# frozen_string_literal: true

require 'json'

module FlippRubyKafka
  module Utils
    # Generates the Microservice Platform schema validation file.
    # Run this before committing schema changes (or include it in your CircleCI
    # config if you don't mind having to build the same image multiple times).
    # Run this using `rails runner` or in Rails console if you're using Rails.
    class PlatformSchemaValidation
      # @param base_path [String] Set this to Rails.root if running Rails.
      def initialize(base_path: '')
        @base_path ||= FlippRubyKafka.config.schema.path.gsub(%r{^#{base_path}\/}, '')
      end

      # @param klass [Class < FlippRubyKafka::Producer]
      # @return [Hash]
      def process_producer(klass)
        schema = klass.config[:schema]
        topic = klass.config[:topic]
        return if topic.blank?

        namespace = klass.config[:namespace] || FlippRubyKafka.config.producers.schema_namespace
        path = namespace.tr('.', '/')
        {
          'file' => File.join(@base_path, path, "#{schema}.avsc"),
          'subject' => "#{topic}-value"
        }
      end

      # @param hash [Hash]
      # @return [Hash]
      def process_consumer(hash)
        klass = hash['handler'].constantize
        topic = hash['topic']
        schema = klass.config[:schema]
        return if schema.blank?

        namespace = klass.config[:namespace] || ''
        path = namespace.tr('.', '/')
        {
          'file' => File.join(@base_path, path, "#{schema}.avsc"),
          'subject' => "#{topic}-value"
        }
      end

      # @return [String]
      def generate_config
        @full_config = []
        FlippRubyKafka::Producer.descendants.each do |klass|
          next if klass.topic.blank?

          config = process_producer(klass)
          @full_config << config if config
        end

        Phobos.config['listeners'].each do |h|
          config = process_consumer(h)
          @full_config << config if config
        end

        {
          environments: {
            default: @full_config
          }
        }
      end

      # :nodoc:
      def run
        full_json = generate_config
        File.write('schema-validation.json', JSON.pretty_generate(full_json))
      end
    end
  end
end