#!/usr/bin/env ruby
# frozen_string_literal: true

require 'loxxy'

class LoxxyRunner
  DefaultLoxExtension = 'lox'
  attr_reader(:cli_options)

  def initialize(prog_name, args)
    my_version = Loxxy::VERSION
    cli = Loxxy::CLIParser.new(prog_name, my_version)
    @cli_options = cli.parse!(args)
  end

  def run!(file_names)
    return if file_names.nil? || file_names.empty?

    lox = Loxxy::Interpreter.new
    begin
      file_names.each do |lox_file|
        fname = validate_filename(lox_file)
        next unless file_exist?(fname)

        File.open(fname, 'r') { |f| lox.evaluate(f.read) }
      end
    rescue Loxxy::ScanError => e
      $stderr.puts e.message
    end
  end

  private

  def validate_filename(raw_fname)
    # When necessary add extension to file name
    fname = raw_fname.dup
    basename = File.basename(fname)
    has_extension = basename =~ /(?<=[^.])\.[^.]+$/
    fname << '.' << DefaultLoxExtension unless has_extension

    fname
  end

  def file_exist?(fname)
    exists = File.exist?(fname)
    $stderr.puts "No such file '#{fname}'" unless exists

    exists
  end
end # class

########################################
# ENTRY POINT
########################################
program = LoxxyRunner.new(File.basename(__FILE__), ARGV)

# All options from CLI gobbled from ARGV, remains only file name
program.run!(ARGV)
# End of file