require 'alias'

module Boson
  class Library
    # [*:class_commands*] A hash of commands to create. A hash key-pair can map command names to any string of ruby code
    #                     that ends with a method call. Or a key-pair can map a class to an array of its class methods
    #                     to create commands of the same name. Example:
    #                      :class_commands=>{'spy'=>'Bond.spy', 'create'=>'Alias.manager.create',
    #                       'Boson::Util'=>['detect', 'any_const_get']}
    # [*:no_alias_creation*] Boolean which doesn't create aliases for a library. Useful for libraries that configure command
    #                        aliases outside of Boson's control. Default is false.
    module Alias
      attr_reader :class_commands, :no_alias_creation
    end
    include Alias

    module AliasLoader
      def load_commands?
        super || @class_commands
      end

      def before_load_commands
        unless @class_commands.nil? || @class_commands.empty? || @method_conflict
          Boson::Manager.create_class_aliases(@module, @class_commands)
        end
        super
      end
    end
    include AliasLoader
  end

  class Manager
    def self.create_class_aliases(mod, class_commands)
      class_commands.dup.each {|k,v|
        if v.is_a?(Array)
          class_commands.delete(k).each {|e| class_commands[e] = "#{k}.#{e}"}
        end
      }
      Alias.manager.create_aliases(:any_to_instance_method, mod.to_s=>class_commands.invert)
    end

    module AliasLib
      def after_create_commands(lib, commands)
        create_command_aliases(lib, commands) if commands.size > 0 && !lib.no_alias_creation
      end

      def create_command_aliases(lib, commands)
        lib.module ? prep_and_create_instance_aliases(commands, lib.module) : check_for_uncreated_aliases(lib, commands)
      end

      def prep_and_create_instance_aliases(commands, lib_module)
        aliases_hash = {}
        select_commands = Boson.commands.select {|e| commands.include?(e.name)}
        select_commands.each do |e|
          if e.alias
            aliases_hash[lib_module.to_s] ||= {}
            aliases_hash[lib_module.to_s][e.name] = e.alias
          end
        end
        create_instance_aliases(aliases_hash)
      end

      def create_instance_aliases(aliases_hash)
        Alias.manager.create_aliases(:instance_method, aliases_hash)
      end

      def check_for_uncreated_aliases(lib, commands)
        if (found_commands = Boson.commands.select {|e| commands.include?(e.name)}) && found_commands.find {|e| e.alias }
          $stderr.puts "No aliases created for library #{lib.name} because it has no module"
        end
      end
    end
    include AliasLib
  end
end