# frozen_string_literal: true

module Xsv
  # StylesHandler interprets the relevant parts of styles.xml
  # This is used internally when opening a sheet.
  class StylesHandler < SaxParser
    def self.get_styles(io)
      handler = new(Xsv::Helpers::BUILT_IN_NUMBER_FORMATS.dup) do |xfs, num_fmts|
        @xfs = xfs
        @num_fmts = num_fmts
      end

      handler.parse(io)

      [@xfs, @num_fmts]
    end

    def initialize(num_fmts, &block)
      @block = block
      @state = nil
      @xfs = []
      @num_fmts = num_fmts
    end

    def start_element(name, attrs)
      case name
      when "cellXfs"
        @state = "cellXfs"
      when "xf"
        @xfs << attrs.transform_values(&:to_i) if @state == "cellXfs"
      when "numFmt"
        @num_fmts[attrs[:numFmtId].to_i] = attrs[:formatCode]
      end
    end

    def end_element(name)
      case name
      when "styleSheet"
        @block.call(@xfs, @num_fmts)
      when "cellXfs"
        @state = nil
      end
    end
  end
end