class Autostyle

# File lib/autostyle.rb, line 5
def self.[](hash)
  self.new.tap{ |a| hash.each{ |k, v| a[k] = v } }
end

# File lib/autostyle.rb, line 9
def [](key)
  super(key) || self[key] = Autostyle.new
end

# File lib/autostyle.rb, line 13
def []=(key, value)
  return super(key, value) if key.empty?
  return super(key, value) if value.is_a?(Autostyle)
  super(key, stylize(value))
end

# File lib/autostyle.rb, line 26
def dup
  Autostyle.new.tap do |a|
    each do |k, v|
      a[k] = v.is_a?(Hash) ? v.dup : v
    end
  end
end

# File lib/autostyle.rb, line 34
def merge(hash)
  dup.tap{ |a| a.merge!(hash) }
end

# File lib/autostyle.rb, line 19
def merge!(hash)
  hash.each do |k, v|
    next self[k] = v if k.empty?
    self[k].merge!(stylize(v))
  end
end

# File lib/autostyle.rb, line 42
def render(master_key = '')
  self.map{ |k, v|
    key = [master_key, k].reject(&:empty?).join('-')
    next v.render(key) if v.is_a?(Autostyle)
    [key, v].join(': ')
  }.join('; ')
end

# File lib/autostyle.rb, line 38
def to_s
  render
end

# File lib/autostyle.rb, line 51
def stylize(value)
  Autostyle[value.is_a?(Hash) ? value : { '' => value }]
end