require 'dub/generator'
require 'erb'

module Dub
  module Lua
    class NamespaceGen < Dub::Generator
      def initialize
        @namespace_template = ::ERB.new(File.read(File.join(File.dirname(__FILE__), 'namespace.cpp.erb')))
      end

      def namespace(namespace)
        @namespace = namespace
        @namespace_template.result(binding)
      end

      def class_generator
        Lua.class_generator
      end

      def function_generator
        Lua.function_generator
      end

      def functions_registration(namespace = @namespace)
        (namespace.members || []).map do |method|
          "{%-32s, #{method.method_name(0)}}" % method.name.inspect
        end.join(",\n")
      end

      def constants_registration(namespace = @namespace)
        res = []
        if namespace.has_enums?
          res << namespace.enums.map do |name|
            "{%-32s, #{namespace.full_type}::#{name}}" % name.inspect
          end.join(",\n")
        end

        if namespace.has_defines?
          res << namespace.defines.map do |name|
            "{%-32s, #{name}}" % name.inspect
          end.join(",\n")
        end

        same = namespace.enums & namespace.defines
        unless same.empty?
          # Should never happen (not sure if it would compile ok in the first place)
          puts "Warning: the following are present both as enum and define: #{same.inspect}"
        end
        res.join(",\n\n")
      end

      def members_list(all_members, ignore_list = [])
        list = (all_members || []).map do |member_or_group|
          if ignore_list.include?(member_or_group.name)
            nil
          elsif member_or_group.kind_of?(Array)
            members_list(member_or_group)
          elsif ignore_member?(member_or_group)
            nil
          else
            member_or_group
          end
        end

        list.compact!
        list == [] ? nil : list
      end

      def ignore_member?(member)
        if member.name =~ /^~/           || # do not build constructor
           member.name =~ /^operator/    || # no conversion operators
           member.original_signature =~ />/ || # no complex types in signature
           member.has_array_arguments? ||
           member.vararg? ||
           member.original_signature =~ /void\s+\*/ ||
           member.has_class_pointer_arguments?

          true # ignore
        elsif return_value = member.return_value
          return_value.type =~ />$/    || # no complex return types
          return_value.is_native? && member.return_value.is_pointer?
        else
          false # ok, do not ignore
        end
      end
    end
  end
end