#!/usr/bin/env ruby

require 'syslogstash'
require 'logger'

logger = Logger.new($stderr)
logger.formatter = ->(s, t, p, m) { "#{s[0]} [#{p}] #{m}\n" }
logger.level = Logger.const_get(ENV['SYSLOGSTASH_LOG_LEVEL'] || "INFO")

begin
  cfg = Syslogstash::Config.new(ENV, logger: logger)
rescue Syslogstash::Config::ConfigurationError => ex
  $stderr.puts "Error in configuration: #{ex.message}"
  exit 1
end

syslogstash = Syslogstash.new(cfg)

sig_r, sig_w = IO.pipe

Signal.trap("USR1") do
  sig_w.print '1'
end
Signal.trap("USR2") do
  sig_w.print '2'
end
Signal.trap("URG") do
  sig_w.print 'U'
end
Signal.trap("HUP") do
  sig_w.print 'H'
end

Thread.new do
  loop do
    begin
      c = sig_r.getc
      if c == '1'
        logger.level -= 1 unless logger.level == Logger::DEBUG
        logger.info("SignalHandler") { "Received SIGUSR1; log level is now #{Logger::SEV_LABEL[logger.level]}." }
      elsif c == '2'
        logger.level += 1 unless logger.level == Logger::ERROR
        logger.info("SignalHandler") { "Received SIGUSR2; log level is now #{Logger::SEV_LABEL[logger.level]}." }
      elsif c == 'U'
        cfg.relay_to_stdout = !cfg.relay_to_stdout
        logger.info("SignalHandler") { "Received SIGURG; Relaying to stdout is now #{cfg.relay_to_stdout ? "enabled" : "disabled"}" }
      elsif c== 'H'
        logger.info("SignalHandler") { "Received SIGHUP" }
        syslogstash.force_disconnect!
      else
        logger.error("SignalHandler") { "Got an unrecognised character from signal pipe: #{c.inspect}" }
      end
    rescue StandardError => ex
      logger.error("SignalHandler") { (["Exception raised: #{ex.message} (#{ex.class})"] + ex.backtrace).join("\n  ") }
    rescue Exception => ex
      $stderr.puts (["Fatal exception in syslogstash signal handler: #{ex.message} (#{ex.class})"] + ex.backtrace).join("\n  ")
      exit 42
    end
  end
end

syslogstash.run