module ActiveNotifier
  module Configurable
    def self.included(base)
      base.extend ClassMethods
    end

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

      def configure
        yield config
      end
    end

    class Configuration
      # 常量名, 简化调用, 符号，默认 :Notifier (如果被占用请更换)
      def const_name
        @const_name || :Notifier
      end

      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 已经存在，请在 initializers 中定义其他值"
        end
        Kernel.const_set(const_name, ActiveNotifier)
        @const_name = const_name
      end

      # 消息适配器, 字符串, 默认 :dingtalk
      def adapter
        @adapter || :dingtalk
      end

      def adapter=(adapter)
        adapter = adapter.to_sym
        unless valid_adapters.include?(adapter)
          raise ActiveNotifier::ConfigureError, "adapter 当前只支持：#{valid_adapters.join(', ')}"
        end
        @adapter = adapter
      end

      # 消息渠道的 webhook 设置
      def channel_webhooks
        @channel_webhooks || {}
      end

      def channel_webhooks=(channel_webhooks)
        channel_webhooks = channel_webhooks.to_h.symbolize_keys
        unless channel_webhooks.key?(:default) && channel_webhooks[:default].present?
          raise ActiveNotifier::ConfigureError, "channel_webhooks 请至少设置 default 键"
        end
        @channel_webhooks = channel_webhooks
      end

      # 消息模版主目录, 字符串, 默认 views/notifier/application), 不需要加模版后缀
      def template_home
        @template_home || "#{__dir__}/templates"
      end

      def template_home=(template_home)
        template_home = template_home.to_s
        raise ActiveNotifier::ConfigureError, "模板主目录不能为空" if template_home.empty?
        @template_home = template_home
      end

      # 消息模版, 字符串, 默认 default($template_home/default), 不需要加模版后缀
      def template
        @template || "default"
      end

      def template=(template)
        template = template.to_s
        raise ActiveNotifier::ConfigureError, "模板名不能为空" if template.empty?
        @template = template
      end

      # 消息优先类型, 字符串, 默认 :markdown, 对应模板后缀名，如果未指定该参数且存在多个模板，则优先选择此类型
      def priority_type
        @priority_type || :markdown
      end

      def priority_type=(priority_type)
        @priority_type = priority_type.to_sym
      end

      private

      def valid_adapters
        @valid_adapters ||= begin
          found_adapters = Dir["*_adapter.rb", base: "#{__dir__}/adapters"]
          found_adapters.map { |adapter| adapter.sub("_adapter.rb", "").to_sym } - [:abstract]
        end
      end
    end
  end
end