# frozen_string_literal: true

module GObjectIntrospection
  # Wraps GIBaseInfo struct, the base \type for all info types.
  # Decendant types will be implemented as needed.
  class IBaseInfo
    def initialize(ptr)
      raise ArgumentError, "ptr must not be null" if ptr.null?

      ObjectSpace.define_finalizer self, self.class.make_finalizer(ptr)

      @pointer = ptr
    end

    attr_reader :pointer

    def self.make_finalizer(ptr)
      proc { finalize ptr }
    end

    class << self
      protected

      def finalize(ptr)
        Lib.g_base_info_unref ptr
      end
    end

    def to_ptr
      @pointer
    end

    # This is a helper method to construct a method returning an array, out
    # of the methods returning their number and the individual elements.
    #
    # For example, given the methods +n_foos+ and +foo+(+i+), this method
    # will create an additional method +foos+ returning all foos.
    #
    # Provide the second parameter if the plural is not trivially
    # constructed by adding +s+ to the singular.
    #
    # Examples:
    #
    #   build_array_method :fields
    #   build_array_method :properties, :property
    #   build_array_method :get_methods
    #
    def self.build_array_method(method, single = nil)
      method = method.to_s
      cache_ivar = "@#{method}_cache"
      single ||= method[0..-2]
      count = method.sub(/^(get_)?/, "\\1n_")
      class_eval <<-CODE, __FILE__, __LINE__ + 1
        def #{method}                       # def fields
          #{cache_ivar} ||=                 #   @fields_cache ||=
            (0..(#{count} - 1)).map do |i|  #     (0..(n_fields - 1)).map do |i|
              #{single} i                   #       field i
            end                             #     end
        end                                 # end
      CODE
    end

    # This is a helper method to construct a method for finding an element, out
    # of the methods returning their number and the individual elements.
    #
    # For example, given the methods +n_foos+ and +foo+(+i+), this method will
    # create an additional method +find_foo+ returning the foo with the
    # matching name.
    #
    # Optionally provide counter and fetcher methods if they cannot be
    # trivially derived from the finder method.
    #
    # Examples:
    #
    #   build_finder_method :find_field
    #   build_finder_method :find_property, :n_properties
    #   build_finder_method :find_method, :get_n_methods, :get_method
    #
    def self.build_finder_method(method, counter = nil, fetcher = nil)
      method = method.to_s
      cache_ivar = "@#{method}_cache"
      single = method.sub(/^find_/, "")
      counter ||= "n_#{single}s"
      fetcher ||= single
      class_eval <<-CODE, __FILE__, __LINE__ + 1
        def #{method}(name)           # def find_field(name)
          #{cache_ivar} ||= begin     #   @find_field_cache ||= begin
              hash = {}               #       hash = {}
              #{counter}.times do |i| #       n_fields.times do |i|
                it = #{fetcher}(i)    #         it = field(i)
                hash[it.name] = it    #         hash[it.name] = it
              end                     #       end
              hash                    #       hash
            end                       #     end
          name = name.to_s            #   name = name.to_s
          #{cache_ivar}[name]         #   @find_field_cache[name]
        end                           # end
      CODE
    end

    def name
      @name ||= Lib.g_base_info_get_name self
    end

    def info_type
      @info_type ||= Lib.g_base_info_get_type self
    end

    def namespace
      @namespace ||= Lib.g_base_info_get_namespace self
    end

    def safe_namespace
      namespace.sub(/^[a-z]/, &:upcase)
    end

    def container
      @container ||= begin
                       ptr = Lib.g_base_info_get_container self
                       unless ptr.null?
                         Lib.g_base_info_ref ptr
                         IRepository.wrap_ibaseinfo_pointer ptr
                       end
                     end
    end

    def deprecated?
      Lib.g_base_info_is_deprecated self
    end

    def attribute(name)
      Lib.g_base_info_get_attribute self, name
    end

    def self.wrap(ptr)
      new ptr unless ptr.null?
    end

    def ==(other)
      other.is_a?(IBaseInfo) && Lib.g_base_info_equal(self, other)
    end
  end
end
