diff options
Diffstat (limited to 'app/lib/command_tag/processor.rb')
| -rw-r--r-- | app/lib/command_tag/processor.rb | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/app/lib/command_tag/processor.rb b/app/lib/command_tag/processor.rb new file mode 100644 index 000000000..77be29eba --- /dev/null +++ b/app/lib/command_tag/processor.rb @@ -0,0 +1,343 @@ +# frozen_string_literal: true + +# .~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~. # +################### Cthulhu Code! ################### +# `~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~` # +# - Interprets and executes user input. THIS CAN BE VERY DANGEROUS! # +# - Has a high complexity level and needs tests. # +# - May destroy objects passed to it. # +# - Incurs a high performance penalty. # +# # +############################################################################### + +require_relative 'commands' + +class CommandTag::Break < Mastodon::Error + def initialize(msg = 'A handler stopped execution.') + super + end +end + +class CommandTag::Processor + include Redisable + include ImgProxyHelper + include CommandTag::Commands + + MENTIONS_OR_HASHTAGS_RE = /(?:(?:#{Account::MENTION_RE}|#{Tag::HASHTAG_RE})\s*)+/.freeze + PARSEABLE_RE = /^\s*(?:#{MENTIONS_OR_HASHTAGS_RE})?#!|%%.+?%%/.freeze + STATEMENT_RE = /^\s*#!\s*[^\n]+ (?:start|begin|do)$.*?\n\s*#!\s*(?:end|stop|done)\s*$|^\s*#!\s*.*?\s*$/im.freeze + STATEMENT_PARSE_RE = /'([^']*)'|"([^"]*)"|(\S+)|\s+(?:start|begin|do)\s*$\n+(.*)\n\s*#!\s*(?:end|stop|done)\s*\z/im.freeze + TEMPLATE_RE = /%%\s*(\S+.*?)\s*%%/.freeze + ESCAPE_MAP = { + '\n' => "\n", + '\r' => "\r", + '\t' => "\t", + '\\\\' => '\\', + '\%' => '%', + }.freeze + + def initialize(account, status) + @account = account + @status = status + @parent = status.thread + @conversation = status.conversation + @text = status.text + @run_once = Set[] + @vars = { 'statement_uuid' => [nil] } + @statements = {} + + return unless @account.present? && @account.local? && @status.present? + end + + def process! + reset_status_caches + all_handlers!(:startup) + + unless @text.match?(PARSEABLE_RE) + process_inline_images! + @status.save! + return + end + + @text = parse_statements_from!(@text, @statements) + + execute_statements(:at_start) + execute_statements(:with_return, true) + @text = replace_templates(@text) + execute_statements(:before_save) + + if status_text_blank? + execute_statements(:when_blank) + + unless (@status.published? && !@status.edited.zero?) || @text.present? + execute_statements(:before_destroy) + @status.update(published: false) + @status.destroy + execute_statements(:after_destroy) + end + elsif @status.destroyed? + execute_statements(:after_destroy) + else + @status.text = @text + process_inline_images! + if @status.save + execute_statements(:after_save) + else + execute_statements(:after_save_fail) + end + end + + execute_statements(:at_end) + all_handlers!(:shutdown) + rescue CommandTag::Break + nil + rescue StandardError + @status.update(published: false) + @status.destroy + raise + ensure + reset_status_caches + end + + private + + def all_handlers!(affix) + self.class.instance_methods.grep(/\Ahandle_\w+_#{affix}\z/).sort.each do |name| + public_send(name) + end + end + + # Calls an arbitary public method (if it exists) on a given value and returns the result. + def transform_using(name, value, args = []) + respond_to?(name) ? public_send(name, value, args) : value + end + + # Moves command tags placed after hashtags and mentions to their own line. + def prepare_input(text) + text.gsub(/\r\n|\n\r|\r/, "\n").gsub(/^\s*(#{MENTIONS_OR_HASHTAGS_RE})#!/, "\\1\n#!") + end + + # Translates %%...%% templates. + def replace_templates(text) + text.gsub(TEMPLATE_RE) do + template = unescape_literals(Regexp.last_match(1)) + next if template.blank? + next template[1..-2] if template.match?(/\A'.*'\z/) + + template = template.match?(/\A".*"\z/) ? template[1..-2] : "\#{#{template}}" + template.gsub(/#\{\s*(.*?)\s*\}/) do + next if Regexp.last_match(1).blank? + + parts = Regexp.last_match(1).scan(/'([^']*)'|"([^"]*)"|(\S+)/).flatten.compact + name = normalize(parts[0]) + separator = "\n" + + if parts.count > 2 + if %w(: by: with: using: sep: separator: delim: delimiter:).include?(parts[-2].downcase) + separator = parts[-1] + parts = parts[0..-3] + elsif !parts[-1].match?(/\A[-+]?[0-9]+\z/) + separator = parts[-1] + parts.pop + end + end + + index = to_integer(parts[1]) + str_start = to_integer(parts[2]) + str_end = to_integer(parts[3]) + + str_start, str_end = [str_end, str_start] if str_start > str_end + + old_value = (['all', '[]'].include?(parts[1]) ? var(name).join(separator) : var(name)[index].to_s) + name = name.gsub(/[^\w_]+/, '_') + new_value = transform_using("transform_#{name}_template_return", old_value, [index, str_start, str_end]) + next new_value if new_value != old_value + + new_value = transform_using("transform_#{name}_template_value", new_value, [index, str_start, str_end]) + (str_end - str_start).zero? ? new_value : new_value[str_start..str_end] + end + end.rstrip + end + + # Parses statements from text and merges them into statement queues. + # Mutates statement queues hash! + def parse_statements_from!(text, statement_queues) + @run_once.clear + + text = prepare_input(text) + text.gsub!(STATEMENT_RE) do + statement = unescape_literals(Regexp.last_match(0).strip[2..-1]) + next if statement.blank? + + statement_array = statement.scan(STATEMENT_PARSE_RE).flatten.compact.map { |arg| arg.gsub('\#!', '#!') } + statement_array[0] = statement_array[0].strip.tr(':.\- ', '_').gsub(/__+/, '_').downcase + next unless statement_array[0].match?(/\A[\w_]+\z/) + + statement_array[-1].rstrip! if statement_array.count > 1 + add_statement_handlers_for!(statement_array, statement_queues) + end + + @run_once.clear + text + end + + # Yields all possible handler names for a command. + def potential_handlers_for(name) + ['_once', ''].each_with_index do |count_affix, index| + %w(at_start with_return when_blank at_end).each do |when_affix| + yield ["#{count_affix}_#{when_affix}", "handle_#{name}#{count_affix}_#{when_affix}", index.zero?] + end + + %w(destroy save postprocess save_fail).each do |event_affix| + %w(before after).each do |when_affix| + yield ["#{count_affix}_#{when_affix}_#{event_affix}", "handle_#{name}#{count_affix}_#{when_affix}_#{event_affix}", index.zero?] + end + end + end + end + + # Expands a statement to a handler method call, arguments, and template UUID for each handler affix. + # Mutates statement queues hash! + def add_statement_handlers_for!(statement_array, statement_queues = {}) + statement_uuid = SecureRandom.uuid + + potential_handlers_for(statement_array[0]) do |when_affix, handler, once| + if !(once && @run_once.include?(handler)) && respond_to?(handler) + statement_queues[when_affix] ||= [] + statement_queues[when_affix] << [handler, statement_array[1..-1], statement_uuid] + @run_once << handler if once + end + end + + # Template for statement return value. + "%% statement:#{statement_uuid} all %%" + end + + # Calls all handlers for a queue of statements in order. + def execute_statements(event, with_return = false, statements: nil) + statements = @statements if statements.blank? + + ["_#{event}", "_once_#{event}"].each do |when_affix| + next if statements[when_affix].blank? + + statements[when_affix].each do |handler, arguments, uuid| + @vars['statement_uuid'][0] = uuid + if with_return + @vars["statement:#{uuid}"] = [public_send(handler, arguments)] + else + public_send(handler, arguments) + end + end + end + end + + # Expire cached statuses after potentially updating them. + def reset_status_caches(statuses = nil) + statuses = [@status, @parent] if statuses.blank? + statuses.each do |status| + next unless @account.id == status&.account_id + + Rails.cache.delete_matched("statuses/#{status.id}-*") + Rails.cache.delete("statuses/#{status.id}") + Rails.cache.delete(status) + Rails.cache.delete_matched("format:#{status.id}:*") + redis.zremrangebyscore("spam_check:#{status.account.id}", status.id, status.id) + end + end + + def author_of_status? + @account.id == @status.account_id + end + + def author_of_parent? + @account.id == @parent&.account_id + end + + def status_text_blank? + @text.blank? || @text.gsub(MENTIONS_OR_HASHTAGS_RE, '').strip.blank? + end + + def destroy_status! + return if @status.destroyed? + + @status.update(published: false) + @status.destroy + end + + def replace_status!(new_status) + return if new_status.blank? + + destroy_status! + @status = new_status + end + + def normalize(text) + text.to_s.strip.downcase + end + + def to_integer(text) + text&.strip.to_i + end + + def unescape_literals(text) + ESCAPE_MAP.each { |escaped, unescaped| text.gsub!(escaped, unescaped) } + text + end + + def html_encode(text) + (@html_entities ||= HTMLEntities.new).encode(text) + end + + def var(name) + @vars[name].presence || [] + end + + def read_visibility_from(arg) + return if arg.strip.blank? + + arg = case arg.strip + when 'p', 'pu', 'all', 'world' + 'public' + when 'u', 'ul' + 'unlisted' + when 'f', 'follower', 'followers', 'packmates', 'follower-only', 'followers-only', 'packmates-only' + 'private' + when 'd', 'dm', 'pm', 'directmessage' + 'direct' + when 'default', 'reset' + @account.user.setting_default_privacy + when 'to', 'allow', 'allow-from', 'from' + 'cc' + when 'm', 'l', 'mp', 'monsterpit', 'local' + 'community' + else + arg.strip + end + + %w(public unlisted private limited direct cc community).include?(arg) ? arg : nil + end + + def read_falsy_from(arg) + %w(f n false no off disable).include?(arg) + end + + def read_truthy_from(arg) + %w(t y true yes on enable).include?(arg) + end + + def read_boolean_from(arg) + arg.present? && (read_truthy_from(arg) || !read_falsy_from(arg)) + end + + def normalize_domain(domain) + return if domain&.strip.blank? || !domain.include?('.') + + domain.split('.').map(&:strip).reject(&:blank?).join('.').downcase + end + + def federating_with_domain?(domain) + return false if domain.blank? + + DomainAllow.where(domain: domain).exists? || Account.where(domain: domain, suspended_at: nil).exists? + end +end |