ctx, conversation); err != nil {
			return nil, err
		}
	}
	return conversation, nil
}

func (s *WidgetService) PublicGetConversation(ctx context.Context, inboxIdentifier, sourceID string, displayID uint) (*model.Conversation, error) {
	_, contactInbox, err := s.resolvePublicContactInbox(ctx, inboxIdentifier, sourceID)
	if err != nil {
		return nil, err
	}
	conversations, err := s.PublicListConversations(ctx, inboxIdentifier, sourceID)
	if err != nil {
		return nil, err
	}
	for i := range conversations {
		if publicConversationID(conversations[i]) == displayID && conversations[i].InboxID == contactInbox.InboxID {
			return &conversations[i], nil
		}
	}
	return nil, errors.New("conversation not found")
}

func (s *WidgetService) PublicToggleStatus(ctx context.Context, inboxIdentifier, sourceID string, displayID uint) (*model.Conversation, error) {
	conversation, err := s.PublicGetConversation(ctx, inboxIdentifier, sourceID, displayID)
	if err != nil {
		return nil, err
	}
	conversation.Status = string(model.ConversationStatusResolved)
	if err := s.conversationRepo.Update(ctx, conversation); err != nil {
		return nil, err
	}
	return conversation, nil
}

func (s *WidgetService) PublicUpdateLastSeen(ctx context.Context, inboxIdentifier, sourceID string, displayID uint) (*model.Conversation, error) {
	conversation, err := s.PublicGetConversation(ctx, inboxIdentifier, sourceID, displayID)
	if err != nil {
		return nil, err
	}
	now := time.Now().Unix()
	conversation.ContactLastSeenAt = &now
	if err := s.conversationRepo.Update(ctx, conversation); err != nil {
		return nil, err
	}
	return conversation, nil
}

func (s *WidgetService) PublicToggleTyping(ctx context.Context, inboxIdentifier, sourceID string, displayID uint, typing bool) error {
	conversation, err := s.PublicGetConversation(ctx, inboxIdentifier, sourceID, displayID)
	if err != nil {
		return err
	}
	if s.typingIndicator == nil {
		return nil
	}
	performer := &ws.Performer{ID: conversation.ContactID, Type: "contact"}
	if typing {
		return s.typingIndicator.SetTypingOn(ctx, conversation.AccountID, conversation.ID, performer)
	}
	return s.typingIndicator.SetTypingOff(ctx, conversation.AccountID, conversation.ID, performer)
}

func (s *WidgetService) PublicListMessages(ctx context.Context, inboxIdentifier, sourceID string, displayID uint, offset, limit int) ([]model.Message, int64, *model.Conversation, error) {
	conversation, err := s.PublicGetConversation(ctx, inboxIdentifier, sourceID, displayID)
	if err != nil {
		return nil, 0, nil, err
	}
	messages, total, err := s.messageRepo.FindByConversation(ctx, conversation.ID, offset, limit)
	return messages, total, conversation, err
}

func (s *WidgetService) PublicCreateMessage(ctx context.Context, inboxIdentifier, sourceID string, displayID uint, req PublicMessageRequest) (*model.Message, *model.Conversation, error) {
	if strings.TrimSpace(req.Content) == "" {
		return nil, nil, errors.New("content is required")
	}
	conversation, err := s.PublicGetConversation(ctx, inboxIdentifier, sourceID, displayID)
	if err != nil {
		return nil, nil, err
	}
	message := &model.Message{
		ConversationID: conversation.ID,
		AccountID:      conversation.AccountID,
		InboxID:        conversation.InboxID,
		SenderID:       &conversation.ContactID,
		SenderType:     "Contact",
		Content:        req.Content,
		ContentType:    "text",
		MessageType:    "incoming",
		Status:         "sent",
		SourceID:       req.EchoID,
	}
	if err := s.messageRepo.Create(ctx, message); err != nil {
		return nil, nil, err
	}
	return message, conversation, nil
}

func (s *WidgetService) PublicUpdateMessage(ctx context.Context, inboxIdentifier, sourceID string, displayID, messageID uint, req PublicMessageRequest) (*model.Message, *model.Conversation, error) {
	conversation, err := s.PublicGetConversation(ctx, inboxIdentifier, sourceID, displayID)
	if err != nil {
		return nil, nil, err
	}
	message, err := s.messageRepo.FindByConversationAndID(ctx, conversation.ID, messageID)
	if err != nil {
		return nil, nil, err
	}
	attrs := jsonMap(message.ContentAttributes)
	if req.SubmittedValues != nil {
		if message.ContentType == "input_csat" && automation.IsCsatSurveyLocked(message.CreatedAt, time.Now()) {
			return nil, nil, automation.ErrCsatSurveyLocked
		}
		attrs["submitted_values"] = req.SubmittedValues
		message.ContentAttributes = mustJSON(attrs)
	}
	if err := s.messageRepo.Update(ctx, message); err != nil {
		return nil, nil, err
	}
	if message.ContentType == "input_csat" && req.SubmittedValues != nil {
		if _, err := automation.ApplyCsatSubmission(ctx, s.messageRepo.DB(), message, conversation, req.SubmittedValues); err != nil {
			return nil, nil, err
		}
	}
	return message, conversation, nil
}

// GetMessages returns messages for a conversation belonging to a widget contact.
func (s *WidgetService) GetMessages(ctx context.Context, widgetToken string, conversationID uint, offset, limit int) ([]model.Message, int64, error) {
	contactInbox, err := s.contactInboxRepo.FindByPubsubToken(ctx, widgetToken)
	if err != nil {
		return nil, 0, fmt.Errorf("invalid widget_token: %w", err)
	}

	// Verify conversation belongs to this contact
	conversation, err := s.conversationRepo.FindByID(ctx, conversationID)
	if err != nil {
		return nil, 0, err
	}
	if conversation.ContactID != contactInbox.ContactID {
		return nil, 0, errors.New("conversation does not belong to this contact")
	}

	return s.messageRepo.FindByConversation(ctx, conversationID, offset, limit)
}

func (s *WidgetService) GetMessageAttachments(ctx context.Context, messageID uint) ([]model.Attachment, error) {
	var attachments []model.Attachment
	err := s.messageRepo.DB().WithContext(ctx).Where("message_id = ?", messageID).Order("id ASC").Find(&attachments).Error
	return attachments, err
}

// GetCableToken returns the pubsub_token for WebSocket connection.
// Reference: Chatwoot widget SDK — fetches token for ActionCable subscription
// The contact connects to /cable with pubsub_token to receive real-time events.
func (s *WidgetService) GetCableToken(ctx context.Context, widgetToken string) (*WidgetGetCableTokenResponse, error) {
	contactInbox, err := s.contactInboxRepo.FindByPubsubToken(ctx, widgetToken)
	if err != nil {
		return nil, fmt.Errorf("invalid widget_token: %w", err)
	}

	// Resolve inbox to get account_id
	inbox, err := s.inboxRepo.FindByID(ctx, contactInbox.InboxID)
	if err != nil {
		return nil, fmt.Errorf("inbox not found: %w", err)
	}

	return &WidgetGetCableTokenResponse{
		PubsubToken: contactInbox.PubsubToken,
		ContactID:   contactInbox.ContactID,
		InboxID:     contactInbox.InboxID,
		AccountID:   inbox.AccountID,
	}, nil
}

// UpdateContact updates the contact's profile from the widget.
// Reference: Chatwoot widget SDK — update contact name/email
func (s *WidgetService) UpdateContact(ctx context.Context, widgetToken string, name, email string) (*model.Contact, error) {
	return s.UpdateContactProfile(ctx, widgetToken, WidgetContactUpdate{Name: name, Email: email})
}

func (s *WidgetService) GetContact(ctx context.Context, widgetToken string) (*model.Contact, error) {
	contactInbox, err := s.contactInboxRepo.FindByPubsubToken(ctx, widgetToken)
	if err != nil {
		return nil, fmt.Errorf("invalid widget_token: %w", err)
	}
	return s.contactRepo.FindByID(ctx, contactInbox.ContactID)
}

func (s *WidgetService) UpdateContactProfile(ctx context.Context, widgetToken string, req WidgetContactUpdate) (*model.Contact, error) {
	contactInbox, err := s.contactInboxRepo.FindByPubsubToken(ctx, widgetToken)
	if err != nil {
		return nil, fmt.Errorf("invalid widget_token: %w", err)
	}

	contact, err := s.contactRepo.FindByID(ctx, contactInbox.ContactID)
	if err != nil {
		return nil, err
	}

	return s.updateContactFields(ctx, contact, req)
}

func (s *WidgetService) SetUser(ctx context.Context, req WidgetSetUserRequest) (*WidgetSetUserResponse, error) {
	if req.WebsiteToken == "" {
		return nil, errors.New("website_token is required")
	}
	if req.WidgetToken == "" {
		return nil, errors.New("widget_token required")
	}
	if req.Identifier == "" {
		return nil, errors.New("identifier is required")
	}

	inbox, err := s.GetInboxByWebsiteToken(ctx, req.WebsiteToken)
	if err != nil {
		return nil, err
	}
	widgetConfig, err := ParseWebWidgetConfig(inbox.ChannelConfig)
	if err != nil {
		return nil, fmt.Errorf("invalid widget config: %w", err)
	}
	if req.IdentifierHash != "" && !VerifyHMAC(widgetConfig.HMACToken, req.Identifier, req.IdentifierHash) {
		return nil, errors.New("HMAC failed: Invalid Identifier Hash Provided")
	}

	currentContactInbox, err := s.contactInboxRepo.FindByPubsubToken(ctx, req.WidgetToken)
	if err != nil {
		return nil, fmt.Errorf("invalid widget_token: %w", err)
	}
	if currentContactInbox.InboxID != inbox.ID {
		return nil, errors.New("widget_token does not belong to this inbox")
	}

	contact := &currentContactInbox.Contact
	widgetAuthToken := ""
	if contact.Identifier != "" && contact.Identifier != req.Identifier {
		contact, err = s.findOrCreateContactByIdentifier(ctx, inbox.AccountID, req.Identifier)
		if err != nil {
			return nil, err
		}
		currentContactInbox, err = s.findOrCreateContactInbox(ctx, contact.ID, inbox.ID)
		if err != nil {
			return nil, err
		}
		widgetAuthToken = currentContactInbox.PubsubToken
	}

	contact, err = s.updateContactFields(ctx, contact, WidgetContactUpdate{
		Name:                 req.Name,
		Email:                strings.ToLower(req.Email),
		PhoneNumber:          req.PhoneNumber,
		Identifier:           req.Identifier,
		AvatarURL:            req.AvatarURL,
		CustomAttributes:     req.CustomAttributes,
		AdditionalAttributes: req.AdditionalAttributes,
	})
	if err != nil {
		return nil, err
	}
	if req.IdentifierHash != "" && !currentContactInbox.HMACVerified {
		currentContactInbox.HMACVerified = true
		if err := s.contactInboxRepo.Update(ctx, currentContactInbox); err != nil {
			return nil, err
		}
	}
	return &WidgetSetUserResponse{Contact: contact, WidgetAuthToken: widgetAuthToken}, nil
}

func (s *WidgetService) UpdateMessage(ctx context.Context, req WidgetMessageUpdate) (*model.Contact, *model.Message, error) {
	if req.WidgetToken == "" {
		return nil, nil, errors.New("widget_token required")
	}
	contactInbox, err := s.contactInboxRepo.FindByPubsubToken(ctx, req.WidgetToken)
	if err != nil {
		return nil, nil, fmt.Errorf("invalid widget_token: %w", err)
	}
	message, err := s.messageRepo.FindByID(ctx, req.MessageID)
	if err != nil {
		return nil, nil, err
	}
	conversation, err := s.conversationRepo.FindByID(ctx, message.ConversationID)
	if err != nil {
		return nil, nil, err
	}
	if conversation.ContactID != contactInbox.ContactID || conversation.InboxID != contactInbox.InboxID {
		return nil, nil, errors.New("message does not belong to this contact")
	}

	contact := &contactInbox.Contact
	if strings.TrimSpace(req.ContactEmail) != "" || strings.TrimSpace(req.ContactName) != "" {
		contact, err = s.updateContactFields(ctx, contact, WidgetContactUpdate{
			Name:  strings.TrimSpace(req.ContactName),
			Email: strings.ToLower(strings.TrimSpace(req.ContactEmail)),
		})
		if err != nil {
			return nil, nil, err
		}
	}
	attrs := jsonMap(message.ContentAttributes)
	if strings.TrimSpace(req.ContactEmail) != "" {
		attrs["submitted_email"] = strings.ToLower(strings.TrimSpace(req.ContactEmail))
		attrs["submitted_values"] = nil
	} else if req.SubmittedValues != nil {
		attrs["submitted_values"] = req.SubmittedValues
	}
	message.ContentAttributes = mustJSON(attrs)
	if err := s.messageRepo.Update(ctx, message); err != nil {
		return nil, nil, err
	}
	return contact, message, nil
}

func (s *WidgetService) SendTranscript(ctx context.Context, widgetToken string) error {
	conversation, err := s.GetLatestConversation(ctx, widgetToken)
	if err != nil {
		return err
	}
	contact, err := s.contactRepo.FindByID(ctx, conversation.ContactID)
	if err != nil {
		return err
	}
	if contact.Email == "" {
		return nil
	}
	return nil
}

func (s *WidgetService) AddDyteParticipant(ctx context.Context, websiteToken string, messageID uint) (map[string]any, error) {
	if websiteToken == "" {
		return nil, errors.New("website_token is required")
	}
	inbox, err := s.GetInboxByWebsiteToken(ctx, websiteToken)
	if err != nil {
		return nil, err
	}
	message, err := s.messageRepo.FindByID(ctx, messageID)
	if err != nil {
		return nil, err
	}
	if message.InboxID != inbox.ID {
		return nil, errors.New("message does not belong to this inbox")
	}
	if message.ContentType != "integrations" {
		return nil, errors.New("invalid message type")
	}
	attrs := jsonMap(message.ContentAttributes)
	data, _ := attrs["data"].(map[string]any)
	meetingID, _ := data["meeting_id"].(string)
	if meetingID == "" {
		return nil, errors.New("meeting_id is required")
	}
	return map[string]any{"token": "dyte_" + meetingID}, nil
}

func (s *WidgetService) DeleteContactCustomAttributes(ctx context.Context, widgetToken string, keys []string) (*model.Contact, error) {
	contact, err := s.GetContact(ctx, widgetToken)
	if err != nil {
		return nil, err
	}
	attrs := jsonMap(contact.CustomAttributes)
	for _, key := range keys {
		delete(attrs, key)
	}
	contact.CustomAttributes = mustJSON(attrs)
	if err := s.contactRepo.Update(ctx, contact); err != nil {
		return nil, err
	}
	return contact, nil
}

// ToggleTyping signals that the widget contact is typing or stopped typing.
// Reference: Chatwoot ConversationTypingOnJob / ConversationTypingOffJob
func (s *WidgetService) ToggleTyping(ctx context.Context, widgetToken string, conversationID uint, typing bool) error {
	contactInbox, err := s.contactInboxRepo.FindByPubsubToken(ctx, widgetToken)
	if err != nil {
		return fmt.Errorf("invalid widget_token: %w", err)
	}

	conversation, err := s.conversationRepo.FindByID(ctx, conversationID)
	if err != nil {
		return fmt.Errorf("conversation not found: %w", err)
	}

	// Verify conversation belongs to this contact
	if conversation.ContactID != contactInbox.ContactID {
		return errors.New("conversation does not belong to this contact")
	}

	performer := &ws.Performer{
		ID:   contactInbox.ContactID,
		Name: contactInbox.Contact.Name,
		Type: "contact",
	}

	if typing {
		return s.typingIndicator.SetTypingOn(ctx, conversation.AccountID, conversationID, performer)
	}
	return s.typingIndicator.SetTypingOff(ctx, conversation.AccountID, conversationID, performer)
}

func (s *WidgetService) UpdateLastSeen(ctx context.Context, widgetToken string) (*model.Conversation, error) {
	conversation, err := s.GetLatestConversation(ctx, widgetToken)
	if err != nil {
		return nil, err
	}
	now := time.Now().Unix()
	conversation.ContactLastSeenAt = &now
	if err := s.conversationRepo.Update(ctx, conversation); err != nil {
		return nil, err
	}
	return conversation, nil
}

func (s *WidgetService) ResolveLatestConversation(ctx context.Context, widgetToken string) (*model.Conversation, error) {
	conversation, err := s.GetLatestConversation(ctx, widgetToken)
	if err != nil {
		return nil, err
	}
	conversation.Status = string(model.ConversationStatusResolved)
	if err := s.conversationRepo.Update(ctx, conversation); err != nil {
		return nil, err
	}
	return conversation, nil
}

func (s *WidgetService) SetLatestConversationCustomAttributes(ctx context.Context, widgetToken string, attrs map[string]any) (*model.Conversation, error) {
	conversation, err := s.GetLatestConversation(ctx, widgetToken)
	if err != nil {
		return nil, err
	}
	conversation.CustomAttributes = mustJSON(attrs)
	if err := s.conversationRepo.Update(ctx, conversation); err != nil {
		return nil, err
	}
	return conversation, nil
}

func (s *WidgetService) DeleteLatestConversationCustomAttributes(ctx context.Context, widgetToken string, keys []string) (*model.Conversation, error) {
	conversation, err := s.GetLatestConversation(ctx, widgetToken)
	if err != nil {
		return nil, err
	}
	attrs := jsonMap(conversation.CustomAttributes)
	for _, key := range keys {
		delete(attrs, key)
	}
	conversation.CustomAttributes = mustJSON(attrs)
	if err := s.conversationRepo.Update(ctx, conversation); err != nil {
		return nil, err
	}
	return conversation, nil
}

// --- Helper methods ---

// findInboxByWebsiteToken scans all web_widget inboxes to find one with matching
// website_token in its channel_config JSON. Website tokens are unique per inbox.
func (s *WidgetService) findInboxByWebsiteToken(ctx context.Context, websiteToken string) (*model.Inbox, error) {
	inboxes, err := s.inboxRepo.FindByChannelType(ctx, "web_widget", 500)
	if err != nil || len(inboxes) == 0 {
		return nil, fmt.Errorf("no web_widget inboxes found: %w", err)
	}

	for _, inbox := range inboxes {
		config, err := ParseWebWidgetConfig(inbox.ChannelConfig)
		if err != nil {
			continue
		}
		if config.WebsiteToken == websiteToken {
			return &inbox, nil
		}
	}

	return nil, fmt.Errorf("no inbox found for website_token %s", websiteToken)
}

// GetInboxByWebsiteToken is the public wrapper for findInboxByWebsiteToken,
// used by the widget handler's offline message submission endpoint.
func (s *WidgetService) GetInboxByWebsiteToken(ctx context.Context, websiteToken string) (*model.Inbox, error) {
	return s.findInboxByWebsiteToken(ctx, websiteToken)
}

// findOrCreateWidgetContact identifies or creates a contact for the widget session.
// If email/phone/identifier is provided, tries to find existing contact.
// If none found or no identifiers provided, creates an anonymous contact.
func (s *WidgetService) findOrCreateWidgetContact(ctx context.Context, accountID uint, req WidgetInitRequest) (*model.Contact, error) {
	// Try to find existing contact by email (FindByEmail takes accountID + email)
	if req.ContactEmail != "" {
		contact, err := s.contactRepo.FindByEmail(ctx, accountID, req.ContactEmail)
		if err == nil {
			return contact, nil
		}
	}
	// Try to find existing contact by identifier or phone using Search
	if req.Identifier != "" || req.ContactPhone != "" {
		searchQuery := req.Identifier
		if searchQuery == "" {
			searchQuery = req.ContactPhone
		}
		contacts, _, err := s.contactRepo.Search(ctx, accountID, searchQuery, 0, 5, "id ASC", search.SearchModeILike)
		if err == nil && len(contacts) > 0 {
			return &contacts[0], nil
		}
	}

	// Create new contact
	name := req.ContactName
	if name == "" {
		name = "Anonymous Visitor"
	}

	contact := model.Contact{
		AccountID:   accountID,
		Name:        name,
		Email:       req.ContactEmail,
		PhoneNumber: req.ContactPhone,
		Identifier:  req.Identifier,
		ContactType: "visitor",
	}

	if err := s.contactRepo.Create(ctx, &contact); err != nil {
		return nil, err
	}

	return &contact, nil
}

func (s *WidgetService) findOrCreateContactByIdentifier(ctx context.Context, accountID uint, identifier string) (*model.Contact, error) {
	contact, err := s.contactRepo.FindByIdentifier(ctx, accountID, identifier)
	if err == nil {
		return contact, nil
	}
	contact = &model.Contact{
		AccountID:   accountID,
		Identifier:  identifier,
		ContactType: "visitor",
	}
	if err := s.contactRepo.Create(ctx, contact); err != nil {
		return nil, err
	}
	return contact, nil
}

// findOrCreateContactInbox ensures a ContactInbox exists for the contact+inbox pair.
// Generates pubsub_token and hmac_token for WebSocket auth and message verification.
func (s *WidgetService) findOrCreateContactInbox(ctx context.Context, contactID, inboxID uint) (*model.ContactInbox, error) {
	// Check if one already exists
	ci, err := s.contactInboxRepo.FindByContactAndInbox(ctx, contactID, inboxID)
	if err == nil {
		// If pubsub_token is empty, generate one
		if ci.PubsubToken == "" {
			pubsubToken, err := generateToken(32)
			if err != nil {
				return nil, fmt.Errorf("failed to generate pubsub_token: %w", err)
			}
			hmacToken, err := generateToken(32)
			if err != nil {
				return nil, fmt.Errorf("failed to generate hmac_token: %w", err)
			}
			ci.PubsubToken = pubsubToken
			ci.HMACToken = hmacToken
			if err := s.contactInboxRepo.Update(ctx, ci); err != nil {
				return nil, err
			}
		}
		return ci, nil
	}

	// Create new ContactInbox
	pubsubToken, err := generateToken(32)
	if err != nil {
		return nil, fmt.Errorf("failed to generate pubsub_token: %w", err)
	}
	hmacToken, err := generateToken(32)
	if err != nil {
		return nil, fmt.Errorf("failed to generate hmac_token: %w", err)
	}
	sourceID := strconv.FormatUint(uint64(contactID), 10)
	ci = &model.ContactInbox{
		ContactID:   contactID,
		InboxID:     inboxID,
		SourceID:    sourceID,
		PubsubToken: pubsubToken,
		HMACToken:   hmacToken,
	}

	if err := s.contactInboxRepo.Create(ctx, ci); err != nil {
		return nil, err
	}
	return ci, nil
}

// createWidgetConversation creates a new conversation for a widget contact.
func (s *WidgetService) createWidgetConversation(ctx context.Context, contactInbox *model.ContactInbox) (*model.Conversation, error) {
	inbox, err := s.inboxRepo.FindByID(ctx, contactInbox.InboxID)
	if err != nil {
		return nil, err
	}

	conversation := model.Conversation{
		AccountID:      inbox.AccountID,
		InboxID:        inbox.ID,
		ContactID:      contactInbox.ContactID,
		ContactInboxID: &contactInbox.ID,
		Status:         "open",
		ChannelType:    inbox.ChannelType,
		Channel:        inbox.ChannelType,
	}

	if err := s.conversationRepo.Create(ctx, &conversation); err != nil {
		return nil, err
	}
	return &conversation, nil
}

// VerifyHMAC validates the HMAC signature from the widget client.
// Reference: Chatwoot web_widget HMAC verification — ensures the client
// hasn't tampered with the identifier (used for authenticated contacts).
func VerifyHMAC(hmacToken, identifier, signature string) bool {
	if hmacToken == "" || identifier == "" || signature == "" {
		return false
	}
	mac := hmac.New(sha256.New, []byte(hmacToken))
	mac.Write([]byte(identifier))
	expectedMAC := hex.EncodeToString(mac.Sum(nil))
	return hmac.Equal([]byte(signature), []byte(expectedMAC))
}

// ParseWebWidgetConfig parses the JSON channel_config string into WebWidgetConfig.
func ParseWebWidgetConfig(channelConfig string) (*WebWidgetConfig, error) {
	if channelConfig == "" {
		return nil, errors.New("empty channel_config")
	}
	var config WebWidgetConfig
	if err := json.Unmarshal([]byte(channelConfig), &config); err != nil {
		return nil, fmt.Errorf("invalid JSON: %w", err)
	}
	return &config, nil
}

// --- Offline Message Methods ---
// Reference: Chatwoot's offline messaging feature — when no agents are available
// (outside business hours or all agents offline), visitors can submit messages
// that get stored and later converted to conversations when an agent returns.

// SubmitOfflineMessage stores a message from a visitor when agents are offline.
// Returns the created offline message record.
func (s *WidgetService) SubmitOfflineMessage(ctx context.Context, inboxID uint, accountID uint, submission *model.WidgetOfflineMessageSubmission, referer, browserInfo string) (*model.WidgetOfflineMessage, error) {
	msg := &model.WidgetOfflineMessage{
		InboxID:        inboxID,
		AccountID:      accountID,
		ContactName:    submission.Name,
		ContactEmail:   submission.Email,
		ContactPhone:   submission.Phone,
		ContactCompany: submission.Company,
		ContactCity:    submission.City,
		ContactCountry: submission.Country,
		Content:        submission.Message,
		Referer:        referer,
		BrowserInfo:    browserInfo,
		Status:         model.OfflineStatusPending,
	}
	if err := s.offlineMessageRepo.Create(ctx, msg); err != nil {
		return nil, fmt.Errorf("failed to create offline message: %w", err)
	}
	return msg, nil
}

// GetOfflineMessages retrieves all pending offline messages for an inbox.
func (s *WidgetService) GetOfflineMessages(ctx context.Context, inboxID uint) ([]model.WidgetOfflineMessage, error) {
	return s.offlineMessageRepo.FindByInboxID(ctx, inboxID)
}

// ListOfflineMessagesByAccount retrieves paginated offline messages for an account (admin view).
func (s *WidgetService) ListOfflineMessagesByAccount(ctx context.Context, accountID uint, page, pageSize int) ([]model.WidgetOfflineMessage, int64, error) {
	offset := (page - 1) * pageSize
	return s.offlineMessageRepo.FindByAccountID(ctx, accountID, offset, pageSize)
}

// ConvertOfflineMessageToConversation creates a conversation + first message
// from a pending offline message, then marks it as converted.
// This is the Chatwoot pattern: when an agent comes online (or manually picks up
// an offline message), it becomes a real conversation the agent can respond to.
func (s *WidgetService) ConvertOfflineMessageToConversation(ctx context.Context, offlineMsgID uint) (*model.Conversation, *model.Message, error) {
	// 1. Find the offline message
	offlineMsg, err := s.offlineMessageRepo.FindByID(ctx, offlineMsgID)
	if err != nil {
		return nil, nil, fmt.Errorf("offline message not found: %w", err)
	}
	if offlineMsg.Status != model.OfflineStatusPending {
		return nil, nil, fmt.Errorf("offline message is not pending (status=%s)", offlineMsg.Status)
	}

	// 2. Resolve the inbox
	inbox, err := s.inboxRepo.FindByID(ctx, offlineMsg.InboxID)
	if err != nil {
		return nil, nil, fmt.Errorf("inbox not found: %w", err)
	}

	// 3. Find or create a contact from the offline message's contact info
	contact, err := s.findOrCreateContactFromOfflineMessage(ctx, inbox.AccountID, offlineMsg)
	if err != nil {
		return nil, nil, fmt.Errorf("failed to identify contact: %w", err)
	}

	// 4. Find or create ContactInbox
	contactInbox, err := s.findOrCreateContactInbox(ctx, contact.ID, inbox.ID)
	if err != nil {
		return nil, nil, fmt.Errorf("failed to create contact inbox: %w", err)
	}

	// 5. Create a new conversation
	conversation := &model.Conversation{
		AccountID:      inbox.AccountID,
		InboxID:        inbox.ID,
		ContactID:      contact.ID,
		ContactInboxID: &contactInbox.ID,
		Status:         string(model.ConversationStatusOpen),
		ChannelType:    string(model.InboxChannelTypeWebWidget),
	}
	if err := s.conversationRepo.Create(ctx, conversation); err != nil {
		return nil, nil, fmt.Errorf("failed to create conversation: %w", err)
	}

	// 6. Create the first message from the offline message content
	message := &model.Message{
		ConversationID: conversation.ID,
		AccountID:      inbox.AccountID,
		InboxID:        inbox.ID,
		SenderType:     "contact",
		Content:        offlineMsg.Content,
		ContentType:    "text",
		MessageType:    string(model.MessageTypeIncoming),
	}
	if err := s.messageRepo.Create(ctx, message); err != nil {
		return nil, nil, fmt.Errorf("failed to create message: %w", err)
	}

	// 7. Mark the offline message as converted
	if err := s.offlineMessageRepo.MarkConverted(ctx, offlineMsgID, conversation.ID); err != nil {
		return nil, nil, fmt.Errorf("failed to mark offline message as converted: %w", err)
	}

	return conversation, message, nil
}

// findOrCreateContactFromOfflineMessage creates a contact from an offline message's
// visitor info (name, email). If email matches an existing contact, reuse it.
func (s *WidgetService) findOrCreateContactFromOfflineMessage(ctx context.Context, accountID uint, offlineMsg *model.WidgetOfflineMessage) (*model.Contact, error) {
	// Try to find by email first
	if offlineMsg.ContactEmail != "" {
		contact, err := s.contactRepo.FindByEmail(ctx, accountID, offlineMsg.ContactEmail)
		if err == nil && contact != nil {
			return contact, nil
		}
	}

	// Create new contact
	contact := &model.Contact{
		AccountID:   accountID,
		Name:        offlineMsg.ContactName,
		Email:       offlineMsg.ContactEmail,
		PhoneNumber: offlineMsg.ContactPhone,
	}
	if err := s.contactRepo.Create(ctx, contact); err != nil {
		return nil, err
	}
	return contact, nil
}

// MarkOfflineMessageConverted marks an offline message as converted to a conversation.
func (s *WidgetService) MarkOfflineMessageConverted(ctx context.Context, offlineMsgID uint, conversationID uint) error {
	return s.offlineMessageRepo.MarkConverted(ctx, offlineMsgID, conversationID)
}

// DismissOfflineMessage marks an offline message as dismissed by an agent.
func (s *WidgetService) DismissOfflineMessage(ctx context.Context, offlineMsgID uint) error {
	return s.offlineMessageRepo.MarkDismissed(ctx, offlineMsgID)
}

// CountPendingOfflineMessages returns how many pending offline messages exist for an inbox.
func (s *WidgetService) CountPendingOfflineMessages(ctx context.Context, inboxID uint) (int64, error) {
	return s.offlineMessageRepo.CountPendingByInboxID(ctx, inboxID)
}

func jsonMap(raw datatypes.JSON) map[string]any {
	return jsonMapBytes(raw)
}

func jsonMapBytes(raw []byte) map[string]any {
	out := map[string]any{}
	if len(raw) == 0 {
		return out
	}
	_ = json.Unmarshal(raw, &out)
	if out == nil {
		out = map[string]any{}
	}
	return out
}

func mustJSON(value map[string]any) datatypes.JSON {
	if value == nil {
		value = map[string]any{}
	}
	b, err := json.Marshal(value)
	if err != nil {
		return datatypes.JSON([]byte("{}"))
	}
	return datatypes.JSON(b)
}

func splitWidgetLabels(raw string) []string {
	if raw == "" {
		return []string{}
	}
	parts := strings.Split(raw, ",")
	labels := make([]string, 0, len(parts))
	for _, part := range parts {
		label := strings.TrimSpace(part)
		if label != "" {
			labels = append(labels, label)
		}
	}
	return labels
}

func (s *WidgetService) findPublicContact(ctx context.Context, accountID uint, req PublicContactRequest) (*model.Contact, error) {
	if req.Identifier != "" {
		if contact, err := s.contactRepo.FindByIdentifier(ctx, accountID, req.Identifier); err == nil {
			return contact, nil
		}
	}
	if req.Email != "" {
		if contact, err := s.contactRepo.FindByEmail(ctx, accountID, strings.ToLower(req.Email)); err == nil {
			return contact, nil
		}
	}
	contact := &model.Contact{
		AccountID:        accountID,
		Name:             req.Name,
		Email:            strings.ToLower(req.Email),
		PhoneNumber:      req.PhoneNumber,
		AvatarURL:        req.AvatarURL,
		Identifier:       req.Identifier,
		ContactType:      "visitor",
		CustomAttributes: mustJSON(req.CustomAttributes),
	}
	if err := s.contactRepo.Create(ctx, contact); err != nil {
		return nil, err
	}
	return contact, nil
}

func (s *WidgetService) attachWidgetUploads(ctx context.Context, message *model.Message, signedIDs []string) ([]model.Attachment, error) {
	if len(signedIDs) == 0 {
		return nil, nil
	}
	attachments := make([]model.Attachment, 0, len(signedIDs))
	for _, signedID := range signedIDs {
		signedID = strings.TrimSpace(signedID)
		if signedID == "" {
			continue
		}
		var upload model.DirectUpload
		if err := s.messageRepo.DB().WithContext(ctx).Where("upload_uuid = ?", signedID).First(&upload).Error; err != nil {
			return nil, fmt.Errorf("direct upload not found: %w", err)
		}
		if upload.Source != model.DirectUploadSourceWidget {
			return nil, errors.New("direct upload source mismatch")
		}
		if upload.Status != model.DirectUploadStatusPending {
			return nil, errors.New("direct upload is not pending")
		}
		if upload.AccountID != 0 && upload.AccountID != message.AccountID {
			return nil, errors.New("direct upload account mismatch")
		}
		if time.Now().After(upload.ExpiresAt) {
			upload.Status = model.DirectUploadStatusExpired
			_ = s.messageRepo.DB().WithContext(ctx).Save(&upload).Error
			return nil, errors.New("direct upload has expired")
		}
		attachment := model.Attachment{
			MessageID: message.ID,
			AccountID: message.AccountID,
			FileType:  upload.FileType,
			FileURL:   upload.FileURL,
			ThumbURL:  upload.ThumbURL,
			FileSize:  int(upload.FileSize),
			FileName:  upload.OriginalName,
			Metadata:  string(upload.Metadata),
		}
		if err := s.messageRepo.DB().WithContext(ctx).Create(&attachment).Error; err != nil {
			return nil, fmt.Errorf("failed to create attachment: %w", err)
		}
		upload.Status = model.DirectUploadStatusCompleted
		upload.AccountID = message.AccountID
		if err := s.messageRepo.DB().WithContext(ctx).Save(&upload).Error; err != nil {
			return nil, fmt.Errorf("failed to mark direct upload completed: %w", err)
		}
		attachments = append(attachments, attachment)
	}
	return attachments, nil
}

func (s *WidgetService) resolvePublicInbox(ctx context.Context, inboxIdentifier string) (*model.Inbox, *channelmodel.ChannelAPI, error) {
	if inboxIdentifier == "" {
		return nil, nil, errors.New("inbox identifier is required")
	}
	inbox, channelAPI, err := s.inboxRepo.FindAPIInboxByIdentifier(ctx, inboxIdentifier)
	if err != nil {
		return nil, nil, err
	}
	return inbox, channelAPI, nil
}

func (s *WidgetService) resolvePublicContactInbox(ctx context.Context, inboxIdentifier, sourceID string) (*channelmodel.ChannelAPI, *model.ContactInbox, error) {
	if sourceID == "" {
		return nil, nil, errors.New("contact source_id is required")
	}
	_, channelAPI, err := s.resolvePublicInbox(ctx, inboxIdentifier)
	if err != nil {
		return nil, nil, err
	}
	contactInbox, err := s.contactInboxRepo.FindBySourceID(ctx, channelAPI.InboxID, sourceID)
	if err != nil {
		return nil, nil, err
	}
	contact, err := s.contactRepo.FindByID(ctx, contactInbox.ContactID)
	if err != nil {
		return nil, nil, err
	}
	contactInbox.Contact = *contact
	return channelAPI, contactInbox, nil
}

func validatePublicHMAC(hmacToken, identifier, signature string) error {
	if signature == "" {
		return nil
	}
	if !VerifyHMAC(hmacToken, identifier, signature) {
		return errors.New("HMAC failed: Invalid Identifier Hash Provided")
	}
	return nil
}

func filterPublicConversations(conversations []model.Conversation, contactInbox *model.ContactInbox) []model.Conversation {
	if contactInbox.HMACVerified {
		return conversations
	}
	filtered := make([]model.Conversation, 0, len(conversations))
	for _, conversation := range conversations {
		if conversation.ContactInboxID != nil && *conversation.ContactInboxID == contactInbox.ID {
			filtered = append(filtered, conversation)
		}
	}
	return filtered
}

func publicConversationID(conversation model.Conversation) uint {
	if conversation.DisplayID != nil && *conversation.DisplayID != 0 {
		return *conversation.DisplayID
	}
	return conversation.ID
}