#!/usr/bin/env ruby
# -*- mode: enh-ruby -*-

require 'uri/ni'
require 'pathname'
require 'optparse'

options = {}
op = OptionParser.new do |opts|
  opts.banner = "Usage: ni-uri [options] FILES"

  opts.on("-a", "--algorithm STRING", "algorithm") do |a|
    options[:algorithm] = a.to_sym
  end
end

op.parse!

options[:algorithm] ||= :"sha-256"
unless URI::NI.valid_algo? options[:algorithm]
  $stderr.puts "#{options[:algorithm]} is not a valid algorithm"
  exit 1
end

if ARGV.empty?
  puts op.to_s
  exit 1
end

ARGV.each do |fn|
  fn = Pathname(fn).expand_path
  begin
    fh = fn.open
    ni = URI::NI.compute fh, algorithm: options[:algorithm]
    puts ni.to_s
  rescue SystemCallError => e
    $stderr.puts "Could not compute digest for #{fn}: #{e.message}"
    next
  end
end