[ES|QL] Add a TS variation of GenerativeIT

x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/generative/EsqlQueryGenerator.java

@@ -19,18 +19,19 @@
 import org.elasticsearch.xpack.esql.qa.rest.generative.command.pipe.KeepGenerator;
 import org.elasticsearch.xpack.esql.qa.rest.generative.command.pipe.LimitGenerator;
 import org.elasticsearch.xpack.esql.qa.rest.generative.command.pipe.LookupJoinGenerator;
-import org.elasticsearch.xpack.esql.qa.rest.generative.command.pipe.MetricsStatsGenerator;
 import org.elasticsearch.xpack.esql.qa.rest.generative.command.pipe.MvExpandGenerator;
 import org.elasticsearch.xpack.esql.qa.rest.generative.command.pipe.RenameGenerator;
 import org.elasticsearch.xpack.esql.qa.rest.generative.command.pipe.SortGenerator;
 import org.elasticsearch.xpack.esql.qa.rest.generative.command.pipe.StatsGenerator;
+import org.elasticsearch.xpack.esql.qa.rest.generative.command.pipe.TimeSeriesStatsGenerator;
 import org.elasticsearch.xpack.esql.qa.rest.generative.command.pipe.WhereGenerator;
 import org.elasticsearch.xpack.esql.qa.rest.generative.command.source.FromGenerator;
-import org.elasticsearch.xpack.esql.qa.rest.generative.command.source.MetricGenerator;
+import org.elasticsearch.xpack.esql.qa.rest.generative.command.source.TimeSeriesGenerator;
 
 import java.util.List;
 import java.util.Set;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import static org.elasticsearch.test.ESTestCase.randomAlphaOfLength;
 import static org.elasticsearch.test.ESTestCase.randomBoolean;
@@ -56,7 +57,7 @@ public record QueryExecuted(String query, int depth, List<Column> outputSchema,
     /**
      * Commands at the beginning of queries that begin queries on time series indices, eg. TS
      */
-    static List<CommandGenerator> TIME_SERIES_SOURCE_COMMANDS = List.of(MetricGenerator.INSTANCE);
+    static List<CommandGenerator> TIME_SERIES_SOURCE_COMMANDS = List.of(TimeSeriesGenerator.INSTANCE);
 
     /**
      * These are downstream commands, ie. that cannot appear as the first command in a query
@@ -79,24 +80,10 @@ public record QueryExecuted(String query, int depth, List<Column> outputSchema,
         WhereGenerator.INSTANCE
     );
 
-    static List<CommandGenerator> TIME_SERIES_PIPE_COMMANDS = List.of(
-        ChangePointGenerator.INSTANCE,
-        DissectGenerator.INSTANCE,
-        DropGenerator.INSTANCE,
-        EnrichGenerator.INSTANCE,
-        EvalGenerator.INSTANCE,
-        ForkGenerator.INSTANCE,
-        GrokGenerator.INSTANCE,
-        KeepGenerator.INSTANCE,
-        LimitGenerator.INSTANCE,
-        LookupJoinGenerator.INSTANCE,
-        MetricsStatsGenerator.INSTANCE,
-        MvExpandGenerator.INSTANCE,
-        RenameGenerator.INSTANCE,
-        SortGenerator.INSTANCE,
-        StatsGenerator.INSTANCE,
-        WhereGenerator.INSTANCE
-    );
+    static List<CommandGenerator> TIME_SERIES_PIPE_COMMANDS = Stream.concat(
+        PIPE_COMMANDS.stream(),
+        Stream.of(TimeSeriesStatsGenerator.INSTANCE)
+    ).toList();
 
     public static CommandGenerator sourceCommand() {
         return randomFrom(SOURCE_COMMANDS);
@@ -111,7 +98,6 @@ public static CommandGenerator randomPipeCommandGenerator() {
     }
 
     public static CommandGenerator randomMetricsPipeCommandGenerator() {
-        // todo better way
         return randomFrom(TIME_SERIES_PIPE_COMMANDS);
     }
 
@@ -143,7 +129,7 @@ public static void generatePipeline(
             if (executor.currentSchema().isEmpty()) {
                 break;
             }
-            commandGenerator = isTimeSeries ? randomMetricsPipeCommandGenerator() : EsqlQueryGenerator.randomPipeCommandGenerator();
+            commandGenerator = isTimeSeries ? randomMetricsPipeCommandGenerator() : randomPipeCommandGenerator();
             desc = commandGenerator.generate(executor.previousCommands(), executor.currentSchema(), schema);
             if (desc == CommandGenerator.EMPTY_DESCRIPTION) {
                 continue;
@@ -262,10 +248,17 @@ public static String metricsAgg(List<Column> previousOutput) {
                 if (numericPlusAggMetricFieldName == null) {
                     yield null;
                 }
-                yield switch ((randomIntBetween(0, 3))) {
+                yield switch ((randomIntBetween(0, 5))) {
                     case 0 -> "max_over_time(" + numericPlusAggMetricFieldName + ")";
                     case 1 -> "min_over_time(" + numericPlusAggMetricFieldName + ")";
                     case 2 -> "sum_over_time(" + numericPlusAggMetricFieldName + ")";
+                    case 3 -> {
+                        if (outerCommand.equals("sum") || outerCommand.equals("avg")) {
+                            yield null;
+                        }
+                        yield "present_over_time(" + numericPlusAggMetricFieldName + ")";
+                    }
+                    case 4 -> "count_over_time(" + numericPlusAggMetricFieldName + ")";
                     default -> "avg_over_time(" + numericPlusAggMetricFieldName + ")";
                 };
             }
@@ -279,11 +272,19 @@ yield switch ((randomIntBetween(0, 3))) {
             }
             case 2 -> {
                 // numerics except aggregate_metric_double
-                // TODO: move to case 0 when support for aggregate_metric_double is added to these functions
+                // TODO: add to case 0 when support for aggregate_metric_double is added to these functions
+                // TODO: add to case 1 when support for counters is added
                 String numericFieldName = randomNumericField(previousOutput);
                 if (numericFieldName == null) {
                     yield null;
                 }
+                if (previousOutput.stream()
+                    .noneMatch(
+                        column -> column.name.equals("@timestamp") && (column.type.equals("date_nanos") || column.type.equals("datetime"))
+                    )) {
+                    // first_over_time and last_over_time require @timestamp to be available and be either datetime or date_nanos
+                    yield null;
+                }
                 yield (randomBoolean() ? "first_over_time(" : "last_over_time(") + numericFieldName + ")";
             }
             default -> {

x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/generative/GenerativeRestTest.java

@@ -62,7 +62,12 @@ public abstract class GenerativeRestTest extends ESRestTestCase {
         "optimized incorrectly due to missing references", // https://github.com/elastic/elasticsearch/issues/131509
 
         // Awaiting fixes for correctness
-        "Expecting at most \\[.*\\] columns, got \\[.*\\]" // https://github.com/elastic/elasticsearch/issues/129561
+        "Expecting at most \\[.*\\] columns, got \\[.*\\]", // https://github.com/elastic/elasticsearch/issues/129561
+
+        // TS-command tests
+        "Invalid call to dataType on an unresolved object \\?LASTOVERTIME", // https://github.com/elastic/elasticsearch/issues/134791
+        "class org.elasticsearch.compute.data..*Block cannot be cast to class org.elasticsearch.compute.data..*Block", // https://github.com/elastic/elasticsearch/issues/134793
+        "Output has changed from \\[.*\\] to \\[.*\\]" // https://github.com/elastic/elasticsearch/issues/134794
     );
 
     public static final Set<Pattern> ALLOWED_ERROR_PATTERNS = ALLOWED_ERRORS.stream()

x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/generative/command/pipe/MetricsStatsGenerator.java → x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/generative/command/pipe/TimeSeriesStatsGenerator.java

@@ -18,10 +18,10 @@
 import static org.elasticsearch.test.ESTestCase.randomIntBetween;
 import static org.elasticsearch.xpack.esql.qa.rest.generative.EsqlQueryGenerator.randomDateField;
 
-public class MetricsStatsGenerator implements CommandGenerator {
+public class TimeSeriesStatsGenerator implements CommandGenerator {
 
     public static final String STATS = "stats";
-    public static final CommandGenerator INSTANCE = new MetricsStatsGenerator();
+    public static final CommandGenerator INSTANCE = new TimeSeriesStatsGenerator();
 
     @Override
     public CommandDescription generate(
@@ -31,8 +31,9 @@ public CommandDescription generate(
     ) {
         // generates stats in the form of:
         // `STATS some_aggregation(some_field) by optional_grouping_field, non_optional = bucket(time_field, 5minute)`
-        // where `some_aggregation` can be a time series aggregation, or a regular aggregation
-        // There is a variable number of aggregations per command
+        // where `some_aggregation` can be a time series aggregation in the form of agg1(agg2_over_time(some_field)),
+        // or a regular aggregation.
+        // There is a variable number of aggregations per pipe
 
         List<EsqlQueryGenerator.Column> nonNull = previousOutput.stream()
             .filter(EsqlQueryGenerator::fieldCanBeUsed)
@@ -80,12 +81,9 @@ public CommandDescription generate(
             }
         }
         // TODO: add alternative time buckets
-        cmd.append(
-            (randomBoolean() ? EsqlQueryGenerator.randomIdentifier() : EsqlQueryGenerator.randomName(previousOutput))
-                + " = bucket("
-                + timestamp
-                + ",1hour)"
-        );
+        // TODO: replace name of bucket with half chance of being EsqlQueryGenerator.randomName(previousOutput) if
+        // is fixed https://github.com/elastic/elasticsearch/issues/134796
+        cmd.append(EsqlQueryGenerator.randomIdentifier() + " = bucket(" + timestamp + ",1hour)");
         return new CommandDescription(STATS, this, cmd.toString(), Map.of());
     }
 

x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/generative/command/source/MetricGenerator.java → x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/generative/command/source/TimeSeriesGenerator.java

@@ -16,9 +16,9 @@
 import static org.elasticsearch.test.ESTestCase.randomIntBetween;
 import static org.elasticsearch.xpack.esql.qa.rest.generative.EsqlQueryGenerator.indexPattern;
 
-public class MetricGenerator implements CommandGenerator {
+public class TimeSeriesGenerator implements CommandGenerator {
 
-    public static final MetricGenerator INSTANCE = new MetricGenerator();
+    public static final TimeSeriesGenerator INSTANCE = new TimeSeriesGenerator();
 
     @Override
     public CommandDescription generate(