glitchier-soc/app/models/glitch/keyword_mute.rb
David Yip 05fecda52d Switch to Regexp.union for building the mute expression.
Also make the keyword-building methods private: they always probably
should have been private, but now I have encoded enough fun and games
into them that it now seems wrong for them to *not* be private.
2017-10-24 18:31:34 -05:00

66 lines
1.6 KiB
Ruby

# frozen_string_literal: true
# == Schema Information
#
# Table name: glitch_keyword_mutes
#
# id :integer not null, primary key
# account_id :integer not null
# keyword :string not null
# whole_word :boolean default(TRUE), not null
# created_at :datetime not null
# updated_at :datetime not null
#
class Glitch::KeywordMute < ApplicationRecord
belongs_to :account, required: true
validates_presence_of :keyword
after_commit :invalidate_cached_matcher
def self.matcher_for(account_id)
Matcher.new(account_id)
end
private
def invalidate_cached_matcher
Rails.cache.delete("keyword_mutes:regex:#{account_id}")
end
class Matcher
attr_reader :account_id
attr_reader :regex
def initialize(account_id)
@account_id = account_id
regex_text = Rails.cache.fetch("keyword_mutes:regex:#{account_id}") { regex_text_for_account }
@regex = /#{regex_text}/i
end
def =~(str)
regex ? regex =~ str : nil
end
private
def keywords
Glitch::KeywordMute.where(account_id: account_id).select(:keyword, :id, :whole_word)
end
def regex_text_for_account
kws = keywords.find_each.with_object([]) do |kw, a|
a << (kw.whole_word ? boundary_regex_for_keyword(kw.keyword) : kw.keyword)
end
Regexp.union(kws).source
end
def boundary_regex_for_keyword(keyword)
sb = keyword =~ /\A[[:word:]]/ ? '\b' : ''
eb = keyword =~ /[[:word:]]\Z/ ? '\b' : ''
/#{sb}#{Regexp.escape(keyword)}#{eb}/
end
end
end