#
# $Id$
#
# Copyright (c) 2001 akira yamada <akira@ruby-lang.org>
# You can redistribute it and/or modify it under the same term as Ruby.
#

require 'uri/generic'

module URI

=begin

== URI::MailTo

=== Super Class

((<URI::Generic>))

=end

  # RFC2368, The mailto URL scheme
  class MailTo < Generic
    include REGEXP

    DEFAULT_PORT = nil

    COMPONENT = [
      :scheme,
      :to, :headers
    ].freeze

    #  "hname" and "hvalue" are encodings of an RFC 822 header name and
    #  value, respectively. As with "to", all URL reserved characters must
    #  be encoded.
    #
    #  "#mailbox" is as specified in RFC 822 [RFC822]. This means that it
    #  consists of zero or more comma-separated mail addresses, possibly
    #  including "phrase" and "comment" components. Note that all URL
    #  reserved characters in "to" must be encoded: in particular,
    #  parentheses, commas, and the percent sign ("%"), which commonly occur
    #  in the "mailbox" syntax.
    #
    #  Within mailto URLs, the characters "?", "=", "&" are reserved.

    # hname      =  *urlc
    # hvalue     =  *urlc
    # header     =  hname "=" hvalue
    HEADER_PATTERN = "(?:[^?=&]*=[^?=&]*)".freeze
    HEADER_REGEXP  = Regexp.new(HEADER_PATTERN, 'N').freeze
    # headers    =  "?" header *( "&" header )
    # to         =  #mailbox
    # mailtoURL  =  "mailto:" [ to ] [ headers ]
    MAILBOX_PATTERN = "(?:#{PATTERN::ESCAPED}|[^(),%?=&])".freeze
    MAILTO_REGEXP = Regexp.new("
      \\A
      (#{MAILBOX_PATTERN}*?)                          (?# 1: to)
      (?:
        \\?
        (#{HEADER_PATTERN}(?:\\&#{HEADER_PATTERN})*)  (?# 2: headers)
      )?
      \\z
    ", Regexp::EXTENDED, 'N').freeze

=begin

=== Class Methods

--- URI::MailTo::build
    Create a new URI::MailTo object from components of URI::MailTo
    with check.  It is to and headers. It provided by an Array of a
    Hash. You can provide headers as an String like
    "subject=subscribe&cc=addr" or an Array like [["subject",
    "subscribe"], ["cc", "addr"]]

--- URI::MailTo::new
    Create a new URI::MailTo object from ``generic'' components with
    no check. Because, this method is usually called from URI::parse
    and the method checks validity of each components.

=end

    def self.build(args)
      tmp = Util::make_components_hash(self, args)

      if tmp[:to]
	tmp[:opaque] = tmp[:to]
      else
	tmp[:opaque] = ''
      end

      if tmp[:headers]
	tmp[:opaque] << '?'

	if tmp[:headers].kind_of?(Array)
	  tmp[:opaque] << tmp[:headers].collect { |x|
	    if x.kind_of?(Array)
	      x[0] + '=' + x[1..-1].to_s
	    else
	      x.to_s
	    end
	  }.join('&')

	elsif tmp[:headers].kind_of?(Hash)
	  tmp[:opaque] << tmp[:headers].collect { |h,v|
	    h + '=' + v
	  }.join('&')

	else
	  tmp[:opaque] << tmp[:headers].to_s
	end
      end

      return super(tmp)
    end

    def initialize(*arg)
      super(*arg)

      @to = nil
      @headers = []

      if MAILTO_REGEXP =~ @opaque
 	if arg[-1]
	  self.to = $1
	  self.headers = $2
	else
	  set_to($1)
	  set_headers($2)
	end

      else
	raise InvalidComponentError,
	  "unrecognised opaque part for mailtoURL: #{@opaque}"
      end
    end
    attr_reader :to
    attr_reader :headers

=begin

=== Instance Methods

--- URI::MailTo#to

--- URI::MailTo#to=(v)

=end

    #
    # methods for to
    #

    def check_to(v)
      return true unless v
      return true if v.size == 0

      if OPAQUE !~ v || /\A#{MAILBOX_PATTERN}*\z/o !~ v
	raise InvalidComponentError,
	  "bad component(expected opaque component): #{v}"
      end

      return true
    end
    private :check_to

    def set_to(v)
      @to = v
    end
    protected :set_to

    def to=(v)
      check_to(v)
      set_to(v)
      v
    end

=begin

--- URI::MailTo#headers

--- URI::MailTo#headers=(v)

=end

    #
    # methods for headers
    #

    def check_headers(v)
      return true unless v
      return true if v.size == 0

      if OPAQUE !~ v || 
	  /\A(#{HEADER_PATTERN}(?:\&#{HEADER_PATTERN})*)\z/o !~ v
	raise InvalidComponentError,
	  "bad component(expected opaque component): #{v}"
      end

      return true
    end
    private :check_headers

    def set_headers(v)
      @headers = []
      if v
	v.scan(HEADER_REGEXP) do |x|
	  @headers << x.split(/=/o, 2)
	end
      end
    end
    protected :set_headers

    def headers=(v)
      check_headers(v)
      set_headers(v)
      v
    end

    def to_str
      @scheme + ':' + 
	if @to 
	  @to
	else
	  ''
	end + 
	if @headers.size > 0
	  '?' + @headers.collect{|x| x.join('=')}.join('&')
	else
	  ''
	end
    end

=begin

--- URI::MailTo#to_mailtext

=end
    def to_mailtext
      to = URI::unescape(@to)
      head = ''
      body = ''
      @headers.each do |x|
	case x[0]
	when 'body'
	  body = URI::unescape(x[1])
	when 'to'
	  to << ', ' + URI::unescape(x[1])
	else
	  head << URI::unescape(x[0]).capitalize + ': ' +
	    URI::unescape(x[1])  + "\n"
	end
      end

      return "To: #{to}
#{head}
#{body}
"
    end
    alias to_rfc822text to_mailtext
  end # MailTo

  @@schemes['MAILTO'] = MailTo
end # URI