public SegmentMappingsChartViewModel(IProjectService projectService, SegmentMappingsChartSegmentPairViewModel.Factory segmentPairFactory, SegmentMappingViewModel.Factory mappingFactory,
			IEnumerable<SegmentMappingViewModel> mappings, SoundType soundType, int threshold)
        {
            _threshold = threshold;

            _soundType = soundType;
            FeatureSymbol segmentType;
            switch (_soundType)
            {
                case SoundType.Consonant:
                    segmentType = CogFeatureSystem.ConsonantType;
                    break;
                case SoundType.Vowel:
                    segmentType = CogFeatureSystem.VowelType;
                    break;
                default:
                    throw new InvalidEnumArgumentException();
            }

            var segmentComparer = new SegmentComparer();
            var categoryComparer = new SegmentCategoryComparer();
            _segments = new ReadOnlyList<SegmentMappingsChartSegmentViewModel>(projectService.Project.Varieties.SelectMany(v => v.SegmentFrequencyDistribution.ObservedSamples)
                .Where(s => s.Type == segmentType).Distinct().OrderBy(s => s.Category(), categoryComparer).ThenBy(s => s, segmentComparer)
                .Select(s => new SegmentMappingsChartSegmentViewModel(s, _soundType)).Concat(new SegmentMappingsChartSegmentViewModel(null, _soundType)).ToArray());
            _categories = new ReadOnlyList<SegmentCategoryViewModel>(_segments.GroupBy(s => s.DomainSegment == null ? string.Empty : s.DomainSegment.Category())
                .OrderBy(g => g.Key, categoryComparer).Select(g => new SegmentCategoryViewModel(g.Key, g)).ToArray());

            var mappingLookup = new Dictionary<UnorderedTuple<string, string>, HashSet<UnorderedTuple<string, string>>>();
            foreach (SegmentMappingViewModel mapping in mappings)
            {
                string seg1, seg2;
                FeatureSymbol leftEnv1, rightEnv1, leftEnv2, rightEnv2;
                if (ListSegmentMappings.Normalize(projectService.Project.Segmenter, mapping.Segment1, out seg1, out leftEnv1, out rightEnv1)
                    && ListSegmentMappings.Normalize(projectService.Project.Segmenter, mapping.Segment2, out seg2, out leftEnv2, out rightEnv2))
                {
                    UnorderedTuple<string, string> key = UnorderedTuple.Create(seg1, seg2);
                    HashSet<UnorderedTuple<string, string>> m = mappingLookup.GetValue(key, () => new HashSet<UnorderedTuple<string, string>>());
                    m.Add(UnorderedTuple.Create(mapping.Segment1, mapping.Segment2));
                }
            }

            IWordAligner aligner = projectService.Project.WordAligners[ComponentIdentifiers.PrimaryWordAligner];
            foreach (SegmentMappingsChartSegmentViewModel segment1 in _segments)
            {
                bool isEnabled = true;
                foreach (SegmentMappingsChartSegmentViewModel segment2 in _segments)
                {
                    if (EqualityComparer<Segment>.Default.Equals(segment1.DomainSegment, segment2.DomainSegment))
                        isEnabled = false;

                    int delta = segment1.DomainSegment == null || segment2.DomainSegment == null ? -1
                        : aligner.Delta(segment1.DomainSegment.FeatureStruct, segment2.DomainSegment.FeatureStruct);
                    SegmentMappingsChartSegmentPairViewModel segmentPair = segmentPairFactory(segment1, segment2, delta, isEnabled);
                    segmentPair.MeetsThreshold = delta != -1 && delta <= _threshold;
                    HashSet<UnorderedTuple<string, string>> pairMappings;
                    if (mappingLookup.TryGetValue(UnorderedTuple.Create(segment1.StrRep, segment2.StrRep), out pairMappings))
                        segmentPair.Mappings.Mappings.AddRange(pairMappings.Select(m => mappingFactory(m.Item1, m.Item2)));
                    segment1.SegmentPairs.Add(segmentPair);
                }
            }
        }
            public TestEnvironment()
            {
                DispatcherHelper.Initialize();
                _projectService = Substitute.For<IProjectService>();
                var dialogService = Substitute.For<IDialogService>();
                var importService = Substitute.For<IImportService>();

                SegmentMappingViewModel.Factory mappingFactory = (segment1, segment2) => new SegmentMappingViewModel(_projectService, segment1, segment2);
                NewSegmentMappingViewModel.Factory newMappingFactory = () => new NewSegmentMappingViewModel(_projectService);

                var segmentMappings = new SegmentMappingsViewModel(dialogService, importService, mappingFactory, newMappingFactory);
                _segmentPair = new SegmentMappingsChartSegmentPairViewModel(segmentMappings, mappingFactory,
                    new SegmentMappingsChartSegmentViewModel(new Segment(FeatureStruct.New().Symbol(CogFeatureSystem.ConsonantType).Feature(CogFeatureSystem.StrRep).EqualTo("b").Value), SoundType.Consonant),
                    new SegmentMappingsChartSegmentViewModel(new Segment(FeatureStruct.New().Symbol(CogFeatureSystem.ConsonantType).Feature(CogFeatureSystem.StrRep).EqualTo("c").Value), SoundType.Consonant),
                    100, true);

                var project = new CogProject(_spanFactory);
                _projectService.Project.Returns(project);
            }