private static String toMongo()

in calcite-adapter/src/main/java/software/amazon/documentdb/jdbc/calcite/adapter/DocumentDbAggregate.java [212:252]
36 lines of code
12 McCabe index (conditional complexity)

    private static String toMongo(final SqlAggFunction aggregation, final List<String> inNames,
            final List<Integer> args, final boolean isDistinct) {

        // Apart from COUNT(*) which has 0 arguments, supported aggregations should be a called with only 1 argument.
        if (!(args.isEmpty() && aggregation == SqlStdOperatorTable.COUNT) && args.size() != 1) {
            throw new AssertionError("aggregate with incorrect number of arguments: " + aggregation);
        }

        // For distinct calls, add to a set and get aggregate after.
        if (isDistinct) {
            assert args.size() == 1;
            final String inName = inNames.get(args.get(0));
            return "{$addToSet: " + maybeQuote("$" + inName) + "}";
        }

        if (aggregation == SqlStdOperatorTable.COUNT) {
            if (args.isEmpty()) {
                return "{$sum: 1}";
            } else {
                final String inName = inNames.get(args.get(0));
                return "{$sum: {$cond: [ {$gt: " + "[" + maybeQuote("$" + inName) + ", null]}, 1, 0]}}";
            }
        } else if (aggregation == SqlStdOperatorTable.SUM) {
            final String inName = inNames.get(args.get(0));
            return "{$push: " + maybeQuote("$" + inName) + "}";
        } else if (aggregation == SqlStdOperatorTable.SUM0) {
            final String inName = inNames.get(args.get(0));
            return "{$sum: " + maybeQuote("$" + inName) + "}";
        } else if (aggregation == SqlStdOperatorTable.MIN) {
            final String inName = inNames.get(args.get(0));
            return "{$min: " + maybeQuote("$" + inName) + "}";
        } else if (aggregation == SqlStdOperatorTable.MAX) {
            final String inName = inNames.get(args.get(0));
            return "{$max: " + maybeQuote("$" + inName) + "}";
        } else if (aggregation == SqlStdOperatorTable.AVG) {
            final String inName = inNames.get(args.get(0));
            return "{$avg: " + maybeQuote("$" + inName) + "}";
        } else {
            throw new AssertionError("unknown aggregate " + aggregation);
        }
    }