module ActionView::Helpers::PrototypeHelper::JavaScriptGenerator::GeneratorMethods

def <<(javascript)
  @lines << javascript
end

def [](id)
  case id
    when String, Symbol, NilClass
      JavaScriptElementProxy.new(self, id)
    else
      JavaScriptElementProxy.new(self, ActionController::RecordIdentifier.dom_id(id))
  end
end

def alert(message)
  call 'alert', message
end

def arguments_for_call(arguments, block = nil)
  arguments << block_to_function(block) if block
  arguments.map { |argument| javascript_object_for(argument) }.join ', '
end

def assign(variable, value)
  record "#{variable} = #{javascript_object_for(value)}"
end

def block_to_function(block)
  generator = self.class.new(@context, &block)
  literal("function() { #{generator.to_s} }")
end

def call(function, *arguments, &block)
  record "#{function}(#{arguments_for_call(arguments, block)})"
end

def delay(seconds = 1)
  record "setTimeout(function() {\n\n"
  yield
  record "}, #{(seconds * 1000).to_i})"
end

def draggable(id, options = {})
  record @context.send(:draggable_element_js, id, options)
end

def drop_receiving(id, options = {})
  record @context.send(:drop_receiving_element_js, id, options)
end

def hide(*ids)
  loop_on_multiple_args 'Element.hide', ids
end

def insert_html(position, id, *options_for_render)
  content = javascript_object_for(render(*options_for_render))
  record "Element.insert(\"#{id}\", { #{position.to_s.downcase}: #{content} });"
end

def javascript_object_for(object)
  ::ActiveSupport::JSON.encode(object)
end

def literal(code)
  ::ActiveSupport::JSON::Variable.new(code.to_s)
end

def loop_on_multiple_args(method, ids)
  record(ids.size>1 ?
    "#{javascript_object_for(ids)}.each(#{method})" :
    "#{method}(#{javascript_object_for(ids.first)})")
end

def method_missing(method, *arguments)
  JavaScriptProxy.new(self, method.to_s.camelize)
end

def page
  self
end

def record(line)
  line = "#{line.to_s.chomp.gsub(/\;\z/, '')};"
  self << line
  line
end

def redirect_to(location)
  url = location.is_a?(String) ? location : @context.url_for(location)
  record "window.location.href = #{url.inspect}"
end

def reload
  record 'window.location.reload()'
end

def remove(*ids)
  loop_on_multiple_args 'Element.remove', ids
end

def render(*options)
  with_formats(:html) do
    case option = options.first
    when Hash
      @context.render(*options)
    else
      option.to_s
    end
  end
end

def replace(id, *options_for_render)
  call 'Element.replace', id, render(*options_for_render)
end

def replace_html(id, *options_for_render)
  call 'Element.update', id, render(*options_for_render)
end

def select(pattern)
  JavaScriptElementCollectionProxy.new(self, pattern)
end

def show(*ids)
  loop_on_multiple_args 'Element.show', ids
end

def sortable(id, options = {})
  record @context.send(:sortable_element_js, id, options)
end

def to_s #:nodoc:
  (@lines * $/).tap do |javascript|
    if ActionView::Base.debug_rjs
      source = javascript.dup
      javascript.replace "try {\n#{source}\n} catch (e) "
      javascript << "{ alert('RJS error:\\n\\n' + e.toString()); alert('#{source.gsub('\\','\0\0').gsub(/\r\n|\n|\r/, "\\n").gsub(/["']/) { |m| "\\#{m}" }}'); throw e }"
    end
  end
end

def toggle(*ids)
  loop_on_multiple_args 'Element.toggle', ids
end

def visual_effect(name, id = nil, options = {})
  record @context.send(:visual_effect, name, id, options)
end

def with_formats(*args)
  @context ? @context.update_details(:formats => args) { yield } : yield
end