module ActiveNotifier
  module Configurable
    extend ActiveSupport::Concern

    module ClassMethods
      # Configure for ActiveNotifier.
      #
      # @example
      #   ActiveNotifier.configure do |config|
      #     config.const_name = :Message
      #     config.adapter = :slack
      #     # ...
      #   end
      # @yield [config] Give a Configuration instance for settings
      # @raise [ConfigureError]
      def configure
        yield config
      end

      def config
        @config ||= Configuration.new
      end
    end

    class Configuration
      # Alias const for ActiveNotifier
      # @!attribute [r]
      attr_reader :const_name

      # Set alias const for ActiveNotifier
      # @param const_name [#to_sym] (:Notifier) Alias const name
      # @example
      #   ActiveNotifier.config.const_name = :Message
      #   ::Message == ::ActiveNotifier # => true
      def const_name=(const_name)
        const_name = const_name.to_sym
        const_name = :Notifier if const_name.empty?
        if Kernel.const_defined?(const_name)
          raise ActiveNotifier::ConfigureError, "const_name is already defined, please set another value"
        end
        Kernel.const_set(const_name, ActiveNotifier)
        @const_name = const_name
      end

      # Message Adapter
      def adapter
        @adapter || :dingtalk
      end

      # Set message Adapter
      # @param adapter [#to_sym] (:dingtalk)
      def adapter=(adapter)
        adapter = adapter.to_sym
        unless adapters_with_base_url.key?(adapter)
          raise ActiveNotifier::ConfigureError, "adapter only support: #{adapters_with_base_url.keys.join(', ')}"
        end
        @adapter = adapter
      end

      # The tokens of channel
      def channel_tokens
        @channel_tokens || {}
      end

      # Set the tokens of channel
      # @param channel_tokens [#to_h] ({})
      # @example
      #   ActiveNotifier.config.channel_tokens = {
      #     default: "xxx",
      #     order: "xxx"
      #   }
      def channel_tokens=(channel_tokens)
        channel_tokens = channel_tokens.to_h.symbolize_keys
        @channel_tokens = channel_tokens
      end

      # The template home directory
      def template_home
        @template_home || "#{File.expand_path(__dir__)}/templates"
      end

      # Set the template home directory
      # @param template_home [#to_s] (lib/active_notifier/templates)
      def template_home=(template_home)
        template_home = template_home.to_s
        raise ActiveNotifier::ConfigureError, "template_home value can't be blank" if template_home.empty?
        @template_home = template_home
      end

      # The priority type for message, if notifier execute without type option and there are multiple valid types,
      # then ActiveNotifier will use the template with this type first
      def priority_type
        @priority_type || :markdown
      end

      # Set the priority type
      # @param priority_type [#to_sym] (:markdown)
      def priority_type=(priority_type)
        @priority_type = priority_type.to_sym
      end

      # The adapters and its base url
      def adapters_with_base_url
        @adapters_with_base_url ||= {
          dingtalk: "https://oapi.dingtalk.com/robot/send?access_token="
        }
      end
    end
  end
end