require 'roo'

class ReportParser
  SHEET_NAME = 'Сведения об организации'
  CELL_MAP = {
    full_name: { row: 6,  col: 13 },
    inn:       { row: 10, col: 13 },
    kpp:       { row: 11, col: 13 },
    okpo:      { row: 12, col: 13 },
    okfs:      { row: 13, col: 13 },
    okopf:     { row: 14, col: 13 },
    okved2:    { row: 15, col: 13 },
    address:   { row: 16, col: 13 }
  }.freeze

  AUDITOR_MAP = {
    name: { row: 19, col: 13 },
    inn:  { row: 20, col: 13 },
    ogrn: { row: 21, col: 13 }
  }.freeze

  def initialize(yearly_file)
    @yearly_file = yearly_file
  end

  def call
    ActiveRecord::Base.transaction do
      parse_organization
      parse_auditor
      extract_year
    end
  end

  private

  def spreadsheet
    @spreadsheet ||= begin
      tempfile = Tempfile.new(['report', '.xlsx'])
      tempfile.binmode
      @yearly_file.file.download { |chunk| tempfile.write(chunk) }
      tempfile.rewind
      Roo::Excelx.new(tempfile.path)
    end
  end

  def info_sheet
    @info_sheet ||= spreadsheet.sheet(SHEET_NAME)
  end

  def read_cell(sheet, row, col)
    value = sheet.cell(row, col)
    value.is_a?(String) ? value.strip.presence : value
  end

  def parse_organization
    org_data = CELL_MAP.each_with_object({}) do |(attr, pos), hash|
      hash[attr] = read_cell(info_sheet, pos[:row], pos[:col])
    end

    organization = @yearly_file.organization
    organization.update!(org_data)
    organization
  end

  def parse_auditor
    auditor_data = AUDITOR_MAP.each_with_object({}) do |(attr, pos), hash|
      hash[attr] = read_cell(info_sheet, pos[:row], pos[:col])
    end

    return if auditor_data[:name].blank?

    auditor_inn = auditor_data[:inn].to_s.strip
    auditor = if auditor_inn.present?
                Auditor.find_or_initialize_by(inn: auditor_inn)
              else
                Auditor.find_or_initialize_by(name: auditor_data[:name])
              end

    auditor.assign_attributes(
      name: auditor_data[:name],
      inn: auditor_inn.presence,
      ogrn: auditor_data[:ogrn].to_s.strip.presence
    )
    auditor.save!

    @yearly_file.update!(auditor: auditor)
    auditor
  end

  def extract_year
    balance_sheet = spreadsheet.sheet('Бухгалтерский баланс')
    period_text = balance_sheet.cell(4, 1).to_s
    year = period_text.match(/(\d{4})/)&.captures&.first&.to_i

    @yearly_file.update!(year: year) if year
    year
  end
end