require 'delegate'
require 'forwardable'

require 'nokogiri' # TODO => replace with Builder
require 'sass'
require 'ice_nine'
require 'equalizer'

module Hexp
  # Inject the Hexp::DSL module into classes that include Hexp
  #
  # @param [Class] klazz
  #   The class that included Hexp
  #
  # @return [Class]
  #
  # @api private
  def self.included(klazz)
    klazz.send(:include, Hexp::DSL)
  end

  # Deep freeze an object
  #
  # Delegates to IceNine
  #
  # @param [Array] args
  #   arguments to pass on
  # @return [Object]
  #
  # @api private
  def self.deep_freeze(*args)
    IceNine.deep_freeze(*args)
  end

  # Variant of ::Array with slightly modified semantics
  #
  # `Array()` is often used to wrap a value in an Array, unless it's already
  # an array. However if your object implements `#to_a`, then `Array()` will use
  # that value. Because of this objects that aren't Array-like will get
  # converted as well, such as Struct objects.
  #
  # This implementation relies on #to_ary, which signals that the Object is
  # a drop-in replacement for an actual Array.
  #
  # @param [Object] arg
  #
  # @return [Array]
  #
  # @api private
  def self.Array(arg)
    if arg.respond_to? :to_ary
      arg.to_ary
    else
      [ arg ]
    end
  end

  # Parse HTML to Hexp
  #
  # The input have a single root element. If there are multiple only the first
  # will be converted. If there is no root element (e.g. an empty document, or
  # only a DTD or comment) then an error is raised
  #
  # @example
  #   Hexp.parse('<div>hello</div>') #=> H[:div, "hello"]
  #
  # @param [String] html
  #   A HTML document
  #
  # @return [Hexp::Node]
  #
  # @api public
  def self.parse(html)
    root = Nokogiri(html).root
    raise Hexp::ParseError, "Failed to parse HTML : no document root" if root.nil?
    Hexp::Nokogiri::Reader.new.call(root)
  end

  # Use builder syntax to create a Hexp
  #
  # @see Hexp::Builder
  #
  # @example
  #   list = Hexp.build do
  #     ul do
  #      3.times do |i|
  #        li i.to_s
  #      end
  #     end
  #   end
  #
  # @param [Array] args
  #
  # @yieldparam [Hexp::Builder]
  #
  # @return [Hexp::Builder]
  #
  # @api public
  def self.build(*args, &block)
    Hexp::Builder.new(*args, &block)
  end

end

require 'hexp/version'

require 'hexp/node/attributes'
require 'hexp/node/children'
require 'hexp/node'

require 'hexp/dsl'

require 'hexp/node/normalize'
require 'hexp/node/domize'
require 'hexp/node/pp'
require 'hexp/node/rewriter'
require 'hexp/node/selection'
require 'hexp/node/css_selection'

require 'hexp/text_node'
require 'hexp/list'
require 'hexp/dom'

require 'hexp/css_selector'
require 'hexp/css_selector/sass_parser'
require 'hexp/css_selector/parser'

require 'hexp/errors'

require 'hexp/nokogiri/equality' # TODO => replace this with equivalent-xml
require 'hexp/nokogiri/reader'
require 'hexp/sass/selector_parser'

require 'hexp/h'

require 'hexp/builder'