nyastodon/app/models/concerns/account_search.rb
2023-05-02 18:21:36 +02:00

140 lines
4.7 KiB
Ruby
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# frozen_string_literal: true
module AccountSearch
extend ActiveSupport::Concern
DISALLOWED_TSQUERY_CHARACTERS = /['?\\:]/
TEXT_SEARCH_RANKS = <<~SQL.squish
(
setweight(to_tsvector('simple', accounts.display_name), 'A') ||
setweight(to_tsvector('simple', accounts.username), 'B') ||
setweight(to_tsvector('simple', coalesce(accounts.domain, '')), 'C')
)
SQL
REPUTATION_SCORE_FUNCTION = <<~SQL.squish
(
greatest(0, coalesce(s.followers_count, 0)) / (
greatest(0, coalesce(s.following_count, 0)) + 1.0
)
)
SQL
FOLLOWERS_SCORE_FUNCTION = <<~SQL.squish
log(
greatest(0, coalesce(s.followers_count, 0)) + 2
)
SQL
TIME_DISTANCE_FUNCTION = <<~SQL.squish
(
case
when s.last_status_at is null then 0
else exp(
-1.0 * (
(
greatest(0, abs(extract(DAY FROM age(s.last_status_at))) - 30.0)^2) /#{' '}
(2.0 * ((-1.0 * 30^2) / (2.0 * ln(0.3)))
)
)
)
end
)
SQL
BOOST = <<~SQL.squish
(
(#{REPUTATION_SCORE_FUNCTION} + #{FOLLOWERS_SCORE_FUNCTION} + #{TIME_DISTANCE_FUNCTION}) / 3.0
)
SQL
BASIC_SEARCH_SQL = <<~SQL.squish
SELECT
accounts.*,
#{BOOST} * ts_rank_cd(#{TEXT_SEARCH_RANKS}, to_tsquery('simple', :tsquery), 32) AS rank
FROM accounts
LEFT JOIN users ON accounts.id = users.account_id
LEFT JOIN account_stats AS s ON accounts.id = s.account_id
WHERE to_tsquery('simple', :tsquery) @@ #{TEXT_SEARCH_RANKS}
AND accounts.suspended_at IS NULL
AND accounts.moved_to_account_id IS NULL
AND (accounts.domain IS NOT NULL OR (users.approved = TRUE AND users.confirmed_at IS NOT NULL))
ORDER BY rank DESC
LIMIT :limit OFFSET :offset
SQL
ADVANCED_SEARCH_WITH_FOLLOWING = <<~SQL.squish
WITH first_degree AS (
SELECT target_account_id
FROM follows
WHERE account_id = :id
UNION ALL
SELECT :id
)
SELECT
accounts.*,
(count(f.id) + 1) * #{BOOST} * ts_rank_cd(#{TEXT_SEARCH_RANKS}, to_tsquery('simple', :tsquery), 32) AS rank
FROM accounts
LEFT OUTER JOIN follows AS f ON (accounts.id = f.account_id AND f.target_account_id = :id)
LEFT JOIN account_stats AS s ON accounts.id = s.account_id
WHERE accounts.id IN (SELECT * FROM first_degree)
AND to_tsquery('simple', :tsquery) @@ #{TEXT_SEARCH_RANKS}
AND accounts.suspended_at IS NULL
AND accounts.moved_to_account_id IS NULL
GROUP BY accounts.id, s.id
ORDER BY rank DESC
LIMIT :limit OFFSET :offset
SQL
ADVANCED_SEARCH_WITHOUT_FOLLOWING = <<~SQL.squish
SELECT
accounts.*,
#{BOOST} * ts_rank_cd(#{TEXT_SEARCH_RANKS}, to_tsquery('simple', :tsquery), 32) AS rank,
count(f.id) AS followed
FROM accounts
LEFT OUTER JOIN follows AS f ON
(accounts.id = f.account_id AND f.target_account_id = :id) OR (accounts.id = f.target_account_id AND f.account_id = :id)
LEFT JOIN users ON accounts.id = users.account_id
LEFT JOIN account_stats AS s ON accounts.id = s.account_id
WHERE to_tsquery('simple', :tsquery) @@ #{TEXT_SEARCH_RANKS}
AND accounts.suspended_at IS NULL
AND accounts.moved_to_account_id IS NULL
AND (accounts.domain IS NOT NULL OR (users.approved = TRUE AND users.confirmed_at IS NOT NULL))
GROUP BY accounts.id, s.id
ORDER BY followed DESC, rank DESC
LIMIT :limit OFFSET :offset
SQL
class_methods do
def search_for(terms, limit: 10, offset: 0)
tsquery = generate_query_for_search(terms)
find_by_sql([BASIC_SEARCH_SQL, { limit: limit, offset: offset, tsquery: tsquery }]).tap do |records|
ActiveRecord::Associations::Preloader.new.preload(records, :account_stat)
end
end
def advanced_search_for(terms, account, limit: 10, following: false, offset: 0)
tsquery = generate_query_for_search(terms)
sql_template = following ? ADVANCED_SEARCH_WITH_FOLLOWING : ADVANCED_SEARCH_WITHOUT_FOLLOWING
find_by_sql([sql_template, { id: account.id, limit: limit, offset: offset, tsquery: tsquery }]).tap do |records|
ActiveRecord::Associations::Preloader.new.preload(records, :account_stat)
end
end
private
def generate_query_for_search(unsanitized_terms)
terms = unsanitized_terms.gsub(DISALLOWED_TSQUERY_CHARACTERS, ' ')
# The final ":*" is for prefix search.
# The trailing space does not seem to fit any purpose, but `to_tsquery`
# behaves differently with and without a leading space if the terms start
# with `./`, `../`, or `.. `. I don't understand why, so, in doubt, keep
# the same query.
"' #{terms} ':*"
end
end
end