require 'net/http'
require 'json'
require 'concurrent'

module Vizsla
  class Reporter
    attr_reader :logger, :config, :storage

    def initialize(storage = Vizsla::Agent.storage, config = Vizsla::Agent.config, logger = Vizsla::Agent.logger)
      @logger = logger
      @config = config
      @storage = storage

      host = Vizsla::Agent.config.host
      path = Vizsla::Agent.config.report_path
      @uri = URI("#{host}/#{path}")

      @bin_id = Vizsla::Agent.config.bin_id
    end

    def start!
      @task = Concurrent::TimerTask.new do
        unless storage.unloaded?
          payload = storage.unload
          res = send_data payload

          handle_response res, payload
        end
      end

      logger.info 'TRACEBIN: Reporter starting.'
      @task.execute
    end

    def stop!
      logger.info 'TRACEBIN: Reporter stopping. The agent will no longer report metrics to the server.'
      @task.shutdown if @task && @task.running?
    end

    private

    def send_data(payload)
      logger.info 'TRACEBIN: Sending analytics data to the server.'

      Net::HTTP.start(@uri.host, @uri.port) do |http|
        body = {
          bin_id: @bin_id,
          report: payload
        }.to_json

        req = Net::HTTP::Post.new @uri
        req.content_type = 'application/json'
        req.body = body

        http.request req
      end
    rescue Exception => e
      logger.warn "TRACEBIN: Exception occurred sending data to the server: #{e.message}"
    end

    def handle_response(res, payload)
      case res
      when Net::HTTPSuccess
        logger.info 'TRACEBIN: Successfully sent payload to the server.'
      when Net::HTTPBadRequest
        logger.warn 'TRACEBIN: App bin ID not found. Please create a new app bin and add it to the config.'
        self.stop!
      else
        logger.warn 'TRACEBIN: Failed to send data to the server. Will try again in 1 minute.'
        @storage.add_payload payload
      end
    end
  end
end