# frozen_string_literal: true

require_relative '../core_extensions/string'

module SimpleCommand
  # Handles class and module transformations.
  module KlassTransform
    # Returns a constantized class (as a Class constant), given the klass and klass_modules.
    #
    # @param klass [Symbol or String] the class name.
    # @param klass_modules [Hash, Array or String] the modules klass belongs to.
    # @param options [Hash] the options that determine how klass_modules is transformed.
    # @option options [Boolean] :camelize (false) determines whether or not both klass and klass_modules
    #    should be camelized.
    # @option options [Boolean] :titleize (false) determines whether or not both klass and klass_modules
    #    should be titleized.
    # @option options [Boolean] :class_titleize (false) determines whether or not klass names should be
    #    titleized.
    # @option options [Boolean] :class_camelized (false) determines whether or not klass names should be
    #    camelized.
    # @option options [Boolean] :module_titleize (false) determines whether or not klass_modules names
    #    should be titleized.
    # @option options [Boolean] :module_camelized (false) determines whether or not klass_modules names
    #    should be camelized.
    #
    # @return [Class] the class constant. Can be used to call ClassConstant.constantize.
    #
    # @raise [NameError] if the constantized class string cannot be constantized; that is, if it is not
    #    a valid class constant.
    #
    # @example
    #
    #   to_constantized_class("Authenticate", "Api") # => Api::Authenticate
    #   to_constantized_class(:Authenticate, [:Api, :AppName, :V1]) # => Api::AppName::V1::Authenticate
    #   to_constantized_class(:Authenticate, { :api :Api, app_name: :AppName, api_version: :V2 })
    #     # => Api::AppName::V2::Authenticate
    #   to_constantized_class("authenticate", { :api :api, app_name: :app_name, api_version: :v1 },
    #     { class_titleize: true, module_titleize: true }) # => Api::AppName::V1::Authenticate
    #
    def to_constantized_class(klass, klass_modules = [], options = {})
      constantized_class_string = to_constantized_class_string(klass, klass_modules, options)

      begin
        constantized_class_string.constantize
      rescue StandardError
        raise NameError, "\"#{constantized_class_string}\" is not a valid class constant."
      end
    end

    # Returns a fully-qualified constantized class (as a string), given the klass and klass_modules.
    #
    # @param [Symbol or String] klass the class name.
    # @param [Hash, Array or String] klass_modules the modules klass belongs to.
    # @param [Hash] options the options that determine how klass_modules is transformed.
    # @option options [Boolean] :class_titleize (false) Determines whether or not klass should be
    #    titleized.
    # @option options [Boolean] :module_titleize (false) Determines whether or not klass_modules
    #    should be titleized.
    #
    # @return [String] the fully qualified class, which includes module(s) and class name.
    #
    # @example
    #
    #   to_constantized_class_string("Authenticate", "Api") # => "Api::Authenticate"
    #   to_constantized_class_string(:Authenticate, [:Api, :AppName, :V1]) # => "Api::AppName::V1::Authenticate"
    #   to_constantized_class_string(:Authenticate, { :api :Api, app_name: :AppName, api_version: :V2 })
    #      # => "Api::AppName::V2::Authenticate"
    #   to_constantized_class_string("authenticate", { :api :api, app_name: :app_name, api_version: :v1 },
    #      { class_titleize: true, module_titleize: true }) # => "Api::AppName::V1::Authenticate"
    #
    def to_constantized_class_string(klass, klass_modules = [], options = {})
      options = ensure_options(options)
      klass_modules = to_modules_string(klass_modules, options)
      klass_string = to_class_string(klass, options)
      "#{klass_modules}#{klass_string}"
    end

    # Returns a string of modules that can be subsequently prepended to a class, to create a constantized class.
    #
    # @param [Hash, Array or String] klass_modules the modules a class belongs to.
    # @param [Hash] options the options that determine how klass_modules is transformed.
    # @option options [Boolean] :module_titleize (false) Determines whether or not klass_modules should be titleized.
    #
    # @return [String] a string of modules that can be subsequently prepended to a class, to create a
    #    constantized class.
    #
    # @raise [ArgumentError] if the klass_modules is not of type String, Hash or Array.
    #
    # @example
    #
    #   to_modules_string("Api") # => "Api::"
    #   to_modules_string([:Api, :AppName, :V1]) # => "Api::AppName::V1::"
    #   to_modules_string({ :api :Api, app_name: :AppName, api_version: :V1 }) # => "Api::AppName::V1::"
    #   to_modules_string({ :api :api, app_name: :app_name, api_version: :v1 }, { module_titleize: true })
    #      # => "Api::AppName::V1::"
    #
    def to_modules_string(klass_modules = [], options = {})
      klass_modules = validate_klass_modules(klass_modules)

      options = ensure_options(options)

      klass_modules_string = ''
      unless klass_modules.empty?
        case klass_modules
        when String
          klass_modules_string = klass_modules
        when Array
          klass_modules_string = klass_modules.join('::').to_s
        when Hash
          klass_modules_string = ''
          klass_modules.to_a.each_with_index.map do |value, index|
            klass_modules_string = index.zero? ? value[1].to_s : "#{klass_modules_string}::#{value[1]}"
          end
        else
          raise ArgumentError, 'Class modules is not a String, Hash or Array.'
        end
        klass_modules_string = klass_modules_string.split('::').map(&:titleize).join('::') if options[:module_titleize]
        klass_modules_string = camelize(klass_modules_string) if options[:module_camelize]
        klass_modules_string = klass_modules_string.trim_all
        klass_modules_string = "#{klass_modules_string}::" unless klass_modules_string.empty?
      end

      klass_modules_string
    end

    # Returns the klass as a string after transformations have been applied.
    #
    # @param [Symbol or String] klass the class name to be transformed.
    # @param [Hash] options the options that determine how klass will be transformed.
    # @option options [Boolean] :class_titleize (false) Determines whether or not klass should be titleized.
    #
    # @return [String] the transformed class as a string.
    #
    # @example
    #
    #   to_class_string("MyClass") # => "MyClass"
    #   to_class_string("myClass", { class_titleize: true }) # => "MyClass"
    #   to_class_string(:MyClass) # => "MyClass"
    #   to_class_string(:myClass, { class_titleize: true }) # => "MyClass"
    #
    def to_class_string(klass, options = {})
      klass = validate_klass(klass, options)
      klass = klass.titleize if options[:class_titleize]
      klass = camelize(klass) if options[:class_camelize]
      klass
    end

    # Transforms a route into a module string
    #
    # @return [String] the camelized token.
    #
    # @example
    #
    #   camelize("/api/app/auth/v1") # => "Api::App::Auth::V1"
    #   camelize("/api/app_name/auth/v1") # => "Api::AppName::Auth::V1"
    #
    def camelize(token)
      raise ArgumentError, 'Token is not a String' unless token.instance_of? String

      token.titlecase.camelize.sub(/^:*/, '').trim_all unless token.empty?
    end

    private

    # @!visibility public
    #
    # Ensures options are initialized and valid before accessing them.
    #
    # @param [Hash] options the options that determine how processing and transformations will be handled.
    # @option options [Boolean] :camelize (false) determines whether or not both class and module names
    #    should be camelized.
    # @option options [Boolean] :titleize (false) determines whether or not both class and module names
    #    should be titleized.
    # @option options [Boolean] :class_titleize (false) determines whether or not class names should be titleized.
    # @option options [Boolean] :module_titleize (false) determines whether or not module names should be titleized.
    # @option options [Boolean] :class_camelized (false) determines whether or not class names should be camelized.
    # @option options [Boolean] :module_camelized (false) determines whether or not module names should be camelized.
    #
    # @return [Hash] the initialized, validated options.
    #
    def ensure_options(options)
      options = {} unless options.instance_of? Hash
      options = { camelize: false, titleize: false, class_titleize: false, module_titleize: false,
                  class_camelize: false, module_camelize: false }.merge(options)

      options[:class_camelize] = options[:module_camelize] = true if options[:camelize]

      options[:class_titleize] = options[:module_titleize] = true if options[:titleize]

      options
    end

    # @!visibility public
    #
    # Validates klass and returns klass as a string after all blanks have been removed using klass.gsub(/\s+/, "").
    #
    # @param [Symbol or String] klass the class name to be validated. klass cannot be empty?
    #
    # @return [String] the validated class as a string with blanks removed.
    #
    # @raise [ArgumentError] if the klass is empty? or not of type String or Symbol.
    #
    # @example
    #
    #   validate_klass(" My Class ") # => "MyClass"
    #   validate_klass(:MyClass) # => "MyClass"
    #
    def validate_klass(klass, _options)
      unless klass.is_a?(Symbol) || klass.is_a?(String)
        raise ArgumentError,
          'Class is not a String or Symbol. Class must equal the class name of the ' \
          'SimpleCommand or Command to call in the form of a String or Symbol.'
      end

      klass = klass.to_s.strip

      raise ArgumentError, 'Class is empty?' if klass.empty?

      klass
    end

    # @!visibility public
    #
    # Validates and returns klass_modules.
    #
    # @param [Symbol, Array or String] klass_modules the module(s) to be validated.
    #
    # @return [Symbol, Array or String] the validated module(s).
    #
    # @raise [ArgumentError] if the klass_modules is not of type String, Hash or Array.
    #
    # @example
    #
    #   validate_modules(" Module ") # => " Module "
    #   validate_modules(:Module) # => "Module"
    #   validate_module("ModuleA::ModuleB") # => "ModuleA::ModuleB"
    #
    def validate_klass_modules(klass_modules)
      return {} if klass_modules.nil? || (klass_modules.respond_to?(:empty?) && klass_modules.empty?)

      if !klass_modules.instance_of?(String) && !klass_modules.instance_of?(Hash) && !klass_modules.instance_of?(Array)
        raise ArgumentError, 'Class modules is not a String, Hash or Array.'
      end

      klass_modules
    end
  end
end