module PushRoutes
  class PushRouteUrl
    attr_accessor :source
    #
    # if this push_route_url is a new route that needs to be registered
    # can be determined by if the input passed in was a string or not
    #
    attr_accessor :isNew

    def initialize(input)
      if (input.is_a?(ActionDispatch::Journey::Route))
        #Remove traiing format string
        @source = input.path.spec.to_s.gsub(/\(\.\:format\)\Z/, "")
        @isNew = false
      elsif input.is_a? String
        @source = input
        @isNew = true
      else
        raise ArgumentError.new("Unexpected input: #{input}")
      end
      #Parses out the required parameters for the route as a list of symbols
      @url_args = @source.scan(/\/\:([^\/]+)/).flatten.map { |e| e.to_sym }
    end


    #
    # Returns a true url from the original route with parameters filled in
    # If the route has no parameters this function simply returns the route, ignoring input
    # If the parameters are insufficient an ArgumentError is raised
    #
    # @param params [Hash] params
    #
    # @return [String] completed url
    def notification_string(params)
      if @url_args.count == 0
        @source
      else
        unless (params.is_a?(Hash))
          raise ArgumentError.new("Params for #{@source} must be a hash with: #{@url_args}")
        end
        built_string = @source
        @url_args.each do |e|
          if (params.include?(e))
            built_string = built_string.gsub(Regexp.new("\\:#{e}"), params[e].to_s)
          else
            raise ArgumentError.new("Missing param #{e}")
          end
        end
        built_string
      end
    end

    def to_s
      @source
    end

    #
    # returns true of url is a valid expression of the route represented
    # @param url [string] url to check
    #
    # @return [bool] true if url matches this route
    # TODO: testing on this function
    def matches(url)
      str = @source.gsub(/(?!\/)\:.*?(?=\/|$)/, "([^\/]+?)")
      str = "^" + str + "$"
      Regexp.new(str).match(url)
    end

    # Gets the parameter associations from a url if they are well formed, meaning, each
    # parameter is preceded by another token
    # @return [Hash] parameter_symbol => preceding symbol
    def param_associations
      @source.scan(/\/([^\/]*?)\/\:([^\/]+)/).map {|k,v| [v.to_sym,k]}.to_h
    end
  end
end