module Agents
  class JsonParseAgent < Agent
    include FormConfigurable

    cannot_be_scheduled!
    can_dry_run!

    description <<~MD
      The JSON Parse Agent parses a JSON string and emits the data in a new event or merge with with the original event.

      `data` is the JSON to parse. Use [Liquid](https://github.com/huginn/huginn/wiki/Formatting-Events-using-Liquid) templating to specify the JSON string.

      `data_key` sets the key which contains the parsed JSON data in emitted events

      `mode` determines whether create a new `clean` event or `merge` old payload with new values (default: `clean`)
    MD

    def default_options
      {
        'data' => '{{ data }}',
        'data_key' => 'data',
        'mode' => 'clean',
      }
    end

    event_description do
      "Events will looks like this:\n\n    %s" % Utils.pretty_print(interpolated['data_key'] => { parsed: 'object' })
    end

    form_configurable :data
    form_configurable :data_key
    form_configurable :mode, type: :array, values: ['clean', 'merge']

    def validate_options
      errors.add(:base, "data needs to be present") if options['data'].blank?
      errors.add(:base, "data_key needs to be present") if options['data_key'].blank?
      if options['mode'].present? && !options['mode'].to_s.include?('{{') && !%(clean merge).include?(options['mode'].to_s)
        errors.add(:base, "mode must be 'clean' or 'merge'")
      end
    end

    def working?
      received_event_without_error?
    end

    def receive(incoming_events)
      incoming_events.each do |event|
        mo = interpolated(event)
        existing_payload = mo['mode'].to_s == 'merge' ? event.payload : {}
        create_event payload: existing_payload.merge({ mo['data_key'] => JSON.parse(mo['data']) })
      rescue JSON::JSONError => e
        error("Could not parse JSON: #{e.class} '#{e.message}'")
      end
    end
  end
end