# frozen_string_literal: true
module ShopifyAPI
  class ApiVersion
    class UnknownVersion < StandardError; end
    class ApiVersionNotSetError < StandardError; end
    include Comparable

    UNSTABLE_HANDLE = 'unstable'
    HANDLE_FORMAT = /((\d{4}-\d{2})|#{UNSTABLE_HANDLE})/.freeze
    UNSTABLE_AS_DATE = Time.utc(3000, 1, 1)
    API_PREFIX = '/admin/api/'
    LOOKUP_MODES = [:raise_on_unknown, :define_on_unknown].freeze

    class << self
      attr_reader :versions

      def version_lookup_mode
        @version_lookup_mode ||= :define_on_unknown
      end

      def version_lookup_mode=(mode)
        raise ArgumentError, "Mode must be one of #{LOOKUP_MODES}" unless LOOKUP_MODES.include?(mode)
        sanitize_known_versions if mode == :raise_on_unknown
        @version_lookup_mode = mode
      end

      def find_version(version_or_handle)
        raise ArgumentError, "NullVersion is not a valid version or version handle." if version_or_handle == NullVersion
        return version_or_handle if version_or_handle.is_a?(ApiVersion)
        handle = version_or_handle.to_s
        @versions ||= {}
        @versions.fetch(handle) do
          if @version_lookup_mode == :raise_on_unknown
            raise UnknownVersion, unknown_version_error_message(handle)
          else
            add_to_known_versions(ApiVersion.new(handle: handle))
          end
        end
      end

      def coerce_to_version(version_or_handle)
        warn(
          '[DEPRECATED] ShopifyAPI::ApiVersion.coerce_to_version be removed in a future version. ' \
            'Use `find_version` instead.'
        )
        find_version(version_or_handle)
      end

      def fetch_known_versions
        @versions = Meta.admin_versions.map do |version|
          [version.handle, ApiVersion.new(version.attributes.merge(verified: version.persisted?))]
        end.to_h
      end

      def define_known_versions
        warn(
          '[DEPRECATED] ShopifyAPI::ApiVersion.define_known_versions is deprecated and will be removed in a future version. ' \
            'Use `fetch_known_versions` instead.'
        )
        fetch_known_versions
      end

      def add_to_known_versions(version)
        @versions[version.handle] = version
      end

      def clear_known_versions
        @versions = {}
      end

      def clear_defined_versions
        warn(
          '[DEPRECATED] ShopifyAPI::ApiVersion.clear_defined_versions is deprecated and will be removed in a future version. ' \
            'Use `clear_known_versions` instead.'
        )
        clear_known_versions
      end

      def latest_stable_version
        warn(
          '[DEPRECATED] ShopifyAPI::ApiVersion.latest_stable_version is deprecated and will be removed in a future version.'
        )
        versions.values.find(&:latest_supported?)
      end

      private

      def sanitize_known_versions
        return if @versions.nil?
        @versions = @versions.keys.map do |handle|
          next unless @versions[handle].verified?
          [handle, @versions[handle]]
        end.compact.to_h
      end

      def unknown_version_error_message(handle)
        msg = "ApiVersion.version_lookup_mode is set to `:raise_on_unknown`. \n"
        return msg + "No versions defined. You must call `ApiVersion.fetch_known_versions` first." if @versions.empty?
        msg + "`#{handle}` is not in the defined version set. Available versions: #{@versions.keys}"
      end
    end

    attr_reader :handle, :display_name, :supported, :latest_supported, :verified

    def initialize(attributes)
      attributes = ActiveSupport::HashWithIndifferentAccess.new(attributes)
      @handle = attributes[:handle].to_s
      @display_name = attributes.fetch(:display_name, attributes[:handle].to_s)
      @supported = attributes.fetch(:supported, false)
      @latest_supported = attributes.fetch(:latest_supported, false)
      @verified = attributes.fetch(:verified, false)
    end

    def to_s
      handle
    end

    def latest_supported?
      latest_supported
    end

    def supported?
      supported
    end

    def verified?
      verified
    end

    def <=>(other)
      handle_as_date <=> other.handle_as_date
    end

    def ==(other)
      other.class == self.class && handle == other.handle
    end

    def hash
      handle.hash
    end

    def construct_api_path(path)
      "#{API_PREFIX}#{handle}/#{path}"
    end

    def construct_graphql_path
      construct_api_path('graphql.json')
    end

    def name
      warn(
        '[DEPRECATED] ShopifyAPI::ApiVersion#name is deprecated and will be removed in a future version. ' \
          'Use `handle` instead.'
      )
      handle
    end

    def stable?
      warn(
        '[DEPRECATED] ShopifyAPI::ApiVersion#stable? is deprecated and will be removed in a future version. ' \
          'Use `supported?` instead.'
      )
      supported?
    end

    def unstable?
      handle == UNSTABLE_HANDLE
    end

    def handle_as_date
      return UNSTABLE_AS_DATE if unstable?
      year, month, day = handle.split('-')
      Time.utc(year, month, day)
    end

    class NullVersion
      class << self
        def new(*_args)
          raise NoMethodError, "NullVersion is an abstract class and cannot be instantiated."
        end

        def matches?(version)
          version.nil? || version == self
        end

        def raise_not_set_error(*_args)
          raise ApiVersionNotSetError, "You must set ShopifyAPI::Base.api_version before making a request."
        end
        alias_method :stable?, :raise_not_set_error
        alias_method :construct_api_path, :raise_not_set_error
        alias_method :construct_graphql_path, :raise_not_set_error
        alias_method :latest_supported?, :raise_not_set_error
        alias_method :supported?, :raise_not_set_error
        alias_method :verified?, :raise_not_set_error
        alias_method :unstable?, :raise_not_set_error
        alias_method :handle, :raise_not_set_error
        alias_method :display_name, :raise_not_set_error
        alias_method :supported, :raise_not_set_error
        alias_method :verified, :raise_not_set_error
        alias_method :latest_supported, :raise_not_set_error
        alias_method :name, :raise_not_set_error
      end
    end
  end
end