module Netzke::GridInterface
  def post_data(params)
    [:create, :update].each do |operation|
      data = JSON.parse(params.delete("#{operation}d_records".to_sym)) if params["#{operation}d_records".to_sym]
      process_data(data, operation) if !data.nil?
    end
    {:success => true, :flash => @flash}
  end
  
  def get_data(params = {})
    if @permissions[:read]
      records = get_records(params)
      {:data => records, :total => records.total_records}
    else
      flash :error => "You don't have permissions to read data"
      {:success => false, :flash => @flash}
    end
  end

  def delete_data(params = {})
    if @permissions[:delete]
      record_ids = JSON.parse(params.delete(:records))
      klass = config[:data_class_name].constantize
      klass.delete(record_ids)
      flash :notice => "Deleted #{record_ids.size} record(s)"
      success = true
    else
      flash :error => "You don't have permissions to delete data"
      success = false
    end
    {:success => success, :flash => @flash}
  end

  def resize_column(params)
    raise "Called interface_resize_column while not configured to do so" unless config[:column_resize]
    l_item = layout_manager_class.by_widget(id_name).layout_items[params[:index].to_i]
    l_item.width = params[:size]
    l_item.save!
    {}
  end
  
  def move_column(params)
    raise "Called interface_move_column while not configured to do so" unless config[:column_move]
    layout_manager_class.by_widget(id_name).move_item(params[:old_index].to_i, params[:new_index].to_i)
    {}
  end

  # Return the choices for the column
  def get_cb_choices(params)
    column = params[:column]
    query = params[:query]
    
    {:data => config[:data_class_name].constantize.choices_for(column, query).map{|s| [s]}}
  end
  
  
  protected
  #
  # operation => :update || :create
  #
  def process_data(data, operation)
    if @permissions[operation]
      klass = config[:data_class_name].constantize
      modified_records = 0
      data.each do |record_hash|
        record = operation == :create ? klass.create : klass.find(record_hash.delete('id'))
        logger.debug { "!!! record: #{record.inspect}" }
        success = true
        exception = nil
        
        # process all attirubutes for the same record (OPTIMIZE: we can use update_attributes separately for regular attributes to speed things up)
        record_hash.each_pair do |k,v|
          begin
            record.send("#{k}=",v)
          rescue ArgumentError => exc
            flash :error => exc.message
            success = false
            break
          end
        end
        
        # try to save
        modified_records += 1 if success && record.save

        # flash eventual errors
        record.errors.each_full do |msg|
          flash :error => msg
        end
        
        flash :notice => "#{operation.to_s.capitalize}d #{modified_records} records"
      end
    else
      flash :error => "You don't have permissions to #{operation} data"
    end
  end
  
  # get records
  def get_records(params)
    conditions = normalize_params(params)
    raise ArgumentError, "No data_class_name specified for widget '#{config[:name]}'" if !config[:data_class_name]
    records = config[:data_class_name].constantize.all(conditions)
    output_array = []
    records.each do |r|
      r_array = []
      self.get_columns.each do |column|
        r_array << r.send(column[:name])
      end
      output_array << r_array
    end

    # add total_entries method to the result
    class << output_array
      attr :total_records, true
    end
    total_records_count = config[:data_class_name].constantize.count(conditions)
    output_array.total_records = total_records_count

    output_array
  end
  
  # make params understandable to searchlogic
  def normalize_params(params)
    # sorting
    order_by = if params[:sort]
      assoc, method = params[:sort].split('__')
      method.nil? ? assoc : {assoc => method}
    end
    
    page = params[:start].to_i/params[:limit].to_i + 1 if params[:limit]
    {:per_page => params[:limit], :page => page, :order_by => order_by, :order_as => params[:dir]}
  end
end