module Webrat
  class Field
    
    def self.class_for_element(element)
      if element.name == "input"
        if %w[submit image].include?(element["type"])
          field_class = "button"
        else
          field_class = element["type"]
        end
      else
        field_class = element.name
      end
      
      Webrat.const_get("#{field_class.capitalize}Field")
    rescue NameError
      raise "Invalid field element: #{element.inspect}"
    end
    
    def initialize(form, element)
      @form     = form
      @element  = element
      
      @value    = default_value
    end
 
    def label_text
      return nil unless label
      label.text
    end
    
    def matches_id?(id)
      @element["id"] == id.to_s
    end
    
    def matches_name?(name)
      @element["name"] == name.to_s
    end
    
    def matches_label?(label_text)
      return false unless label
      label.matches_text?(label_text)
    end
    
    def to_param
      param_parser.parse_query_parameters("#{name}=#{@value}")
    end
    
    def set(value)
      @value = value
    end
    
    def unset
      @value = default_value
    end
    
  protected
  
    def id
      @element["id"]
    end
    
    def name
      @element["name"]
    end
    
    def label
      return nil if label_element.nil?
      @label ||= Label.new(self, label_element)
    end
    
    def label_element
      @label_element ||= begin
        parent = @element.parent
        while parent.respond_to?(:parent)
          return parent if parent.name == "label"
          parent = parent.parent
        end
      
        if id.blank?
          nil
        else
          @form.element.at("label[@for=#{id}]")
        end
      end
    end
    
    def default_value
      @element["value"]
    end
    
    def param_parser
      if defined?(CGIMethods)
        CGIMethods
      else
        ActionController::AbstractRequest
      end
    end
    
  end
  
  class ButtonField < Field
 
    def matches_value?(value)
      @element["value"] =~ /^\W*#{Regexp.escape(value.to_s)}/i
    end
 
    def to_param
      return nil if @value.nil?
      super
    end
 
    def default_value
      nil
    end
 
    def click
      set(@element["value"]) unless @element["name"].blank?
      @form.submit
    end
 
  end
 
  class HiddenField < Field
 
    def to_param
      if collection_name?
        super
      else
        checkbox_with_same_name = @form.find_field(name, CheckboxField)
 
        if checkbox_with_same_name.to_param.nil?
          super
        else
          nil
        end
      end
    end
 
  protected
 
    def collection_name?
      name =~ /\[\]/
    end
 
  end
 
  class CheckboxField < Field
 
    def to_param
      return nil if @value.nil?
      super
    end
 
    def check
      set(@element["value"] || "on")
    end
 
    def uncheck
      set(nil)
    end
 
  protected
 
    def default_value
      if @element["checked"] == "checked"
        @element["value"] || "on"
      else
        nil
      end
    end
 
  end
 
  class PasswordField < Field
  end
 
  class RadioField < Field
 
    def to_param
      return nil if @value.nil?
      super
    end
    
    def choose
      other_options.each do |option|
        option.unset
      end
      
      set(@element["value"] || "on")
    end
    
  protected
 
    def other_options
      @form.fields.select { |f| f.name == name }
    end
    
    def default_value
      if @element["checked"] == "checked"
        @element["value"] || "on"
      else
        nil
      end
    end
 
  end
 
  class TextareaField < Field
 
  protected
 
    def default_value
      @element.inner_html
    end
 
  end
  
  class FileField < Field
  end
 
  class TextField < Field
  end
 
  class ResetField < Field
  end
 
  class SelectField < Field
 
    def find_option(text)
      options.detect { |o| o.matches_text?(text) }
    end
 
  protected
 
    def default_value
      selected_options = @element / "option[@selected='selected']"
      selected_options = @element / "option:first" if selected_options.empty? 
      selected_options.map do |option|
        return "" if option.nil?
        option["value"] || option.innerHTML
      end
    end
 
    def options
      option_elements.map { |oe| SelectOption.new(self, oe) }
    end
 
    def option_elements
      (@element / "option")
    end
 
  end
end