# frozen-string-literal: true

#
class Roda
  module RodaPlugins
    # The _optimized_matching plugin is automatically used internally to speed
    # up matching when a single argument String instance, String class, Integer
    # class, or Regexp matcher is passed to +r.on+, +r.is_+, or a verb method
    # such as +r.get+ or +r.post+.
    # 
    # The optimization works by avoiding the +if_match+ method if possible.
    # Instead of clearing the captures array on every call, and having the
    # matching append to the captures, it checks directly for the match,
    # and on succesful match, it yields directly to the block without using
    # the captures array.
    module OptimizedMatching 
      TERM = Base::RequestMethods::TERM

      module RequestMethods
        # Optimize the r.is method handling of a single string, String, Integer,
        # regexp, or true, argument.
        def is(*args, &block)
          case args.length
          when 1
            _is1(args, &block)
          when 0
            always(&block) if @remaining_path.empty?
          else
            if_match(args << TERM, &block)
          end
        end

        # Optimize the r.on method handling of a single string, String, Integer,
        # or regexp argument.  Inline the related matching code to avoid the
        # need to modify @captures.
        def on(*args, &block)
          case args.length
          when 1
            case matcher = args[0]
            when String
              always{yield} if _match_string(matcher)
            when Class
              if matcher == String
                rp = @remaining_path
                if rp.getbyte(0) == 47
                  if last = rp.index('/', 1)
                    @remaining_path = rp[last, rp.length]
                    always{yield rp[1, last-1]}
                  elsif (len = rp.length) > 1
                    @remaining_path = ""
                    always{yield rp[1, len]}
                  end
                end
              elsif matcher == Integer
                if matchdata = /\A\/(\d+)(?=\/|\z)/.match(@remaining_path)
                  @remaining_path = matchdata.post_match
                  always{yield(matchdata[1].to_i)}
                end
              else
                path = @remaining_path
                captures = @captures.clear
                meth = :"_match_class_#{matcher}"
                if respond_to?(meth, true)
                  # Allow calling private methods, as match methods are generally private
                  if send(meth, &block)
                    block_result(yield(*captures))
                    throw :halt, response.finish
                  else
                    @remaining_path = path
                    false
                  end
                else
                  unsupported_matcher(matcher)
                end
              end
            when Regexp
              if matchdata = self.class.cached_matcher(matcher){matcher}.match(@remaining_path)
                @remaining_path = matchdata.post_match
                always{yield(*matchdata.captures)}
              end
            when true
              always(&block)
            when false, nil
              # nothing
            else
              path = @remaining_path
              captures = @captures.clear

              matched = case matcher
              when Array
                _match_array(matcher)
              when Hash
                _match_hash(matcher)
              when Symbol
                _match_symbol(matcher)
              when Proc
                matcher.call
              else
                unsupported_matcher(matcher)
              end

              if matched
                block_result(yield(*captures))
                throw :halt, response.finish
              else
                @remaining_path = path
                false
              end
            end
          when 0
            always(&block)
          else
            if_match(args, &block)
          end
        end

        private

        # Optimize the r.get/r.post method handling of a single string, String, Integer,
        # regexp, or true, argument.
        def _verb(args, &block)
          case args.length
          when 0
            always(&block)
          when 1
            _is1(args, &block)
          else
            if_match(args << TERM, &block)
          end
        end

        # Internals of r.is/r.get/r.post optimization.  Inline the related matching
        # code to avoid the need to modify @captures.
        def _is1(args, &block)
          case matcher = args[0]
          when String
            rp = @remaining_path
            if _match_string(matcher)
              if @remaining_path.empty?
                always{yield}
              else
                @remaining_path = rp
                nil
              end
            end
          when Class
            if matcher == String
              rp = @remaining_path
              if rp.getbyte(0) == 47 && !rp.index('/', 1) && (len = rp.length) > 1
                @remaining_path = ''
                always{yield rp[1, len]}
              end
            elsif matcher == Integer
              if matchdata = /\A\/(\d+)\z/.match(@remaining_path)
                @remaining_path = ''
                always{yield(matchdata[1].to_i)}
              end
            else
              path = @remaining_path
              captures = @captures.clear
              meth = :"_match_class_#{matcher}"
              if respond_to?(meth, true)
                # Allow calling private methods, as match methods are generally private
                if send(meth, &block) && @remaining_path.empty?
                  block_result(yield(*captures))
                  throw :halt, response.finish
                else
                  @remaining_path = path
                  false
                end
              else
                unsupported_matcher(matcher)
              end
            end
          when Regexp
            if (matchdata = self.class.cached_matcher(matcher){matcher}.match(@remaining_path)) && matchdata.post_match.empty?
              @remaining_path = ''
              always{yield(*matchdata.captures)}
            end
          when true
            always(&block) if @remaining_path.empty?
          when false, nil
            # nothing
          else
            path = @remaining_path
            captures = @captures.clear

            matched = case matcher
            when Array
              _match_array(matcher)
            when Hash
              _match_hash(matcher)
            when Symbol
              _match_symbol(matcher)
            when Proc
              matcher.call
            else
              unsupported_matcher(matcher)
            end

            if matched && @remaining_path.empty?
              block_result(yield(*captures))
              throw :halt, response.finish
            else
              @remaining_path = path
              false
            end
          end
        end
      end
    end

    register_plugin(:_optimized_matching, OptimizedMatching)
  end
end
