require 'facet/inflect'

require 'nitro/helper/form/controls'

module Nitro

# A collection of useful helpers for creating and manipulating
# Forms.
#--
# This helper may by applied at run time so try to optimize 
# this.
#++

module FormHelper

  def self.included(base)
    super
    base.send :include, XhtmlHelper
  end

  # Override these methods to customize the rendering.
  #
  # An alternative schema could be:
  # 
  # <dl>
  #   <dt class="#{prop.symbol}">#{label(prop)}</dt>
  #   <dd class="#{prop.symbol}">#{html}</dd>
  # </dl>
  
  module FormBuilder
    class << self
      # Emit form prologue.
      
      def prologue
        ''
      end
      
      # Emit form epilogue.
      
      def epilogue
        ''
      end

      # Emit a label.
            
      def label(prop)
        %{<label for="#{prop.name}">#{prop[:title] || prop.name.to_s.humanize}</label>}
      end
      
      # Emit a form element.
      
      def element(prop, html)
        %{
          <p class="form_#{prop.symbol}">
            <div>#{label(prop)}</div>
            #{html}
          </p>
        }        
      end
    end
  end

  # Render a standard form for the given object.
  #--
  # RETHINK this method.
  #++
    
  def form_for(obj, options = {})
    str = ''
    
    name = obj.class.name.underscore
  
    method = options.fetch(:method, 'post')
    action = options.fetch(:action, "save_#{obj.class.name.underscore}")
    submit = options.fetch(:submit, 'Save')
    cancel = options.fetch(:cancel, "#@base/#{Scaffolding.class_to_list(obj.class)}")  
    
    if enctype = options.fetch(:enctype, nil) 
      enctype_attribute = " enctype=\"#{enctype}\""
    else
      enctype_attribute = ''
      for prop in obj.class.properties.values
        if prop.klass.ancestors.include? Og::Blob                
          enctype_attribute = ' enctype="multipart/form-data"'
        end
      end
    end
    
    action = "#{@base}/#{action}" unless action =~ /\//
    
    str << %{<form action="#{action}" method="post"#{enctype_attribute}>}    
    str << %{<input type="hidden" name="oid" value="#{obj.oid}" />} if obj.oid
    str << controls_for(obj, options)
    str << %{<input type="submit" value="#{submit}" />}
    str << %{ or <a href="#{cancel}">Cancel</a>} if cancel
    str << %{</form>}
    
    return str  
  end

  # Render the controls for the given object.
    
  def controls_for(obj, options = {})
    str = FormBuilder.prologue
        
    controls_for_properties(str, obj, options)
    controls_for_relations(str, obj, options)
    
    str << FormBuilder.epilogue
    
    return str
  end

  # Render the controls for the properties of the given object.
  
  def controls_for_properties(str, obj, options = {})
    for prop in obj.class.properties.values
      unless options[:all]
        next if prop.symbol == obj.class.primary_key.symbol or prop[:control] == :none or prop[:relation]
      end
      control = Control.fetch(obj, prop, options).render
      str << FormBuilder.element(prop, control)
    end
  end
  
  # Render the controls for the relations of the given object.
  
  def controls_for_relations(str, obj, options = {})
    for rel in obj.class.relations        
      unless options[:all]
        next if rel[:control] == :none
      end
      control = Control.fetch(obj, rel, options).render
      str << FormBuilder.element(rel, control)      
    end  
  end

end

end

# * George Moschovitis <gm@navel.gr>
# * Chris Farmiloe <chris.farmiloe@farmiloe.com>
# * Rob Pitt <rob@motionpath.co.uk>