# frozen_string_literal: true

require "much-mixin/version"

module MuchMixin
  def self.included(receiver)
    receiver.class_eval{ extend ClassMethods }
  end

  module ClassMethods
    # install an included block that first checks if this plugin's receiver mixin
    # has already been included.  If it has not been, include the receiver mixin
    # and run all of the `mixin_included` blocks
    def included(plugin_receiver)
      return if plugin_receiver.include?(self.much_mixin_included_detector)
      plugin_receiver.send(:include, self.much_mixin_included_detector)

      self.much_mixin_included_blocks.each do |block|
        plugin_receiver.class_eval(&block)
      end

      self.much_plugin_class_method_blocks.each do |block|
        self.much_mixin_class_methods_module.class_eval(&block)
      end
      plugin_receiver.send(:extend, self.much_mixin_class_methods_module)

      self.much_plugin_instance_method_blocks.each do |block|
        self.much_mixin_instance_methods_module.class_eval(&block)
      end
      plugin_receiver.send(:include, self.much_mixin_instance_methods_module)

      self.much_plugin_after_included_blocks.each do |block|
        plugin_receiver.class_eval(&block)
      end
    end

    # the included detector is an empty module that is only used to detect if
    # the plugin has been included or not, it doesn't add any behavior or
    # methods to the object receiving the plugin; we use `const_set` to name the
    # module so if its seen in the ancestors it doesn't look like some random
    # module and it can be tracked back to much-mixin
    def much_mixin_included_detector
      @much_mixin_included_detector ||= Module.new.tap do |m|
        self.const_set("MuchMixinIncludedDetector", m)
      end
    end

    def much_mixin_class_methods_module
      @much_mixin_class_methods_module ||= Module.new.tap do |m|
        self.const_set("MuchMixinClassMethods", m)
      end
    end

    def much_mixin_instance_methods_module
      @much_mixin_instance_methods_module ||= Module.new.tap do |m|
        self.const_set("MuchMixinInstanceMethods", m)
      end
    end

    def much_mixin_included_blocks
      @much_mixin_included_blocks ||= []
    end

    def much_plugin_after_included_blocks
      @much_plugin_after_included_blocks ||= []
    end

    def much_plugin_class_method_blocks
      @much_plugin_class_method_blocks ||= []
    end

    def much_plugin_instance_method_blocks
      @much_plugin_instance_method_blocks ||= []
    end

    def mixin_included(&block)
      self.much_mixin_included_blocks << block
    end
    alias_method :plugin_included, :mixin_included

    def after_mixin_included(&block)
      self.much_plugin_after_included_blocks << block
    end
    alias_method :after_plugin_included, :after_mixin_included

    def mixin_class_methods(&block)
      self.much_plugin_class_method_blocks << block
    end
    alias_method :plugin_class_methods, :mixin_class_methods

    def mixin_instance_methods(&block)
      self.much_plugin_instance_method_blocks << block
    end
    alias_method :plugin_instance_methods, :mixin_instance_methods
  end
end