require 'fileutils'
require 'flydata/fluent-plugins/preference'

module Flydata
  module Preference
    class DataEntryPreference
      CONFS_HOME = File.join(FLYDATA_HOME, 'confs')
      CUSTOM_CONFIG_PARAMS = {
        RedshiftMysqlDataEntry: ::Fluent::MysqlBinlogFlydataInputPreference::CUSTOM_CONFIG_PARAMS
      }

      class << self
        # data_entry must be hash
        def load_conf(data_entry)
          path = conf_path(data_entry)
          raise "Conf file does not exist. path:#{path}" unless File.exists?(path)
          custom_conf = YAML::load(File.open(path, 'r'))
          data_entry.each_key do |k|
            v = custom_conf[k]
            case v
            when Hash
              data_entry[k].merge!(v)
            when NilClass
            else
              data_entry[k] = v
            end
          end
          filter_data_entry(data_entry)
          data_entry
        end

        def filter_data_entry(de)
          configurable_params = CUSTOM_CONFIG_PARAMS[de['type'].to_sym]
          return de if configurable_params.nil? or configurable_params.empty?

          configurable_params.each do |pref_name, param_info|
            # skip if the data entry doesn't have the information
            de_pref = de[pref_name.to_s]
            next unless de_pref

            param_info.each do |param_name, options|
              next if options.nil? or options.empty?
              param_name_str = param_name.to_s
              next if de_pref[param_name_str].nil? or de_pref[param_name_str].empty?

              options.each do |option_name, option_value|
                de_pref[param_name_str] = Fluent::DataEntryPreferenceConfigurable.replace_value_with_option(
                  param_name_str, de_pref[param_name_str], option_name, option_value, key: de['data_port_key'])
              end
            end
          end
        end


        def copy_template(data_entry)
          return unless File.exists?(conf_template_path(data_entry))
          FileUtils.mkdir_p(CONFS_HOME)
          FileUtils.cp(conf_template_path(data_entry), conf_path(data_entry)+".tmpl")

          # Do not overwrite a current conf file
          unless File.exists?(conf_path(data_entry))
            FileUtils.cp(conf_template_path(data_entry), conf_path(data_entry))
          end
        end

        def conf_path(data_entry)
          "#{File.join(CONFS_HOME, data_entry['name'])}.conf"
        end

        def conf_exists?(data_entry)
          File.exists?(conf_path(data_entry))
        end

        def conf_name(data_entry)
          "#{data_entry['name']}.conf"
        end

        def configurable?(data_entry)
          File.exists?(conf_template_path(data_entry))
        end

        def conf_template_path(data_entry)
          File.join(FLYDATA_TMPL_DIR, conf_template_name(data_entry))
        end

        def conf_template_name(data_entry)
          type = ActiveSupport::Inflector.underscore(data_entry['type'])
          "#{type}.conf.tmpl"
        end

        def create(type)
          custom_config_params = CUSTOM_CONFIG_PARAMS[type]
          return nil unless custom_config_params
        end
      end
    end
  end
end