alert

#!/usr/bin/env ruby -w

require 'time'

# Usage:
#
#   alert
#   alert yellow
#   alert at 17:00
#   alert red at 11:29
#   alert green to "Green tea has finished brewing" in 2:45
#
# If no time is specified, alert immediately.
# If no color is specified, default to white.

# TODO:
#   - Add an actual help message.
#   - Move Alert to its own class.


# Check whether any blink(1)s are attached, by checking the exit status of the
# blink1-tool `--list` command.

def blink1_present?
  %x(blink1-tool --list)

  $?.success?
end


# Take a duration of the form
#
# [<hours>:][<minutes>:]seconds
#
# e.g. '2:30', '15:00', '1:30:00', etc.
#
# Return the equivalent number of seconds.
#
# TODO: Add support for "5m", "2m3s", etc.

def parse_delay(delay)
  values = delay.split(':').map(&:to_i)
  total = 0
  offset = 1

  until values.empty? do
    value = values.pop
    total += value * offset
    offset *= 60
  end

  total
end


def parse_args
  time = 0
  message = ""
  color = 'white'

  until ARGV.empty? do
    arg = ARGV.shift

    now = Time.now

    if arg.eql?('at')
      later = Time.parse(ARGV.shift)
      # If the specified time was earlier today, push it to tomorrow,
      # and alert the user that we're doing so.
      if now > later
        later += (24 * 3600)
        puts "Alert set for #{later.strftime('%H:%M:%S')} tomorrow."
      end
      time = later - now
    elsif arg.eql?('in')
      time = parse_delay(ARGV.shift)
    elsif arg.eql?('to')
      message = ARGV.shift
    else
      color = arg
    end

  end

  [time, message, color]
end

# ------------------

abort 'No blink(1) detected!' unless blink1_present?

time, message, color = parse_args

# fork() won't work on Windows or NetBSD. (File under "Boo frickin' hoo".)

fork do
  actions = [
    %Q(blink1-tool -q -m 0 -t 250 --#{color} --blink 10)
  ]

  unless message.empty?
    actions.concat [
      # I didn't pick Daniel because my ego likes the sound of my own name.
      # I just liked the sound of the voice.
      %Q(say -v Daniel "#{message}"),
      %Q(terminal-notifier -title "Alert" -message "#{message}")
    ]
  end

  sleep(time)
  actions.each do |action|
    fork { system(action) }
  end
end