# frozen_string_literal: true
# encoding: utf-8

require 'spec_helper'

describe Mongo::Index::View do

  let(:subscriber) { Mrss::EventSubscriber.new }

  let(:client) do
    authorized_client.tap do |client|
      client.subscribe(Mongo::Monitoring::COMMAND, subscriber)
    end
  end

  let(:authorized_collection) do
    client[TEST_COLL]
  end

  let(:view) do
    described_class.new(authorized_collection, options)
  end

  let(:options) do
    {}
  end

  before do
    begin
      authorized_collection.delete_many
    rescue Mongo::Error::OperationFailure
    end
    begin
      authorized_collection.indexes.drop_all
    rescue Mongo::Error::OperationFailure
    end
  end

  describe '#drop_one' do

    let(:spec) do
      { another: -1 }
    end

    before do
      view.create_one(spec, unique: true)
    end

    context 'when provided a session' do

      let(:view_with_session) do
        described_class.new(authorized_collection, session: session)
      end

      let(:client) do
        authorized_client
      end

      let(:operation) do
        view_with_session.drop_one('another_-1')
      end

      let(:failed_operation) do
        view_with_session.drop_one('_another_-1')
      end

      it_behaves_like 'an operation using a session'
      it_behaves_like 'a failed operation using a session'
    end

    context 'when the index exists' do

      let(:result) do
        view.drop_one('another_-1')
      end

      it 'drops the index' do
        expect(result).to be_successful
      end
    end

    context 'when passing a * as the name' do

      it 'raises an exception' do
        expect {
          view.drop_one('*')
        }.to raise_error(Mongo::Error::MultiIndexDrop)
      end
    end

    context 'when the collection has a write concern' do

      let(:collection) do
        authorized_collection.with(write: INVALID_WRITE_CONCERN)
      end

      let(:view_with_write_concern) do
        described_class.new(collection)
      end

      let(:result) do
        view_with_write_concern.drop_one('another_-1')
      end

      context 'when the server accepts writeConcern for the dropIndexes operation' do
        min_server_fcv '3.4'

        it 'applies the write concern' do
          expect {
            result
          }.to raise_exception(Mongo::Error::OperationFailure)
        end
      end

      context 'when the server does not accept writeConcern for the dropIndexes operation' do
        max_server_version '3.2'

        it 'does not apply the write concern' do
          expect(result).to be_successful
        end
      end
    end

    context 'when there are multiple indexes with the same key pattern' do
      min_server_fcv '3.4'

      before do
        view.create_one({ random: 1 }, unique: true)
        view.create_one({ random: 1 },
                          name: 'random_1_with_collation',
                          unique: true,
                          collation: { locale: 'en_US', strength: 2 })
      end

      context 'when a name is supplied' do

        let!(:result) do
          view.drop_one('random_1_with_collation')
        end

        let(:index_names) do
          view.collect { |model| model['name'] }
        end

        it 'returns ok' do
          expect(result).to be_successful
        end

        it 'drops the correct index' do
          expect(index_names).not_to include('random_1_with_collation')
          expect(index_names).to include('random_1')
        end
      end
    end

    context 'with a comment' do
      min_server_version '4.4'

      it 'drops the index' do
        expect(view.drop_one('another_-1', comment: "comment")).to be_successful
        command = subscriber.command_started_events("dropIndexes").last&.command
        expect(command).not_to be_nil
        expect(command["comment"]).to eq("comment")
      end
    end
  end

  describe '#drop_all' do

    let(:spec) do
      { another: -1 }
    end

    before do
      view.create_one(spec, unique: true)
    end

    context 'when indexes exists' do

      let(:result) do
        view.drop_all
      end

      it 'drops the index' do
        expect(result).to be_successful
      end

      context 'when provided a session' do

        let(:view_with_session) do
          described_class.new(authorized_collection, session: session)
        end

        let(:operation) do
          view_with_session.drop_all
        end

        let(:client) do
          authorized_client
        end

        it_behaves_like 'an operation using a session'
      end

      context 'when the collection has a write concern' do

        let(:collection) do
          authorized_collection.with(write: INVALID_WRITE_CONCERN)
        end

        let(:view_with_write_concern) do
          described_class.new(collection)
        end

        let(:result) do
          view_with_write_concern.drop_all
        end

        context 'when the server accepts writeConcern for the dropIndexes operation' do
          min_server_fcv '3.4'

          it 'applies the write concern' do
            expect {
              result
            }.to raise_exception(Mongo::Error::OperationFailure)
          end
        end

        context 'when the server does not accept writeConcern for the dropIndexes operation' do
          max_server_version '3.2'

          it 'does not apply the write concern' do
            expect(result).to be_successful
          end
        end
      end

      context 'with a comment' do
        min_server_version '4.4'

        it 'drops indexes' do
          expect(view.drop_all(comment: "comment")).to be_successful
          command = subscriber.command_started_events("dropIndexes").last&.command
          expect(command).not_to be_nil
          expect(command["comment"]).to eq("comment")
        end
      end
    end
  end

  describe '#create_many' do

    context 'when the indexes are created' do

      context 'when passing multi-args' do

        context 'when the index creation is successful' do

          let!(:result) do
            view.create_many(
              { key: { random: 1 }, unique: true },
              { key: { testing: -1 }, unique: true }
            )
          end

          it 'returns ok' do
            expect(result).to be_successful
          end

          context 'when provided a session' do

            let(:view_with_session) do
              described_class.new(authorized_collection, session: session)
            end

            let(:operation) do
              view_with_session.create_many(
                  { key: { random: 1 }, unique: true },
                  { key: { testing: -1 }, unique: true }
              )
            end

            let(:client) do
              authorized_client
            end

            let(:failed_operation) do
              view_with_session.create_many(
                  { key: { random: 1 }, invalid: true }
              )
            end

            it_behaves_like 'an operation using a session'
            it_behaves_like 'a failed operation using a session'
          end
        end

        context 'when commit quorum options are specified' do
          require_topology :replica_set, :sharded
          context 'on server versions >= 4.4' do
            min_server_fcv '4.4'

            let(:subscriber) { Mrss::EventSubscriber.new }

            let(:client) do
              authorized_client.tap do |client|
                client.subscribe(Mongo::Monitoring::COMMAND, subscriber)
              end
            end

            let(:authorized_collection) { client['view-subscribed'] }

            context 'when commit_quorum value is supported' do
              let!(:result) do
                view.create_many(
                  { key: { random: 1 }, unique: true },
                  { key: { testing: -1 }, unique: true },
                  { commit_quorum: 'majority' }
                )
              end

              let(:events) do
                subscriber.command_started_events('createIndexes')
              end

              it 'returns ok' do
                expect(result).to be_successful
              end

              it 'passes the commit_quorum option to the server' do
                expect(events.length).to eq(1)
                command = events.first.command
                expect(command['commitQuorum']).to eq('majority')
              end
            end

            context 'when commit_quorum value is not supported' do
              it 'raises an exception' do
                expect do
                  view.create_many(
                    { key: { random: 1 }, unique: true },
                    { key: { testing: -1 }, unique: true },
                    { commit_quorum: 'unsupported-value' }
                  )
                # 4.4.4 changed the text of the error message
                end.to raise_error(Mongo::Error::OperationFailure, /Commit quorum cannot be satisfied with the current replica set configuration|No write concern mode named 'unsupported-value' found in replica set configuration/)
              end
            end
          end

          context 'on server versions < 4.4' do
            max_server_fcv '4.2'

            it 'raises an exception' do
              expect do
                view.create_many(
                  { key: { random: 1 }, unique: true },
                  { key: { testing: -1 }, unique: true },
                  { commit_quorum: 'majority' }
                )
              end.to raise_error(Mongo::Error::UnsupportedOption, /The MongoDB server handling this request does not support the commit_quorum option/)
            end
          end
        end

        context 'when hidden is specified' do
          let(:index) { view.get('with_hidden_1') }

          context 'on server versions <= 3.2' do
            # DRIVERS-1220 Server versions 3.2 and older do not perform any option
            # checking on index creation. The server will allow the user to create
            # the index with the hidden option, but the server does not support this
            # option and will not use it.
            max_server_fcv '3.2'

            let!(:result) do
              view.create_many({ key: { with_hidden: 1 }, hidden: true })
            end

            it 'returns ok' do
              expect(result).to be_successful
            end

            it 'creates an index' do
              expect(index).to_not be_nil
            end
          end

          context 'on server versions between 3.4 and 4.2' do
            max_server_fcv '4.2'
            min_server_fcv '3.4'

            it 'raises an exception' do
              expect do
                view.create_many({ key: { with_hidden: 1 }, hidden: true })
              end.to raise_error(/The field 'hidden' is not valid for an index specification/)
            end
          end

          context 'on server versions >= 4.4' do
            min_server_fcv '4.4'

            context 'when hidden is true' do
              let!(:result) do
                view.create_many({ key: { with_hidden: 1 }, hidden: true })
              end

              it 'returns ok' do
                expect(result).to be_successful
              end

              it 'creates an index' do
                expect(index).to_not be_nil
              end

              it 'applies the hidden option to the index' do
                expect(index['hidden']).to be true
              end
            end

            context 'when hidden is false' do
              let!(:result) do
                view.create_many({ key: { with_hidden: 1 }, hidden: false })
              end

              it 'returns ok' do
                expect(result).to be_successful
              end

              it 'creates an index' do
                expect(index).to_not be_nil
              end

              it 'does not apply the hidden option to the index' do
                expect(index['hidden']).to be_nil
              end
            end
          end
        end

        context 'when collation is specified' do
          min_server_fcv '3.4'

          let(:result) do
            view.create_many(
              { key: { random: 1 },
                unique: true,
                collation: { locale: 'en_US', strength: 2 } }
            )
          end

          let(:index_info) do
            view.get('random_1')
          end

          context 'when the server supports collations' do
            min_server_fcv '3.4'

            it 'returns ok' do
              expect(result).to be_successful
            end

            it 'applies the collation to the new index' do
              result
              expect(index_info['collation']).not_to be_nil
              expect(index_info['collation']['locale']).to eq('en_US')
              expect(index_info['collation']['strength']).to eq(2)
            end
          end

          context 'when the server does not support collations' do
            max_server_version '3.2'

            it 'raises an exception' do
              expect {
                result
              }.to raise_exception(Mongo::Error::UnsupportedCollation)
            end

            context 'when a String key is used' do

              let(:result) do
                view.create_many(
                  { key: { random: 1 },
                    unique: true,
                    'collation' => { locale: 'en_US', strength: 2 } }
                )
              end

              it 'raises an exception' do
                expect {
                  result
                }.to raise_exception(Mongo::Error::UnsupportedCollation)
              end
            end
          end
        end

        context 'when the collection has a write concern' do

          let(:collection) do
            authorized_collection.with(write: INVALID_WRITE_CONCERN)
          end

          let(:view_with_write_concern) do
            described_class.new(collection)
          end

          let(:result) do
            view_with_write_concern.create_many(
                { key: { random: 1 }, unique: true },
                { key: { testing: -1 }, unique: true }
            )
          end

          context 'when the server accepts writeConcern for the createIndexes operation' do
            min_server_fcv '3.4'

            it 'applies the write concern' do
              expect {
                result
              }.to raise_exception(Mongo::Error::OperationFailure)
            end
          end

          context 'when the server does not accept writeConcern for the createIndexes operation' do
            max_server_version '3.2'

            it 'does not apply the write concern' do
              expect(result).to be_successful
            end
          end
        end
      end

      context 'when passing an array' do

        context 'when the index creation is successful' do

          let!(:result) do
            view.create_many([
                                 { key: { random: 1 }, unique: true },
                                 { key: { testing: -1 }, unique: true }
                             ])
          end

          it 'returns ok' do
            expect(result).to be_successful
          end

          context 'when provided a session' do

            let(:view_with_session) do
              described_class.new(authorized_collection, session: session)
            end

            let(:operation) do
              view_with_session.create_many([
                                             { key: { random: 1 }, unique: true },
                                             { key: { testing: -1 }, unique: true }
                                            ])
            end

            let(:failed_operation) do
              view_with_session.create_many([ { key: { random: 1 }, invalid: true }])
            end

            let(:client) do
              authorized_client
            end

            it_behaves_like 'an operation using a session'
            it_behaves_like 'a failed operation using a session'
          end
        end

        context 'when collation is specified' do

          let(:result) do
            view.create_many([
                                 { key: { random: 1 },
                                   unique: true,
                                   collation: { locale: 'en_US', strength: 2 }},
                             ])
          end

          let(:index_info) do
            view.get('random_1')
          end

          context 'when the server supports collations' do
            min_server_fcv '3.4'

            it 'returns ok' do
              expect(result).to be_successful
            end

            it 'applies the collation to the new index' do
              result
              expect(index_info['collation']).not_to be_nil
              expect(index_info['collation']['locale']).to eq('en_US')
              expect(index_info['collation']['strength']).to eq(2)
            end
          end

          context 'when the server does not support collations' do
            max_server_version '3.2'

            it 'raises an exception' do
              expect {
                result
              }.to raise_exception(Mongo::Error::UnsupportedCollation)
            end

            context 'when a String key is used' do

              let(:result) do
                view.create_many([
                                   { key: { random: 1 },
                                     unique: true,
                                     'collation' => { locale: 'en_US', strength: 2 }},
                                 ])
              end

              it 'raises an exception' do
                expect {
                  result
                }.to raise_exception(Mongo::Error::UnsupportedCollation)
              end
            end
          end
        end

        context 'when the collection has a write concern' do

          let(:collection) do
            authorized_collection.with(write: INVALID_WRITE_CONCERN)
          end

          let(:view_with_write_concern) do
            described_class.new(collection)
          end

          let(:result) do
            view_with_write_concern.create_many([
                                 { key: { random: 1 }, unique: true },
                                 { key: { testing: -1 }, unique: true }
                             ])
          end

          context 'when the server accepts writeConcern for the createIndexes operation' do
            min_server_fcv '3.4'

            it 'applies the write concern' do
              expect {
                result
              }.to raise_exception(Mongo::Error::OperationFailure)
            end
          end

          context 'when the server does not accept writeConcern for the createIndexes operation' do
            max_server_version '3.2'

            it 'does not apply the write concern' do
              expect(result).to be_successful
            end
          end
        end
      end

      context 'when index creation fails' do

        let(:spec) do
          { name: 1 }
        end

        before do
          view.create_one(spec, unique: true)
        end

        it 'raises an exception' do
          expect {
            view.create_many([{ key: { name: 1 }, unique: false }])
          }.to raise_error(Mongo::Error::OperationFailure)
        end
      end
    end

    context 'when using bucket option' do
      # Option is removed in 4.9
      max_server_version '4.7'

      let(:spec) do
        { 'any' => 1 }
      end

      let(:result) do
        view.create_many([key: spec, bucket_size: 1])
      end

      it 'warns of deprecation' do
        RSpec::Mocks.with_temporary_scope do
          view.client.should receive(:log_warn).and_call_original

          result
        end
      end
    end

    context 'with a comment' do
      min_server_version '4.4'

      it 'creates indexes' do
        expect(
          view.create_many(
            [
              { key: { random: 1 }, unique: true },
              { key: { testing: -1 }, unique: true }
            ],
            comment: "comment"
          )
        ).to be_successful
        command = subscriber.single_command_started_event("createIndexes")&.command
        expect(command).not_to be_nil
        expect(command["comment"]).to eq("comment")
      end
    end
  end

  describe '#create_one' do

    context 'when the index is created' do

      let(:spec) do
        { random: 1 }
      end

      let(:result) do
        view.create_one(spec, unique: true)
      end

      it 'returns ok' do
        expect(result).to be_successful
      end

      context 'when provided a session' do

        let(:view_with_session) do
          described_class.new(authorized_collection, session: session)
        end

        let(:operation) do
          view_with_session.create_one(spec, unique: true)
        end

        let(:failed_operation) do
          view_with_session.create_one(spec, invalid: true)
        end

        let(:client) do
          authorized_client
        end

        it_behaves_like 'an operation using a session'
        it_behaves_like 'a failed operation using a session'
      end

      context 'when the collection has a write concern' do

        let(:collection) do
          authorized_collection.with(write: INVALID_WRITE_CONCERN)
        end

        let(:view_with_write_concern) do
          described_class.new(collection)
        end

        let(:result) do
          view_with_write_concern.create_one(spec, unique: true)
        end

        context 'when the server accepts writeConcern for the createIndexes operation' do
          min_server_fcv '3.4'

          it 'applies the write concern' do
            expect {
              result
            }.to raise_exception(Mongo::Error::OperationFailure)
          end
        end

        context 'when the server does not accept writeConcern for the createIndexes operation' do
          max_server_version '3.2'

          it 'does not apply the write concern' do
            expect(result).to be_successful
          end
        end
      end

      context 'when the index is created on an subdocument field' do

        let(:spec) do
          { 'sub_document.random' => 1 }
        end

        let(:result) do
          view.create_one(spec, unique: true)
        end

        it 'returns ok' do
          expect(result).to be_successful
        end
      end

      context 'when using bucket option' do
        # Option is removed in 4.9
        max_server_version '4.7'

        let(:spec) do
          { 'any' => 1 }
        end

        let(:result) do
          view.create_one(spec, bucket_size: 1)
        end

        it 'warns of deprecation' do
          RSpec::Mocks.with_temporary_scope do
            view.client.should receive(:log_warn).and_call_original

            result
          end
        end
      end
    end

    context 'when index creation fails' do

      let(:spec) do
        { name: 1 }
      end

      before do
        view.create_one(spec, unique: true)
      end

      it 'raises an exception' do
        expect {
          view.create_one(spec, unique: false)
        }.to raise_error(Mongo::Error::OperationFailure)
      end
    end

    context 'when providing an index name' do

      let(:spec) do
        { random: 1 }
      end

      let!(:result) do
        view.create_one(spec, unique: true, name: 'random_name')
      end

      it 'returns ok' do
        expect(result).to be_successful
      end

      it 'defines the index with the provided name' do
        expect(view.get('random_name')).to_not be_nil
      end
    end

    context 'when providing an invalid partial index filter' do
      min_server_fcv '3.2'

      it 'raises an exception' do
        expect {
          view.create_one({'x' => 1}, partial_filter_expression: 5)
        }.to raise_error(Mongo::Error::OperationFailure)
      end
    end

    context 'when providing a valid partial index filter' do
      min_server_fcv '3.2'

      let(:expression) do
        {'a' => {'$lte' => 1.5}}
      end

      let!(:result) do
        view.create_one({'x' => 1}, partial_filter_expression: expression)
      end

      let(:indexes) do
        authorized_collection.indexes.get('x_1')
      end

      it 'returns ok' do
        expect(result).to be_successful
      end

      it 'creates an index' do
        expect(indexes).to_not be_nil
      end

      it 'passes partialFilterExpression correctly' do
        expect(indexes[:partialFilterExpression]).to eq(expression)
      end
    end

    context 'when providing an invalid wildcard projection expression' do
      min_server_fcv '4.2'

      it 'raises an exception' do
        expect {
          view.create_one({ '$**' => 1 }, wildcard_projection: 5)
        }.to raise_error(Mongo::Error::OperationFailure, /Error in specification.*wildcardProjection|wildcardProjection.*must be a non-empty object/)
      end
    end

    context 'when providing a wildcard projection to an invalid base index' do
      min_server_fcv '4.2'

      it 'raises an exception' do
        expect {
          view.create_one({ 'x' => 1 }, wildcard_projection: { rating: 1 })
        }.to raise_error(Mongo::Error::OperationFailure, /Error in specification.*wildcardProjection|wildcardProjection.*is only allowed/)
      end
    end

    context 'when providing a valid wildcard projection' do
      min_server_fcv '4.2'

      let!(:result) do
        view.create_one({ '$**' => 1 }, wildcard_projection: { 'rating' => 1 })
      end

      let(:indexes) do
        authorized_collection.indexes.get('$**_1')
      end

      it 'returns ok' do
        expect(result).to be_successful
      end

      it 'creates an index' do
        expect(indexes).to_not be_nil
      end

      context 'on server versions <= 4.4' do
        max_server_fcv '4.4'

        it 'passes wildcardProjection correctly' do
          expect(indexes[:wildcardProjection]).to eq({ 'rating' => 1 })
        end
      end

      context 'on server versions >= 5.0' do
        min_server_fcv '5.0'

        it 'passes wildcardProjection correctly' do
          expect(indexes[:wildcardProjection]).to eq({ '_id' => false, 'rating' => true })
        end
      end
    end

    context 'when providing hidden option' do
      let(:index) { view.get('with_hidden_1') }

      context 'on server versions <= 3.2' do
        # DRIVERS-1220 Server versions 3.2 and older do not perform any option
        # checking on index creation. The server will allow the user to create
        # the index with the hidden option, but the server does not support this
        # option and will not use it.
        max_server_fcv '3.2'

        let!(:result) do
          view.create_one({ 'with_hidden' => 1 }, { hidden: true })
        end

        it 'returns ok' do
          expect(result).to be_successful
        end

        it 'creates an index' do
          expect(index).to_not be_nil
        end
      end

      context 'on server versions between 3.4 and 4.2' do
        max_server_fcv '4.2'
        min_server_fcv '3.4'

        it 'raises an exception' do
          expect do
            view.create_one({ 'with_hidden' => 1 }, { hidden: true })
          end.to raise_error(/The field 'hidden' is not valid for an index specification/)
        end
      end

      context 'on server versions >= 4.4' do
        min_server_fcv '4.4'

        context 'when hidden is true' do
          let!(:result) { view.create_one({ 'with_hidden' => 1 }, { hidden: true }) }

          it 'returns ok' do
            expect(result).to be_successful
          end

          it 'creates an index' do
            expect(index).to_not be_nil
          end

          it 'applies the hidden option to the index' do
            expect(index['hidden']).to be true
          end
        end

        context 'when hidden is false' do
          let!(:result) { view.create_one({ 'with_hidden' => 1 }, { hidden: false }) }

          it 'returns ok' do
            expect(result).to be_successful
          end

          it 'creates an index' do
            expect(index).to_not be_nil
          end

          it 'does not apply the hidden option to the index' do
            expect(index['hidden']).to be_nil
          end
        end
      end
    end

    context 'when providing commit_quorum option' do
      require_topology :replica_set, :sharded
      context 'on server versions >= 4.4' do
        min_server_fcv '4.4'

        let(:subscriber) { Mrss::EventSubscriber.new }

        let(:client) do
          authorized_client.tap do |client|
            client.subscribe(Mongo::Monitoring::COMMAND, subscriber)
          end
        end

        let(:authorized_collection) { client['view-subscribed'] }

        let(:indexes) do
          authorized_collection.indexes.get('x_1')
        end

        context 'when commit_quorum value is supported' do
          let!(:result) { view.create_one({ 'x' => 1 }, commit_quorum: 'majority') }

          it 'returns ok' do
            expect(result).to be_successful
          end

          it 'creates an index' do
            expect(indexes).to_not be_nil
          end

          let(:events) do
            subscriber.command_started_events('createIndexes')
          end

          it 'passes the commit_quorum option to the server' do
            expect(events.length).to eq(1)
            command = events.first.command
            expect(command['commitQuorum']).to eq('majority')
          end
        end

        context 'when commit_quorum value is not supported' do
          it 'raises an exception' do
            expect do
              view.create_one({ 'x' => 1 }, commit_quorum: 'unsupported-value')
            # 4.4.4 changed the text of the error message
            end.to raise_error(Mongo::Error::OperationFailure, /Commit quorum cannot be satisfied with the current replica set configuration|No write concern mode named 'unsupported-value' found in replica set configuration/)
          end
        end
      end

      context 'on server versions < 4.4' do
        max_server_fcv '4.2'

        it 'raises an exception' do
          expect do
            view.create_one({ 'x' => 1 }, commit_quorum: 'majority')
          end.to raise_error(Mongo::Error::UnsupportedOption, /The MongoDB server handling this request does not support the commit_quorum option/)
        end
      end
    end

    context 'with a comment' do
      min_server_version '4.4'

      it 'creates index' do
        expect(
          view.create_one(
            { 'x' => 1 },
            comment: "comment"
          )
        ).to be_successful
        command = subscriber.single_command_started_event("createIndexes")&.command
        expect(command).not_to be_nil
        expect(command["comment"]).to eq("comment")
      end
    end
  end

  describe '#get' do

    let(:spec) do
      { random: 1 }
    end

    let!(:result) do
      view.create_one(spec, unique: true, name: 'random_name')
    end

    context 'when providing a name' do

      let(:index) do
        view.get('random_name')
      end

      it 'returns the index' do
        expect(index['name']).to eq('random_name')
      end
    end

    context 'when providing a spec' do

      let(:index) do
        view.get(random: 1)
      end

      it 'returns the index' do
        expect(index['name']).to eq('random_name')
      end
    end

    context 'when provided a session' do

      let(:view_with_session) do
        described_class.new(authorized_collection, session: session)
      end

      let(:operation) do
        view_with_session.get(random: 1)
      end

      let(:client) do
        authorized_client
      end

      it_behaves_like 'an operation using a session'
    end

    context 'when the index does not exist' do

      it 'returns nil' do
        expect(view.get(other: 1)).to be_nil
      end
    end
  end

  describe '#each' do

    context 'when the collection exists' do

      let(:spec) do
        { name: 1 }
      end

      before do
        view.create_one(spec, unique: true)
      end

      let(:indexes) do
        view.each
      end

      it 'returns all the indexes for the database' do
        expect(indexes.to_a.count).to eq(2)
      end
    end

    context 'when the collection does not exist' do
      min_server_fcv '3.0'

      let(:nonexistent_collection) do
        authorized_client[:not_a_collection]
      end

      let(:nonexistent_view) do
        described_class.new(nonexistent_collection)
      end

      it 'raises a nonexistent collection error' do
        expect {
          nonexistent_view.each.to_a
        }.to raise_error(Mongo::Error::OperationFailure)
      end
    end
  end

  describe '#normalize_models' do

    context 'when providing options' do

      let(:options) do
        {
          :key => { :name => 1 },
          :bucket_size => 5,
          :default_language => 'deutsch',
          :expire_after => 10,
          :language_override => 'language',
          :sphere_version => 1,
          :storage_engine => 'wiredtiger',
          :text_version => 2,
          :version => 1
        }
      end

      let(:models) do
        view.send(:normalize_models, [ options ], authorized_primary)
      end

      let(:expected) do
        {
          :key => { :name => 1 },
          :name => 'name_1',
          :bucketSize => 5,
          :default_language => 'deutsch',
          :expireAfterSeconds => 10,
          :language_override => 'language',
          :'2dsphereIndexVersion' => 1,
          :storageEngine => 'wiredtiger',
          :textIndexVersion => 2,
          :v => 1
        }
      end

      it 'maps the ruby options to the server options' do
        expect(models).to eq([ expected ])
      end

      context 'when using alternate names' do

        let(:extended_options) do
          options.merge!(expire_after_seconds: 5)
        end

        let(:extended_expected) do
          expected.tap { |exp| exp[:expireAfterSeconds] = 5 }
        end

        let(:models) do
          view.send(:normalize_models, [ extended_options ], authorized_primary)
        end

        it 'maps the ruby options to the server options' do
          expect(models).to eq([ extended_expected ])
        end
      end

      context 'when the server supports collations' do
        min_server_fcv '3.4'

        let(:extended_options) do
          options.merge(:collation => { locale: 'en_US' } )
        end

        let(:models) do
          view.send(:normalize_models, [ extended_options ], authorized_primary)
        end

        let(:extended_expected) do
          expected.tap { |exp| exp[:collation] = { locale: 'en_US' } }
        end

        it 'maps the ruby options to the server options' do
          expect(models).to eq([ extended_expected ])
        end
      end
    end
  end
end