human-media-time

#!/usr/bin/env ruby

require 'open3'
require 'optparse'
require 'pathname'

# Options
ARGV.push('--help') if ARGV.empty?

options = {}
OptionParser.new do |parser|
  parser.banner = <<~BANNER
    Calculate and present total running time of media files in a human-readable way.
    Options are mutually exclusive.

    Usage:
      #{File.basename($PROGRAM_NAME)} [options] <file...>

    Options:
  BANNER

  parser.on(
    '-u <s|d|h|m>', '--unit', %w[s d h m],
    'Output a whole number of the total time rounded to the unit.'
  )

  parser.on(
    '-p <s|d|h|m>', '--precision', %w[s d h m],
    'Output human-readable result rounded and truncated to the chosen unit. Values of zero are ommited unless there is only one.'
  )
end.parse!(into: options)

input_files = ARGV.map { |arg|
  init_path = Pathname.new(arg)

  next nil unless init_path.exist?
  next init_path if init_path.file?
  next init_path.glob('**/*').select(&:file?) if init_path.directory?
  next nil
}.flatten.compact

# Parse time values
total_time = {} # Each unit has the total value of everything
split_time = {} # Each unit has its corresponding value with the others discounted

seconds_total = input_files.map { |file|
  Open3.capture2(
    'ffprobe',
    '-loglevel', 'quiet',
    '-output_format', 'csv=p=0',
    '-show_entries', 'format=duration',
    file.to_path
  ).first.to_f
}.reduce(0, :+)

# Building the hashes in this order simplifies the 'reduce' later on
total_time['d'] = seconds_total / (60 * 60 * 24)
total_time['h'] = seconds_total / (60 * 60)
total_time['m'] = seconds_total / (60)
total_time['s'] = seconds_total

split_time['d'] = total_time['d'] % 365
split_time['h'] = total_time['h'] % 24
split_time['m'] = total_time['m'] % 60
split_time['s'] = total_time['s'] % 60

# Output unit
if options[:unit]
  puts total_time[options[:unit]].round
  exit 0
end

# If no precision is given, assume seconds
options[:precision] = 's' if options[:precision].nil?

# The split_times hash includes floats, so here is where we round the values we want and discard the ones we do not
time_hash = {}

split_time.keys.each do |unit|
  if unit == options[:precision]
    time_hash[unit] = split_time[unit].round
    break # Since we already reached our desired precision, all further keys can be ignored
  end

  time_hash[unit] = split_time[unit].to_i
end

# Normalise rare cases where rounding precision would give an underisable result
# Without this, a starting point of '1d 23h 50m 53s' rounded to hours would result in '1d 24h' instead of '2d'
if time_hash['s'] == 60
  time_hash['m'] += 1
  time_hash.delete('s')
end

if time_hash['m'] == 60
  time_hash['h'] += 1
  time_hash.delete('m')
end

if time_hash['h'] == 24
  time_hash['d'] += 1
  time_hash.delete('h')
end

# Eliminate zeros
time_hash.reject! { |_, value| value.zero? }

# Output when all zeroes
if time_hash.empty?
  puts "0#{options[:precision]}"
  exit 0
end

# Output human-readable format
puts time_hash.reduce('') { |string, (key, value)| "#{string}#{value}#{key} " }.strip