require 'pathname'

module Gemgem
  class << self
    attr_accessor :dir, :spec
  end

  module_function
  def all_files
    @all_files ||= find_files(Pathname.new(dir)).map{ |file|
      if file.to_s =~ %r{\.git/|\.git$}
        nil
      else
        file.to_s
      end
    }.compact.sort
  end

  def ignored_files
    @ignored_file ||= all_files.select{ |path| ignore_patterns.find{ |ignore|
      path =~ ignore && !git_files.include?(path)}}
  end

  def git_files
    @git_files ||= if File.exist?("#{dir}/.git")
                     `git ls-files`.split("\n")
                   else
                     []
                   end
  end

  # protected
  def find_files path
    path.children.select(&:file?).map{|file| file.to_s[(dir.size+1)..-1]} +
    path.children.select(&:directory?).map{|dir| find_files(dir)}.flatten
  end

  def ignore_patterns
    @ignore_files ||= expand_patterns(
      gitignore.split("\n").reject{ |pattern|
        pattern.strip == ''
      }).map{ |pattern| %r{^([^/]+/)*?#{Regexp.escape(pattern)}(/[^/]+)*?$} }
  end

  def expand_patterns pathes
    pathes.map{ |path|
      if path !~ /\*/
        path
      else
        expand_patterns(
          Dir[path] +
          Pathname.new(File.dirname(path)).children.select(&:directory?).
            map{ |prefix| "#{prefix}/#{File.basename(path)}" })
      end
    }.flatten
  end

  def gitignore
    if File.exist?(path = "#{dir}/.gitignore")
      File.read(path)
    else
      ''
    end
  end
end

desc 'Remove ignored files'
task :clean do
  trash = "~/.Trash/#{File.basename(Dir.pwd)}"
  sh "mkdir -p #{trash}" unless File.exist?(File.expand_path(trash))
  Gemgem.ignored_files.each{ |file| sh "mv #{file} #{trash}" }
end

task :default do
  puts `#{Gem.ruby} -S #{$PROGRAM_NAME} -T`
end

Gemgem.dir = File.dirname(__FILE__)