# encoding: utf-8

module OneApm
  class EnvironmentReport

    def self.report_on(key, &block)
      registered_reporters[key] = block
    end

    def self.registered_reporters
      @registered_reporters ||= Hash.new
    end

    def self.registered_reporters=(logic)
      @registered_reporters = logic
    end

    report_on('Gems') do
      begin
        Bundler.rubygems.all_specs.map { |_gem| "#{_gem.name}(#{_gem.version})" }
      rescue
        Bundler.load.specs.map do |spec|
          version = (spec.respond_to?(:version) && spec.version)
          spec.name + (version ? "(#{version})" : "")
        end
      end
    end
    report_on('Plugin List'       ) { ::Rails.configuration.plugins.to_a }
    report_on('Ruby version'      ) { RUBY_VERSION                       }
    report_on('Ruby description'  ) { RUBY_DESCRIPTION                   }
    report_on('Ruby platform'     ) { RUBY_PLATFORM                      }
    report_on('Ruby patchlevel'   ) { RUBY_PATCHLEVEL.to_s               }
    report_on('JRuby version'     ) { JRUBY_VERSION                      }
    report_on('Java VM version'   ) { ENV_JAVA['java.vm.version']        }
    report_on('Logical Processors') { OneApm::Support::SystemInfo.num_logical_processors }
    report_on('Physical Cores'    ) { OneApm::Support::SystemInfo.num_physical_cores     }
    report_on('Arch'              ) { OneApm::Support::SystemInfo.processor_arch         }
    report_on('OS version'        ) { OneApm::Support::SystemInfo.os_version             }
    report_on('OS'                ) { OneApm::Support::SystemInfo.ruby_os_identifier     }
    report_on('Database adapter'  ) do
      ActiveRecord::Base.configurations[OneApm::Probe.instance.env]['adapter']
    end
    report_on('Framework'       ) { OneApm::Manager.config[:framework].to_s  }
    report_on('Dispatcher'      ) { OneApm::Manager.config[:dispatcher].to_s }
    report_on('Environment'     ) { OneApm::Probe.instance.env }
    report_on('Rails version'   ) { ::Rails::VERSION::STRING       }
    report_on('Rails threadsafe') do
      ::Rails.configuration.action_controller.allow_concurrency
    end
    report_on('Rails Env') do
      if defined? ::Rails and ::Rails.respond_to?(:env)
        ::Rails.env.to_s
      else
        ENV['RAILS_ENV']
      end
    end

    attr_reader :data

    def initialize
      @data = self.class.registered_reporters.inject(Hash.new) do |data, (key, logic)|
        begin
          value = logic.call
          if value
            data[key] = value

            OneApm::Manager.record_metric("Supportability/EnvironmentReport/success", 0.0)
            OneApm::Manager.record_metric("Supportability/EnvironmentReport/success/#{key}", 0.0)
          else
            OneApm::Manager.logger.debug("EnvironmentReport ignoring value for #{key.inspect} which came back falsey: #{value.inspect}")
            OneApm::Manager.record_metric("Supportability/EnvironmentReport/empty", 0.0)
            OneApm::Manager.record_metric("Supportability/EnvironmentReport/empty/#{key}", 0.0)
          end
        rescue => e
          OneApm::Manager.logger.debug("EnvironmentReport failed to retrieve value for #{key.inspect}: #{e}")
          OneApm::Manager.record_metric("Supportability/EnvironmentReport/error", 0.0)
          OneApm::Manager.record_metric("Supportability/EnvironmentReport/error/#{key}", 0.0)
        end
        data
      end
    end

    def [](key)
      @data[key]
    end

    def []=(key, value)
      @data[key] = value
    end

    def to_a
      @data.to_a
    end
  end
end