require "base64"
require "socket"
require "json"

module InfluxDB
  module Rails
    class ExceptionPresenter # rubocop:disable Style/Documentation
      attr_reader :exception
      attr_reader :backtrace
      attr_reader :params
      attr_reader :session_data
      attr_reader :current_user
      attr_reader :controller
      attr_reader :action
      attr_reader :request_url
      attr_reader :referer
      attr_reader :remote_ip
      attr_reader :user_agent
      attr_reader :custom_data

      def initialize(ex, params = {})
        ex = ex.continued_exception if ex.respond_to?(:continued_exception)
        ex = ex.original_exception if ex.respond_to?(:original_exception)

        @exception    = ex.is_a?(String) ? Exception.new(ex) : ex
        @backtrace    = InfluxDB::Rails::Backtrace.new(@exception.backtrace)
        @dimensions   = {}
        configure_from_params(params)

        @environment_variables = ENV.to_hash || {}
      end

      def context # rubocop:disable Metrics/MethodLength
        c = {
          application_name:  InfluxDB::Rails.configuration.application_name,
          application_root:  InfluxDB::Rails.configuration.application_root,
          framework:         InfluxDB::Rails.configuration.framework,
          framework_version: InfluxDB::Rails.configuration.framework_version,
          language:          "Ruby",
          language_version:  "#{RUBY_VERSION}-p#{RUBY_PATCHLEVEL}",
          custom_data:       @custom_data,
        }

        InfluxDB::Rails.configuration.add_custom_exception_data(self)
        c
      end

      def dimensions
        {
          class:    @exception.class.to_s,
          method:   "#{@controller}##{@action}",
          filename: File.basename(@backtrace.lines.first.try(:file)),
          server:   Socket.gethostname,
          status:   "open",
        }.merge(@dimensions)
      end

      def values
        {
          exception_message:   @exception.message,
          exception_backtrace: JSON.generate(@backtrace.to_a),
        }
      end

      def request_data
        {
          params:       @params,
          session_data: @session_data,
          controller:   @controller,
          action:       @action,
          request_url:  @request_url,
          referer:      @referer,
          remote_ip:    @remote_ip,
          user_agent:   @user_agent,
        }
      end

      private

      def configure_from_params(params)
        @params       = params[:params]
        @session_data = params[:session_data] || {}
        @current_user = params[:current_user]
        @controller   = params[:controller]
        @action       = params[:action]
        @request_url  = params[:request_url]
        @user_agent   = params[:user_agent]
        @referer      = params[:referer]
        @remote_ip    = params[:remote_ip]
        @custom_data  = params[:custom_data] || {}
      end
    end
  end
end