backend/internal/dto/message_converter.go

package dto

import (
	"with_you/internal/model"
)

// ==================== Message 转换 ====================

// ConvertMessageToResponse 将Message转换为MessageResponse
func ConvertMessageToResponse(message *model.Message) *MessageResponse {
	return ConvertMessageToResponseWithExpiry(message, nil)
}

// ConvertMessageToResponseWithExpiry 将Message转换为MessageResponse，并对已过期的 file segment 注入 expired 标记。
// expiredURLSet 为已从 S3 清理的文件 URL 集合（可为 nil，表示不标记）。
// 注意：注入时对 file segment 的 Data 做深拷贝，避免污染消息缓存。
func ConvertMessageToResponseWithExpiry(message *model.Message, expiredURLSet map[string]struct{}) *MessageResponse {
	if message == nil {
		return nil
	}

	// 直接使用 segments，不需要解析
	segments := make(model.MessageSegments, len(message.Segments))
	for i, seg := range message.Segments {
		// 对 file 类型且 URL 已过期的 segment，深拷贝 Data 并注入 expired 标记
		if seg.Type == string(model.ContentTypeFile) && len(expiredURLSet) > 0 {
			url, _ := seg.Data["url"].(string)
			if _, expired := expiredURLSet[url]; expired {
				newData := make(map[string]any, len(seg.Data)+1)
				for k, v := range seg.Data {
					newData[k] = v
				}
				newData["expired"] = true
				segments[i] = model.MessageSegment{Type: seg.Type, Data: newData}
				continue
			}
		}
		segments[i] = model.MessageSegment{
			Type: seg.Type,
			Data: seg.Data,
		}
	}

	return &MessageResponse{
		ID:             message.ID,
		ConversationID: message.ConversationID,
		SenderID:       message.SenderID,
		Seq:            message.Seq,
		Segments:       segments,
		ReplyToID:      message.ReplyToID,
		Status:         string(message.Status),
		Category:       string(message.Category),
		CreatedAt:      FormatTime(message.CreatedAt),
	}
}

// ConvertConversationToResponse 将Conversation转换为ConversationResponse
// participants: 会话参与者列表（用户信息）
// unreadCount: 当前用户的未读消息数
// lastMessage: 最后一条消息
func ConvertConversationToResponse(conv *model.Conversation, participants []*model.User, unreadCount int, lastMessage *model.Message, isPinned bool, notificationMuted bool) *ConversationResponse {
	if conv == nil {
		return nil
	}

	var participantResponses []*UserResponse
	for _, p := range participants {
		participantResponses = append(participantResponses, ConvertUserToResponse(p))
	}

	// 转换群组信息
	var groupResponse *GroupResponse
	if conv.Group != nil {
		groupResponse = GroupToResponse(conv.Group)
	}

	return &ConversationResponse{
		ID:                conv.ID,
		Type:              string(conv.Type),
		IsPinned:          isPinned,
		NotificationMuted: notificationMuted,
		Group:             groupResponse,
		LastSeq:           conv.LastSeq,
		LastMessage:       ConvertMessageToResponse(lastMessage),
		LastMessageAt:     FormatTimePointer(conv.LastMsgTime),
		UnreadCount:       unreadCount,
		Participants:      participantResponses,
		CreatedAt:         FormatTime(conv.CreatedAt),
		UpdatedAt:         FormatTime(conv.UpdatedAt),
	}
}

// ConvertConversationToDetailResponse 将Conversation转换为ConversationDetailResponse
func ConvertConversationToDetailResponse(conv *model.Conversation, participants []*model.User, unreadCount int64, lastMessage *model.Message, myLastReadSeq int64, otherLastReadSeq int64, isPinned bool, notificationMuted bool) *ConversationDetailResponse {
	if conv == nil {
		return nil
	}

	var participantResponses []*UserResponse
	for _, p := range participants {
		participantResponses = append(participantResponses, ConvertUserToResponse(p))
	}

	return &ConversationDetailResponse{
		ID:                conv.ID,
		Type:              string(conv.Type),
		IsPinned:          isPinned,
		NotificationMuted: notificationMuted,
		LastSeq:           conv.LastSeq,
		LastMessage:       ConvertMessageToResponse(lastMessage),
		LastMessageAt:     FormatTimePointer(conv.LastMsgTime),
		UnreadCount:       unreadCount,
		Participants:      participantResponses,
		MyLastReadSeq:     myLastReadSeq,
		OtherLastReadSeq:  otherLastReadSeq,
		CreatedAt:         FormatTime(conv.CreatedAt),
		UpdatedAt:         FormatTime(conv.UpdatedAt),
	}
}

// ConvertMessagesToResponse 将Message列表转换为响应列表
func ConvertMessagesToResponse(messages []*model.Message) []*MessageResponse {
	result := make([]*MessageResponse, 0, len(messages))
	for _, msg := range messages {
		result = append(result, ConvertMessageToResponse(msg))
	}
	return result
}

// ConvertMessagesToResponseWithExpiry 将Message列表转换为响应列表，并标记过期文件
func ConvertMessagesToResponseWithExpiry(messages []*model.Message, expiredURLSet map[string]struct{}) []*MessageResponse {
	result := make([]*MessageResponse, 0, len(messages))
	for _, msg := range messages {
		result = append(result, ConvertMessageToResponseWithExpiry(msg, expiredURLSet))
	}
	return result
}


// ==================== PushRecord 转换 ====================

// PushRecordToResponse 将PushRecord转换为PushRecordResponse
func PushRecordToResponse(record *model.PushRecord) *PushRecordResponse {
	if record == nil {
		return nil
	}
	resp := &PushRecordResponse{
		ID:          record.ID,
		MessageID:   record.MessageID,
		PushChannel: string(record.PushChannel),
		PushStatus:  string(record.PushStatus),
		RetryCount:  record.RetryCount,
		CreatedAt:   record.CreatedAt,
	}
	if record.PushedAt != nil {
		resp.PushedAt = *record.PushedAt
	}
	if record.DeliveredAt != nil {
		resp.DeliveredAt = *record.DeliveredAt
	}
	return resp
}

// PushRecordsToResponse 将PushRecord列表转换为响应列表
func PushRecordsToResponse(records []*model.PushRecord) []*PushRecordResponse {
	result := make([]*PushRecordResponse, 0, len(records))
	for _, record := range records {
		result = append(result, PushRecordToResponse(record))
	}
	return result
}

// ==================== DeviceToken 转换 ====================

// DeviceTokenToResponse 将DeviceToken转换为DeviceTokenResponse
func DeviceTokenToResponse(token *model.DeviceToken) *DeviceTokenResponse {
	if token == nil {
		return nil
	}
	resp := &DeviceTokenResponse{
		ID:         token.ID,
		DeviceID:   token.DeviceID,
		DeviceType: string(token.DeviceType),
		IsActive:   token.IsActive,
		DeviceName: token.DeviceName,
		CreatedAt:  token.CreatedAt,
	}
	if token.LastUsedAt != nil {
		resp.LastUsedAt = *token.LastUsedAt
	}
	return resp
}

// DeviceTokensToResponse 将DeviceToken列表转换为响应列表
func DeviceTokensToResponse(tokens []*model.DeviceToken) []*DeviceTokenResponse {
	result := make([]*DeviceTokenResponse, 0, len(tokens))
	for _, token := range tokens {
		result = append(result, DeviceTokenToResponse(token))
	}
	return result
}