private MasterLabelSchema rewrite()

in src/main/java/com/amazonaws/services/neptune/propertygraph/io/RewriteCsv.java [99:189]
70 lines of code
10 McCabe index (conditional complexity)

    private MasterLabelSchema rewrite(PropertyGraphTargetConfig targetConfig,
                                      GraphElementType graphElementType,
                                      MasterLabelSchema masterLabelSchema) throws Exception {

        LabelSchema originalLabelSchema = masterLabelSchema.labelSchema();
        LabelSchema masterSchema = originalLabelSchema.createCopy();
        masterSchema.initStats();

        Collection<String> renamedFiles = new ArrayList<>();

        for (FileSpecificLabelSchema fileSpecificLabelSchema : masterLabelSchema.fileSpecificLabelSchemas()) {

            LabelSchema labelSchema = fileSpecificLabelSchema.labelSchema();
            Label label = labelSchema.label();
            File sourceCsvFile = new File(fileSpecificLabelSchema.outputId());


            if (!sourceCsvFile.exists()) {
                if (label.labels().size() > 1) {
                    logger.warn("Skipping multi-label file {} because it has already been rewritten under another label", sourceCsvFile);
                    continue;
                }
            }

            String[] additionalElementHeaders = label.hasFromAndToLabels() ?
                    new String[]{"~fromLabels", "~toLabels"} :
                    new String[]{};

            String[] filePropertyHeaders =
                    labelSchema.propertySchemas().stream()
                            .map(p -> p.property().toString())
                            .collect(Collectors.toList())
                            .toArray(new String[]{});

            String[] fileHeaders = ArrayUtils.addAll(
                    graphElementType.tokenNames().toArray(new String[]{}),
                    ArrayUtils.addAll(additionalElementHeaders, filePropertyHeaders));

            try (DeletableFile sourceFile = new DeletableFile(sourceCsvFile);
                 Reader in = sourceFile.reader();
                 PropertyGraphPrinter target = graphElementType.writerFactory().createPrinter(
                         targetConfig.format().replaceExtension(sourceCsvFile.getName(), "modified"),
                         masterSchema,
                         targetConfig.forFileConsolidation());
            ) {

                if (featureToggles.containsFeature(FeatureToggle.Keep_Rewritten_Files)){
                    sourceFile.doNotDelete();
                }

                renamedFiles.add(target.outputId());

                CSVFormat format = CSVFormat.RFC4180.withHeader(fileHeaders);
                Iterable<CSVRecord> records = format.parse(in);

                int recordCount = 0;

                for (CSVRecord record : records) {
                    target.printStartRow();

                    if (graphElementType == GraphElementType.nodes) {
                        target.printNode(record.get("~id"), Arrays.asList(record.get("~label").split(";")));
                    } else if (graphElementType == GraphElementType.edges) {
                        if (label.hasFromAndToLabels()) {
                            target.printEdge(
                                    record.get("~id"),
                                    record.get("~label"),
                                    record.get("~from"),
                                    record.get("~to"),
                                    Arrays.asList(record.get("~fromLabels").split(";")),
                                    Arrays.asList(record.get("~toLabels").split(";")));
                        } else {
                            target.printEdge(record.get("~id"), record.get("~label"), record.get("~from"), record.get("~to"));
                        }
                    }

                    target.printProperties(record.toMap(), false);
                    target.printEndRow();

                    recordCount++;
                }

                logger.info("Original: {}, Rewritten: {}, RecordCount: {}", sourceFile, target.outputId(), recordCount);
            }

        }

        return new MasterLabelSchema(
                masterSchema,
                renamedFiles.stream().map(f -> new FileSpecificLabelSchema(f, targetConfig.format(), masterSchema)).collect(Collectors.toList()));
    }