#!/usr/bin/env ruby

# better? -> https://github.com/bluepill-rb/bluepill

# ~/forever/forever.txt
# test:  /Users/dux/.rvm/rubies/ruby-2.3.1/bin/ruby /Users/dux/dev/lux-fw/raumdog.com/test.rb
# test2: /Users/dux/.rvm/rubies/ruby-2.3.1/bin/ruby /Users/dux/dev/lux-fw/raumdog.com/test2.rb

# creates ~/forever/logs and ~/forever/pids
# keeps logs in size

# 1 1 * * * bash -l -c 'ruby /User/adsad/../forever'

require 'colorize'
require 'fileutils'

@root = File.expand_path('~/forever')
@max_file_size_in_mb = 1

def die(data)
  puts data.red
  exit
end

def demonize(id, script)
  size = @max_file_size_in_mb * 1_000_000

  # rotate big files
  for log_file in ["#{@root}/logs/#{id}.log", "#{@root}/logs/#{id}.err"]
    if File.size?(log_file).to_i > (size * 3)
      puts "truncate #{log_file} to #{size}".yellow
      data = File.read(log_file)
      data = data[data.length - size, size]
      File.open(log_file, 'w') { |f| f.write(data) }
    end
  end

  pid_file = "#{@root}/pids/#{id}.pid"
  pid = File.read(pid_file).chomp rescue nil

  env_id = "FOREVER_ID=#{id}_END"

  if pid && `ps aux | grep #{env_id} | grep #{pid}`.index(script)
    puts "exists #{id.ljust(15)} pid #{pid}".green
  else
    print "starting #{id.ljust(15)} pid ".yellow
    `nohup #{script} #{env_id} >> #{@root}/logs/#{id}.log 2>> #{@root}/logs/#{id}.err < /dev/null & echo $! > #{pid_file}`
    puts File.read(pid_file)
  end
end

file = "#{@root}/forever.txt"
die "~/forever/forever.txt not present (#{file})" unless File.exist?(file)

FileUtils.mkdir_p "#{@root}/logs"
FileUtils.mkdir_p "#{@root}/pids"

apps = File.read(file).to_s.split("\n")

for line in apps
  next if line[0,1] == '#'
  id, script = line.split(/\s*:\s*/, 2)
  next unless script
  demonize id, script
end