require 'enumerator'

module Adhearsion
  module Asterisk
    class ConfigurationManager

      class << self
        def normalize_configuration(file_contents)
          # cat sip.conf | sed -e 's/\s*;.*$//g' | sed -e '/^;.*$/d' | sed -e '/^\s*$/d'
          file_contents.split(/\n+/).map do |line|
            line.sub(/;.+$/, '').strip
          end.join("\n").squeeze("\n")
        end
      end

      attr_reader :filename

      def initialize(filename)
        @filename = filename
      end

      def sections
        @sections ||= read_configuration
      end

      def [](section_name)
        result = sections.find { |(name, *rest)| section_name == name }
        result.last if result
      end

      def delete_section(section_name)
        sections.reject! { |(name, *rest)| section_name == name }
      end

      def new_section(name, properties={})
        sections << [name, properties]
      end

      private

      def read_configuration
        normalized_file = self.class.normalize_configuration File.open(@filename, 'r'){|f| f.read}
        sections = normalized_file.split(/^\[([-_\w]+)\]$/)[1..-1]
        return [] if sections.nil?
        sections.each_slice(2).map do |(name,properties)|
          [name, hash_from_properties(properties)]
        end
      end

      def hash_from_properties(properties)
        properties.split(/\n+/).inject({}) do |property_hash,property|
          all, name, value = *property.match(/^\s*([^=]+?)\s*=\s*(.+)\s*$/)
          next property_hash unless name && value
          property_hash[name] = value
          property_hash
        end
      end
    end
  end
end