# frozen_string_literal: true

require "active_support/concern"

module Exportable
  extend ActiveSupport::Concern

  #
  # Generates a sample excel file as a stream
  #
  def sample_file
    export(sample_data)
  end

  def sample_data
    sample_data = []
    100.times { sample_data << export_columns.map { |_, c| c.options[:example] || "" } }
    sample_data
  end

  #
  # Generates an export based on the attributes and scope.
  #
  def export_file
    export(export_data)
  end

  def export_data
    export_scope.map { |record| export_row(record) }
  end

  def export_scope
    if self.class.allow_export?
      model.all
    else
      model.none
    end
  end

  def export_row(record)
    export_columns.map do |_, c|
      value = ""

      if c.options[:attribute]
        if c.options[:export]&.key?(:value)
          value = c.options[:export][:value].call(record) if c.options[:export][:value].is_a?(Proc)
        elsif record.respond_to?(c.options[:attribute])
          value = record.send(c.options[:attribute])
          value = value&.body&.to_html if value.is_a?(ActionText::RichText)
        end
        value ||= record.attributes[c.options[:attribute].to_s] if value.nil?
      end

      value
    end
  end

  def export(data_rows)
    xls = Axlsx::Package.new
    xls.use_shared_strings = true
    workbook = xls.workbook
    sheet = workbook.add_worksheet(name: friendly_name&.pluralize || model.name.demodulize.pluralize)
    workbook.styles do |style|
      introduction_style = style.add_style(bg_color: "E2EEDA")
      header_style = style.add_style(b: true, bg_color: "A8D08E", border: {style: :thin, color: "000000"})
      header_required_style = style.add_style(b: true, bg_color: "A8D08E", fg_color: "C00100", border: {style: :thin, color: "000000"})

      # Introduction
      introduction.each_with_index do |intro, i|
        text = intro.is_a?(Symbol) ? I18n.t(intro, scope: [:importers, self.class.name.underscore.to_s, :introduction]) : intro
        sheet.add_row [text], style: [introduction_style] * export_columns.count
        sheet.merge_cells "A#{i + 1}:#{nr_to_col(export_columns.count - 1)}#{i + 1}"
      end

      # Header row
      sheet.add_row export_columns.values.map(&:name), style: export_columns.map { |_, c| c.options[:required] ? header_required_style : header_style }

      export_columns.each.with_index do |f, i|
        field = f.last
        sheet.add_comment ref: "#{nr_to_col(i)}#{introduction.count + 1}", author: "", text: field.hint, visible: false if field.hint.present?
      end
      styles = export_columns.map do |_, c|
        if c.options.dig(:export, :format) == "number" || (c.options.dig(:export, :format).nil? && c.options.dig(:export, :example).is_a?(Numeric))
          number = workbook.styles.add_style format_code: "#"
        elsif c.options.dig(:export, :format) == "text" || (c.options.dig(:export, :format).nil? && c.options.dig(:export, :example).is_a?(String))
          text = workbook.styles.add_style format_code: "@"
        elsif c.options.dig(:export, :format)
          workbook.styles.add_style format_code: c.options.dig(:export, :format).to_s
        else
          workbook.styles.add_style format_code: "General"
        end
      end
      # Examples
      data_rows.each do |data|
        sheet.add_row data, style: styles
      end
    end

    sheet.column_info[0].width = 10

    sheet = workbook.add_worksheet(name: I18n.t("importo.sheet.explanation.name"))

    workbook.styles do |style|
      introduction_style = style.add_style(bg_color: "E2EEDA")
      header_style = style.add_style(b: true, bg_color: "A8D08E", border: {style: :thin, color: "000000"})

      column_style = style.add_style(b: true)
      required_style = style.add_style(b: true, fg_color: "C00100")
      wrap_style = workbook.styles.add_style alignment: {wrap_text: true}

      # Introduction
      introduction.each_with_index do |intro, i|
        text = intro.is_a?(Symbol) ? I18n.t(intro, scope: [:importers, self.class.name.underscore.to_s, :introduction]) : intro
        sheet.add_row [text], style: [introduction_style] * 2
        sheet.merge_cells "A#{i + 1}:B#{i + 1}"
      end

      # Header row
      sheet.add_row [I18n.t("importo.sheet.explanation.column"), I18n.t("importo.sheet.explanation.value"), I18n.t("importo.sheet.explanation.explanation"), I18n.t("importo.sheet.explanation.example")], style: [header_style] * 4
      export_columns.each do |_, c|
        styles = [c.options[:required] ? required_style : column_style, wrap_style]
        sheet.add_row [c.name, c.value, c.explanation, c.example], style: styles
      end
    end

    sheet.column_info[0].width = 40
    sheet.column_info[1].width = 150

    xls.to_stream
  end

  def export_columns
    @export_columns ||= columns.reject { |_, column| column.options[:hidden] }
  end
end