require 'ostruct'

module Adhearsion
  module VoIP
    module DSL
      module Dialplan
        #TODO: This is obsolete, but we still need it for Freeswitch until we port that to the new 0.8.0 APIs
        module DialplanParser

          # Create a container and then clone that. when the container is created
          # it should have all the contexts meta_def'd into it. for each call coming
          # in, the cloned copy has the variables meta_def'd and set as instance
          # variables

          #TODO: separate into smaller pieces
          def self.get_contexts
            envelope = ContextsEnvelope.new

            dialplans = AHN_CONFIG.files_from_setting "paths", "dialplan"
            ahn_log.dialplan.warn "No dialplan files were found!" if dialplans.empty?

            {}.tap do |contexts|
              dialplans.each do |file|
                raise "Dialplan file #{file} does not exist!" unless File.exists? file
                envelope.instance_eval do
                  eval File.read(file)
                end
                current_contexts = envelope.parsed_contexts
                current_contexts.each_pair do |name, block|
                  if contexts.has_key? name
                    warn %'Dialplan context "#{name}" exists in both #{contexts[name].file} and #{file}.' +
                         %' Using the "#{name}" context from #{contexts[name].file}.'
                  else
                    contexts[name] = OpenStruct.new.tap do |metadata|
                      metadata.file  = file
                      metadata.name  = name
                      metadata.block = block
                    end
                  end
                end
              end
            end
          end
        end

        class ContextsEnvelope

          keep = [:define_method, :instance_eval, :meta_def, :meta_eval, :metaclass, :methods, :object_id]
          (instance_methods.map{|m| m.to_sym} - keep).each { |m| undef_method m unless m.to_s =~ /^__/ }

          def initialize
            @parsed_contexts = {}
          end

          attr_reader :parsed_contexts

          def method_missing(name, *args, &block)
            super unless block_given?
            @parsed_contexts[name] = block
            meta_def(name) { block }
          end

        end

      end

    end
  end
end