# frozen_string_literal: true
require "google/protobuf"
# This module provides classes for the Makit gem.
module Makit
  module Proto3Formats
    JSON = 0,
           PRETTY_JSON = 1,
           YAML = 2,
    BINARY = 3
  end

  # This class provide methods for serializing and deserializing objects.
  #
  class Serializer
    attr_accessor :format_map

    def self.save_as(filename, object)
      extension = File.extname(filename)
      case extension
      when ".json"
        File.write(filename, Makit::Serializer.new(Makit::Proto3Formats::PRETTY_JSON).serialize(object))
      when ".yml"
        File.write(filename, Makit::Serializer.new(Makit::Proto3Formats::YAML).serialize(object))
      when ".pb"
        File.open(filename, "wb") do |file|
          file.write(Makit::Serializer.new(Makit::Proto3Formats::BINARY).serialize(object))
        end

        #File.write(filename, Makit::Serializer.new(Makit::Proto3Formats::BINARY).serialize(object))
      else
        raise "unsupported file extension: #{extension}"
      end
    end

    def self.open(filename, type)
      extension = File.extname(filename)
      case extension
      when ".json"
        Makit::Serializer.new(Makit::Proto3Formats::PRETTY_JSON).deserialize(type, File.read(filename))
      when ".yml"
        Makit::Serializer.new(Makit::Proto3Formats::YAML).deserialize(type, File.read(filename))
      when ".pb"
        data = File.open(filename, "rb") { |file| file.read }
        Makit::Serializer.new(Makit::Proto3Formats::BINARY).deserialize(type, data)
      else
        raise "unsupported file extension: #{extension}"
      end
    end

    def initialize(proto3_format = Proto3Formats::PRETTY_JSON)
      @format_maps = {
        ::Google::Protobuf::MessageExts => proto3_format,
      }
    end

    # Serialize an object to a byte[] or a string
    def serialize(object)
      raise "Object is nil" if object.nil?
      raise "object is not of type ::Google::Protobuf::MessageExts" if !object.is_a? ::Google::Protobuf::MessageExts

      case @format_maps[::Google::Protobuf::MessageExts]
      when Proto3Formats::JSON
        #puts "Serializing to protobuf json format"
        object.to_json
      when Proto3Formats::PRETTY_JSON
        #puts "Serializing to protobuf pretty json format"
        json = object.to_json
        pretty_json = JSON.pretty_generate(JSON.parse(json))
        pretty_json
      when Proto3Formats::YAML
        #puts "Serializing to protobuf yaml format"
        data = JSON.parse(object.to_json)
        data.to_yaml.sub(/^---\n/, "")
      when Proto3Formats::BINARY
        #puts "Serializing to protobuf binary format"
        serialized_object = object.to_proto
      else
        raise "Unknown serialization format"
      end
    end

    # Deserialize a byte[] or a string to an object
    def deserialize(type, data)
      raise "data is nil" if data.nil?
      case @format_maps[::Google::Protobuf::MessageExts]
      when Proto3Formats::JSON
        raise "data is not of type string" if !data.is_a? String
        json = data
        #puts "Deserializing from protobuf json format into type #{type}"
        # use the from_json method to deserialize the object
        type.decode_json(json)
      when Proto3Formats::PRETTY_JSON
        raise "data is not of type string" if !data.is_a? String
        json = data
        #puts "Deserializing from protobuf pretty json format into type #{type}"
        # use the from_json method to deserialize the object
        type.decode_json(json)
      when Proto3Formats::YAML
        raise "data is not of type string" if !data.is_a? String
        yaml = data
        # convert yaml to json
        json = JSON.pretty_generate(YAML.safe_load(yaml))
        #puts "Deserializing from protobuf yaml format into type #{type}"
        type.decode_json(json)
      when Proto3Formats::BINARY
        #raise "data is not of type byte[]" if !data.is_a? Array
        bytes = data
        #puts "Deserializing from protobuf binary format into type #{type}"
        type.decode(bytes)
      else
        raise "Unknown serialization format"
      end
    end
  end # class Storage
end # module Makit