import sys
 from pip.basecommand import Command
 
 BASE_COMPLETION = """
 # pip %(shell)s completion start%(script)s# pip %(shell)s completion end
 """
 
 COMPLETION_SCRIPTS = {
     'bash': """
 _pip_completion()
 {
     COMPREPLY=( $( COMP_WORDS="${COMP_WORDS[*]}" \\
                    COMP_CWORD=$COMP_CWORD \\
                    PIP_AUTO_COMPLETE=1 $1 ) )
 }
 complete -o default -F _pip_completion pip
 """, 'zsh': """
 function _pip_completion {
   local words cword
   read -Ac words
   read -cn cword
   reply=( $( COMP_WORDS="$words[*]" \\
              COMP_CWORD=$(( cword-1 )) \\
              PIP_AUTO_COMPLETE=1 $words[1] ) )
 }
 compctl -K _pip_completion pip
 """}
 
 
 class CompletionCommand(Command):
     """A helper command to be used for command completion."""
     name = 'completion'
     summary = 'A helper command to be used for command completion'
     hidden = True
 
     def __init__(self, *args, **kw):
         super(CompletionCommand, self).__init__(*args, **kw)
         self.parser.add_option(
             '--bash', '-b',
             action='store_const',
             const='bash',
             dest='shell',
             help='Emit completion code for bash')
         self.parser.add_option(
             '--zsh', '-z',
             action='store_const',
             const='zsh',
             dest='shell',
             help='Emit completion code for zsh')
 
     def run(self, options, args):
         """Prints the completion code of the given shell"""
         shells = COMPLETION_SCRIPTS.keys()
         shell_options = ['--' + shell for shell in sorted(shells)]
         if options.shell in shells:
             script = COMPLETION_SCRIPTS.get(options.shell, '')
             print(BASE_COMPLETION % {'script': script, 'shell': options.shell})
         else:
             sys.stderr.write('ERROR: You must pass %s\n' % ' or '.join(shell_options))