require 'csv'
require 'optparse'

def process_csv(input_file)
  # Open the input file and process it line by line
  CSV.foreach(input_file) do |row|
    # Write only the first two columns to stdout
    puts row[0..1].to_csv
  end
end

def main
  options = {}
  
  # Define the command-line options
  OptionParser.new do |opts|
    opts.banner = "Usage: process_csv.rb -i INPUT_FILE"

    opts.on("-i", "--input INPUT_FILE", "Path to the input CSV file") do |input|
      options[:input] = input
    end
  end.parse!

  # Check if the input file is provided
  unless options[:input]
    puts "Error: Input file is required."
    puts "Usage: process_csv.rb -i INPUT_FILE"
    exit 1
  end

  # Process the CSV file
  begin
    process_csv(options[:input])
  rescue Errno::ENOENT
    STDERR.puts "Error: File '#{options[:input]}' not found."
    exit 1
  end
end

# Run the script
main if __FILE__ == $PROGRAM_NAME