#!/usr/bin/env ruby

# Install: kid3-common

require "fileutils"

$stdout.sync = true
files = Dir.glob("*.mp3").sort

if files.empty?
  $stderr.puts "No .mp3 files found"
  exit 1
end

unless File.exist?("albumart.jpg")
  $stderr.puts "albumart.jpg not found"
  exit 1
end

unless File.exist?("info.txt")
  $stderr.puts "info.txt not found"
  exit 1
end

info = File.read("info.txt")
info =~ /^artist: (.*)$/
artist = $1
info =~ /^album: (.*)$/
album = $1
info =~ /^year: (.*)$/
date = $1

unless artist && album && date
  $stderr.puts "invalid info.txt format"
  exit 1
end

#$stdout.write("Release date (YYYY-MM-DD): ")
#date = gets.chomp
#unless date =~ /^\d{4}-\d{2}-\d{2}$/
#  $stderr.puts "Unexpected date format"
#  exit 1
#end

files.each do |file|
  if file =~ /^(\d+)\s*(.*)\.mp3$/
    track_number, title = $1.to_i, $2
    command = %w[kid3-cli]
    command += ["-c", "revert", "-c", "save"]
    command += ["-c", %[set artist "#{artist}" 12]]
    command += ["-c", %[set title "#{title}" 12]]
    command += ["-c", %[set album "#{album}" 12]]
    command += ["-c", %[set date "#{date}" 12]]
    command += ["-c", %[set track "#{track_number}" 12]]
    command += ["-c", %[set picture:albumart.jpg 'Front Cover' 2]]
    command += ["-c", "save"]
    command << file
    system(*command)
  else
    $stderr.puts "Warning: skipping #{file}, unrecognized name format"
  end
end