$:.unshift(File.dirname(__FILE__)) unless
  $:.include?(File.dirname(__FILE__)) || $:.include?(File.expand_path(File.dirname(__FILE__)))

module Hosts
  
  def self.search(pattern='')
    regex = Regexp.new(pattern)
    results = []
    addresses.each do |address, entries|
      if address =~ regex
        entries.each do |hostname, editable|
          results << [address, hostname, editable]
        end
      end
    end
    hostnames.each do |hostname, entries|
      if hostname =~ regex
        entries.each do |address, editable|
          results << [address, hostname, editable]
        end
      end
    end
    results.uniq.sort do |a,b|
      r = 0
      r = a[0] <=> b[0] if r == 0
      r = a[1] <=> b[1] if r == 0
      r
    end
  end
  
  def self.hostnames
    @hostnames ||= {}
  end
  
  def self.addresses
    @addresses ||= {}
  end
  
  def self.hostname(hostname)
    hostnames[hostname] ||= {}
  end
  
  def self.address(address)
    addresses[address] ||= {}
  end
  
  def self.editable?(hostname, address)
    return true if hostname(hostname).nil? or hostname(hostname)[address].nil?
    return hostname(hostname)[address]
  end
  
  def self.add(hostname, address, editable=true)
    if editable?(hostname, address)
      address(address)[hostname] = editable
      hostname(hostname)[address] = editable
    end
  end
  
  def self.remove(hostname, address)
    if editable?(hostname, address)
      hostname(hostname).delete(address)
      address(address).delete(hostname)
    end
  end
  
  def self.lines
    @lines ||= []
  end
  
  def self.read
    editable = false
    lines.clear
    File.readlines('/etc/hosts').collect{ |line| line.strip }.each do |line|
      lines << line unless editable
      editable = true if line == '### AUTOGENERATED HOST ENTRIES ###'
      next if line =~ /^\s+|#.*$/
      
      segements = line.split(/\s+/)
      address = segements.shift
      segements.each do |segement|
        add(segement, address, editable)
      end
    end
    lines << '### AUTOGENERATED HOST ENTRIES ###' unless editable
  end
  
  def self.write
    begin
      File.open('/etc/hosts', 'w+') do |f|
        lines.each { |l| f.puts l }
        addresses.each do |address, hostnames|
          editable_hostnames = []
          hostnames.each do |hostname, editable|
            editable_hostnames << hostname if editable
          end
          f.puts "#{address} #{editable_hostnames.join(' ')}" unless editable_hostnames.empty?
        end
      end
    rescue => e
      puts e
      exit(1)
    end
  end
  
end