module Axlsx
  # A Series defines the title, data and labels for chart data.
  # @note The recommended way to manage series is to use Chart#add_series
  # @see Worksheet#add_chart
  # @see Chart#add_series
  class Series

    # The series title.
    # @return [String]
    attr_accessor :title

    # The chart that owns this series
    # @return [Chart]
    attr_reader :chart
    
    # The data for this series. 
    # @return [Array, SimpleTypedList]
    attr_reader :data


    # The index of this series in the chart's series.
    # @return [Integer]
    attr_reader :index

    # The labels for this series.
    # @return [Array, SimpleTypedList]
    attr_reader :labels


    # Creates a new series
    # @option options [Array, SimpleTypedList] data
    # @option options [Array, SimpleTypedList] labels
    # @option options [String] title
    # @param [Chart] chart
    def initialize(chart, options={})
      self.chart = chart
      @chart.series << self
      self.data = options[:data]  || []
      self.labels = options[:labels] || []
      @title = options[:title] || ''
    end    

    # Serializes the series
    # @param [Nokogiri::XML::Builder] xml The document builder instance this objects xml will be added to.
    # @return [String]
    def to_xml(xml)
      xml.send('c:ser') {
        xml.send('c:idx', :val=>index)
        xml.send('c:order', :val=>index)
        xml.send('c:tx') {
          xml.send('c:v', self.title)
        }
        
        if !labels.empty?
          xml.send('c:cat') {
            xml.send('c:strRef') {
              xml.send('c:f', range(labels))
              xml.send('c:strCache') {
                xml.send('c:ptCount', :val=>labels.size)
                labels.each_with_index do |cell, index|
                  v = cell.is_a?(Cell) ? cell.value : cell
                  xml.send('c:pt', :idx=>index) {
                    xml.send('c:v', v)
                  }                          
                end
              }
            }
          }
        end
        xml.send('c:val') {
          xml.send('c:numRef') {
            xml.send('c:f', range(data))
            xml.send('c:numCache') {
              xml.send('c:formatCode', 'General')
              xml.send('c:ptCount', :val=>data.size)
              data.each_with_index do |cell, index|
                v = cell.is_a?(Cell) ? cell.value : cell
                xml.send('c:pt', :idx=>index) {
                  xml.send('c:v', v) 
                }
              end
            }                        
          }
        }
      }                  
      
    end

    def index
      @chart.series.index(self)
    end
    
    private 

    # determines the cell range for the items provided
    def range(items)
      return "" unless items.first.is_a? Cell      

      "#{items.first.row.worksheet.name}!" +
        "#{items.first.r_abs}:#{items.last.r_abs}"
    end


    # assigns the data for this series
    def data=(v) DataTypeValidator.validate "Series.data", [Array, SimpleTypedList], v; @data = v; end

    # assigns the labels for this series
    def labels=(v) DataTypeValidator.validate "Series.labels", [Array, SimpleTypedList], v; @labels = v; end

    # assigns the chart for this series
    def chart=(v)  DataTypeValidator.validate "Series.chart", [Chart, Pie3DChart], v; @chart = v; end    
  end

end