#!/usr/bin/env ruby
#
# omptagger
# http://github.com/omp/omptagger
# Modify and display metadata of audio files.
#
# Copyright 2007-2010 David Vazgenovich Shakaryan <dvshakaryan@gmail.com>
# Distributed under the terms of the GNU General Public License v3.
# See http://www.gnu.org/licenses/gpl.txt for the full license text.

require 'getoptlong'

def help
  puts <<-end
Usage: omptagger [options] [files]

Options:
  --view        -v  View all tags
  --view-tag    -t  View a tag
  --set-tag     -s  Set a tag
  --remove      -r  Remove all tags
  --remove-tag  -d  Remove a tag
  --generate    -g  Generate tags based on filename
  --rename      -m  Generate filename based on tags
  --scheme      -n  Specify a file naming scheme
  --pretend     -p  Do not make any actual changes
  --list        -l  Display list of available tags
  --help        -h  Display help information

Notes:
  * The default file naming scheme is Artist - Title.
  * Schemes must be specified prior to actions that use them.
  end

  exit
end

def list
  puts <<-end
┌────────────────────────┐
│ Keys   Vorbis Comments │
├────────────────────────┤
│ %a     Artist          │
│ %b     Album           │
│ %d     Date            │
│ %n     TrackNumber     │
│ %t     Title           │
│ %*     Wildcard        │
├────────────────────────┤
│        Contact         │
│        Copyright       │
│        Description     │
│        Genre           │
│        ISRC            │
│        License         │
│        Location        │
│        Organization    │
│        Performer       │
│        Version         │
└────────────────────────┘
  end

  exit
end

actions = Array.new
options = Array.new
scheme  = '%a - %t'

GetoptLong.new(
  ['--view',       '-v', GetoptLong::NO_ARGUMENT],
  ['--view-tag',   '-t', GetoptLong::REQUIRED_ARGUMENT],
  ['--set-tag',    '-s', GetoptLong::REQUIRED_ARGUMENT],
  ['--remove',     '-r', GetoptLong::NO_ARGUMENT],
  ['--remove-tag', '-d', GetoptLong::REQUIRED_ARGUMENT],
  ['--generate',   '-g', GetoptLong::NO_ARGUMENT],
  ['--rename',     '-m', GetoptLong::NO_ARGUMENT],
  ['--scheme',     '-n', GetoptLong::REQUIRED_ARGUMENT],
  ['--pretend',    '-p', GetoptLong::NO_ARGUMENT],
  ['--list',       '-l', GetoptLong::NO_ARGUMENT],
  ['--help',       '-h', GetoptLong::NO_ARGUMENT]
).each do |option, argument|
  option = option.delete('-').intern

  case option
  when :scheme
    scheme = argument
  when :help, :list, :pretend
    options << option
  when :viewtag, :settag, :removetag
    actions << [option, argument]
  when :generate, :rename
    actions << [option, scheme]
  else
    actions << option
  end
end

help if options.include?(:help)
list if options.include?(:list)
help if actions.empty?

puts 'No files specified.' if ARGV.empty?