about summary refs log tree commit diff
path: root/app/models/concerns/status_threading_concern.rb
blob: 1e5c52c46f001f8bb7252976bb086011539241f4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
# frozen_string_literal: true

module StatusThreadingConcern
  extend ActiveSupport::Concern

  def ancestors(limit, account = nil)
    find_statuses_from_tree_path(ancestor_ids(limit), account)
  end

  def descendants(limit, account = nil, max_child_id = nil, since_child_id = nil, depth = nil)
    find_statuses_from_tree_path(descendant_ids(limit, max_child_id, since_child_id, depth), account, promote: true)
  end

  def self_replies(limit)
    account.statuses.where(in_reply_to_id: id, visibility: [:public, :unlisted, :local]).reorder(id: :asc).limit(limit)
  end

  private

  def ancestor_ids(limit)
    key = "ancestors:#{id}"
    ancestors = Rails.cache.fetch(key)

    if ancestors.nil? || ancestors[:limit] < limit
      ids = ancestor_statuses(limit).pluck(:id).reverse!
      Rails.cache.write key, limit: limit, ids: ids
      ids
    else
      ancestors[:ids].last(limit)
    end
  end

  def ancestor_statuses(limit)
    Status.find_by_sql([<<-SQL.squish, id: in_reply_to_id, limit: limit])
      WITH RECURSIVE search_tree(id, in_reply_to_id, path)
      AS (
        SELECT id, in_reply_to_id, ARRAY[id]
        FROM statuses
        WHERE id = :id
        UNION ALL
        SELECT statuses.id, statuses.in_reply_to_id, path || statuses.id
        FROM search_tree
        JOIN statuses ON statuses.id = search_tree.in_reply_to_id
        WHERE NOT statuses.id = ANY(path)
      )
      SELECT id
      FROM search_tree
      ORDER BY path
      LIMIT :limit
    SQL
  end

  def descendant_ids(limit, max_child_id, since_child_id, depth)
    descendant_statuses(limit, max_child_id, since_child_id, depth).pluck(:id)
  end

  def descendant_statuses(limit, max_child_id, since_child_id, depth)
    # use limit + 1 and depth + 1 because 'self' is included
    depth += 1 if depth.present?
    limit += 1 if limit.present?

    descendants_with_self = Status.find_by_sql([<<-SQL.squish, id: id, limit: limit, max_child_id: max_child_id, since_child_id: since_child_id, depth: depth])
      WITH RECURSIVE search_tree(id, path)
      AS (
        SELECT id, ARRAY[id]
        FROM statuses
        WHERE id = :id AND COALESCE(id < :max_child_id, TRUE) AND COALESCE(id > :since_child_id, TRUE)
        UNION ALL
        SELECT statuses.id, path || statuses.id
        FROM search_tree
        JOIN statuses ON statuses.in_reply_to_id = search_tree.id
        WHERE COALESCE(array_length(path, 1) < :depth, TRUE) AND NOT statuses.id = ANY(path)
      )
      SELECT id
      FROM search_tree
      ORDER BY path
      LIMIT :limit
    SQL

    descendants_with_self - [self]
  end

  def find_statuses_from_tree_path(ids, account, promote: false)
    statuses    = statuses_with_accounts(ids).to_a
    account_ids = statuses.map(&:account_id).uniq
    domains     = statuses.map(&:account_domain).compact.uniq
    relations   = relations_map_for_account(account, account_ids, domains)

    statuses.reject! { |status| filter_from_context?(status, account, relations) }

    # Order ancestors/descendants by tree path
    statuses.sort_by! { |status| ids.index(status.id) }

    # Bring self-replies to the top
    if promote
      promote_by!(statuses) { |status| status.in_reply_to_account_id == status.account_id }
    else
      statuses
    end
  end

  def promote_by!(arr)
    insert_at = arr.find_index { |item| !yield(item) }

    return arr if insert_at.nil?

    arr.each_with_index do |item, index|
      next if index <= insert_at || !yield(item)

      arr.insert(insert_at, arr.delete_at(index))
      insert_at += 1
    end

    arr
  end

  def relations_map_for_account(account, account_ids, domains)
    return {} if account.nil?

    {
      blocking: Account.blocking_map(account_ids, account.id),
      blocked_by: Account.blocked_by_map(account_ids, account.id),
      muting: Account.muting_map(account_ids, account.id),
      following: Account.following_map(account_ids, account.id),
      domain_blocking_by_domain: Account.domain_blocking_map_by_domain(domains, account.id),
    }
  end

  def statuses_with_accounts(ids)
    Status.where(id: ids).includes(:account)
  end

  def filter_from_context?(status, account, relations)
    StatusFilter.new(status, account, relations).filtered?
  end
end