# frozen_string_literal: true
module StarTrek
  # Adapted from graphql-relay-js
  # https://github.com/graphql/graphql-relay-js/blob/master/src/__tests__/StarTrekSchema.js

  class Ship < GraphQL::Schema::Object
    implements GraphQL::Types::Relay::Node
    global_id_field :id
    field :name, String
    # Test cyclical connection types:
    field :ships, Ship.connection_type, null: false
  end

  class ResidentType < GraphQL::Schema::Object
    global_id_field :id
    field :name, String
  end

  class BaseType < GraphQL::Schema::Object
    graphql_name "Base"
    implements GraphQL::Types::Relay::Node
    global_id_field :id
    field :name, String, null: false

    def name
      LazyWrapper.new {
        if object.id.nil?
          raise GraphQL::ExecutionError, "Boom!"
        else
          object.name
        end
      }
    end

    field :sector, String
    field :residents, ResidentType.connection_type
  end

  class BaseConnectionWithTotalCountType < GraphQL::Types::Relay::BaseConnection
    graphql_name "BasesConnectionWithTotalCount"
    edge_type(BaseType.edge_type)
    field :total_count, Integer

    def total_count
      object.items.count
    end
  end

  class CustomBaseEdge < GraphQL::Pagination::Connection::Edge
    def upcased_name
      node.name.upcase
    end

    def upcased_parent_name
      parent.name.upcase
    end
  end

  class CustomBaseEdgeType < GraphQL::Types::Relay::BaseEdge
    node_type(BaseType)
    field :upcased_name, String
    field :upcased_parent_name, String
    field :edge_class_name, String

    def edge_class_name
      object.class.name
    end
  end

  class CustomEdgeBaseConnectionType < GraphQL::Types::Relay::BaseConnection
    edge_type(CustomBaseEdgeType, edge_class: CustomBaseEdge)

    field :total_count_times_100, Integer
    def total_count_times_100
      obj.items.to_a.count * 100
    end

    field :field_name, String
    def field_name
      object.field.name
    end
  end

  class ShipsWithMaxPageSize < GraphQL::Schema::Resolver
    argument :name_includes, String, required: false
    type Ship.connection_type, null: true

    def resolve(name_includes: nil)
      all_ships = object.ships.map { |ship_id| StarTrek::DATA["Ship"][ship_id] }
      if name_includes
        all_ships = all_ships.select { |ship| ship.name.include?(name_includes)}
      end
      all_ships
    end
  end

  class ShipConnectionWithParentType < GraphQL::Types::Relay::BaseConnection
    edge_type(Ship.edge_type)
    graphql_name "ShipConnectionWithParent"
    field :parent_class_name, String, null: false
    def parent_class_name
      object.parent.class.name
    end
  end

  class Faction < GraphQL::Schema::Object
    implements GraphQL::Types::Relay::Node
    field :name, String
    field :ships, ShipConnectionWithParentType, connection: true, max_page_size: 1000, null: true do
      argument :name_includes, String, required: false
    end

    def ships(name_includes: nil)
      all_ships = object.ships.map {|ship_id| StarTrek::DATA["Ship"][ship_id] }
      if name_includes
        case name_includes
        when "error"
          all_ships = GraphQL::ExecutionError.new("error from within connection")
        when "raisedError"
          raise GraphQL::ExecutionError.new("error raised from within connection")
        when "lazyError"
          all_ships = LazyWrapper.new { GraphQL::ExecutionError.new("lazy error from within connection") }
        when "lazyRaisedError"
          all_ships = LazyWrapper.new { raise GraphQL::ExecutionError.new("lazy raised error from within connection") }
        when "null"
          all_ships = nil
        when "lazyObject"
          prev_all_ships = all_ships
          all_ships = LazyWrapper.new { prev_all_ships }
        else
          all_ships = all_ships.select { |ship| ship.name.include?(name_includes)}
        end
      end
      all_ships
    end

    field :shipsWithMaxPageSize, "Ships with max page size", max_page_size: 2, resolver: ShipsWithMaxPageSize

    field :bases, BaseConnectionWithTotalCountType, connection: true do
      argument :name_includes, String, required: false
    end

    def bases(name_includes: nil)
      all_bases = object.bases
      if name_includes
        all_bases = all_bases.where(name: Regexp.new(name_includes))
      end
      all_bases
    end

    field :bases_clone, BaseType.connection_type
    field :bases_by_name, BaseType.connection_type do
      argument :order, String, default_value: "name", required: false
    end
    def bases_by_name(order: nil)
      if order.present?
        @object.bases.order_by(name: order)
      else
        @object.bases
      end
    end

    def all_bases
      Base.all
    end

    def all_bases_array
      all_bases.to_a
    end

    field :basesWithMaxLimitRelation, BaseType.connection_type, max_page_size: 2, resolver_method: :all_bases
    field :basesWithMaxLimitArray, BaseType.connection_type, max_page_size: 2, resolver_method: :all_bases_array
    field :basesWithDefaultMaxLimitRelation, BaseType.connection_type, resolver_method: :all_bases
    field :basesWithDefaultMaxLimitArray, BaseType.connection_type, resolver_method: :all_bases_array
    field :basesWithLargeMaxLimitRelation, BaseType.connection_type, max_page_size: 1000, resolver_method: :all_bases

    field :bases_with_custom_edge, CustomEdgeBaseConnectionType, connection: true
    def bases_with_custom_edge
      LazyNodesWrapper.new(object.bases)
    end
  end

  class IntroduceShipMutation < GraphQL::Schema::RelayClassicMutation
    description "Add a ship to this faction"

    # Nested under `input` in the query:
    argument :ship_name, String, required: false
    argument :faction_id, ID

    # Result may have access to these fields:
    field :ship_edge, Ship.edge_type
    field :faction, Faction
    field :aliased_faction, Faction, hash_key: :aliased_faction, null: true

    def resolve(ship_name: nil, faction_id:)
      if ship_name == 'USS Voyager'
        GraphQL::ExecutionError.new("Sorry, USS Voyager ship is reserved")
      elsif ship_name == 'IKS Korinar'
        raise GraphQL::ExecutionError.new("🔥")
      elsif ship_name == 'Scimitar'
        LazyWrapper.new { raise GraphQL::ExecutionError.new("💥")}
      end
    end
  end

  # GraphQL-Batch knockoff
  class LazyLoader
    def self.defer(ctx, model, id)
      ids = ctx.namespace(:loading)[model] ||= []
      ids << id
      self.new(model: model, id: id, context: ctx)
    end

    def initialize(model:, id:, context:)
      @model = model
      @id = id
      @context = context
    end

    def value
      loaded = @context.namespace(:loaded)[@model] ||= {}
      if loaded.empty?
        ids = @context.namespace(:loading)[@model]
        # Example custom tracing
        @context.trace("lazy_loader", { ids: ids, model: @model}) do
          records = @model.where(id: ids)
          records.each do |record|
            loaded[record.id.to_s] = record
          end
        end
      end

      loaded[@id]
    end
  end

  class LazyWrapper
    def initialize(value = nil, &block)
      if block_given?
        @lazy_value = block
      else
        @value = value
      end
    end

    def value
      @resolved_value = @value || @lazy_value.call
    end
  end

  LazyNodesWrapper = Struct.new(:relation)
  class LazyNodesRelationConnection < GraphQL::Pagination::MongoidRelationConnection
    def initialize(wrapper, *args)
      super(wrapper.relation, *args)
    end

    def edge_nodes
      LazyWrapper.new { super }
    end
  end

  class QueryType < GraphQL::Schema::Object
    graphql_name "Query"

    field :federation, Faction

    def federation
      StarTrek::DATA["Faction"]["1"]
    end

    field :klingons, Faction
    def klingons
      StarTrek::DATA["Faction"]["2"]
    end

    field :romulans, Faction

    def romulans
      StarTrek::DATA["Faction"]["3"]
    end

    field :largest_base, BaseType

    def largest_base
      Base.find(3)
    end

    field :newest_bases_grouped_by_faction, BaseType.connection_type

    def newest_bases_grouped_by_faction
      agg = Base.collection.aggregate([{
        "$group" => {
          "_id" => "$faction_id",
          "baseId" => { "$max" => "$_id" }
        }
      }])
      Base.
        in(id: agg.map { |doc| doc['baseId'] }).
        order_by(faction_id: -1)
    end

    field :bases_with_null_name, BaseType.connection_type, null: false

    def bases_with_null_name
      [OpenStruct.new(id: nil)]
    end

    include GraphQL::Types::Relay::HasNodeField

    field :node_with_custom_resolver, GraphQL::Types::Relay::Node do
      argument :id, ID
    end
    def node_with_custom_resolver(id:)
      StarTrek::DATA["Faction"]["1"]
    end

    include GraphQL::Types::Relay::HasNodesField

    field :nodes_with_custom_resolver, [GraphQL::Types::Relay::Node, null: true] do
      argument :ids, [ID]
    end
    def nodes_with_custom_resolver(ids:)
      [StarTrek::DATA["Faction"]["1"], StarTrek::DATA["Faction"]["2"]]
    end

    field :batched_base, BaseType do
      argument :id, ID
    end

    def batched_base(id:)
      LazyLoader.defer(@context, Base, id)
    end
  end

  class MutationType < GraphQL::Schema::Object
    graphql_name "Mutation"
    field :introduceShip, mutation: IntroduceShipMutation
  end

  class Schema < GraphQL::Schema
    query(QueryType)
    mutation(MutationType)
    default_max_page_size 3

    def self.resolve_type(type, object, ctx)
      if object == :test_error
        :not_a_type
      elsif object.is_a?(Base)
        BaseType
      elsif DATA["Faction"].values.include?(object)
        Faction
      elsif DATA["Ship"].values.include?(object)
        Ship
      else
        nil
      end
    end

    connections.add(LazyNodesWrapper, LazyNodesRelationConnection)

    def self.object_from_id(node_id, ctx)
      type_name, id = GraphQL::Schema::UniqueWithinType.decode(node_id)
      StarTrek::DATA[type_name][id]
    end

    def self.id_from_object(object, type, ctx)
      GraphQL::Schema::UniqueWithinType.encode(type.graphql_name, object.id)
    end

    lazy_resolve(LazyWrapper, :value)
    lazy_resolve(LazyLoader, :value)
  end
end