class FilenameIncrement

# File lib/filename_increment.rb, line 13
def initialize(filepath, options = {})
  @options = options

  @platform = @options[:platform] || Gem::Platform.local.os
  @file = parse(filepath)
  @start = @options[:start] || 1

  @file = parse(filepath)

  if @start == 1 && (@platform == 'win32' || @platform == 'windows')
    @start += 1
  end

  if @options[:fs].is_a? TrueClass
    if File.exist?(filepath)
      name = @file[:name]
      dest = filepath

      while File.exist?(dest)
        @start += 1
        @file[:basename] = format(name, @start) + @file[:extname]

        dest = File.join(@file[:dirname], @file[:basename])
      end
    else
      # raise error if file not found
      raise FileNotFound.new('File not found')
    end
  else
    @file[:basename] = format(@file[:name], @start) + @file[:extname]
  end

  @path = Pathname.new(@file[:dirname]).join(@file[:basename])
end

# File lib/filename_increment.rb, line 48
def to_s
  @path.cleanpath.to_s
end

# File lib/filename_increment.rb, line 78
def format(stem, number)
  case @platform
  when 'win32', 'windows'
    number > 1 ? "#{stem} (#{number})" : stem
  when 'linux'
    if number == 0
      stem
    elsif number == 1
      "#{stem} (copy)"
    elsif number == 2
      "#{stem} (another copy)"
    else
      "#{stem} (#{to_ordinal(number)} copy)"
    end
  when 'darwin'
    if number == 1
      "#{stem} copy"
    elsif number > 1
      "#{stem} (#{stem} copy #{number})"
    end
  else
    number > 1 ? "#{stem} (#{number})" : stem
  end
end

# File lib/filename_increment.rb, line 66
def ordinal(number)
  raise TypeError.new('expected a number') unless number.is_a? Numeric

  ORDINALS[((number % 100) - 20) % 10] || ORDINALS[number % 100] || ORDINALS[0]
end

# File lib/filename_increment.rb, line 54
def parse(filepath)
  pathname = Pathname.new(filepath)

  path = {path: filepath}
  path[:dirname] = pathname.dirname
  path[:basename] = pathname.basename
  path[:name] = pathname.basename(pathname.extname)
  path[:extname] = pathname.extname

  path
end

# File lib/filename_increment.rb, line 72
def to_ordinal(number)
  raise TypeError.new('expected a number') unless number.is_a? Numeric

  "#{number}#{ordinal(number)}"
end