#  Copyright 2009 Max Howell and other contributors.
#
#  Redistribution and use in source and binary forms, with or without
#  modification, are permitted provided that the following conditions
#  are met:
#
#  1. Redistributions of source code must retain the above copyright
#     notice, this list of conditions and the following disclaimer.
#  2. Redistributions in binary form must reproduce the above copyright
#     notice, this list of conditions and the following disclaimer in the
#     documentation and/or other materials provided with the distribution.
#
#  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
#  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
#  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
#  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
#  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
#  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
#  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
#  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
#  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
#  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
class UsageError <RuntimeError; end
class FormulaUnspecifiedError <UsageError; end
class KegUnspecifiedError <UsageError; end

module HomebrewArgvExtension
  def named
    @named ||= reject{|arg| arg[0..0] == '-'}
  end
  def options
    select {|arg| arg[0..0] == '-'}
  end
  def formulae
    require 'formula'
    @formulae ||= downcased_unique_named.collect {|name| Formula.factory name}
    raise FormulaUnspecifiedError if @formulae.empty?
    @formulae
  end
  def kegs
    require 'keg'
    @kegs ||= downcased_unique_named.collect do |name|
      d=HOMEBREW_CELLAR+name
      dirs = d.children.select{ |pn| pn.directory? } rescue []
      raise "#{name} is not installed" if not d.directory? or dirs.length == 0
      raise "#{name} has multiple installed versions" if dirs.length > 1
      Keg.new dirs.first
    end
    raise KegUnspecifiedError if @kegs.empty?
    @kegs
  end

  # self documenting perhaps?
  def include? arg
    @n=index arg
  end
  def next
    at @n+1 or raise UsageError
  end

  def force?
    flag? '--force'
  end
  def verbose?
    flag? '--verbose' or ENV['HOMEBREW_VERBOSE']
  end
  def debug?
    flag? '--debug' or ENV['HOMEBREW_DEBUG']
  end
  def quieter?
    flag? '--quieter'
  end
  def interactive?
    flag? '--interactive'
  end

  def flag? flag
    options.each do |arg|
      return true if arg == flag
      next if arg[1..1] == '-'
      return true if arg.include? flag[2..2]
    end
    return false
  end

  def usage
    <<-EOS
Usage: brew command [formula] ...
Usage: brew [--prefix] [--cache] [--version|-v]
Usage: brew [--verbose|-v]

Commands:
  install formula ... [--ignore-dependencies] [--HEAD|-H]
  remove formula ...
  search [/regex/] [substring]
  list [--unbrewed] [formula] ...
  link formula ...
  unlink formula ...
  home formula ...
  info [formula] [--github]
  cleanup [formula]
  prune
  update

Commands useful when contributing:
  log formula
  create URL
  edit [formula]
  install formula [--debug|-d] [--interactive|-i] [--verbose|-v]

To visit the Homebrew homepage type:
  brew home
    EOS
  end

  private

  def downcased_unique_named
    @downcased_unique_named ||= named.collect{|arg| arg.downcase}.uniq
  end
end