path: root/app/lib/bangtags.rb

# frozen_string_literal: true

class Bangtags
  attr_reader :status, :account

  def initialize(status)
    @status        = status
    @account       = status.account
    @parent_status = Status.find(status.in_reply_to_id) if status.reply?

    @prefix_ns = {
      'permalink' => ['link'],
      'cloudroot' => ['link'],
      'blogroot' => ['link'],
    }

    @aliases = {
      ['media', 'end'] => ['var', 'end'],
      ['media', 'stop'] => ['var', 'end'],
      ['media', 'endall'] => ['var', 'endall'],
      ['media', 'stopall'] => ['var', 'endall'],
    }

    # sections of the final status text
    @chunks = []
    # list of transformation commands
    @tf_cmds = []
    # list of post-processing commands
    @post_cmds = [['signature']]
    # hash of bangtag variables
    @vars = account.vars
    # keep track of what variables we're appending the value of between chunks
    @vore_stack = []
    # keep track of what type of nested components are active so we can !end them in order
    @component_stack = []
  end

  def process
    return unless status.text&.present?

    status.text.gsub!('#!!', "#\u200c!")

    status.text.split(/(#!(?:.*:!#|{.*?}|[^\s#]+))/).each do |chunk|
      if chunk.starts_with?("#!")
        chunk.sub!(/(\\:)?+:+?!#\Z/, '\1')
        chunk.sub!(/{(.*)}\Z/, '\1')

        if @vore_stack.last != '_comment'
          cmd = chunk[2..-1].strip
          next if cmd.blank?
          cmd = cmd.split(':::')
          cmd = cmd[0].split('::') + cmd[1..-1]
          cmd = cmd[0].split(':') + cmd[1..-1]

          cmd.map! {|c| c.gsub(/\\:/, ':').gsub(/\\\\:/, '\:')}

          prefix = @prefix_ns[cmd[0]]
          cmd = prefix + cmd unless prefix.nil?

          @aliases.each_key do |old_cmd|
            cmd = aliases[old_cmd] + cmd.drop(old_cmd.length) if cmd.take(old_cmd.length) == old_cmd
          end
        elsif chunk.in?(['#!comment:end', '#!comment:stop', '#!comment:endall', '#!comment:stopall'])
          @vore_stack.pop
          @component_stack.pop
          next
        else
          next
        end

        next if cmd[0].nil?
        case cmd[0].downcase
        when 'var'
          chunk = nil
          next if cmd[1].nil?
          case cmd[1].downcase
          when 'end', 'stop'
            @vore_stack.pop
            @component_stack.pop
          when 'endall', 'stopall'
            @vore_stack = []
            @component_stack.reject! {|c| c == :var}
          else
            var = cmd[1]
            next if var.nil? || var.starts_with?('_')
            new_value = cmd[2..-1]
            if new_value.blank?
              chunk = @vars[var]
            elsif new_value.length == 1 && new_value[0] == '-'
              @vore_stack.push(var)
              @component_stack.push(:var)
            else
              @vars[var] = new_value.join(':')
            end
          end
        when 'tf'
          chunk = nil
          next if cmd[1].nil?
          case cmd[1].downcase
          when 'end', 'stop'
            @tf_cmds.pop
            @component_stack.pop
          when 'endall', 'stopall'
            @tf_cmds = []
            @component_stack.reject! {|c| c == :tf}
          else
            @tf_cmds.push(cmd[1..-1])
            @component_stack.push(:tf)
          end
        when 'end', 'stop'
          chunk = nil
          case @component_stack.pop
          when :tf
            @tf_cmds.pop
          when :var, :hide
            @vore_stack.pop
          end
        when 'endall', 'stopall'
          chunk = nil
          @tf_cmds = []
          @vore_stack = []
          @component_stack = []
        when 'emojify'
          chunk = nil
          next if cmd[1].nil?
          src_img = nil
          shortcode = cmd[2]
          case cmd[1].downcase
          when 'avatar'
            src_img = status.account.avatar
          when 'parent'
            next unless cmd[3].present? && reply?
            shortcode = cmd[3]
            next if cmd[2].nil? || @parent_status.nil?
            case cmd[2].downcase
            when 'avatar'
              src_img = @parent_status.account.avatar
            end
          end

          next if src_img.nil? || shortcode.nil? || !shortcode.match?(/\A\w+\Z/)

          chunk = ":#{shortcode}:"
          emoji = CustomEmoji.find_or_initialize_by(shortcode: shortcode, domain: nil)
          if emoji.id.nil?
            emoji.image = src_img
            emoji.save
          end
        when 'emoji'
          next if cmd[1].nil?
          shortcode = cmd[1]
          domain = (cmd[2].blank? ? nil : cmd[2].downcase)
          chunk = ":#{shortcode}:"
          ours = CustomEmoji.find_or_initialize_by(shortcode: shortcode, domain: nil)
          if ours.id.nil?
            if domain.nil?
              theirs = CustomEmoji.find_by(shortcode: shortcode)
            else
              theirs = CustomEmoji.find_by(shortcode: shortcode, domain: domain)
            end
            unless theirs.nil?
              ours.image = theirs.image
              ours.save
            end
          end
        when 'char'
          chunk = nil
          charmap = {
            'zws' => "\u200b",
            'zwnj' => "\u200c",
            'zwj' => "\u200d",
            '\n' => "\n",
            '\r' => "\r",
            '\t' => "\t",
            '\T' => '    '
          }
          cmd[1..-1].each do |c|
            next if c.nil?
            if c.in?(charmap)
              @chunks << charmap[cmd[1]]
            elsif (/^\h{1,5}$/ =~ c) && c.to_i(16) > 0
              begin
                @chunks << [c.to_i(16)].pack('U*')
              rescue
                @chunks << '?'
              end
            end
          end
        when 'link'
          chunk = nil
          next if cmd[1].nil?
          case cmd[1].downcase
          when 'permalink', 'self'
            chunk = TagManager.instance.url_for(status)
          when 'cloudroot'
            chunk = "https://monsterpit.cloud/~/#{account.username}"
          when 'blogroot'
            chunk = "https://monsterpit.blog/~/#{account.username}"
          end
        when 'ping'
          mentions = []
          next if cmd[1].nil?
          case cmd[1].downcase
          when 'admins'
            mentions = User.admins.map { |u| "@#{u.account.username}" }
            mentions.sort!
          when 'mods'
            mentions = User.moderators.map { |u| "@#{u.account.username}" }
            mentions.sort!
          when 'staff'
            mentions = User.admins.map { |u| "@#{u.account.username}" }
            mentions += User.moderators.map { |u| "@#{u.account.username}" }
            mentions.uniq!
            mentions.sort!
          end
          chunk = mentions.join(' ')
        when 'tag'
          chunk = nil
          records = []
          valid_name = /^[[:word:]_\-]*[[:alpha:]_·\-][[:word:]_\-]*$/
          cmd[1..-1].select {|t| t.present? && valid_name.match?(t)}.uniq.each do |name|
            next if status.tags.where(name: name).exists?
            tag = Tag.where(name: name).first_or_create(name: name)
            status.tags << tag
            records << tag
            TrendingTags.record_use!(tag, account, status.created_at) if status.distributable?
          end
          if status.distributable?
            account.featured_tags.where(tag_id: records.map(&:id)).each do |featured_tag|
              featured_tag.increment(status.created_at)
            end
          end
        when 'thread'
          chunk = nil
          next if cmd[1].nil?
          case cmd[1].downcase
          when 'reall'
            if status.conversation_id.present?
              mention_ids = Status.where(conversation_id: status.conversation_id).flat_map { |s| s.mentions.pluck(:account_id) }
              mention_ids.uniq!
              mentions = Account.where(id: mention_ids).map { |a| "@#{a.username}" }
              chunk = mentions.join(' ')
            end
          when 'sharekey'
            next if cmd[2].nil?
            case cmd[2].downcase
            when 'revoke'
              if status.conversation_id.present?
                roars = Status.where(conversation_id: status.conversation_id, account_id: @account.id)
                roars.each do |roar|
                  if roar.sharekey.present?
                    roar.sharekey = nil
                    roar.save
                  end
                end
              end
            when 'sync', 'new'
              if status.conversation_id.present?
                roars = Status.where(conversation_id: status.conversation_id, account_id: @account.id)
                earliest_roar = roars.last # The results are in reverse-chronological order.
                if cmd[2] == 'new' || earlist_roar.sharekey.blank?
                  sharekey = SecureRandom.urlsafe_base64(32)
                  earliest_roar.sharekey = sharekey
                  earliest_roar.save
                else
                  sharekey = earliest_roar.sharekey
                end
                roars.each do |roar|
                  if roar.sharekey != sharekey
                    roar.sharekey = sharekey
                    roar.save
                  end
                end
              else
                status.sharekey = SecureRandom.urlsafe_base64(32)
                status.save
              end
            end
          end
        when 'parent'
          chunk = nil
          next if cmd[1].nil? || @parent_status.nil?
          case cmd[1].downcase
          when 'permalink'
            chunk = TagManager.instance.url_for(@parent_status)
          end
        when 'media'
          chunk = nil

          media_idx = cmd[1]
          media_cmd = cmd[2]
          media_args = cmd[3..-1]

          next unless media_cmd.present? && media_idx.present? && media_idx.scan(/\D/).empty?
          media_idx = media_idx.to_i
          next if status.media_attachments[media_idx-1].nil?

          case media_cmd.downcase
          when 'desc'
            if media_args.present?
              @vars["media_#{media_idx}_desc"] = media_args.join(':')
            else
              @vore_stack.push("media_#{media_idx}_desc")
              @component_stack.push(:var)
            end
          end

          @post_cmds.push(['media', media_idx, media_cmd])
        when 'bangtag'
          chunk = chunk.sub('bangtag:', '').gsub(':', ":\u200c")
        when 'join'
          chunk = nil
          next if cmd[1].nil?
          charmap = {
            'zws' => "\u200b",
            'zwnj' => "\u200c",
            'zwj' => "\u200d",
            '\n' => "\n",
            '\r' => "\r",
            '\t' => "\t",
            '\T' => '    '
          }
          sep = charmap[cmd[1]]
          chunk = cmd[2..-1].join(sep.nil? ? cmd[1] : sep)
        when 'hide'
          chunk = nil
          next if cmd[1].nil?
          case cmd[1].downcase
          when 'end', 'stop', 'endall', 'stopall'
            @vore_stack.reject! {|v| v == '_'}
            @compontent_stack.reject! {|c| c == :hide}
          else
            if cmd[1].nil? && !'_'.in?(@vore_stack)
              @vore_stack.push('_')
              @component_stack.push(:hide)
            end
          end
        when 'comment'
          chunk = nil
          if cmd[1].nil?
            @vore_stack.push('_comment')
            @component_stack.push(:var)
          end
        when 'i', 'we'
          chunk = nil
          next if cmd[1].nil?
          case cmd[1].downcase
          when 'am', 'are'
            who = cmd[2]
            if who.blank?
              @vars.delete('_they:are')
              next
            elsif who == 'not'
              who = cmd[3]
              next if who.blank?
              name = who.downcase.gsub(/\s+/, '')
              @vars.delete("_they:are:#{name}")
              @vars.delete('_they:are') if @vars['_they:are'] == name
              next
            end
            name = who.downcase.gsub(/\s+/, '')
            description = cmd[3..-1].join(':').strip
            if description.blank?
              if @vars["_they:are:#{name}"].nil?
                @vars["_they:are:#{name}"] = who.strip
              end
            else
              @vars["_they:are:#{name}"] = description
            end
            @vars['_they:are'] = name.strip
          end
        when 'sharekey'
          next if cmd[1].nil?
          case cmd[1].downcase
          when 'new'
            chunk = nil
            status.sharekey = SecureRandom.urlsafe_base64(32)
            status.save
          end
        end
      end

      if chunk.present? && @tf_cmds.present?
        @tf_cmds.each do |tf_cmd|
          next if chunk.nil? || tf_cmd[0].nil?
          case tf_cmd[0].downcase
          when 'replace', 'sub', 's'
            tf_cmd[1..-1].in_groups_of(2) do |args|
              chunk.sub!(*args) if args.all?
            end
          when 'replaceall', 'gsub', 'gs'
            tf_cmd[1..-1].in_groups_of(2) do |args|
              chunk.gsub!(*args) if args.all?
            end
          end
        end
      end

      unless chunk.blank? || @vore_stack.empty?
        var = @vore_stack.last
        next if var == '_'
        if @vars[var].nil?
          @vars[var] = chunk.lstrip
        else
          @vars[var] += chunk.rstrip
        end
        chunk = nil
      end

      @chunks << chunk unless chunk.nil?
    end

    @vars.transform_values! {|v| v.rstrip}

    postprocess

    account.save

    status.text = @chunks.join('')
    status.save
  end

  private

  def postprocess
    @post_cmds.each do |post_cmd|
      case post_cmd[0]
      when 'signature'
        name = @vars['_they:are']
        next if name.blank?
        description = @vars["_they:are:#{name}"]
        next if description.blank? || @chunks.last(5).any? {|c| c.include?('—')}
        status.local_only = true if Status::LOCAL_ONLY_TOKENS.match?(@chunks.last)
        @chunks << "\n\n[right]— #{description}\u200c[/right]"
      when 'media'
        media_idx = post_cmd[1]
        media_cmd = post_cmd[2]
        media_args = post_cmd[3..-1]

        case media_cmd
        when 'desc'
          status.media_attachments[media_idx-1].description = @vars["media_#{media_idx}_desc"]
          status.media_attachments[media_idx-1].save
        end
      end
    end
  end

end