package chat

import (
	"errors"
	"gorm.io/gorm"
	"gorm.io/gorm/clause"
	"hfb_sys/backend/internal/model"
	"hfb_sys/backend/internal/modules/chathub"
	"time"
)

type Repository struct {
	db  *gorm.DB
	hub *chathub.Hub
}

const (
	defaultSupportRoleCode = "cs"
)

func NewRepository(db *gorm.DB, hub *chathub.Hub) *Repository {
	return &Repository{db: db, hub: hub}
}
func EnsureOrderConversation(tx *gorm.DB, order model.RentalOrder) (*model.ChatConversation, error) {
	var existing model.ChatConversation
	err := tx.Where("order_id = ?", order.ID).First(&existing).Error
	if err == nil {
		return &existing, nil
	}
	if !errors.Is(err, gorm.ErrRecordNotFound) {
		return nil, err
	}

	now := time.Now()
	conversation := model.ChatConversation{
		OrderID: &order.ID,
		Type:    "order_group",
		Title:   orderConversationTitle(order),
		Status:  "active",
	}
	if err := tx.Create(&conversation).Error; err != nil {
		return nil, err
	}

	participants := []model.ChatParticipant{
		{
			ConversationID:  conversation.ID,
			ParticipantType: "user",
			ParticipantID:   order.RenterID,
			Role:            "renter",
			JoinedAt:        now,
		},
		{
			ConversationID:  conversation.ID,
			ParticipantType: "user",
			ParticipantID:   order.OwnerID,
			Role:            "owner",
			JoinedAt:        now,
		},
	}
	if supportID := defaultSupportAdminID(tx); supportID > 0 {
		participants = append(participants, model.ChatParticipant{
			ConversationID:  conversation.ID,
			ParticipantType: "admin",
			ParticipantID:   supportID,
			Role:            "support",
			JoinedAt:        now,
		})
	}
	for _, participant := range participants {
		if err := tx.Clauses(clause.OnConflict{DoNothing: true}).Create(&participant).Error; err != nil {
			return nil, err
		}
	}

	// 获取自动话术
	autoMessage := "订单已支付，群聊已创建。租客、号主和客服可在这里沟通交接与结账问题。"
	var cfg model.SystemConfig
	if err := tx.Where("`key` = ?", "chat.auto_welcome_message").First(&cfg).Error; err == nil && cfg.Value != "" {
		autoMessage = cfg.Value
	}
	message := model.ChatMessage{
		ConversationID: conversation.ID,
		SenderType:     "system",
		SenderRole:     "system",
		ContentType:    "system",
		Content:        autoMessage,
		AttachmentURLS: emptyJSONList(),
	}
	if err := tx.Create(&message).Error; err != nil {
		return nil, err
	}
	conversation.LastMessageID = &message.ID
	conversation.LastMessagePreview = truncatePreview(message.Content)
	conversation.LastMessageAt = &message.CreatedAt
	if err := tx.Save(&conversation).Error; err != nil {
		return nil, err
	}
	return &conversation, nil
}
func (r *Repository) NotifyNewConversation(conversationID uint64) {
	if r.hub == nil {
		return
	}
	r.hub.NotifyConversation(conversationID, &chathub.ChatEvent{
		Type:           "conversation_updated",
		ConversationID: conversationID,
	})
}