effuse

#!/usr/bin/env ruby

require 'optparse'
require 'ostruct'
require 'fileutils'

options = OpenStruct.new(:verbose   => false,
                         :clean     => false,
                         :noconfirm => nil,
                         :backup    => true,
                         :prefix    => '',
                         :exclude   => %w[.effuseignore .git .gitignore .gitmodules *~ .*~ .*.swp])

if File.exist?('.effuseignore')
  File.open('.effuseignore').lines.each do |line| # Ruby 1.8 (.each)
    options.exclude << line.chomp
  end
end

OptionParser.new do |o|
  o.banner = 'Usage: effuse [OPTION...] [DEST]'

  o.on('-c', '--clean', 'Remove symlinks') do
    options.clean = true
  end

  o.separator ''

  o.on('-e', '--exclude GLOB', 'Exclude GLOB from symlinking') do |glob|
    options.exclude << glob
  end

  o.on('-i', '--include GLOB', 'Include GLOB in symlinking') do |glob|
    options.exclude.delete(glob)
  end

  o.separator ''

  o.on('-y', '--noconfirm CHOICE', 'Assume CHOICE on file conflicts') do |choice|
    options.noconfirm = choice.downcase[0].chr # Shakes fist at Ruby 1.8 (.chr)
  end

  o.on('-n', '--no-backup', 'Do not create backup files') do
    options.backup = false
  end

  o.separator ''

  o.on('-p', '--prefix PREFIX', 'Prefix relative paths with PREFIX') do |prefix|
    options.prefix = prefix
  end

  o.separator ''

  o.on('-v', '--verbose', 'Show verbose output') do
    options.verbose = true
  end

  o.on_tail("-h", "--help", "Show this message") do
    puts o
    exit
  end
end.parse!

dest_dir = ARGV[0] || ENV['HOME'] # Shakes fist at Ruby 1.8 (Dir.home)

if File.identical?(dest_dir, '.')
  puts 'error: destination directory is current directory'
  exit 1
end

files = {}
dirs = ['.']

dirs.each do |dir|
  puts "scanning #{dir}" if options.verbose
  Dir.foreach(dir) do |file|
    next if ['.', '..'].include?(file)

    if options.exclude.any? {|e| File.fnmatch(e, file)}
      puts "excluding #{File.join(dir, file)}" if options.verbose
      next
    end

    file = File.join(dir, file)

    if File.directory?(file)
      dirs << file
      puts "adding #{file}" if options.verbose
      next
    end

    puts "found #{file}" if options.verbose
    relpath = file.split('/')[1..-1]
    dest = File.join([dest_dir, options.prefix + relpath[0]] + relpath[1..-1])
    files[File.expand_path(file)] = dest # Shakes fist at Ruby 1.8 (File.absolute_path)
  end
end

if options.clean
  files.each_pair do |src, dest|
    if File.exist?(dest) && File.identical?(src, dest)
      puts dest
      File.delete(dest)
    else
      puts "not symlinked #{dest}" if options.verbose
    end
  end
else
  files.each_pair do |src, dest|
    if File.exist?(dest)
      if File.identical?(src, dest)
        puts "already symlinked #{dest}" if options.verbose
        next
      else
        if options.noconfirm
          input = options.noconfirm
          puts "assuming '#{input}' for #{dest}" if options.verbose
        else
          puts "File already exists: #{dest}"
          puts " [R] Backup and replace"
          puts " [i] Import original file and symlink"
          puts " [k] Keep original file"

          loop do
            input = gets.chomp.downcase[0].chr || 'r' # Shakes fist at Ruby 1.8 (.chr)
            break if 'rik'.include?(input)
            puts "Error: '#{input}' is not an option"
          end
        end

        case input
        when 'r'
          if options.backup
            puts "renaming #{dest} -> #{dest + '~'}" if options.verbose
            File.rename(dest, dest + '~')
          end
        when 'i'
          if options.backup
            puts "renaming #{src} -> #{src + '~'}" if options.verbose
            File.rename(src, src + '~')
          end
          puts "renaming #{dest} -> #{src}" if options.verbose
          File.rename(dest, src)
        when 'k'
          puts "skipping #{dest}" if options.verbose
          next
        end
      end
    end

    puts "#{dest} -> #{src}"
    FileUtils.mkdir_p(File.dirname(dest))
    File.symlink(src, dest)
  end
end