class Utils::Editor

def activate
  edit_remote("stupid_trick#{rand}")
  sleep pause_duration
  edit_remote_send('<ESC>:bw<CR>')
end

def cmd(*parts)
  command = parts.inject([]) do |a, p|
    case
    when p == nil, p == []
      a
    when p.respond_to?(:to_ary)
      a.concat p.to_ary
    else
      a << p.to_s
    end
  end
  $DEBUG and warn command * ' '
  system(*command)
end

def edit(*filenames)
  if filenames.size == 1
    filename = filenames.first
    if m = file_linenumber?(filename)
      edit_file_linenumber(*m.captures)
    else
      edit_file(filename)
    end
  elsif !filenames.empty?
    edit_file(*filenames)
  end
end

def edit_file(*filenames)
  edit_remote_file(*filenames)
end

def edit_file_linenumber(filename, linenumber)
  if wait?
    edit_remote(filename)
    sleep pause_duration
    edit_remote_send("<ESC>:#{linenumber}<CR>")
    edit_remote_wait(filename)
  else
    edit_remote(filename)
    sleep pause_duration
    edit_remote_send("<ESC>:#{linenumber}<CR>")
  end
end

def edit_remote(*args)
  cmd(vim, '-g', '--servername', servername, '--remote', *args)
end

def edit_remote_file(*filenames)
  if wait?
    edit_remote_wait(*filenames)
  else
    edit_remote(*filenames)
  end
end

def edit_remote_send(*args)
  cmd(vim, '-g', '--servername', servername, '--remote-send', *args)
end

def edit_remote_wait(*args)
  cmd(vim, '-g', '--servername', servername, '--remote-wait', *args)
end

def ensure_running
  started? ? activate : start
  self
end

def file_linenumber?(filename)
  filename.match(/^\s*([^:]+):(\d+)/)
end

def fullscreen=(enabled)
  started? or start
  sleep pause_duration
  if enabled
    edit_remote_send '<ESC>:set fullscreen<CR>'
  else
    edit_remote_send '<ESC>:set nofullscreen<CR>'
  end
  activate
end

def initialize
  self.wait           = false
  self.pause_duration = 1
  self.servername     = "G#{ENV['USER'].upcase}"
  yield self if block_given?
end

def serverlist
  @serverlist ||= `#{vim} -g --serverlist`.split
end

def start
  cmd(vim, '-g', '--servername', servername)
end

def started?(name = servername)
  serverlist.member?(name)
end

def stop
  started? and edit_remote_send('<ESC>:qa<CR>')
end

def vim
  @vim ||= case `uname -s`
  when /\Adarwin/i
    if File.directory?('/Applications')
      '/Applications/MacVim.app/Contents/MacOS/Vim'
    else
      'gvim'
    end
  else
    'gvim'
  end
end