# encoding: UTF-8

module NdrImport
  module NonTabular
    # This class stores the mapping for an individual non-tabular column, encapsulating
    # the logic associated with finding matching lines of source data and subsequently
    # capturing arrays of values within them.
    class ColumnMapping
      attr_accessor :name, :cell_mapping, :lines, :capture, :join

      def initialize(column_mapping)
        @name         = column_mapping['rawtext_name'] ||
                        column_mapping['column'] ||
                        column_mapping['standard_mapping']
        @cell_mapping = column_mapping['non_tabular_cell']

        validate_cell_mapping

        @lines = @cell_mapping['lines']
        @join  = @cell_mapping['join']
      end

      # This method returns the range of matching source data lines. If the range is a
      # RegexpRange then it will calculate it for the text provided.
      def matching_lines(text)
        if @lines.is_a?(RegexpRange)
          @lines.to_range(text)
        else
          @lines
        end
      end

      # capture the required part of the line by replacing (recusively) the line,
      # with the first captured regular expression group. This is hardcoded in an attempt
      # to preserve the rawtext as much as possible.
      # The captured value is `String#strip`ed by default.
      def capture_value(line)
        value = line.dup
        [@cell_mapping['capture']].flatten.each do |pattern|
          if matchdata = value.to_s.match(pattern)
            value = matchdata[1]
          else
            value = nil
          end
        end
        value.nil? ? value : value.strip
      end

      def validate_cell_mapping
        validate_presence_of_non_tabular_cell
        validate_presence_of_non_tabular_cell_lines
        validate_presence_of_non_tabular_cell_capture
      end

      def validate_presence_of_non_tabular_cell
        return if @cell_mapping
        fail NdrImport::MappingError,
             I18n.t('mapping.errors.missing_non_tabular_cell', :name => @name)
      end

      def validate_presence_of_non_tabular_cell_lines
        return if @cell_mapping['lines']
        fail NdrImport::MappingError,
             I18n.t('mapping.errors.missing_non_tabular_cell_lines', :name => @name)
      end

      def validate_presence_of_non_tabular_cell_capture
        return if @cell_mapping['capture']
        fail NdrImport::MappingError,
             I18n.t('mapping.errors.missing_non_tabular_cell_capture', :name => @name)
      end
    end
  end
end