require 'puppet/property'

# This property will get automatically added to any type that responds
# to the methods 'exists?', 'create', and 'destroy'.
class Puppet::Property::Ensure < Puppet::Property
    @name = :ensure

    def self.defaultvalues
        newvalue(:present) do
            if @resource.provider and @resource.provider.respond_to?(:create)
                @resource.provider.create
            else
                @resource.create
            end
            nil # return nil so the event is autogenerated
        end

        newvalue(:absent) do
            if @resource.provider and @resource.provider.respond_to?(:destroy)
                @resource.provider.destroy
            else
                @resource.destroy
            end
            nil # return nil so the event is autogenerated
        end

        defaultto do
            if @resource.managed?
                :present
            else
                nil
            end
        end

        # This doc will probably get overridden
        @doc ||= "The basic property that the resource should be in."
    end

    def self.inherited(sub)
        # Add in the two properties that everyone will have.
        sub.class_eval do
        end
    end

    def change_to_s(currentvalue, newvalue)
        begin
            if currentvalue == :absent or currentvalue.nil?
                return "created"
            elsif newvalue == :absent
                return "removed"
            else
                return "%s changed '%s' to '%s'" % [self.name, self.is_to_s(currentvalue), self.should_to_s(newvalue)]
            end
        rescue Puppet::Error, Puppet::DevError
            raise
        rescue => detail
            raise Puppet::DevError, "Could not convert change %s to string: %s" % [self.name, detail]
        end
    end

    def retrieve
        # XXX This is a problem -- whether the object exists or not often
        # depends on the results of other properties, yet we're the first property
        # to get checked, which means that those other properties do not have
        # @is values set.  This seems to be the source of quite a few bugs,
        # although they're mostly logging bugs, not functional ones.
        if prov = @resource.provider and prov.respond_to?(:exists?)
            result = prov.exists?
        elsif @resource.respond_to?(:exists?)
            result = @resource.exists?
        else
            raise Puppet::DevError, "No ability to determine if %s exists" % @resource.class.name
        end
        if result
            return :present
        else
            return :absent
        end
    end

    # If they're talking about the thing at all, they generally want to
    # say it should exist.
    #defaultto :present
    defaultto do
        if @resource.managed?
            :present
        else
            nil
        end
    end
end