# -*- coding: utf-8 -*-
###############################################################################
#
# Scatter - A class for writing Excel Scatter charts.
#
# Used in conjunction with Chart.
#
# See formatting note in Chart.
#
# Copyright 2000-2011, John McNamara, jmcnamara@cpan.org
# Convert to ruby by Hideo NAKAMURA, cxn03651@msj.biglobe.ne.jp
#

require 'write_xlsx/package/xml_writer_simple'
require 'write_xlsx/chart'
require 'write_xlsx/utility'

module Writexlsx
  class Chart
    # The Scatter chart module also supports the following sub-types:
    #
    #     markers_only (the default)
    #     straight_with_markers
    #     straight
    #     smooth_with_markers
    #     smooth
    # These can be specified at creation time via the add_chart() Worksheet
    # method:
    #
    #     chart = workbook.add_chart(
    #         :type    => 'scatter',
    #         :subtype => 'straight_with_markers'
    #     )
    #
    class Scatter < self
      include Writexlsx::Utility

      def initialize
        super(self.class)
        @subtype        = 'marker_only'
        @cross_between  = 'midCat'
        @horiz_val_axis = 0
      end

      #
      # Override the virtual superclass method with a chart specific method.
      #
      def write_chart_type
        # Write the c:areaChart element.
        write_scatter_chart
      end

      #
      # Write the <c:pieChart> element.
      #
      def write_scatter_chart
        style   = 'lineMarker'
        subtype = @subtype

        # Set the user defined chart subtype
        case subtype
        when 'marker_only', 'straight_with_markers', 'straight'
          style = 'lineMarker'
        when 'smooth_with_markers', 'smooth'
          style = 'smoothMarker'
        end

        # Add default formatting to the series data.
        modify_series_formatting

        @writer.tag_elements('c:scatterChart') do
          # Write the c:scatterStyle element.
          write_scatter_style(style)
          # Write the series elements.
          write_series
        end
      end

      #
      # Over-ridden to write c:xVal/c:yVal instead of c:cat/c:val elements.
      #
      # Write the <c:ser> element.
      #
      def write_ser(index, series)
        @writer.tag_elements('c:ser') do
          # Write the c:idx element.
          write_idx(index)
          # Write the c:order element.
          write_order(index)
          # Write the series name.
          write_series_name(series)
          # Write the c:spPr element.
          write_sp_pr(series)
          # Write the c:marker element.
          write_marker(series[:_marker])
          # Write the c:dLbls element.
          write_d_lbls(series[:_labels])
          # Write the c:trendline element.
          write_trendline(series[:_trendline])
          # Write the c:xVal element.
          write_x_val(series)
          # Write the c:yVal element.
          write_y_val(series)
          # Write the c:smooth element.
          write_c_smooth
        end
      end

      #
      # Over-ridden to have 2 valAx elements for scatter charts instead of
      # catAx/valAx.
      #
      # Write the <c:plotArea> element.
      #
      def write_plot_area
        @writer.tag_elements('c:plotArea') do
          # Write the c:layout element.
          write_layout
          # Write the subclass chart type element.
          write_chart_type
          # Write the c:catAx element.
          write_cat_val_axis('b', 1)
          # Write the c:catAx element.
          @horiz_val_axis = 1

          write_val_axis('l')
        end
      end

      #
      # Write the <c:xVal> element.
      #
      def write_x_val(series)
        write_val_base(series[:_categories], series[:_cat_data_id], 'c:xVal')
      end

      #
      # Write the <c:yVal> element.
      #
      def write_y_val(series)
        write_val_base(series[:_values], series[:_val_data_id], 'c:yVal')
      end

      #
      # Write the <c:scatterStyle> element.
      #
      def write_scatter_style(val)
        attributes = ['val', val]

        @writer.empty_tag('c:scatterStyle', attributes)
      end

      #
      # Write the <c:smooth> element.
      #
      def write_c_smooth
        subtype = @subtype
        val     = 1

        return unless subtype =~ /smooth/

        attributes = ['val', val]

        @writer.empty_tag('c:smooth', attributes)
      end

      #
      # Add default formatting to the series data unless it has already been
      # specified by the user.
      #
      def modify_series_formatting
        subtype = @subtype

        # The default scatter style "markers only" requires a line type
        if subtype == 'marker_only'
          # Go through each series and define default values.
          @series.each do |series|
            # Set a line type unless there is already a user defined type.
            if series[:_line][:_defined] == 0
              series[:_line] = { :width => 2.25, :none => 1, :_defined => 1 }
            end
          end
        end

        # Turn markers off for subtypes that don't have them
        unless subtype =~ /marker/
          # Go through each series and define default values.
          @series.each do |series|
            # Set a marker type unless there is already a user defined type.
            if series[:_marker][:_defined] == 0
              series[:_marker] = { :type => 'none', :_defined => 1 }
            end
          end
        end
      end
    end
  end
end