backend/internal/dto/segment.go

package dto

import (
	"encoding/json"
	"fmt"
	"slices"

	"with_you/internal/model"
)

// NewTextSegment 创建文本Segment
func NewTextSegment(content string) model.MessageSegment {
	return model.MessageSegment{
		Type: string(SegmentTypeText),
		Data: map[string]any{"text": content},
	}
}

// ExtractVoteSegmentData 从消息链中提取投票Segment数据
func ExtractVoteSegmentData(segments model.MessageSegments) *VoteSegmentData {
	for _, segment := range segments {
		if segment.Type == string(SegmentTypeVote) {
			dataBytes, err := json.Marshal(segment.Data)
			if err != nil {
				continue
			}
			var voteData VoteSegmentData
			if err := json.Unmarshal(dataBytes, &voteData); err != nil {
				continue
			}
			return &voteData
		}
	}
	return nil
}

// HasVoteSegment 检查消息链中是否包含投票Segment
func HasVoteSegment(segments model.MessageSegments) bool {
	return HasSegmentType(segments, SegmentTypeVote)
}

// ExtractTextContentFromModel 从 model.MessageSegments 中提取纯文本内容
func ExtractTextContentFromModel(segments model.MessageSegments) string {
	var result string
	for _, segment := range segments {
		switch segment.Type {
		case "text":
			if text, ok := segment.Data["text"].(string); ok {
				result += text
			}
		case "at":
			userID, _ := segment.Data["user_id"].(string)
			if userID == "all" {
				result += "@所有人 "
			} else if userID != "" {
				// 昵称由前端实时解析，后端文本提取仅用于推送通知兜底
				result += "@某人 "
			}
		case "image":
			result += "[图片]"
		case "voice":
			result += "[语音]"
		case "video":
			result += "[视频]"
		case "file":
			if name, ok := segment.Data["name"].(string); ok && name != "" {
				result += fmt.Sprintf("[文件:%s]", name)
			} else {
				result += "[文件]"
			}
		case "face":
			if name, ok := segment.Data["name"].(string); ok && name != "" {
				result += fmt.Sprintf("[%s]", name)
			} else {
				result += "[表情]"
			}
		case "link":
			if title, ok := segment.Data["title"].(string); ok && title != "" {
				result += fmt.Sprintf("[链接:%s]", title)
			} else {
				result += "[链接]"
			}
		case "vote":
			result += "[投票]"
		case "post_ref":
			if title, ok := segment.Data["title"].(string); ok && title != "" {
				result += fmt.Sprintf("[帖子:%s]", title)
			} else {
				result += "[帖子引用]"
			}
		}
	}
	return result
}

// ExtractTextContent 从消息链中提取纯文本内容
// 用于搜索、通知展示等场景
func ExtractTextContent(segments model.MessageSegments) string {
	return ExtractTextContentFromModel(segments)
}

// ExtractMentionedUsers 从消息链中提取被@的用户ID列表
// 不包括 "all"（@所有人）
func ExtractMentionedUsers(segments model.MessageSegments) []string {
	var userIDs []string
	seen := make(map[string]bool)

	for _, segment := range segments {
		if segment.Type == string(SegmentTypeAt) {
			userID, _ := segment.Data["user_id"].(string)
			if userID != "all" && userID != "" && !seen[userID] {
				userIDs = append(userIDs, userID)
				seen[userID] = true
			}
		}
	}
	return userIDs
}

// ExtractReferencedPosts 从消息链中提取所有被引用的帖子ID
func ExtractReferencedPosts(segments model.MessageSegments) []string {
	var postIDs []string
	seen := make(map[string]bool)

	for _, segment := range segments {
		if segment.Type == string(SegmentTypePostRef) {
			postID, _ := segment.Data["post_id"].(string)
			if postID != "" && !seen[postID] {
				postIDs = append(postIDs, postID)
				seen[postID] = true
			}
		}
	}
	return postIDs
}

// HasSegmentType 检查消息链中是否包含指定类型的segment
func HasSegmentType(segments model.MessageSegments, segmentType SegmentType) bool {
	return slices.ContainsFunc(segments, func(segment model.MessageSegment) bool {
		return segment.Type == string(segmentType)
	})
}