# Original version from RubyGems, Copyright (c) 2007 Eric Hodel

require 'rbconfig'

# Platform class
#
class Platform

  # A pure-ruby gem that may use Gem::Specification#extensions to build
  # binary files.
  RUBY = 'ruby'

  # A platform-specific gem that is built for the packaging ruby's platform.
  # This will be replaced with Gem::Platform::local.
  CURRENT = 'current'

  @local      = nil
  @supported  = nil

  #
  attr_accessor :cpu

  #
  attr_accessor :os

  #
  attr_accessor :version

  ##RbConfig = Config unless defined? ::RbConfig

  ##DEPRECATED_CONSTS = [
  ##  :DARWIN,
  ##  :LINUX_586,
  ##  :MSWIN32,
  ##  :PPC_DARWIN,
  ##  :WIN32,
  ##  :X86_LINUX
  ##]

  # Array of supported platforms (ie. pure-Ruby and local platform).

  def self.supported
    @suported ||= [Platform::RUBY, Platform.local]
  end

  ##def self.const_missing(name) # TODO remove six months from 2007/12
  ##  if DEPRECATED_CONSTS.include? name then
  ##    raise NameError, "#{name} has been removed, use CURRENT instead"
  ##  else
  ##    super
  ##  end
  ##end

  #
  def self.local
    arch = Config::CONFIG['arch']
    arch = "#{arch}_60" if arch =~ /mswin32$/
    @local ||= new(arch)
  end

  #
  def self.match(platform)
    supported.any? do |local_platform|
      platform.nil? or local_platform == platform or
        (local_platform != Platform::RUBY and local_platform =~ platform)
    end
  end

  #
  def self.new(arch) # :nodoc:
    case arch
    when Platform::CURRENT then
      Platform.local
    when Platform::RUBY, nil, '' then
      Platform::RUBY
    else
      super
    end
  end

  #
  def initialize(arch)
    case arch
    when Array then
      @cpu, @os, @version = arch
    when String then
      arch = arch.split '-'

      if arch.length > 2 and arch.last !~ /\d/ then # reassemble x86-linux-gnu
        extra = arch.pop
        arch.last << "-#{extra}"
      end

      cpu = arch.shift

      @cpu = case cpu
             when /i\d86/ then 'x86'
             else cpu
             end

      if arch.length == 2 and arch.last =~ /^\d+$/ then # for command-line
        @os, @version = arch
        return
      end

      os, = arch
      @cpu, os = nil, cpu if os.nil? # legacy jruby

      @os, @version = case os
        when /aix(\d+)/ then             [ 'aix',       $1  ]
        when /cygwin/ then               [ 'cygwin',    nil ]
        when /darwin(\d+)?/ then         [ 'darwin',    $1  ]
        when /freebsd(\d+)/ then         [ 'freebsd',   $1  ]
        when /hpux(\d+)/ then            [ 'hpux',      $1  ]
        when /^java$/, /^jruby$/ then    [ 'java',      nil ]
        when /^java([\d.]*)/ then        [ 'java',      $1  ]
        when /linux/ then                [ 'linux',     $1  ]
        when /mingw32/ then              [ 'mingw32',   nil ]
        when /(mswin\d+)(\_(\d+))?/ then
          os, version = $1, $3
          @cpu = 'x86' if @cpu.nil? and os =~ /32$/
          [os, version]
        when /netbsdelf/ then            [ 'netbsdelf', nil ]
        when /openbsd(\d+\.\d+)/ then    [ 'openbsd',   $1  ]
        when /solaris(\d+\.\d+)/ then    [ 'solaris',   $1  ]
        # test
        when /^(\w+_platform)(\d+)/ then [ $1,          $2  ]
        else                             [ 'unknown',   nil ]
      end
    when Platform then
      @cpu = arch.cpu
      @os = arch.os
      @version = arch.version
    else
      raise ArgumentError, "invalid argument #{arch.inspect}"
    end
  end

  #
  def inspect
    "#<%s:0x%x @cpu=%p, @os=%p, @version=%p>" % [self.class, object_id, *to_a]
  end

  #
  def to_a
    [@cpu, @os, @version]
  end

  #
  def to_s
    to_a.compact.join '-'
  end

  #
  def ==(other)
    self.class === other and
      @cpu == other.cpu and @os == other.os and @version == other.version
  end

  #
  def ===(other)
    return nil unless Platform === other

    # cpu
    (@cpu == 'universal' or other.cpu == 'universal' or @cpu == other.cpu) and

    # os
    @os == other.os and

    # version
    (@version.nil? or other.version.nil? or @version == other.version)
  end

  #
  def =~(other)
    case other
    when Platform then # nop
    when String then
      # This data is from http://gems.rubyforge.org/gems/yaml on 19 Aug 2007
      other = case other
        when /^i686-darwin(\d)/ then     ['x86',       'darwin',  $1]
        when /^i\d86-linux/ then         ['x86',       'linux',   nil]
        when 'java', 'jruby' then        [nil,         'java',    nil]
        when /mswin32(\_(\d+))?/ then    ['x86',       'mswin32', $2]
        when 'powerpc-darwin' then       ['powerpc',   'darwin',  nil]
        when /powerpc-darwin(\d)/ then   ['powerpc',   'darwin',  $1]
        when /sparc-solaris2.8/ then     ['sparc',     'solaris', '2.8']
        when /universal-darwin(\d)/ then ['universal', 'darwin',  $1]
        else                             other
      end

      other = Platform.new other
    else
      return nil
    end

    self === other
  end

  # Byte order of CPU.
  #
  # TODO: This doesn't work well apearently. We need to use a chart for possible
  # cpus instead, maybe.
  def byte_order
    if [0x12345678].pack("L") == "\x12\x34\x56\x78"
      BigEndian
    else
      LittleEndian
    end
  end

  #
  alias_method :byteorder, :byte_order

  #
  def little_endian?
    byte_order == :little
  end

  #
  def big_endian?
    byte_order == :big
  end

end