require 'java'

# This hack get rif of the "Use RbConfig instead of obsolete and deprecated Config"
# deprecation warning that is triggered by "java_import 'backtype.storm.Config'".
begin
  Object.send :remove_const, :Config
  Config = RbConfig
rescue NameError
end

# see https://github.com/colinsurprenant/redstorm/issues/7
module Backtype
  java_import 'backtype.storm.Config'
end

java_import 'backtype.storm.LocalCluster'
java_import 'backtype.storm.LocalDRPC'
java_import 'backtype.storm.StormSubmitter'
java_import 'backtype.storm.topology.TopologyBuilder'
java_import 'backtype.storm.coordination.BatchBoltExecutor'
java_import 'backtype.storm.drpc.LinearDRPCTopologyBuilder'
java_import 'backtype.storm.tuple.Fields'
java_import 'backtype.storm.tuple.Tuple'
java_import 'backtype.storm.tuple.Values'

java_package 'redstorm'

# TopologyLauncher is the application entry point when launching a topology. Basically it will
# call require on the specified Ruby topology class file path and call its start method
class TopologyLauncher

  java_signature 'void main(String[])'
  def self.main(args)
    unless args.size > 1
      puts("Usage: redstorm local|cluster topology_class_file_name")
      exit(1)
    end

    env = args[0].to_sym

    # If we're in the "cluster" mode that means we're running in an embedded JRuby
    # and we should modify our environment to suit that, see:
    # <https://github.com/jruby-gradle/redstorm/issues/12>
    if env == :cluster
      Dir.chdir('uri:classloader:/')
      ENV['JARS_HOME'] = 'uri:classloader:/jars'
      $LOAD_PATH.unshift('uri:classloader://')
    end
    class_path = args[1]

    launch_path = Dir.pwd
    $:.unshift File.expand_path(launch_path)
    $:.unshift File.expand_path(launch_path + '/lib')
    $:.unshift File.expand_path(launch_path + '/target/lib')

    begin
      require 'jars/setup'
      require "#{class_path}"
    rescue => ex
      puts "Failed to load #{class_path}! (#{ex.inspect})"
      puts ex.backtrace.join("\n")
      # Re-raising to exit out of the scripting container
      raise
    end

    if RedStorm::Configuration.topology_class.nil? || !RedStorm::Configuration.topology_class.method_defined?(:start)
      puts("\nERROR: invalid topology class. make sure your topology class is a subclass of one of the DSL topology classes or that your class sets RedStorm::Configuration.topology_class and defines the start method\n\n")
      exit(1)
    end

    topology_name = RedStorm::Configuration.topology_class.respond_to?(:topology_name) ? "/#{RedStorm::Configuration.topology_class.topology_name}" : ''
    puts("RedStorm v#{RedStorm::VERSION} starting topology #{RedStorm::Configuration.topology_class.name}#{topology_name} in #{env.to_s} environment")
    RedStorm::Configuration.topology_class.new.start(env)
  end

  private

  def self.camel_case(s)
    s.to_s.gsub(/\/(.?)/) { "::#{$1.upcase}" }.gsub(/(?:^|_)(.)/) { $1.upcase }
  end
end