fix: wire Image B source data — was hardcoded null, never generated

Root cause: both attach_generated_images() in post-assembler and the
retroactive handler in executor passed null as source_data to the image
pipeline. The pipeline's Image B branch requires non-null source_data
to fire, so Image B was silently skipped on every article since the
feature was built.

Fix: added get_source_data_for_image() to Source_Collector to retrieve
the original Reddit post title/content by source_ids. Post-assembler
now pulls source_ids from the Article_Idea; executor pulls them from
the _prautoblogger_source_ids post meta saved by the publisher.

Also added a regression test proving Image B is skipped when source_data
is null, so this handoff gap will be caught if re-introduced.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

includes/class-executor.php

@@ -135,13 +135,26 @@ class PRAutoBlogger_Executor {
 				'post_content' => $post->post_content,
 			];
 
-			$result = $pipeline->generate_and_attach_images( $post_id, $article_data, null );
+			// Retrieve original source IDs from post meta so Image B can generate
+			// a source-driven prompt even on retroactive regeneration.
+			$source_ids_json = get_post_meta( $post_id, '_prautoblogger_source_ids', true );
+			$source_ids      = is_string( $source_ids_json ) ? json_decode( $source_ids_json, true ) : [];
+			$source_data     = ( new PRAutoBlogger_Source_Collector() )->get_source_data_for_image(
+				is_array( $source_ids ) ? array_map( 'absint', $source_ids ) : []
+			);
+
+			$result = $pipeline->generate_and_attach_images( $post_id, $article_data, $source_data );
 
 			// Set featured image if Image A was generated.
 			if ( ! empty( $result['image_a_id'] ) ) {
 				set_post_thumbnail( $post_id, $result['image_a_id'] );
 			}
 
+			// Store Image B in post meta if generated.
+			if ( ! empty( $result['image_b_id'] ) ) {
+				update_post_meta( $post_id, '_prautoblogger_image_b_id', $result['image_b_id'] );
+			}
+
 			wp_send_json_success( $result );
 		} catch ( \Exception $e ) {
 			PRAutoBlogger_Logger::instance()->error(

includes/core/class-post-assembler.php

@@ -132,7 +132,10 @@ class PRAutoBlogger_Post_Assembler {
 	 * @param array                      $post_data Post data array (for article content).
 	 */
 	public static function attach_generated_images( int $post_id, PRAutoBlogger_Article_Idea $idea, array $post_data ): void {
-		$source_data = null;
+		// Fetch the original Reddit source data for Image B's source-driven prompt.
+		// The idea's source_ids point to rows in the source_data table collected
+		// during the pipeline's collection step.
+		$source_data = ( new PRAutoBlogger_Source_Collector() )->get_source_data_for_image( $idea->get_source_ids() );
 
 		try {
 			$result = ( new PRAutoBlogger_Image_Pipeline() )->generate_and_attach_images( $post_id, $post_data, $source_data );

includes/core/class-source-collector.php

@@ -57,6 +57,47 @@ class PRAutoBlogger_Source_Collector {
 		return $total_inserted;
 	}
 
+	/**
+	 * Retrieve source data rows by their database IDs.
+	 *
+	 * Used by the image pipeline to build Image B's source-driven prompt from
+	 * the source_ids stored on the Article_Idea. Returns the first matching
+	 * row's title and content; these map directly to what
+	 * Image_Prompt_Builder::build_source_prompt() expects.
+	 *
+	 * Side effects: one SELECT query.
+	 *
+	 * @param int[] $ids Database row IDs from the source_data table.
+	 * @return array{title: string, selftext: string}|null First source row, or null if none found.
+	 */
+	public function get_source_data_for_image( array $ids ): ?array {
+		if ( empty( $ids ) ) {
+			return null;
+		}
+
+		global $wpdb;
+		$table        = $wpdb->prefix . 'prautoblogger_source_data';
+		$placeholders = implode( ',', array_fill( 0, count( $ids ), '%d' ) );
+
+		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare
+		$row = $wpdb->get_row(
+			$wpdb->prepare(
+				"SELECT title, content, subreddit FROM {$table} WHERE id IN ({$placeholders}) ORDER BY score DESC LIMIT 1",
+				...$ids
+			),
+			ARRAY_A
+		);
+
+		if ( null === $row ) {
+			return null;
+		}
+
+		return [
+			'title'    => $row['title'] ?? 'Reddit Discussion',
+			'selftext' => $row['content'] ?? '',
+		];
+	}
+
 	/**
 	 * Store collected source data in the database.
 	 *

tests/unit/Core/ImagePipelineTest.php

@@ -130,6 +130,45 @@ class ImagePipelineTest extends BaseTestCase {
 		$this->assertGreaterThan( 0.05, $result['cost_usd'] );
 	}
 
+	/**
+	 * Test that Image B is NOT generated when source_data is null.
+	 *
+	 * This is the regression test for the Image B data-handoff gap:
+	 * post_assembler.php and executor.php both passed null as source_data,
+	 * so the pipeline silently skipped Image B. If this test ever fails
+	 * with `$this->exactly(2)`, it means someone re-broke the handoff.
+	 */
+	public function test_image_b_skipped_when_source_data_is_null(): void {
+		$provider = $this->createMock( \PRAutoBlogger_Image_Provider_Interface::class );
+		$provider->method( 'estimate_cost' )->willReturn( 0.05 );
+		$provider->method( 'generate_image' )->willReturn( [
+			'bytes'      => 'fake_image_data',
+			'mime_type'  => 'image/png',
+			'width'      => 1200,
+			'height'     => 630,
+			'model'      => 'flux-1-schnell',
+			'cost_usd'   => 0.05,
+			'latency_ms' => 2000,
+		] );
+
+		$cost_tracker = $this->createMock( \PRAutoBlogger_Cost_Tracker::class );
+		$cost_tracker->method( 'would_exceed_budget' )->willReturn( false );
+
+		// Only ONE call to log_image_generation — Image A only.
+		$cost_tracker->expects( $this->exactly( 1 ) )->method( 'log_image_generation' );
+
+		$pipeline = new \PRAutoBlogger_Image_Pipeline( $provider, $cost_tracker );
+
+		Functions\when( 'get_temp_dir' )->justReturn( '/tmp/' );
+		Functions\when( 'media_handle_sideload' )->justReturn( 42 );
+
+		// Pass null source_data — Image B must NOT fire.
+		$result = $pipeline->generate_and_attach_images( 1, [ 'post_title' => 'Test' ], null );
+
+		$this->assertArrayHasKey( 'image_a_id', $result );
+		$this->assertArrayNotHasKey( 'image_b_id', $result );
+	}
+
 	/**
 	 * Test graceful handling when image generation fails.
 	 */