require 'mega/dictionary'

require 'nitro/compiler/morphing'

# Javascript related morphers.

module Nitro

#--
# A useful superclass for morphers. Provides easy access to 
# js/css shared buffers.
#++

class SharedMorpher < Morpher # :nodoc: all
  include JavascriptUtils
  
  # Record javascript to be injected in the template.
  
  def record_js(code)
    (@compiler.shared[:js_buffer] ||= '') << code
  end
  alias_method :js, :record_js
  
  # Record css to be injected in the template.
  
  def record_css(css)
    (@compiler.shared[:css_buffer] ||= '') << css
  end
  alias_method :css, :record_css
  
  # Require javascript files.
  
  def require_script_file(*names)
    files = (@compiler.shared[:js_required_files] ||= Dictionary.new)
    for name in names
      files[name] = true    
    end
  end
  alias_method :add_script_file, :require_script_file
end

# Transform a normal achor into an asynchronous request:
#  <a href="..." async="true">...</a>
# becomes
#  <a href="#" onclick="new Ajax.Request...; return false;">...</a>

class AsyncMorpher < SharedMorpher
  def before_start(buffer)
    require_script_file :prototype
    
    href = @attributes['href'] 
    @attributes['href'] = '#'
    @attributes['onclick'] = "new Ajax.Request('#{href}'); return false;"
    @attributes.delete(@key)
  end
end

# Transform script attributes.
#
# <form script="action">...
# becomes
# <form onsubmit="action(); return false">...
#
# <a script="action">..</a>
# becomes
# <a href="#" onclick="action(); return false">...</a>

class ScriptMorpher < SharedMorpher
  def before_start(buffer)
    require_script_file :prototype
    
    case @name
      when 'form'
        @attributes['onsubmit'] = "#@value(); return false"
      else
        @attributes['href'] = '#'
        @attributes['onclick'] = "#@value(); return false"
    end
    @attributes.delete(@key)
  end
end

# Transform client attributes. '__nc_' marks Nitro generated
# javascript functions.
#
# <form client="action">...
# becomes
# <form onsubmit="__nc_action(); return false">...
#
# <a client="action">..</a>
# becomes
# <a href="#" onclick="__nc_action(); return false">...</a>

class ClientMorpher < SharedMorpher
  def before_start(buffer)
    require_script_file :prototype, :effects
    
    case @name
      when 'form'
        @attributes['onsubmit'] = "__nc_#@value(); return false"
      else
        @attributes['href'] = '#'
        @attributes['onclick'] = "__nc_#@value(); return false"
    end
    @attributes.delete(@key)
  end
end

# Makes a DOM element draggable.

class DraggableMorpher < SharedMorpher
  def before_start(buffer)
    require_script_file :prototype, :effects, :dragdrop
    
    id = @attributes['id'] || @attributes['name']    
    options = @attributes['drag_options'] || ''
    js "new Draggable('#{id}', #{hash_to_js(options)});"
  
    @attributes.delete(@key)
  end
end

# Adds auto-complete functionality to a standard input field.
#
# === Example
# 
# <input type="text" id="myfield" name="myfield" auto_complete="true" />
#
# You need to provide the autocomplete values by means of a
# custom action: {field_id}_auto_complete. The method should
# return a <ul> list. In this example:
#
# def myfield_auto_complete
#   %{<ul><li>....</ul>}

class AutoCompleteMorpher < SharedMorpher
  def before_start(buffer)
    require_script_file :prototype, :effects, :controls
    
    id = @id = @attributes['id'] || @attributes['name']    
    update = @attributes['auto_complete_update'] || "#{id}_auto_complete"
    url = @attributes['auto_complete_url'] || "#{id}_auto_complete"    
    js "new Ajax.Autocompleter('#{id}', '#{update}', '#{url}');"

    @attributes.delete(@key)
  end
  
  def after_end(buffer)
    buffer << %|<div id="#{@id}_auto_complete" class="auto_complete"> </div>|
  end
end

# Install the morphers.

Morphing.add_morpher :async, AsyncMorpher
Morphing.add_morpher :script, ScriptMorpher
Morphing.add_morpher :client, ClientMorpher
Morphing.add_morpher :auto_complete, AutoCompleteMorpher
Morphing.add_morpher :draggable, DraggableMorpher

end

# * George Moschovitis <gm@navel.gr>