require 'active_support/core_ext/hash/keys'
require 'active_support/core_ext/hash/reverse_merge'
require 'active_support/inflector'

class Array
  # Converts the array to a comma-separated sentence where the last element is joined by the connector word. Options:
  # * <tt>:words_connector</tt> - The sign or word used to join the elements in arrays with two or more elements (default: ", ")
  # * <tt>:two_words_connector</tt> - The sign or word used to join the elements in arrays with two elements (default: " and ")
  # * <tt>:last_word_connector</tt> - The sign or word used to join the last element in arrays with three or more elements (default: ", and ")
  def to_sentence(options = {})
    default_words_connector     = I18n.translate(:'support.array.words_connector',     :locale => options[:locale])
    default_two_words_connector = I18n.translate(:'support.array.two_words_connector', :locale => options[:locale])
    default_last_word_connector = I18n.translate(:'support.array.last_word_connector', :locale => options[:locale])

    # Try to emulate to_sentences previous to 2.3
    if options.has_key?(:connector) || options.has_key?(:skip_last_comma)
      ::ActiveSupport::Deprecation.warn(":connector has been deprecated. Use :words_connector instead", caller) if options.has_key? :connector
      ::ActiveSupport::Deprecation.warn(":skip_last_comma has been deprecated. Use :last_word_connector instead", caller) if options.has_key? :skip_last_comma

      skip_last_comma = options.delete :skip_last_comma
      if connector = options.delete(:connector)
        options[:last_word_connector] ||= skip_last_comma ? connector : ", #{connector}"
      else
        options[:last_word_connector] ||= skip_last_comma ? default_two_words_connector : default_last_word_connector
      end
    end

    options.assert_valid_keys(:words_connector, :two_words_connector, :last_word_connector, :locale)
    options.reverse_merge! :words_connector => default_words_connector, :two_words_connector => default_two_words_connector, :last_word_connector => default_last_word_connector

    case length
      when 0
        ""
      when 1
        self[0].to_s
      when 2
        "#{self[0]}#{options[:two_words_connector]}#{self[1]}"
      else
        "#{self[0...-1].join(options[:words_connector])}#{options[:last_word_connector]}#{self[-1]}"
    end
  end


  # Calls <tt>to_param</tt> on all its elements and joins the result with
  # slashes. This is used by <tt>url_for</tt> in Action Pack.
  def to_param
    collect { |e| e.to_param }.join '/'
  end

  # Converts an array into a string suitable for use as a URL query string,
  # using the given +key+ as the param name.
  #
  #   ['Rails', 'coding'].to_query('hobbies') # => "hobbies%5B%5D=Rails&hobbies%5B%5D=coding"
  def to_query(key)
    prefix = "#{key}[]"
    collect { |value| value.to_query(prefix) }.join '&'
  end

  # Converts a collection of elements into a formatted string by calling
  # <tt>to_s</tt> on all elements and joining them:
  #
  #   Blog.find(:all).to_formatted_s # => "First PostSecond PostThird Post"
  #
  # Adding in the <tt>:db</tt> argument as the format yields a prettier
  # output:
  #
  #   Blog.find(:all).to_formatted_s(:db) # => "First Post,Second Post,Third Post"
  def to_formatted_s(format = :default)
    case format
      when :db
        if respond_to?(:empty?) && self.empty?
          "null"
        else
          collect { |element| element.id }.join(",")
        end
      else
        to_default_s
    end
  end
  alias_method :to_default_s, :to_s
  alias_method :to_s, :to_formatted_s

  # Returns a string that represents this array in XML by sending +to_xml+
  # to each element. Active Record collections delegate their representation
  # in XML to this method.
  #
  # All elements are expected to respond to +to_xml+, if any of them does
  # not an exception is raised.
  #
  # The root node reflects the class name of the first element in plural
  # if all elements belong to the same type and that's not Hash:
  #
  #   customer.projects.to_xml
  #
  #   <?xml version="1.0" encoding="UTF-8"?>
  #   <projects type="array">
  #     <project>
  #       <amount type="decimal">20000.0</amount>
  #       <customer-id type="integer">1567</customer-id>
  #       <deal-date type="date">2008-04-09</deal-date>
  #       ...
  #     </project>
  #     <project>
  #       <amount type="decimal">57230.0</amount>
  #       <customer-id type="integer">1567</customer-id>
  #       <deal-date type="date">2008-04-15</deal-date>
  #       ...
  #     </project>
  #   </projects>
  #
  # Otherwise the root element is "records":
  #
  #   [{:foo => 1, :bar => 2}, {:baz => 3}].to_xml
  #
  #   <?xml version="1.0" encoding="UTF-8"?>
  #   <records type="array">
  #     <record>
  #       <bar type="integer">2</bar>
  #       <foo type="integer">1</foo>
  #     </record>
  #     <record>
  #       <baz type="integer">3</baz>
  #     </record>
  #   </records>
  #
  # If the collection is empty the root element is "nil-classes" by default:
  #
  #   [].to_xml
  #
  #   <?xml version="1.0" encoding="UTF-8"?>
  #   <nil-classes type="array"/>
  #
  # To ensure a meaningful root element use the <tt>:root</tt> option:
  #
  #   customer_with_no_projects.projects.to_xml(:root => "projects")
  #
  #   <?xml version="1.0" encoding="UTF-8"?>
  #   <projects type="array"/>
  #
  # By default root children have as node name the one of the root
  # singularized. You can change it with the <tt>:children</tt> option.
  #
  # The +options+ hash is passed downwards:
  #
  #   Message.all.to_xml(:skip_types => true)
  #
  #   <?xml version="1.0" encoding="UTF-8"?>
  #   <messages>
  #     <message>
  #       <created-at>2008-03-07T09:58:18+01:00</created-at>
  #       <id>1</id>
  #       <name>1</name>
  #       <updated-at>2008-03-07T09:58:18+01:00</updated-at>
  #       <user-id>1</user-id>
  #     </message>
  #   </messages>
  #
  def to_xml(options = {})
    raise "Not all elements respond to to_xml" unless all? { |e| e.respond_to? :to_xml }
    require 'builder' unless defined?(Builder)

    options = options.dup
    options[:root]     ||= all? { |e| e.is_a?(first.class) && first.class.to_s != "Hash" } ? ActiveSupport::Inflector.pluralize(ActiveSupport::Inflector.underscore(first.class.name)) : "records"
    options[:children] ||= options[:root].singularize
    options[:indent]   ||= 2
    options[:builder]  ||= Builder::XmlMarkup.new(:indent => options[:indent])

    root     = options.delete(:root).to_s
    children = options.delete(:children)

    if !options.has_key?(:dasherize) || options[:dasherize]
      root = root.dasherize
    end

    options[:builder].instruct! unless options.delete(:skip_instruct)

    opts = options.merge({ :root => children })

    xml = options[:builder]
    if empty?
      xml.tag!(root, options[:skip_types] ? {} : {:type => "array"})
    else
      xml.tag!(root, options[:skip_types] ? {} : {:type => "array"}) {
        yield xml if block_given?
        each { |e| e.to_xml(opts.merge({ :skip_instruct => true })) }
      }
    end
  end
end