# -*- mode: ruby; coding: utf-8 -*-
 
require 'hpricot'
require 'open-uri'
 
=begin
 
required configuration
 
set :package, {
  :name     => 'PACKAGE',
  # $1 is used to specify the version number
  :filename => /PACKAGE-(.*)\.tgz/,
  :uri      => 'http://example.com/path/to/yourpackage/'
}
 
=end
 
desc "force upgrade to latest version"
task :upgrade do
  package = UribasePackage.new( fetch( :package ) )
  if ( !package.installed? or package.current != package.latest )
    puts package.upgrade
  else
    puts 'no need to do.'
  end
end
 
desc "downgrade to previous version"
task :downgrade do
  package = UribasePackage.new( fetch( :package ) )
  if ( !package.installed? )
    puts "install first"
  elsif ( package.current == package.initial )
    puts "no need to do."
  else
    puts package.downgrade
  end
end
 
desc "install latest version"
task :install do
  package = UribasePackage.new( fetch( :package ) )
  if ( package.installed? )
    puts "no need to do."
  else
    puts package.install
  end
end
 
desc "list up Package packages"
task :list do
  puts UribasePackage.new( fetch( :package ) ).collect.join( "\n" )
end
 
desc "check current installed version"
task "check-current" do
  package = UribasePackage.new( fetch( :package ) )
  if ( package.installed? )
    puts package.current
  else
    puts "install first"
  end
end
 
desc "check latest version"
task "check-latest" do
  puts UribasePackage.new( fetch( :package ) ).latest
end
 
desc "uninstall Package"
task :uninstall do
  package = UribasePackage.new( fetch( :package ) )
  if ( package.installed? )
    package.uninstall
  else
    puts "no need to do."
  end
end
 
class UribasePackage
  APACHE_OPTION = 'C=N;O=A;V=1;F=0'
 
  def initialize( opt = {} )
    @base_uri    ||= opt[:uri]
    @filename_re ||= opt[:filename]
    @name        ||= opt[:name]
    @filelist    = nil
    @current     = nil
  end
 
  def collect
    if ( @filelist.nil? )
      u = URI.parse( @base_uri )
      u.query = "?#{APACHE_OPTION}"
      d = Hpricot( u.read )
      @filelist = d.search( 'a' ).map { |e|
        m = e.get_attribute( 'href' ).match( @filename_re )
        ( m.nil? ) ? nil : m.to_s
      }.compact
    end
 
    return @filelist
  end
 
  def current
    if ( @current.nil? )
      @current = pear_message.to_s.split( /\s+/ )[1] if installed?
    end
 
    return @current
  end
 
  def latest
    version( collect.last )
  end
 
  def initial
    version( collect.first )
  end
 
  def absolute_uri( package )
    return @base_uri + package
  end
 
  def installed?
    return ( pear_message.size > 0 ) ? true : nil
  end
 
  def pear_message
    StringIO.new( `pear list -c __uri` ).entries.grep( /\b#{@name}\b/ )
  end
 
  def version( filename )
    filename.match( @filename_re )[1]
  end
 
  def uri( filename )
    return @base_uri + filename
  end
 
  def install
    return `sudo pear install #{uri( latest_filename )}#`
  end
 
  def upgrade
    return `sudo pear upgrade #{uri( latest_filename )}`
  end
 
  def downgrade
    if ( prev_filename )
      return `sudo pear upgrade --force #{uri( prev_filename )}`
    end
  end
 
  def uninstall
    return `sudo pear uninstall __uri/#{@name}`
  end
 
  def prev_filename
    index = current_index
 
    return ( index == 0 ) ? nil : collect[index - 1]
  end
 
  def next_filename
    index = current_index
 
    return ( index == collect.size - 1 ) ? nil : collect[index + 1]
  end
 
  def latest_filename
    return collect.last
  end
 
  def current_index
    current_file = collect.map { |e|
      e.include?( current ) ? e : nil
    }.compact.to_s
 
    return collect.index( current_file )
  end
end