# 
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
# 
#   http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
# 

require 'logger'

module Thrift
  module Processor
    def initialize(handler, logger=nil)
      @handler = handler
      if logger.nil?
        @logger = Logger.new(STDERR)
        @logger.level = Logger::WARN
      else
        @logger = logger
      end
    end

    def process(iprot, oprot)
      name, type, seqid  = iprot.read_message_begin
      if respond_to?("process_#{name}")
        begin
          send("process_#{name}", seqid, iprot, oprot)
        rescue => e
          x = ApplicationException.new(ApplicationException::INTERNAL_ERROR, 'Internal error')
          @logger.debug "Internal error : #{e.message}\n#{e.backtrace.join("\n")}"
          write_error(x, oprot, name, seqid)
        end
        true
      else
        iprot.skip(Types::STRUCT)
        iprot.read_message_end
        x = ApplicationException.new(ApplicationException::UNKNOWN_METHOD, 'Unknown function '+name)
        write_error(x, oprot, name, seqid)
        false
      end
    end

    def read_args(iprot, args_class)
      args = args_class.new
      args.read(iprot)
      iprot.read_message_end
      args
    end

    def write_result(result, oprot, name, seqid)
      oprot.write_message_begin(name, MessageTypes::REPLY, seqid)
      result.write(oprot)
      oprot.write_message_end
      oprot.trans.flush
    end

    def write_error(err, oprot, name, seqid)
      oprot.write_message_begin(name, MessageTypes::EXCEPTION, seqid)
      err.write(oprot)
      oprot.write_message_end
      oprot.trans.flush
    end
  end
end