DataFrame::run method can now return execution report with Schema and…

… Statistics

src/core/etl/src/Flow/ETL/DataFrame.php

@@ -7,6 +7,8 @@
 use function Flow\ETL\DSL\to_output;
 use Flow\ETL\DataFrame\GroupedDataFrame;
 use Flow\ETL\DataFrame\PartitionedDataFrame;
+use Flow\ETL\Dataset\Report;
+use Flow\ETL\Dataset\Statistics;
 use Flow\ETL\Exception\InvalidArgumentException;
 use Flow\ETL\Exception\InvalidFileFormatException;
 use Flow\ETL\Exception\RuntimeException;
@@ -748,17 +750,32 @@ public function rows(Transformer|Transformation $transformer) : self
      * @trigger
      *
      * @param null|callable(Rows $rows): void $callback
+     * @param bool $analyze - when set to true, run will return Report
      */
     #[DSLMethod(exclude: true)]
-    public function run(?callable $callback = null) : void
+    public function run(?callable $callback = null, bool $analyze = false) : null|Report
     {
         $clone = clone $this;
 
+        $totalRows = 0;
+        $schema = new Schema();
+
         foreach ($clone->pipeline->process($clone->context) as $rows) {
             if ($callback !== null) {
                 $callback($rows);
             }
+
+            if ($analyze) {
+                $schema = $schema->merge($rows->schema());
+                $totalRows += $rows->count();
+            }
         }
+
+        if ($analyze) {
+            return new Report($schema, new Statistics($totalRows));
+        }
+
+        return null;
     }
 
     /**

src/core/etl/src/Flow/ETL/Dataset/Report.php

@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Dataset;
+
+use Flow\ETL\Row\Schema;
+
+final class Report
+{
+    public function __construct(
+        private readonly Schema $schema,
+        private readonly Statistics $statistics,
+    ) {
+
+    }
+
+    public function schema() : Schema
+    {
+        return $this->schema;
+    }
+
+    public function statistics() : Statistics
+    {
+        return $this->statistics;
+    }
+}

src/core/etl/src/Flow/ETL/Dataset/Statistics.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Dataset;
+
+final class Statistics
+{
+    public function __construct(
+        private readonly int $totalRows,
+    ) {
+    }
+
+    public function totalRows() : int
+    {
+        return $this->totalRows;
+    }
+}

src/core/etl/tests/Flow/ETL/Tests/Integration/DataFrame/AnalyzeTest.php

@@ -0,0 +1,82 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Tests\Integration\DataFrame;
+
+use function Flow\ETL\Adapter\CSV\from_csv;
+use function Flow\ETL\Adapter\Text\from_text;
+use function Flow\ETL\DSL\datetime_schema;
+use function Flow\ETL\DSL\df;
+use function Flow\ETL\DSL\float_schema;
+use function Flow\ETL\DSL\int_schema;
+use function Flow\ETL\DSL\schema;
+use function Flow\ETL\DSL\str_schema;
+use Flow\ETL\Tests\Integration\IntegrationTestCase;
+
+final class AnalyzeTest extends IntegrationTestCase
+{
+    public function test_analyzing_csv_file_with_auto_cast() : void
+    {
+        $report = df()
+            ->read(from_csv(__DIR__ . '/Fixtures/Analyze/goldstock.csv'))
+            ->autoCast()
+            ->run(analyze: true);
+
+        $this->assertSame(2511, $report->statistics()->totalRows());
+        $this->assertEquals(
+            schema(
+                int_schema('Index'),
+                datetime_schema('Date'),
+                float_schema('Close'),
+                float_schema('Volume'),
+                float_schema('Open'),
+                float_schema('High'),
+                float_schema('Low'),
+            ),
+            $report->schema()
+        );
+        $this->assertSame(7, $report->schema()->count());
+    }
+
+    public function test_analyzing_csv_file_with_limit() : void
+    {
+        $report = df()
+            ->read(from_csv(__DIR__ . '/Fixtures/Analyze/goldstock.csv'))
+            ->limit(100)
+            ->run(analyze: true);
+
+        $this->assertSame(100, $report->statistics()->totalRows());
+        $this->assertEquals(
+            schema(
+                str_schema('Index'),
+                str_schema('Date'),
+                str_schema('Close'),
+                str_schema('Volume'),
+                str_schema('Open'),
+                str_schema('High'),
+                str_schema('Low'),
+            ),
+            $report->schema()
+        );
+        $this->assertSame(7, $report->schema()->count());
+    }
+
+    public function test_analyzing_partitioned_datasets() : void
+    {
+        $report = df()
+            ->read(from_text(__DIR__ . '/Fixtures/Partitioning/multi_partition_pruning_test/year=*/month=*/day=*/*.txt'))
+            ->run(analyze: true);
+
+        $this->assertSame(7, $report->statistics()->totalRows());
+        $this->assertEquals(
+            schema(
+                str_schema('year'),
+                str_schema('month'),
+                str_schema('day'),
+                str_schema('text'),
+            ),
+            $report->schema()
+        );
+    }
+}