# frozen_string_literal: true

require 'lite_spec_helper'
require 'support/shared/server_selector'

describe Mongo::ServerSelector::Nearest do
  let(:name) { :nearest }

  include_context 'server selector'

  let(:default_address) { 'test.host' }

  it_behaves_like 'a server selector mode' do
    let(:secondary_ok) { true }
  end

  it_behaves_like 'a server selector accepting tag sets'
  it_behaves_like 'a server selector accepting hedge'
  it_behaves_like 'a server selector with sensitive data in its options'

  describe '#initialize' do
    context 'when max_staleness is provided' do
      let(:options) do
        { max_staleness: 95 }
      end

      it 'sets the max_staleness option' do
        expect(selector.max_staleness).to eq(options[:max_staleness])
      end
    end
  end

  describe '#==' do
    context 'when max staleness is the same' do
      let(:options) do
        { max_staleness: 95 }
      end

      let(:other) do
        described_class.new(options)
      end

      it 'returns true' do
        expect(selector).to eq(other)
      end
    end

    context 'when max staleness is different' do
      let(:other_options) do
        { max_staleness: 100 }
      end

      let(:other) do
        described_class.new(other_options)
      end

      it 'returns false' do
        expect(selector).not_to eq(other)
      end
    end
  end

  describe '#to_mongos' do
    context 'tag set not provided' do
      let(:expected) do
        { mode: 'nearest' }
      end

      it 'returns a read preference formatted for mongos' do
        expect(selector.to_mongos).to eq(expected)
      end
    end

    context 'tag set provided' do
      let(:tag_sets) do
        [ tag_set ]
      end

      it 'returns a read preference formatted for mongos' do
        expect(selector.to_mongos).to eq(
          { mode: 'nearest', tags: tag_sets }
        )
      end
    end

    context 'max staleness not provided' do
      let(:expected) do
        { mode: 'nearest' }
      end

      it 'returns a read preference formatted for mongos' do
        expect(selector.to_mongos).to eq(expected)
      end
    end

    context 'max staleness provided' do
      let(:max_staleness) do
        100
      end

      let(:expected) do
        { mode: 'nearest', maxStalenessSeconds: 100 }
      end

      it 'returns a read preference formatted for mongos' do
        expect(selector.to_mongos).to eq(expected)
      end
    end
  end

  describe '#select_in_replica_set' do
    context 'no candidates' do
      let(:candidates) { [] }

      it 'returns an empty array' do
        expect(selector.send(:select_in_replica_set, candidates)).to be_empty
      end
    end

    context 'single primary candidates' do
      let(:candidates) { [ primary ] }

      it 'returns an array with the primary' do
        expect(selector.send(:select_in_replica_set, candidates)).to eq([ primary ])
      end
    end

    context 'single secondary candidate' do
      let(:candidates) { [ secondary ] }

      it 'returns an array with the secondary' do
        expect(selector.send(:select_in_replica_set, candidates)).to eq([ secondary ])
      end
    end

    context 'primary and secondary candidates' do
      let(:candidates) { [ primary, secondary ] }

      it 'returns an array with the primary and secondary' do
        expect(selector.send(:select_in_replica_set, candidates)).to contain_exactly(primary, secondary)
      end
    end

    context 'multiple secondary candidates' do
      let(:candidates) { [ secondary, secondary ] }

      it 'returns an array with the secondaries' do
        expect(selector.send(:select_in_replica_set, candidates)).to contain_exactly(secondary, secondary)
      end
    end

    context 'tag sets provided' do
      let(:tag_sets) { [ tag_set ] }
      let(:matching_primary) do
        make_server(:primary, tags: server_tags, address: default_address)
      end
      let(:matching_secondary) do
        make_server(:secondary, tags: server_tags, address: default_address)
      end

      context 'single candidate' do
        context 'primary' do
          let(:candidates) { [ primary ] }

          it 'returns an empty array' do
            expect(selector.send(:select_in_replica_set, candidates)).to be_empty
          end
        end

        context 'matching primary' do
          let(:candidates) { [ matching_primary ] }

          it 'returns an array with the primary' do
            expect(selector.send(:select_in_replica_set, candidates)).to eq([ matching_primary ])
          end
        end

        context 'secondary' do
          let(:candidates) { [ secondary ] }

          it 'returns an empty array' do
            expect(selector.send(:select_in_replica_set, candidates)).to be_empty
          end
        end

        context 'matching secondary' do
          let(:candidates) { [ matching_secondary ] }

          it 'returns an array with the matching secondary' do
            expect(selector.send(:select_in_replica_set, candidates)).to eq([ matching_secondary ])
          end
        end
      end

      context 'multiple candidates' do
        context 'no matching servers' do
          let(:candidates) { [ primary, secondary, secondary ] }

          it 'returns an empty array' do
            expect(selector.send(:select_in_replica_set, candidates)).to be_empty
          end
        end

        context 'one matching primary' do
          let(:candidates) { [ matching_primary, secondary, secondary ] }

          it 'returns an array with the matching primary' do
            expect(selector.send(:select_in_replica_set, candidates)).to eq([ matching_primary ])
          end
        end

        context 'one matching secondary' do
          let(:candidates) { [ primary, matching_secondary, secondary ] }

          it 'returns an array with the matching secondary' do
            expect(selector.send(:select_in_replica_set, candidates)).to eq([ matching_secondary ])
          end
        end

        context 'two matching secondaries' do
          let(:candidates) { [ primary, matching_secondary, matching_secondary ] }
          let(:expected) { [ matching_secondary, matching_secondary ] }

          it 'returns an array with the matching secondaries' do
            expect(selector.send(:select_in_replica_set, candidates)).to eq(expected)
          end
        end

        context 'one matching primary and one matching secondary' do
          let(:candidates) { [ matching_primary, matching_secondary, secondary ] }
          let(:expected) { [ matching_primary, matching_secondary ] }

          it 'returns an array with the matching primary and secondary' do
            expect(selector.send(:select_in_replica_set, candidates)).to match_array(expected)
          end
        end
      end
    end

    context 'high latency servers' do
      let(:far_primary) { make_server(:primary, average_round_trip_time: 0.113, address: default_address) }
      let(:far_secondary) { make_server(:secondary, average_round_trip_time: 0.114, address: default_address) }

      context 'single candidate' do
        context 'far primary' do
          let(:candidates) { [ far_primary ] }

          it 'returns array with far primary' do
            expect(selector.send(:select_in_replica_set, candidates)).to eq([ far_primary ])
          end
        end

        context 'far secondary' do
          let(:candidates) { [ far_secondary ] }

          it 'returns array with far primary' do
            expect(selector.send(:select_in_replica_set, candidates)).to eq([ far_secondary ])
          end
        end
      end

      context 'multiple candidates' do
        context 'local primary, local secondary' do
          let(:candidates) { [ primary, secondary ] }

          it 'returns array with primary and secondary' do
            expect(selector.send(:select_in_replica_set, candidates)).to contain_exactly(primary, secondary)
          end
        end

        context 'local primary, far secondary' do
          let(:candidates) { [ primary, far_secondary ] }

          it 'returns array with local primary' do
            expect(selector.send(:select_in_replica_set, candidates)).to eq([ primary ])
          end
        end

        context 'far primary, local secondary' do
          let(:candidates) { [ far_primary, secondary ] }

          it 'returns array with local secondary' do
            expect(selector.send(:select_in_replica_set, candidates)).to eq([ secondary ])
          end
        end

        context 'far primary, far secondary' do
          let(:candidates) { [ far_primary, far_secondary ] }
          let(:expected) { [ far_primary, far_secondary ] }

          it 'returns array with both servers' do
            expect(selector.send(:select_in_replica_set, candidates)).to match_array(expected)
          end
        end

        context 'two local servers, one far server' do
          context 'local primary, local secondary' do
            let(:candidates) { [ primary, secondary, far_secondary ] }
            let(:expected) { [ primary, secondary ] }

            it 'returns array with local primary and local secondary' do
              expect(selector.send(:select_in_replica_set, candidates)).to match_array(expected)
            end
          end

          context 'two near secondaries' do
            let(:candidates) { [ far_primary, secondary, secondary ] }
            let(:expected) { [ secondary, secondary ] }

            it 'returns array with the two local secondaries' do
              expect(selector.send(:select_in_replica_set, candidates)).to match_array(expected)
            end
          end
        end
      end
    end
  end
end
