require 'roo'

def load_patterns(file)
  xlsx = Roo::Spreadsheet.open(file)
  xlsx.sheets.each_with_object({}) do |sheet_name, patterns|
    xlsx.default_sheet = sheet_name
    matrix = (1..8).map { |row| (1..8).map { |col| xlsx.cell(row, col).to_s.strip.downcase == 'x' ? 1 : -1 } }
    patterns[sheet_name.to_sym] = matrix
  end
end