mce/internal/repository/comment_mention_repo.go

package repository

import (
	"metazone.cc/mce/internal/model"
	"metazone.cc/mce/internal/service"
)

// CreateMention 创建@提及记录
func (r *CommentRepo) CreateMention(mention *model.CommentMention) error {
	return r.db.Create(mention).Error
}

// FindMentionsByComment 查询某条评论的@提及列表
func (r *CommentRepo) FindMentionsByComment(commentID uint) ([]model.CommentMention, error) {
	var list []model.CommentMention
	err := r.db.Where("comment_id = ?", commentID).Find(&list).Error
	return list, err
}

// LoadMentionsForComments 批量加载多条评论的有效@提及映射
// key=创建时的原始@用户名, value={uid, 用户当前显示名}
// 用户改名后：原始名匹配body中的旧@文本，显示名随users表更新
func (r *CommentRepo) LoadMentionsForComments(comments []model.Comment) error {
	if len(comments) == 0 {
		return nil
	}

	commentIDs := make([]uint, len(comments))
	for i, c := range comments {
		commentIDs[i] = c.ID
	}

	type mentionRow struct {
		CommentID        uint
		UID              uint
		OriginalUsername string
		CurrentName      string
	}
	var rows []mentionRow
	err := r.db.Table("comment_mentions").
		Select("comment_mentions.comment_id, comment_mentions.uid, comment_mentions.original_username, users.username AS current_name").
		Joins("LEFT JOIN users ON users.id = comment_mentions.uid").
		Where("comment_mentions.comment_id IN ?", commentIDs).
		Find(&rows).Error
	if err != nil {
		return err
	}

	// 按 comment_id 分组，key = original_username, value = MentionInfo
	mentionMap := make(map[uint]map[string]model.MentionInfo)
	for _, row := range rows {
		if mentionMap[row.CommentID] == nil {
			mentionMap[row.CommentID] = make(map[string]model.MentionInfo)
		}
		mentionMap[row.CommentID][row.OriginalUsername] = model.MentionInfo{
			UID:  row.UID,
			Name: row.CurrentName,
		}
	}

	for i := range comments {
		if m, ok := mentionMap[comments[i].ID]; ok {
			comments[i].Mentions = m
		}
	}
	return nil
}

// SearchUsersByLevel 搜索指定等级及以上用户（用于@艾特），返回 uid/username/avatar/exp
// followerUID > 0 时按已关注优先排序，其次按exp降序
func (r *CommentRepo) SearchUsersByLevel(keyword string, minLevel, limit int, followerUID uint) ([]struct {
	UID      uint
	Username string
	Avatar   string
	Exp      int
}, error,
) {
	type result struct {
		UID      uint
		Username string
		Avatar   string
		Exp      int
	}
	var list []result

	threshold := model.LevelThresholds[minLevel]

	q := r.db.Table("users AS u").
		Select("u.id AS uid, u.username, u.avatar, u.exp").
		Where("u.username LIKE ? AND u.exp >= ? AND u.deleted_at IS NULL", "%"+keyword+"%", threshold).
		Order("u.exp DESC")

	if followerUID > 0 {
		q = q.Joins("LEFT JOIN user_follows f ON f.followee_id = u.id AND f.follower_id = ?", followerUID).
			Order("(f.follower_id IS NOT NULL) DESC, u.exp DESC")
	}

	err := q.Limit(limit).Find(&list).Error

	var res []struct {
		UID      uint
		Username string
		Avatar   string
		Exp      int
	}
	for _, u := range list {
		res = append(res, struct {
			UID      uint
			Username string
			Avatar   string
			Exp      int
		}{UID: u.UID, Username: u.Username, Avatar: u.Avatar, Exp: u.Exp})
	}
	return res, err
}

// GetUsernameByID 通过 userID 获取用户名（用于通知内容）
func (r *CommentRepo) GetUsernameByID(userID uint) (string, error) {
	var username string
	err := r.db.Table("users").Select("username").Where("id = ?", userID).Scan(&username).Error
	return username, err
}

// FindPostIDByComment 查询评论所属的文章ID
func (r *CommentRepo) FindPostIDByComment(commentID uint) (uint, error) {
	var postID uint
	err := r.db.Table("comments").Select("post_id").Where("id = ?", commentID).Scan(&postID).Error
	return postID, err
}

// UpdateRootID 更新评论的 root_id 字段（顶级评论创建后回填）
func (r *CommentRepo) UpdateRootID(id, rootID uint) error {
	return r.db.Model(&model.Comment{}).Where("id = ?", id).Update("root_id", rootID).Error
}

// FindPostAuthorID 查询文章的作者 user_id
func (r *CommentRepo) FindPostAuthorID(postID uint) (uint, error) {
	var authorID uint
	err := r.db.Table("posts").Select("user_id").Where("id = ?", postID).Scan(&authorID).Error
	return authorID, err
}

// AggregateCommentsByAuthor 按日期聚合评论量（作者所有文章在时间段内的评论）
func (r *CommentRepo) AggregateCommentsByAuthor(userID uint, since string) ([]service.TrendPoint, error) {
	var results []service.TrendPoint
	err := r.db.Table("comments").
		Select("TO_CHAR(comments.created_at, 'YYYY-MM-DD') AS date, COUNT(*) AS value").
		Joins("JOIN posts ON posts.id = comments.post_id").
		Where("posts.user_id = ? AND comments.created_at >= ?", userID, since).
		Group("TO_CHAR(comments.created_at, 'YYYY-MM-DD')").
		Order("date ASC").
		Scan(&results).Error
	if results == nil {
		results = []service.TrendPoint{}
	}
	return results, err
}

// ListAllComments 后台评论列表（支持关键词搜索、分页）
func (r *CommentRepo) ListAllComments(keyword string, showDeleted bool, offset, limit int) ([]model.AdminCommentRow, int64, error) {
	var total int64
	q := r.db.Table("comments").
		Joins("LEFT JOIN users ON users.id = comments.user_id").
		Joins("LEFT JOIN posts ON posts.id = comments.post_id")

	if !showDeleted {
		q = q.Where("comments.is_deleted = false")
	}
	if keyword != "" {
		like := "%" + keyword + "%"
		q = q.Where("comments.body LIKE ? OR users.username LIKE ? OR posts.title LIKE ?", like, like, like)
	}

	if err := q.Count(&total).Error; err != nil {
		return nil, 0, err
	}

	var rows []model.AdminCommentRow
	err := q.
		Select("comments.id, comments.post_id, posts.title as post_title, comments.body, users.username as author_name, comments.is_deleted, comments.created_at, comments.updated_at").
		Order("comments.created_at DESC").
		Offset(offset).Limit(limit).
		Scan(&rows).Error
	return rows, total, err
}