#--
# =============================================================================
# Copyright (c) 2004, Jamis Buck (jgb3@email.byu.edu)
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# 
#     * Redistributions of source code must retain the above copyright notice,
#       this list of conditions and the following disclaimer.
# 
#     * Redistributions in binary form must reproduce the above copyright
#       notice, this list of conditions and the following disclaimer in the
#       documentation and/or other materials provided with the distribution.
# 
#     * The names of its contributors may not be used to endorse or promote
#       products derived from this software without specific prior written
#       permission.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
# =============================================================================
#++

require 'copland/impl/include-exclude'

module Copland
  module Implementation

    # This is the implementation of the service factory that provides
    # instances of logging interceptors. It includes the IncludeExcludeFactory
    # functionality.
    class LoggingInterceptorFactory
      include IncludeExcludeFactory

      # Returns a new LoggingInterceptor instance, initialized with the given
      # parameters.
      def create_instance( point, parms )
        includes = build_map( parms[ "include" ] )
        excludes = build_map( parms[ "exclude" ] )

        return LoggingInterceptor.new( point, includes, excludes )
      end

    end

    # A LoggingInterceptor is an interceptor object that logs method
    # invocations and exceptions. It includes the IncludeExclude functionality.
    class LoggingInterceptor
      include IncludeExclude

      # The log used by this interceptor to log messages.
      attr_reader :log

      # The array of patterns of methods to log.
      attr_reader :includes

      # The array of patterns of methods to _not_ log.
      attr_reader :excludes

      # Create a new LoggingInterceptor for the given service point, with the
      # given list of include and exclude patterns. The logger object will be
      # created as well, named with the service point's full name.
      def initialize( point, includes, excludes )
        @log = point.owner.registry.logs.get( point.full_name )
        @includes = includes
        @excludes = excludes
      end

      # Processes a method invocation context. If the current log has debugging
      # activated, and the requested method is not excluded by the
      # interceptor's exclude and include patterns, then a message will be
      # written for the method's invocation, its return code, and any exception
      # that is thrown.
      def process( chain, context )
        if @log.debug? && match( context )
          args = context.args.map { |i| i.inspect } .join( ', ' )
          @log.debug "#{context.sym}( #{args} )"

          begin
            result = chain.process_next( context )
          rescue Exception => e
            @log.debug "#{context.sym} raised #{e.message.inspect} (#{e.class})"
            raise
          end

          @log.debug "#{context.sym} => #{result.inspect}"
          return result
        else
          return chain.process_next( context )
        end
      end

    end

  end
end