class Dit

# File lib/dit.rb, line 182
def self.clean_home
  Dir.chdir(Dir.home) do
    existing_dotfiles = Dir.glob('.*')
    existing_dotfiles.each do |f|
      next if f == '.' || f == '..'
      if File.symlink?(f)
        f_abs = File.readlink(f)
        File.delete(f) unless File.exist?(f_abs)
      end
    end
  end
end

# File lib/dit.rb, line 123
def self.detect_hook(hook)
  return [false, false] unless File.exist?(hook)

  cannot_hook, append_to_hook = false

  if `cat #{hook}`.include?('./.git/hooks/dit')
    puts 'Dit hook already installed.'
    cannot_hook = true
  elsif `cat #{hook}`.include?('#!/usr/bin/env bash')
    puts "You have #{hook} hooks already that use bash, so we'll " \
      'append ourselves to the file.'
    append_to_hook = true
  else
    puts "You have #{hook} hooks that use some foreign language, " \
      "so we won't interfere, but we can't hook in there."
    cannot_hook = true
  end

  [append_to_hook, cannot_hook]
end

# File lib/dit.rb, line 28
def self.exit_if_windows
  if OS.windows?
    puts 'This is a windows system, and dit does not support windows.'
    puts 'See vulpino/dit issue #1 if you have a potential solution.'
    exit 1
  end
end

# File lib/dit.rb, line 71
def self.get_roots(list)
  root_list = Set[]
  list.each do |f|
    f.strip!
    root = f.split('/')[0]
    root ||= f
    root_list |= Set[root]
  end
  root_list.delete?('')
  %w(.gitignore README.md README).each { |i| root_list.delete(i) }
  root_list 
end

# File lib/dit.rb, line 44
def self.hook
  Dir.chdir(File.join('.git', 'hooks')) do
    # The following check for the existence of post-commit or post-merge hooks
    # and will not interfere with them if they exist and do not use bash.
    append_to_post_commit, cannot_post_commit = detect_hook 'post-commit'
    append_to_post_merge, cannot_post_merge = detect_hook 'post-merge'

    write_hook('post-commit', append_to_post_commit) unless cannot_post_commit
    write_hook('post-merge', append_to_post_merge) unless cannot_post_merge

    make_dit
    make_ruby_enforcer

    # Make sure they're executable
    FileUtils.chmod '+x', %w(post-commit post-merge dit force-ruby)
  end
end

# File lib/dit.rb, line 13
def self.init
  exit_if_windows

  if Dir.exist?('.git')
    symlink_all if prompt_for_symlink_all
  else
    Git.init(Dir.getwd)
    puts "Initialized empty Git repository in #{File.join(Dir.getwd, '.git')}"
  end

  hook

  puts 'Dit was successfully hooked into .git/hooks.'
end

# File lib/dit.rb, line 151
def self.make_dit
  File.open('dit', 'a') do |f|
    f.puts '#!/usr/bin/env ./.git/hooks/force-ruby'
    f.puts "require 'dit'"
    f.puts 'Dit.symlink_unlinked'
  end
end

# File lib/dit.rb, line 159
def self.make_ruby_enforcer
  # The following lines are because git hooks do this weird thing
  # where they prepend /usr/bin to the path and a bunch of other stuff
  # meaning git hooks will use /usr/bin/ruby instead of any ruby
  # from rbenv or rvm or chruby, so we make a script forcing the hook
  # to use our ruby
  ruby_path = `which ruby`
  if ruby_path != '/usr/bin/ruby'
    ruby_folder = File.dirname(ruby_path)
    File.open('force-ruby', 'a') do |f|
      f.puts '#!/usr/bin/env bash'
      f.puts 'set -e'
      f.puts 'PATH=#{ruby_folder}:$PATH'
      f.puts "exec ruby \"$@\""
    end
  else
    File.open('force-ruby', 'a') do |f|
      f.puts '#!/usr/bin/env bash'
      f.puts "exec ruby \"$@\""
    end
  end
end

# File lib/dit.rb, line 103
def self.prompt_for_overwrite(a, b)
  return false if @never
  (FileUtils.rm(b); return true) if @always # just this once;
  puts "#{b} conflicts with #{a}. Remove #{b}? [y/n/a/s]"
  puts "To always overwrite, type \"A\". To never overwrite, type \"S\""
  response = STDIN.gets.upcase
  case response
  when 'Y'
    FileUtils.rm(b)
    return true
  when 'A'
    @always = true
    FileUtils.rm(b)
    return true
  when 'S'
    @never = true
  end
  false
end

# File lib/dit.rb, line 36
def self.prompt_for_symlink_all
  puts 'Dit has detected an existing git repo, and will initialize it to ' \
    'populate your ~ directory with symlinks.'
  puts 'Please confirm this by typing y, or anything else to cancel.'
  response = STDIN.gets.chomp.upcase
  response == 'Y'
end

# File lib/dit.rb, line 93
def self.symlink(a, b)
  if File.exist?(b)
    return if File.symlink?(b) && File.readlink(b).include?(Dir.getwd)
    return unless prompt_for_overwrite a, b
  end
  File.symlink(a, b)
rescue
  puts "Failed to symlink #{a} to #{b}"
end

# File lib/dit.rb, line 88
def self.symlink_all
  current_branch = `git rev-parse --abbrev-ref HEAD`.chomp
  symlink_list `git ls-tree -r #{current_branch} --name-only`.split("\n")
end

# File lib/dit.rb, line 62
def self.symlink_list(list)
  list = get_roots list
  list.each do |f|
    wd_f = File.expand_path f
    home_f = File.expand_path(f).gsub(Dir.getwd, Dir.home)
    symlink wd_f, home_f
  end
end

# File lib/dit.rb, line 84
def self.symlink_unlinked
  symlink_list `git show --pretty="format:" --name-only HEAD`.split("\n")
end

# File lib/dit.rb, line 195
def self.version
  '0.4'
end

# File lib/dit.rb, line 144
def self.write_hook(hook_file, do_append)
  File.open(hook_file, 'a') do |f|
    f.puts '#!/usr/bin/env bash' unless do_append
    f.puts '( exec ./.git/hooks/dit )'
  end
end