#--
# =============================================================================== 
# Copyright (c) 2005,2006,2007 Christopher Kleckner
# All rights reserved
#
# This file is part of the Rio library for ruby.
#
# Rio is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# Rio is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Rio; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
# =============================================================================== 
#++
#
# To create the documentation for Rio run the command
#  ruby build_doc.rb
# from the distribution directory.
#
# Suggested Reading
# * RIO::Doc::SYNOPSIS
# * RIO::Doc::INTRO
# * RIO::Doc::HOWTO
# * RIO::Doc::EXAMPLES
# * RIO::Rio
#


#
# = uri/file.rb
#
# Author:: Akira Yamada <kit_kleckner@yahoo.com>
# License:: You can redistribute it and/or modify it under the same term as Ruby.
#

require 'uri/generic'

module URI #:nodoc: all
  

  #
  # RFC1738 section 3.10.
  #
=begin
RFC 1738            Uniform Resource Locators (URL)        December 1994

3.10 FILES

   The file URL scheme is used to designate files accessible on a
   particular host computer. This scheme, unlike most other URL schemes,
   does not designate a resource that is universally accessible over the
   Internet.

   A file URL takes the form:

       file://<host>/<path>

   where <host> is the fully qualified domain name of the system on
   which the <path> is accessible, and <path> is a hierarchical
   directory path of the form <directory>/<directory>/.../<name>.

   For example, a VMS file

     DISK$USER:[MY.NOTES]NOTE123456.TXT

   might become

     <URL:file://vms.host.edu/disk$user/my/notes/note12345.txt>

   As a special case, <host> can be the string "localhost" or the empty
   string; this is interpreted as `the machine from which the URL is
   being interpreted'.

   The file URL scheme is unusual in that it does not specify an
   Internet protocol or access method for such files; as such, its
   utility in network protocols between hosts is limited.
=end

  module REGEXP
    module PATTERN
      DRIVE_SPEC = "[A-Za-z]:"
      FILE_ESCAPED = ESCAPED
      FILE_UNRESERVED = "-_.!~*'()#{ALNUM}"
      FILE_PCHAR = "(?:[#{FILE_UNRESERVED}:@?&=+$,]|#{FILE_ESCAPED})"

      # pchar         = unreserved | escaped |
      #                 ":" | "@" | "&" | "=" | "+" | "$" | ","
      PCHAR = "(?:[#{UNRESERVED}:@&=+$,]|#{ESCAPED})"
      # param         = *pchar
      PARAM = "#{PCHAR}*"
 
      FILE_SEGMENT = "#{FILE_PCHAR}*(?:;#{PARAM})*"
      FILE_PATH_SEGMENTS = "#{FILE_SEGMENT}(?:/#{FILE_SEGMENT})*"
      FILE_ABS_PATH = "(?:/#{DRIVE_SPEC})?/#{FILE_PATH_SEGMENTS}"

      FILE_REL_SEGMENT = "(?:[#{FILE_UNRESERVED};@?&=+$,]|#{FILE_ESCAPED})+"
      FILE_REL_PATH = "#{FILE_REL_SEGMENT}(?:#{FILE_ABS_PATH})?"

      #FILE_ABS_PATH = "(?:/#{DRIVE_SPEC})?/#{FILE_PATH_SEGMENTS}(?:\\?#{QUERY})?"
    end
    EMPTYHOST = Regexp.new("^$", false).freeze #"
    FILE_ABS_PATH = Regexp.new("^#{PATTERN::FILE_ABS_PATH}$", false).freeze
  end # module REGEXP

  class FILE < Generic
    #FILE_ABS_PATH = REGEXP::FILE_ABS_PATH
    COMPONENT = [
      :scheme, 
      :host,
      :path, 
    ].freeze 

    def check_host(v)
      return true if v && EMPTYHOST =~ v
      super
    end
    private :check_host

    def check_path(v)
      # raise if both hier and opaque are not nil, because:
      # absoluteURI   = scheme ":" ( hier_part | opaque_part )
      # hier_part     = ( net_path | abs_path ) [ "?" query ]
      #p "URI::FILE self=#{self} v=#{v}"
      if v && @opaque
        raise InvalidURIError, 
          "path conflicts with opaque"
      end

      if @scheme
        if v && v != '' && FILE_ABS_PATH !~ v
          raise InvalidComponentError, 
            "bad component(expected absolute path component): #{v}"
        end
      else
        if v && v != '' && FILE_ABS_PATH !~ v && FILE_REL_PATH !~ v
          raise InvalidComponentError, 
            "bad component(expected relative path component): #{v}"
        end
      end

      return true
    end
    private :check_path

    def path=(v)
      check_path(v)
      set_path(v)
      v
    end

    def normalize!
      super
      if host && host == 'localhost'
        set_host('')
      end
    end

    def file(*args)
      pth = self.path(*args)
      pth.chop! if pth[-1,1] == '/' && pth != '/'
      return pth
    end

    #
    # == Description
    #
    # Create a new URI::FILE object from components of URI::FILE with
    # check.  It is scheme, userinfo, host, port, path, query and
    # fragment. It provided by an Array of a Hash.
    #
    def self.build(args)
      #p "In build: "+args.inspect
      tmp = Util::make_components_hash(self, args)
      return super(tmp)
    end

    #
    # == Description
    #
    # Create a new URI::FILE object from ``generic'' components with no
    # check.
    #
    def initialize(*arg)
      super(*arg)
      self.host = '' if self.host.nil?
    end
  end

  @@schemes['FILE'] = FILE
end