class Gem::Platform

def self.installable?(spec)
  if spec.respond_to? :installable_platform?
    spec.installable_platform?
  else
    match_spec? spec
  end
end

def self.local
  arch = RbConfig::CONFIG['arch']
  arch = "#{arch}_60" if arch =~ /mswin(?:32|64)$/
  @local ||= new(arch)
end

def self.match(platform)
  match_platforms?(platform, Gem.platforms)
end

def self.match_gem?(platform, gem_name)
  # Note: this method might be redefined by Ruby implementations to
  # customize behavior per RUBY_ENGINE, gem_name or other criteria.
  match_platforms?(platform, Gem.platforms)
end

def self.match_platforms?(platform, platforms)
  platforms.any? do |local_platform|
    platform.nil? or
      local_platform == platform or
      (local_platform != Gem::Platform::RUBY and local_platform =~ platform)
  end
end

def self.match_spec?(spec)
  match_gem?(spec.platform, spec.name)
end

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

def ==(other)
  self.class === other and to_a == other.to_a
end

def ===(other)
  return nil unless Gem::Platform === other
  # cpu
  ([nil,'universal'].include?(@cpu) or [nil, 'universal'].include?(other.cpu) or @cpu == other.cpu or
  (@cpu == 'arm' and other.cpu.start_with?("arm"))) and
  # os
  @os == other.os and
  # version
  (@version.nil? or other.version.nil? or @version == other.version)
end

def =~(other)
  case other
  when Gem::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',  $1    ]
            when /^i\d86-linux/         then ['x86',       'linux',   nil   ]
            when 'java', 'jruby'        then [nil,         'java',    nil   ]
            when /^dalvik(\d+)?$/       then [nil,         'dalvik',  $1    ]
            when /dotnet(\-(\d+\.\d+))?/ then ['universal','dotnet',  $2    ]
            when /mswin32(\_(\d+))?/    then ['x86',       'mswin32', $2    ]
            when /mswin64(\_(\d+))?/    then ['x64',       'mswin64', $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 = Gem::Platform.new other
  else
    return nil
  end
  self === other
end

def hash # :nodoc:
  to_a.hash
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/ # 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+(\.\d+)?$/ # 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',    $1  ]
                    when /^macruby$/ then             [ 'macruby',   nil ]
                    when /freebsd(\d+)?/ then         [ 'freebsd',   $1  ]
                    when /hpux(\d+)?/ then            [ 'hpux',      $1  ]
                    when /^java$/, /^jruby$/ then     [ 'java',      nil ]
                    when /^java([\d.]*)/ then         [ 'java',      $1  ]
                    when /^dalvik(\d+)?$/ then        [ 'dalvik',    $1  ]
                    when /^dotnet$/ then              [ 'dotnet',    nil ]
                    when /^dotnet([\d.]*)/ then       [ 'dotnet',    $1  ]
                    when /linux-?((?!gnu)\w+)?/ 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 /bitrig(\d+\.\d+)?/ then     [ 'bitrig',    $1  ]
                    when /solaris(\d+\.\d+)?/ then    [ 'solaris',   $1  ]
                    # test
                    when /^(\w+_platform)(\d+)?/ then [ $1,          $2  ]
                    else                              [ 'unknown',   nil ]
                    end
  when Gem::Platform then
    @cpu = arch.cpu
    @os = arch.os
    @version = arch.version
  else
    raise ArgumentError, "invalid argument #{arch.inspect}"
  end
end

def inspect
  "%s @cpu=%p, @os=%p, @version=%p>" % [super[0..-2], *to_a]
end

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

def to_s
  to_a.compact.join '-'
end