up

#!/usr/bin/env ruby
#
# Usage: up
#
# Move back up to the project root.
#
# Up has a heuristic to detect the project root.
#
# If no project root is found it stays in the current directory
# If the current directory is already a project root it will try to find
# a parent project

require 'find'
require 'pathname'
require 'uri'

def abort(*)
  puts Dir.pwd
  super
end

case ARGV.shift
when "-h", "--help"
  puts "up is not installed"
  puts

  abort "Usage: eval \"$(up --setup)\""
when "--setup"
  puts <<-SH
up() {
  _up_dir=$(command up "$@")
  if [ $? = 0 ]; then
    [ "$_up_dir" != "$PWD" ] && cd "$_up_dir"
  fi
}
  SH
  exit
end

HOME = Pathname.new(ENV['HOME']) if ENV['HOME']
PWD = ENV['PWD'] ? Pathname.new(ENV['PWD']) : Pathname.pwd

def project_root?(dir)
  (dir + '.git').directory? ||
    (dir + '.hg').directory? ||
    (dir + '.envrc').file? ||
    (dir + 'Gemfile').file? ||
    (dir.to_s == ENV['DIRENV_DIR'].to_s[1..-1]) ||
    false
end

def should_stop?(dir)
  dir.root? || dir == HOME
end

def find_project_root
  dir = PWD

  # Search parent projects if already in a
  # sub-project
  dir = dir.parent if project_root?(dir)

  while !should_stop?(dir)
    return dir if project_root?(dir)
    dir = dir.parent
  end

  PWD
end

puts find_project_root