#!/usr/bin/env ruby
#
# Copyright (c) 2018 Yegor Bugayenko
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the 'Software'), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

STDOUT.sync = true

require 'slop'
require 'tempfile'
require 'open3'

$opts = Slop.parse(ARGV, strict: false, suppress_errors: true) do |o|
  o.banner = "Usage: zold-nohup [options] ...
Run 'zold --help' for the full list of options and commands"
  o.bool '-h', '--help', 'Show these instructions'
  o.string '--log-file',
    'The file to save logs into (default: ./zold-nohup.log)',
    default: './zold-nohup.log'
  o.bool '--skip-log-trim',
    'Don\'t trim the log file before start (default: false)',
    default: false
  o.bool '--skip-install',
    'Don\'t re-install Zold gem (default: false)',
    default: false
  o.bool '--sudo-install',
    'Install Zold gem via sudo (default: false)',
    default: false
end

if $opts.help?
  puts($opts.to_s)
  exit(0)
end

def log(line)
  File.open($opts['log-file'], 'a') { |f| f.print(line) }
end

def exec(cmd)
  Open3.popen2e(cmd) do |stdin, stdout, thr|
    log("Started: #{cmd}")
    stdin.close
    loop do
      line = stdout.gets
      break if line.nil?
      log(line)
    end
    code = thr.value.exitstatus
    log("Exit code is #{code}: #{cmd}")
    raise "Exit code #{code} (non zero)" unless code.zero?
  end
end

File.delete($opts['log-file']) if File.exist?($opts['log-file']) && !$opts['skip-log-trim']

$pid = fork do
  Signal.trap('HUP') do
    print('Received HUP, ignoring...')
  end
  Signal.trap('TERM') do
    print('Received TERM, terminating...')
    exit(-1)
  end
  loop do
    exec("zold #{$opts.arguments.join(' ')}")
    exec(($opts['sudo-install'] ? 'sudo ' : '') + 'gem install zold') unless $opts['skip-install']
  end
end
Process.detach($pid)

puts($pid)