#
#--
# Copyright (c) 2007, John Mettraux, OpenWFE.org
# 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.
# 
# . Neither the name of the "OpenWFE" nor the names of its contributors may 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.
#++
#

#
# "made in Japan"
#
# John Mettraux at openwfe.org
#

#require 'date'

require 'openwfe/service'
require 'openwfe/omixins'
require 'openwfe/rudefinitions'


module OpenWFE
    
    #
    # A Mixin for history modules
    #
    module HistoryMixin
        include ServiceMixin, OwfeServiceLocator

        def service_init (service_name, application_context)

            super

            get_expression_pool.add_observer(:all) do |event, *args|
                log(event, *args)
            end
        end

        def log (event, *args)
            raise NotImplementedError.new(
                "please provide an implementation of log(e, fei, wi)")
        end
    end

    #
    # A base implementation for InMemoryHistory and FileHistory.
    #
    class BaseHistory 
        include HistoryMixin
        include FeiMixin

        attr_reader :entries

        def initialize (service_name, application_context)

            super()

            service_init(service_name, application_context)
        end

        def log (event, *args)

            return if event == :update
            return if event == :reschedule
            return if event == :stop

            msg = "#{Time.now.to_s} -- "

            msg << event.to_s

            if args.length > 0
                fei = extract_fei args[0]
                msg << " #{fei.to_s}"
            end

            #msg << " #{args[1].to_s}" \
            #    if args.length > 1

            @output << msg + "\n"
        end
    end

    #
    # The simplest implementation, stores all history entries in memory.
    #
    # DO NOT USE IN PRODUCTION, it will trigger an 'out of memory' error
    # sooner or later.
    #
    # Is only used for unit testing purposes.
    #
    class InMemoryHistory < BaseHistory

        def initialize (service_name, application_context)
            super

            @output = []
        end

        #
        # Returns the array of entries.
        #
        def entries
            @output
        end

        #
        # Returns all the entries as a String.
        #
        def to_s
            s = ""
            @output.each do |entry|
                s << entry.to_s
            end
            s
        end
    end

    #
    # Simply dumps the history in the work directory in a file named 
    # "history.log"
    # Warning : no fancy rotation or compression implemented here.
    #
    class FileHistory < BaseHistory

        def initialize (service_name, application_context)

            super

            @output = get_work_directory + "/history.log"
            @output = File.open(@output, "w+")

            linfo { "new() outputting history to #{@output.path}" }
        end

        #
        # Returns a handle on the output file instance used by this 
        # FileHistory.
        #
        def output_file
            @output
        end

        def stop
            @output.close
        end
    end

end