module Pluginscan
  # Responsible for checking a string against set of rexgexps and returning all matches
  class Check
    attr_reader :name, :message, :patterns, :ignores

    def initialize(check_hash)
      @name     = check_hash[:name]
      @message  = check_hash[:message]
      @patterns = Array(check_hash[:patterns])
      @ignores  = Array(check_hash[:ignores]).map do |ignore_thing|
        IgnoreThing.new(ignore_thing)
      end
    end

    def run(content)
      pattern_matches(content).map{ |matchdata| match(matchdata) }
    end

    def ignore?(_match, content)
      # `match` is not used in the default case, but is included
      # so that classes inheriting from this one can use it when deciding
      # whether or not to ignore content by overriding this function
      ignores.any? { |ignore_thing| ignore_thing.ignore?(content) }
    end

  private

    def pattern_matches(content)
      @patterns.map { |pattern| content.match(pattern) }.compact
    end

    IgnoreThing = Struct.new(:ignore_thing) do
      def ignore?(content)
        case ignore_thing
        when Regexp
          content.match(ignore_thing)
        when Proc
          ignore_thing.call(content)
        end
      end
    end

    def match(matchdata)
      # Select the string we were interested in from the matchdata
      matchdata.to_a.last
      # This will return what we want assuming that we have either:
      # a single item from a simple regex:
      #   #<MatchData "$_POST">.to_a
      #    => ["$_POST"]
      # a whole match and a specific match, from a function_list item:
      #   #<MatchData "@unlink(" 1:"unlink">.to_a
      #   => ["@unlink(", "unlink"]
    end
  end
end