# frozen_string_literal: true

require "tjson/version"

require "json"
require "set"
require "time"

require "base32"
require "base64"

require "tjson/datatype"
require "tjson/object"

require "tjson/datatype/array"
require "tjson/datatype/boolean"
require "tjson/datatype/binary"
require "tjson/datatype/float"
require "tjson/datatype/integer"
require "tjson/datatype/object"
require "tjson/datatype/set"
require "tjson/datatype/string"
require "tjson/datatype/timestamp"

# Tagged JSON with Rich Types
module TJSON
  # Base class of all TJSON errors
  Error = Class.new(StandardError)

  # Invalid string encoding
  EncodingError = Class.new(Error)

  # Failure to parse TJSON document
  ParseError = Class.new(Error)

  # Invalid types
  TypeError = Class.new(ParseError)

  # Duplicate object name
  DuplicateNameError = Class.new(ParseError)

  # Maximum allowed nesting (TODO: use TJSON-specified maximum)
  MAX_NESTING = 100

  # Reopen the DataType class (defined in tjson/datatype.rb)
  class DataType
    # Table of tag identifiers supported by TJSON
    TAGS = {
      # Object (non-scalar with self-describing types)
      "O" => TJSON::DataType::Object.new(nil).freeze,

      # Non-scalars
      "A" => TJSON::DataType::Array,
      "S" => TJSON::DataType::Set,

      # Scalars
      "b"   => TJSON::DataType::Boolean.new.freeze,
      "d"   => TJSON::DataType::Binary64.new.freeze,
      "d16" => TJSON::DataType::Binary16.new.freeze,
      "d32" => TJSON::DataType::Binary32.new.freeze,
      "d64" => TJSON::DataType::Binary64.new.freeze,
      "f"   => TJSON::DataType::Float.new.freeze,
      "i"   => TJSON::DataType::SignedInt.new.freeze,
      "s"   => TJSON::DataType::String.new.freeze,
      "t"   => TJSON::DataType::Timestamp.new.freeze,
      "u"   => TJSON::DataType::UnsignedInt.new.freeze
    }.freeze
  end

  # Parse the given UTF-8 string as TJSON
  #
  # @param string [String] TJSON string to be parsed
  # @raise [TJSON::ParseError] an error occurred parsing the given TJSON
  # @return [Object] parsed data
  def self.parse(string)
    begin
      utf8_string = string.encode(Encoding::UTF_8)
    rescue ::EncodingError => ex
      raise TJSON::EncodingError, ex.message, ex.backtrace
    end

    begin
      object = ::JSON.parse(
        utf8_string,
        max_nesting:      MAX_NESTING,
        allow_nan:        false,
        symbolize_names:  false,
        create_additions: false,
        object_class:     TJSON::Object
      )
    rescue ::JSON::ParserError => ex
      raise TJSON::ParseError, ex.message, ex.backtrace
    end

    raise TJSON::TypeError, "invalid toplevel type: #{object.class}" unless object.is_a?(TJSON::Object)
    object
  end

  class << self
    alias load parse
  end

  # Load data from a file containing TJSON
  #
  # @param filename [String] name of the .tjson file
  # @raise [TJSON::ParseError] an error occurred parsing the given file
  # @return [Object] parsed data
  def self.load_file(filename)
    load(File.read(filename))
  end

  # Generate TJSON from a Ruby Hash (TJSON only allows objects as toplevel values)
  #
  # @param obj [Hash] Ruby Hash to serialize as TJSON
  # @return [String] serialized TJSON
  def self.generate(obj)
    raise TypeError, "toplevel type must be a Hash" unless obj.is_a?(Hash)
    JSON.generate(TJSON::DataType.encode(obj))
  end

  # Generate TJSON from a Ruby Hash (TJSON only allows objects as toplevel values)
  #
  # @param obj [Hash] Ruby Hash to serialize as TJSON
  # @return [String] serialized TJSON
  def self.pretty_generate(obj)
    raise TypeError, "toplevel type must be a Hash" unless obj.is_a?(Hash)
    JSON.pretty_generate(TJSON::DataType.encode(obj))
  end
end