package impl

import (
	"health-ai/internal/database"
	"health-ai/internal/model"
)

type ConversationRepository struct{}

func NewConversationRepository() *ConversationRepository {
	return &ConversationRepository{}
}

// Create 创建对话
func (r *ConversationRepository) Create(conv *model.Conversation) error {
	return database.DB.Create(conv).Error
}

// GetByID 根据ID获取对话（含消息）
func (r *ConversationRepository) GetByID(id uint) (*model.Conversation, error) {
	var conv model.Conversation
	err := database.DB.Preload("Messages").First(&conv, id).Error
	return &conv, err
}

// GetByUserID 获取用户的所有对话
func (r *ConversationRepository) GetByUserID(userID uint) ([]model.Conversation, error) {
	var convs []model.Conversation
	err := database.DB.Where("user_id = ?", userID).Order("updated_at DESC").Find(&convs).Error
	return convs, err
}

// Delete 删除对话（同时删除消息）
func (r *ConversationRepository) Delete(id uint) error {
	// 先删除消息
	database.DB.Where("conversation_id = ?", id).Delete(&model.Message{})
	return database.DB.Delete(&model.Conversation{}, id).Error
}

// AddMessage 添加消息
func (r *ConversationRepository) AddMessage(msg *model.Message) error {
	// 同时更新对话的更新时间
	database.DB.Model(&model.Conversation{}).Where("id = ?", msg.ConversationID).Update("updated_at", msg.CreatedAt)
	return database.DB.Create(msg).Error
}

// GetMessages 获取对话的消息
func (r *ConversationRepository) GetMessages(convID uint) ([]model.Message, error) {
	var messages []model.Message
	err := database.DB.Where("conversation_id = ?", convID).Order("created_at ASC").Find(&messages).Error
	return messages, err
}

// GetRecentMessages 获取对话最近的N条消息
func (r *ConversationRepository) GetRecentMessages(convID uint, limit int) ([]model.Message, error) {
	var messages []model.Message
	err := database.DB.Where("conversation_id = ?", convID).Order("created_at DESC").Limit(limit).Find(&messages).Error
	if err != nil {
		return nil, err
	}
	// 反转顺序，使消息按时间正序排列
	for i, j := 0, len(messages)-1; i < j; i, j = i+1, j-1 {
		messages[i], messages[j] = messages[j], messages[i]
	}
	return messages, nil
}

// UpdateTitle 更新对话标题
func (r *ConversationRepository) UpdateTitle(id uint, title string) error {
	return database.DB.Model(&model.Conversation{}).Where("id = ?", id).Update("title", title).Error
}

// CheckOwnership 检查对话是否属于用户
func (r *ConversationRepository) CheckOwnership(convID, userID uint) bool {
	var count int64
	database.DB.Model(&model.Conversation{}).Where("id = ? AND user_id = ?", convID, userID).Count(&count)
	return count > 0
}