class Jets::Processors::MainProcessor

def initialize(event, context, handler)
  @event = event
  @context = context
  @handler = handler
end

def run
  # Use the handler to deduce app code to run.
  # Example handlers: handlers/controllers/posts.create, handlers/jobs/sleep.perform
  #
  #   deducer = Jets::Processors::Deducer.new("handlers/controllers/posts.create")
  #
  deducer = Jets::Processors::Deducer.new(handler)
  begin
    # Examples:
    #   deducer.code => PostsController.process(event, context, "show")
    #   deducer.path => app/controllers/posts_controller.rb
    #
    #   deducer.code => HardJob.process(event, context, "dig")
    #   deducer.path => app/jobs/hard_job.rb
    #
    #   deducer.code => HelloFunction.process(event, context, "world")
    #   deducer.path => app/functions/hello.rb
    deducer.load_class
    # result = PostsController.process(event, context, "create")
    result = instance_eval(deducer.code, deducer.path)
    result = HashWithIndifferentAccess.new(result) if result.is_a?(Hash)
    Jets.increase_call_count
    if result.is_a?(Hash) && result["headers"]
      # API Gateway is okay with the header values as Integers but
      # ELBs are more strict about this and require the header values to be Strings
      result["headers"]["x-jets-call-count"] = Jets.call_count.to_s
      result["headers"]["x-jets-prewarm-count"] = Jets.prewarm_count.to_s
    end
    result
  rescue Exception => e
    unless ENV['TEST']
      # Customize error message slightly so nodejs shim can process the
      # returned error message.
      # The "RubyError: " is a marker that the javascript shim scans for.
      $stderr.puts("RubyError: #{e.class}: #{e.message}") # js needs this as the first line
      backtrace = e.backtrace.map {|l| "  #{l}" }
      $stderr.puts(backtrace)
      # No need to having error in stderr above anymore because errors are handled in memory
      # at ruby_server.rb but keeping around for posterity.
    end
    Jets.on_exception(e)
    raise(e) # raise error to ruby_server.rb to rescue and handle
  end
end