#--
# Ruby Whois
#
# An intelligent pure Ruby WHOIS client and parser.
#
# Copyright (c) 2009-2013 Simone Carletti <weppos@weppos.net>
#++


require 'whois/record/part'


module Whois

  class Record

    autoload :Parser, 'whois/record/parser'


    # @return [Whois::Server] The server that originated this record.
    attr_reader :server

    # @return [Array<Whois::Record::Part>] The parts that compose this record.
    attr_reader :parts


    # Initializes a new instance with given +server+ and +parts+.
    #
    # @param  [Whois::Server] server
    # @param  [Array<Whois::Record::Part>] parts
    #
    def initialize(server, parts)
      @parts  = parts
      @server = server
    end


    # Checks if this class respond to given method.
    #
    # Overrides the default implementation to add support
    # for {Parser::PROPERTIES} and {Parser::METHODS}.
    #
    # @return [Boolean]
    #
    def respond_to?(symbol, include_private = false)
      respond_to_parser_method?(symbol) || super
    end

    # Returns a String representation of this record.
    #
    # @return [String] The record content.
    #
    def to_s
      content.to_s
    end

    # Returns a human-readable representation of this record.
    #
    # @return [String] The result of {#inspect} on content.
    #
    def inspect
      content.inspect
    end

    # Returns true if the <tt>object</tt> is the same object,
    # or is a string and has the same content.
    #
    # @param  [Whois::Record] other The record to compare.
    # @return [Boolean]
    #
    def ==(other)
      if equal?(other)
        true
      elsif other.is_a?(self.class)
        to_s == other.to_s
      else
        false
      end
    end

    alias_method :eql?, :==


    # Invokes {#match} on record {#content}
    # and returns the match as <tt>MatchData</tt> or <tt>nil</tt>.
    #
    # @param  [Regexp, String] pattern The regex pattern to match.
    # @return [MatchData] If pattern matches #content
    # @return [nil] If pattern doesn't match #content
    #
    # @see String#match
    #
    def match(pattern)
      content.match(pattern)
    end

    # Invokes {#match} and returns <tt>true</tt> if <tt>pattern</tt>
    # matches {#content}, <tt>false</tt> otherwise.
    #
    # @param  [Regexp, String] pattern The regex pattern to match.
    # @return [Boolean]
    #
    # @see #match
    #
    def match?(pattern)
      !content.match(pattern).nil?
    end

    # Joins and returns all record parts into a single string
    # and separates each response with a newline character.
    #
    # @example Record with one part
    #   record = Whois::Record.new([Whois::Record::Part.new(:body => "First record.")])
    #   record.content
    #   # => "First record."
    #
    # @example Record with multiple parts
    #   record = Whois::Record.new([Whois::Record::Part.new(:body => "First record."), Whois::Record::Part.new(:body => "Second record.")])
    #   record.content
    #   # => "First record.\nSecond record."
    #
    # @return [String] The content of this record.
    #
    def content
      @content ||= parts.map(&:body).join("\n")
    end

    # Lazy-loads and returns the parser proxy for current record.
    #
    # @return [Whois::Record::Parser]
    #
    def parser
      @parser ||= Parser.new(self)
    end

    # Checks if the <tt>property</tt> passed as symbol
    # is supported in any of the parsers.
    #
    # @param  [Symbol] property The name of the property to check.
    # @return [Boolean]
    #
    # @see Whois::Record::Parser#property_any_supported?
    #
    def property_any_supported?(property)
      parser.property_any_supported?(property)
    end


    # @!group Properties

    # Returns a Hash containing all supported properties for this record
    # along with corresponding values.
    #
    # @return [{ Symbol => Object }]
    #
    def properties
      hash = {}
      Parser::PROPERTIES.each { |property| hash[property] = send(property) }
      hash
    end

    # @!endgroup


    # @!group Methods

    # Shortcut for <tt>#registrant_contacts.first</tt>.
    #
    # @return [Whois::Record::Contact]
    #         If the property is supported and a contact exists.
    # @return [nil]
    #         If the property is not supported or the contact doesn't exist.
    #
    # @see Whois::Record#registrant_contacts
    #
    def registrant_contact
      if property_any_supported?(:registrant_contacts)
        parser.registrant_contacts.first
      end
    end

    # Shortcut for <tt>#admin_contacts.first</tt>.
    #
    # @return [Whois::Record::Contact]
    #         If the property is supported and a contact exists.
    # @return [nil]
    #         If the property is not supported or the contact doesn't exist.
    #
    # @see Whois::Record#admin_contacts
    #
    def admin_contact
      if property_any_supported?(:admin_contacts)
        parser.admin_contacts.first
      end
    end

    # Shortcut for <tt>#technical_contacts.first</tt>.
    #
    # @return [Whois::Record::Contact]
    #         If the property is supported and a contact exists.
    # @return [nil]
    #         If the property is not supported or the contact doesn't exist.
    #
    # @see Whois::Record#technical_contacts
    #
    def technical_contact
      if property_any_supported(:technical_contacts)
        parser.technical_contacts.first
      end
    end

    # Collects and returns all the contacts.
    #
    # @return [Array<Whois::Record::Contact>]
    #
    # @see Whois::Record::Parser#contacts
    #
    def contacts
      parser.contacts
    end

    # @!endgroup


    # @!group Response

    # Checks whether this {Whois::Record} is different than +other+.
    #
    # Comparing the {Whois::Record} content is not as trivial as you may think.
    # WHOIS servers can inject into the WHOIS response strings that changes at every request,
    # such as the timestamp the request was generated or the number of requests left
    # for your current IP.
    #
    # These strings causes a simple equal comparison to fail even if
    # the registry data is the same.
    #
    # This method should provide a bulletproof way to detect whether this record
    # changed compared with +other+.
    #
    # @param  [Whois::Record] other The other record instance to compare.
    # @return [Boolean]
    #
    # @see Whois::Record::Parser#changed?
    #
    def changed?(other)
      !unchanged?(other)
    end

    # The opposite of {#changed?}.
    #
    # @param  [Whois::Record] other The other record instance to compare.
    # @return [Boolean]
    #
    # @see Whois::Record::Parser#unchanged?
    #
    def unchanged?(other)
      unless other.is_a?(self.class)
        raise(ArgumentError, "Can't compare `#{self.class}' with `#{other.class}'")
      end

      equal?(other) || parser.unchanged?(other.parser)
    end


    # Checks whether this is an incomplete response.
    #
    # @return [Boolean]
    #
    # @see Whois::Record::Parser#response_incomplete?
    #
    def response_incomplete?
      parser.response_incomplete?
    end

    # Checks whether this is a throttle response.
    #
    # @return [Boolean]
    #
    # @see Whois::Record::Parser#response_throttled?
    #
    def response_throttled?
      parser.response_throttled?
    end

    # Checks whether this is an unavailable response.
    #
    # @return [Boolean]
    #
    # @see Whois::Record::Parser#response_unavailable?
    #
    def response_unavailable?
      parser.response_unavailable?
    end

    # @!endgroup


    private

    # @api private
    def self.define_property_method(method)
      class_eval <<-RUBY, __FILE__, __LINE__ + 1
        def #{method}(*args, &block)
          if property_any_supported?(:#{method})
            parser.#{method}(*args, &block)
          end
        end
      RUBY
    end

    # @api private
    def self.define_method_method(method)
      class_eval <<-RUBY, __FILE__, __LINE__ + 1
        def #{method}(*args, &block)
          if parser.respond_to?(:#{method})
            parser.#{method}(*args, &block)
          end
        end
      RUBY
    end

    # @api private
    def self.define_question_method(method)
      class_eval <<-RUBY, __FILE__, __LINE__ + 1
        def #{method}?
          !#{method}.nil?
        end
      RUBY
    end

    def respond_to_parser_method?(symbol)
      name = symbol.to_s =~ /\?$/ ? symbol.to_s[0..-2] : symbol
      Parser::PROPERTIES.include?(name.to_sym) || Parser::METHODS.include?(name.to_sym)
    end

    # Delegates all method calls to the internal parser.
    def method_missing(method, *args, &block)
      if Parser::PROPERTIES.include?(method)
        self.class.define_property_method(method)
        send(method, *args, &block)
      elsif Parser::METHODS.include?(method)
        self.class.define_method_method(method)
        send(method, *args, &block)
      elsif method.to_s =~ /([a-z_]+)\?/ and (Parser::PROPERTIES + Parser::METHODS).include?($1.to_sym)
        self.class.define_question_method($1)
        send(method)
      else
        super
      end
    end

  end

end