require 'stringio'
require 'bigdecimal'
require 'date'
require 'time'
require "ostruct"

require 'rdf/version'
require 'rdf/extensions'

# When loading, issue deprecation warning on forthcoming unsupported versions of Ruby
warn "[DEPRECATION] Ruby 2.4+ required in next version 3.1 of RDF.rb" if RUBY_VERSION < "2.4"

module RDF
  # RDF mixins
  autoload :Countable,         'rdf/mixin/countable'
  autoload :Durable,           'rdf/mixin/durable'
  autoload :Enumerable,        'rdf/mixin/enumerable'
  autoload :Indexable,         'rdf/mixin/indexable'
  autoload :Mutable,           'rdf/mixin/mutable'
  autoload :Queryable,         'rdf/mixin/queryable'
  autoload :Readable,          'rdf/mixin/readable'
  autoload :TypeCheck,         'rdf/mixin/type_check'
  autoload :Transactable,      'rdf/mixin/transactable'
  autoload :Writable,          'rdf/mixin/writable'

  # RDF objects
  autoload :Graph,             'rdf/model/graph'
  autoload :IRI,               'rdf/model/uri'
  autoload :Literal,           'rdf/model/literal'
  autoload :Node,              'rdf/model/node'
  autoload :Resource,          'rdf/model/resource'
  autoload :Statement,         'rdf/model/statement'
  autoload :URI,               'rdf/model/uri'
  autoload :Value,             'rdf/model/value'
  autoload :Term,              'rdf/model/term'

  # RDF collections
  autoload :List,              'rdf/model/list'

  # RDF serialization
  autoload :Format,            'rdf/format'
  autoload :Reader,            'rdf/reader'
  autoload :ReaderError,       'rdf/reader'
  autoload :Writer,            'rdf/writer'
  autoload :WriterError,       'rdf/writer'

  # RDF serialization formats
  autoload :NTriples,          'rdf/ntriples'
  autoload :NQuads,            'rdf/nquads'

  # RDF storage
  autoload :Changeset,         'rdf/changeset'
  autoload :Dataset,           'rdf/model/dataset'
  autoload :Repository,        'rdf/repository'
  autoload :Transaction,       'rdf/transaction'

  # RDF querying
  autoload :Query,             'rdf/query'

  # RDF vocabularies
  autoload :Vocabulary,        'rdf/vocabulary'
  autoload :StrictVocabulary,  'rdf/vocabulary'

  VOCABS = {
    owl: {uri: "http://www.w3.org/2002/07/owl#", class_name: "OWL"},
    rdfs: {uri: "http://www.w3.org/2000/01/rdf-schema#", class_name: "RDFS"},
    rdfv: {uri: "http://www.w3.org/1999/02/22-rdf-syntax-ns#", class_name: "RDFV"},
    xsd: {uri: "http://www.w3.org/2001/XMLSchema#", class_name: "XSD"},
  }

  # Autoload vocabularies
  VOCABS.each do |id, params|
    v = (params[:class_name] ||= id.to_s.upcase).to_sym
    autoload v, File.expand_path("../rdf/vocab/#{id}", __FILE__)
  end

  # Utilities
  autoload :Util,        'rdf/util'

  # CLI
  autoload :CLI,         'rdf/cli'

  ##
  # Configuration, used open for configuring constants used within the codebase.
  #
  # @example set default cache size to be at most 10,000 entries
  #
  #   RDF.config.cache_size = 10_000
  #
  # @example set cache size for interned URIs to 5,000 entries
  #
  #   RDF.config.uri_cache_size = 5_000
  #
  # Defaults:
  #   * `cache_size`: -1
  #   * `uri_cache_size`: `cache_size`
  #   * `node_cache_size`: `cache_size`
  #
  # @note cache configurations must be set before initial use, when the caches are allocated.
  # @see RDF::Util::Cache.new
  # @return [Object]
  def self.config
    @config ||= OpenStruct.new(cache_size: -1, uri_cache_size: nil, node_cache_size: nil)
  end

  ##
  # Alias for `RDF::Resource.new`.
  #
  # @param (see RDF::Resource#initialize)
  # @return [RDF::Resource]
  def self.Resource(*args)
    Resource.new(*args)
  end

  ##
  # Alias for `RDF::Node.new`.
  #
  # @param (see RDF::Node#initialize)
  # @return [RDF::Node]
  def self.Node(*args)
    Node.new(*args)
  end

  ##
  # Cast to a URI. If already a URI, return the passed argument.
  #
  # @param (see RDF::URI#initialize)
  # @return [RDF::URI]
  def self.URI(*args)
    if args.first.respond_to?(:to_uri)
      args.first.to_uri
    elsif args.first.is_a?(Hash)
      URI.new(**args.first)
    else
      opts = args.last.is_a?(Hash) ? args.pop : {}
      URI.new(*args, **opts)
    end
  end

  ##
  # Alias for `RDF::Literal.new`.
  #
  # @param (see RDF::Literal#initialize)
  # @return [RDF::Literal]
  def self.Literal(literal, **options)
    case literal
      when RDF::Literal then literal
      else Literal.new(literal, **options)
    end
  end

  ##
  # Alias for `RDF::Graph.new`.
  #
  # @param (see RDF::Graph#initialize)
  # @return [RDF::Graph]
  def self.Graph(**options, &block)
    Graph.new(**options, &block)
  end

  ##
  # @overload List()
  #   @return [RDF::URI] returns the IRI for `rdf:List`
  #
  # @overload List(*args)
  #   @param (see RDF::List#[])
  #   @return [RDF::List]
  #
  # @overload List(array)
  #   @param [Array] array
  #   @return [RDF::List]
  #
  # @overload List(list)
  #   @param [RDF::List] list
  #   @return [RDF::List] returns itself
  def self.List(*args)
    case
    when args.empty?
      RDF[:List]
    when args.length == 1 && args.first.is_a?(RDF::List)
      args.first
    when args.length == 1 && args.first.is_a?(Array)
      List[*args.first]
    else
      List[*args]
    end
  end

  ##
  # @overload Statement()
  #   @return [RDF::URI] returns the IRI for `rdf:Statement`
  #
  # @overload Statement(**options)
  #   @param  [Hash{Symbol => Object}] options
  #   @option options [RDF::Resource]  :subject   (nil)
  #   @option options [RDF::URI]       :predicate (nil)
  #   @option options [RDF::Term]      :object    (nil)
  #   @option options [RDF::Resource]  :graph_name   (nil)
  #     Note, a graph_name MUST be an IRI or BNode.
  #   @return [RDF::Statement]
  #
  # @overload Statement(subject, predicate, object, **options)
  #   @param  [RDF::Resource]          subject
  #   @param  [RDF::URI]               predicate
  #   @param  [RDF::Term]              object
  #   @param  [Hash{Symbol => Object}] options
  #   @option options [RDF::Resource]  :graph_name   (nil)
  #   @return [RDF::Statement]
  #
  def self.Statement(*args, **options)
    if args.empty? && options.empty?
      RDF[:Statement]
    else
      Statement.new(*args, **options)
    end
  end

  ##
  # Alias for `RDF::Vocabulary.create`.
  #
  # @param (see RDF::Vocabulary#initialize)
  # @return [Class]
  def self.Vocabulary(uri)
    Vocabulary.create(uri)
  end

  ##
  # Alias for `RDF::StrictVocabulary.create`.
  #
  # @param (see RDF::Vocabulary#initialize)
  # @return [Class]
  def self.StrictVocabulary(uri)
    StrictVocabulary.create(uri)
  end

  ##
  # @return [#to_s] property
  # @return [URI]
  def self.[](property)
    property.to_s.match?(%r{_\d+}) ? RDF::URI("#{to_uri}#{property}") : RDF::RDFV[property]
  end

  ##
  # Return an enumerator over {RDF::Statement} defined for this vocabulary.
  # @return [RDF::Enumerable::Enumerator]
  # @see    Object#enum_for
  def self.enum_for(method = :each_statement, *args)
    # Ensure that enumerators are, themselves, queryable
    Enumerable::Enumerator.new do |yielder|
      RDF::RDFV.send(method, *args) {|*y| yielder << (y.length > 1 ? y : y.first)}
    end
  end
  class << self
    alias_method :to_enum, :enum_for
  end

  ##
  # respond to module or RDFV
  def self.respond_to?(method, include_all = false)
    super || RDF::RDFV.respond_to?(method, include_all)
  end

  RDF_N_REGEXP = %r{_\d+}.freeze

  ##
  # Delegate other methods to RDF::RDFV
  def self.method_missing(property, *args, &block)
    if args.empty?
      # Special-case rdf:_n for all integers
      RDF_N_REGEXP.match?(property) ? RDF::URI("#{to_uri}#{property}") : RDF::RDFV.send(property)
    else
      super
    end
  end
end