# frozen_string_literal: true

# @api public
# @since 0.1.0
class Qonfig::DataSet # rubocop:disable Metrics/ClassLength
  require_relative 'data_set/class_builder'
  require_relative 'data_set/lock'

  # @since 0.1.0
  # @version 0.20.0
  extend Qonfig::DSL

  class << self
    # @param base_dataset_klass [Class<Qonfig::DataSet>]
    # @param config_klass_definitions [Proc]
    # @return [Qonfig::DataSet]
    #
    # @api public
    # @since 0.16.0
    def build(base_dataset_klass = self, &config_klass_definitions)
      unless base_dataset_klass <= Qonfig::DataSet
        raise(Qonfig::ArgumentError, 'Base class should be a type of Qonfig::DataSet')
      end

      Class.new(base_dataset_klass, &config_klass_definitions).new
    end

    # @param base_dataset_klass [Class<Qonfig::DataSet>]
    # @param config_klass_definitions [Proc]
    # @return [Qonfig::Compacted]
    #
    # @api public
    # @since 0.21.0
    def build_compacted(base_dataset_klass = self, &config_klass_definitions)
      build(base_dataset_klass, &config_klass_definitions).compacted
    end

    # @param settings_map [Hash<Symbol|String,Any>]
    # @param configurations [Block]
    # @return [Boolean]
    #
    # @api public
    # @since 0.19.0
    # @version 0.21.0
    def valid_with?(settings_map = {}, &configurations)
      new(settings_map, &configurations)
      true
    rescue Qonfig::ValidationError
      false
    end
  end

  # @return [Qonfig::Settings]
  #
  # @api public
  # @since 0.1.0
  attr_reader :settings

  # @param settings_map [Hash]
  # @param configurations [Proc]
  #
  # @api public
  # @since 0.1.0
  def initialize(settings_map = {}, &configurations)
    @__lock__ = Qonfig::DataSet::Lock.new
    thread_safe_definition { load!(settings_map, &configurations) }
  end

  # @return [void]
  #
  # @api public
  # @since 0.1.0
  def freeze!
    thread_safe_access { settings.__freeze__ }
  end

  # @return [void]
  #
  # @api public
  # @since 0.2.0
  def frozen?
    thread_safe_access { settings.__is_frozen__ }
  end

  # @param settings_map [Hash]
  # @param configurations [Proc]
  # @return [void]
  #
  # @raise [Qonfig::FrozenSettingsError]
  #
  # @api public
  # @since 0.2.0
  def reload!(settings_map = {}, &configurations)
    thread_safe_definition do
      raise Qonfig::FrozenSettingsError, 'Frozen config can not be reloaded' if frozen?
      load!(settings_map, &configurations)
    end
  end

  # @param file_path [String, Symbol, Pathname]
  # @option format [String, Symbol]
  # @option strict [Boolean]
  # @option expose [NilClass, String, Symbol] Environment key
  # @param configurations [Block]
  # @return [void]
  #
  # @see Qonfig::DataSet#load_setting_values_from_file
  #
  # @api public
  # @since 0.17.0
  # @version 0.22.0
  def load_from_file(file_path, format: :dynamic, strict: true, expose: nil, &configurations)
    thread_safe_access do
      load_setting_values_from_file(
        file_path, format: format, strict: strict, expose: expose, &configurations
      )
    end
  end

  # @param file_path [String, Symbol, Pathname]
  # @option strict [Boolean]
  # @option expose [NilClass, String, Symbol] Environment key
  # @param configurations [Block]
  # @return [void]
  #
  # @see Qonfig::DataSet#load_from_file
  #
  # @api public
  # @since 0.17.0
  # @version 0.22.0
  def load_from_yaml(file_path, strict: true, expose: nil, &configurations)
    load_from_file(file_path, format: :yml, strict: strict, expose: expose, &configurations)
  end

  # @param file_path [String, Symbol, Pathname]
  # @option strict [Boolean]
  # @option expose [NilClass, String, Symbol] Environment key
  # @param configurations [Block]
  # @return [void]
  #
  # @see Qonfig::DataSet#load_from_file
  #
  # @api public
  # @since 0.17.0
  # @version 0.22.0
  def load_from_json(file_path, strict: true, expose: nil, &configurations)
    load_from_file(file_path, format: :json, strict: strict, expose: expose, &configurations)
  end

  # @option format [String, Symbol]
  # @option strict [Boolean]
  # @option expose [NilClass, String, Symbol]
  # @param configurations [Block]
  # @return [void]
  #
  # @api public
  # @since 0.17.0
  # @version 0.21.0
  def load_from_self(format: :dynamic, strict: true, expose: nil, &configurations)
    caller_location = ::Kernel.caller(1, 1).first

    thread_safe_access do
      load_setting_values_from_file(
        :self,
        format: format,
        strict: strict,
        expose: expose,
        caller_location: caller_location,
        &configurations
      )
    end
  end

  # @param settings_map [Hash]
  # @yield [cofnig]
  # @yieldparam config [Qonfig::Settings]
  # @return [void]
  #
  # @api public
  # @since 0.1.0
  def configure(settings_map = {}, &configurations)
    thread_safe_access do
      apply_settings(settings_map, &configurations)
    end
  end

  # @option dot_style [Boolean]
  # @option key_transformer [Proc]
  # @option value_transformer [Proc]
  # @return [Hash]
  #
  # @api public
  # @since 0.1.0
  def to_h(
    dot_style: Qonfig::Settings::REPRESENT_HASH_IN_DOT_STYLE,
    key_transformer: Qonfig::Settings::BASIC_SETTING_KEY_TRANSFORMER,
    value_transformer: Qonfig::Settings::BASIC_SETTING_VALUE_TRANSFORMER
  )
    thread_safe_access do
      settings.__to_hash__(
        dot_notation: dot_style,
        transform_key: key_transformer,
        transform_value: value_transformer
      )
    end
  end
  alias_method :to_hash, :to_h

  # @option path [String, Pathname]
  # @option options [Hash<Symbol|String,Any>] Native (ruby-stdlib) ::JSON#generate attributes
  # @param value_processor [Block]
  # @return [void]
  #
  # @api public
  # @since 0.11.0
  def save_to_json(path:, options: Qonfig::Uploaders::JSON::DEFAULT_OPTIONS, &value_processor)
    thread_safe_access do
      Qonfig::Uploaders::JSON.upload(settings, path: path, options: options, &value_processor)
    end
  end
  alias_method :dump_to_json, :save_to_json

  # @option path [String, Pathname]
  # @option symbolize_keys [Boolean]
  # @option options [Hash<Symbol|String,Any>] Native (ruby-stdlib) ::YAML#dump attributes
  # @param value_processor [Block]
  # @return [void]
  #
  # @api public
  # @since 0.11.0
  def save_to_yaml(
    path:,
    symbolize_keys: false,
    options: Qonfig::Uploaders::YAML::DEFAULT_OPTIONS,
    &value_processor
  )
    thread_safe_access do
      Qonfig::Uploaders::YAML.upload(
        settings,
        path: path,
        options: options.merge(symbolize_keys: symbolize_keys),
        &value_processor
      )
    end
  end
  alias_method :dump_to_yaml, :save_to_yaml

  # @param key [String, Symbol]
  # @return [Object]
  #
  # @api public
  # @since 0.2.0
  def [](key)
    thread_safe_access { settings[key] }
  end

  # @param key [String, Symbol]
  # @param value [Any]
  # @return [void]
  #
  # @raise [Qonfig::UnknownSettingError]
  # @raise [Qonfig::FrozenSettingsError]
  # @raise [Qonfig::AmbiguousSettingValueError]
  #
  # @api public
  # @since 0.21.0
  def []=(key, value)
    thread_safe_access { settings[key] = value }
  end

  # @param keys [Array<String, Symbol>]
  # @return [Object]
  #
  # @api public
  # @since 0.2.0
  def dig(*keys)
    thread_safe_access { settings.__dig__(*keys) }
  end

  # @param keys [Array<String, Symbol>]
  # @return [Hash]
  #
  # @api public
  # @since 0.9.0
  def slice(*keys)
    thread_safe_access { settings.__slice__(*keys) }
  end

  # @param keys [Array<String, Symbol>]
  # @return [Hash,Any]
  #
  # @api public
  # @since 0.10.0
  def slice_value(*keys)
    thread_safe_access { settings.__slice_value__(*keys) }
  end

  # @param keys [Array<String, Symbol, Array<String, Symbol>>]
  # @return [Hash]
  #
  # @api private
  # @since 0.16.0
  def subset(*keys)
    thread_safe_access { settings.__subset__(*keys) }
  end

  # @param key_path [Array<String, Symbol>]
  # @return [Boolean]
  #
  # @api public
  # @since 0.17.0
  def key?(*key_path)
    thread_safe_access { settings.__has_key__(*key_path) }
  end
  alias_method :option?, :key?
  alias_method :setting?, :key?

  # @return [void]
  #
  # @api public
  # @since 0.2.0
  def clear!
    thread_safe_access { settings.__clear__ }
  end

  # @param block [Proc]
  # @return [Enumerable]
  #
  # @yield [setting_key, setting_value]
  # @yieldparam setting_key [String]
  # @yieldparam setting_value [Object]
  #
  # @api public
  # @since 0.13.0
  def each_setting(&block)
    thread_safe_access { settings.__each_setting__(&block) }
  end

  # @param block [Proc]
  # @option yield_all [Boolean]
  # @return [Enumerable]
  #
  # @yield [setting_key, setting_value]
  # @yieldparam setting_key [String]
  # @yieldparam setting_value [Object]
  #
  # @api public
  # @since 0.13.0
  def deep_each_setting(yield_all: false, &block)
    thread_safe_access { settings.__deep_each_setting__(yield_all: yield_all, &block) }
  end

  # @return [Boolean]
  #
  # @api public
  # @since 0.13.0
  def valid?
    thread_safe_access { validator.valid? }
  end

  # @param settings_map [Hash<String,Symbol|Any>]
  # @return [Boolean]
  #
  # @api public
  # @since 0.19.0
  # @version 0.21.0
  def valid_with?(settings_map = {}, &configurations)
    # NOTE:
    #  'dup.configure(settings_map)' has better thread-safety than 'with(settings_map)'
    #  pros:
    #    - no arbitrary lock is obtained;
    #    - all threads can read and work :)
    #  cons:
    #    - useless ton of objects (new dataset, new settings, new locks, and etc);
    #    - useless setting options assignment steps (self.dup + self.to_h + configure(to_h))
    dup.configure(settings_map, &configurations)
    true
  rescue Qonfig::ValidationError
    false
  end

  # @return [void]
  #
  # @api public
  # @since 0.13.0
  def validate!
    thread_safe_access { validator.validate! }
  end

  # @option all_variants [Boolean]
  # @option only_root [Boolean]
  # @return [Array<String>]
  #
  # @api public
  # @since 0.18.0
  def keys(all_variants: false, only_root: false)
    thread_safe_access do
      only_root ? settings.__root_keys__ : settings.__keys__(all_variants: all_variants)
    end
  end

  # @return [Array<String>]
  #
  # @api public
  # @since 0.18.0
  def root_keys
    thread_safe_access { settings.__root_keys__ }
  end

  # @param temporary_configurations [Hash<Symbol|String,Any>]
  # @param arbitary_code [Block]
  # @return [void]
  #
  # @api public
  # @since 0.17.0
  def with(temporary_configurations = {}, &arbitary_code)
    with_arbitary_access do
      begin
        original_settings = @settings

        temporary_settings = self.class.build.dup.tap do |copied_config|
          copied_config.configure(temporary_configurations)
        end.settings

        @settings = temporary_settings
        yield if block_given?
      ensure
        @settings = original_settings
      end
    end
  end

  # @return [Qonfig::DataSet]
  #
  # @api public
  # @since 0.17.0
  def dup
    thread_safe_definition do
      self.class.build.tap do |duplicate|
        duplicate.configure(to_h)
      end
    end
  end

  # @param exportable_object [Object]
  # @param exported_setting_keys [Array<String,Symbol>]
  # @option mappings [Hash<String|Symbol,String|Symbol>]
  # @option raw [Boolean]
  # @option prefix [String, Symbol]
  # @option accessor [Boolean]
  # @return [void]
  #
  # @api public
  # @since 0.18.0
  def export_settings(
    exportable_object,
    *exported_setting_keys,
    mappings: Qonfig::Imports::Mappings::EMPTY_MAPPINGS,
    raw: Qonfig::Imports::Abstract::DEFAULT_RAW_BEHAVIOR,
    prefix: Qonfig::Imports::Abstract::EMPTY_PREFIX,
    accessor: Qonfig::Imports::Abstract::AS_ACCESSOR
  )
    thread_safe_access do
      Qonfig::Imports::Export.export!(
        exportable_object,
        self,
        *exported_setting_keys,
        prefix: prefix,
        raw: raw,
        mappings: mappings,
        accessor: accessor
      )
    end
  end

  # @return [Qonfig::Compacted]
  #
  # @api public
  # @since 0.21.0
  def compacted
    Qonfig::Compacted.build_from(self)
  end

  private

  # @return [Qonfig::Validation::Validators::Composite]
  #
  # @api private
  # @since 0.13.0
  # @version 0.20.0
  attr_reader :validator

  # @param settings_map [Hash]
  # @param configurations [Proc]
  # @return [void]
  #
  # @api private
  # @since 0.13.0
  def apply_settings(settings_map = {}, &configurations)
    settings.__apply_values__(settings_map)
    yield(settings) if block_given?
  end

  # @param settings_map [Hash]
  # @param configurations [Proc]
  # @return [void]
  #
  # @api private
  # @since 0.2.0
  # @version 0.21.0
  def load!(settings_map = {}, &configurations)
    Qonfig::Settings::Builder.build(self) do |settings, validator|
      @settings = settings
      @validator = validator
    end
    apply_settings(settings_map, &configurations)
  end

  # @param file_path [String, Symbol, Pathname]
  # @option format [String, Symbol]
  # @option strict [Boolean]
  # @option expose [NilClass, String, Symbol]
  # @option callcer_location [NilClass, String]
  # @param configurations [Block]
  # @return [void]
  #
  # @see Qonfig::Commands::Instantiation::ValuesFile
  #
  # @api private
  # @since 0.17.0
  # @version 0.22.0
  def load_setting_values_from_file(
    file_path,
    format: :dynamic,
    strict: true,
    expose: nil,
    caller_location: nil,
    &configurations
  )
    Qonfig::Commands::Instantiation::ValuesFile.new(
      file_path, caller_location, format: format, strict: strict, expose: expose
    ).call(self, settings)
    apply_settings(&configurations)
  end

  # @param instructions [Block]
  # @return [Any]
  #
  # @api private
  # @since 0.2.0
  def thread_safe_access(&instructions)
    @__lock__.thread_safe_access(&instructions)
  end

  # @param instructions [Block]
  # @return [Any]
  #
  # @api private
  # @since 0.2.0
  def thread_safe_definition(&instructions)
    @__lock__.thread_safe_definition(&instructions)
  end

  # @param instructions [Block]
  # @return [Any]
  #
  # @api priavte
  # @since 0.17.0
  def with_arbitary_access(&instructions)
    @__lock__.with_arbitary_access(&instructions)
  end
end