If a caption is returned but the confidence score is lower than our t…

…hreshold, output an error message instead of just discarding silently. Ensure the caption we save has the first letter uppercased. Ensure the values we want exist before using them

includes/Classifai/Providers/Azure/ComputerVision.php

@@ -510,10 +510,13 @@ public function generate_alt_tags( string $image_url, int $attachment_id ) {
 			$settings  = $feature->get_settings( static::ID );
 			$threshold = $settings['descriptive_confidence_threshold'];
 
-			// Check the first caption to see if it passes the threshold.
-			if ( $caption['confidence'] * 100 > $threshold ) {
-				$rtn = $caption['text'];
+			// Check the caption to see if it passes the threshold.
+			if ( isset( $caption['confidence'] ) && $caption['confidence'] * 100 > $threshold ) {
+				$rtn = ucfirst( $caption['text'] ?? '' );
 			} else {
+				/* translators: 1: Confidence score, 2: Threshold setting */
+				$rtn = new WP_Error( 'threshold', sprintf( esc_html__( 'Caption confidence score is %1$d%% which is lower than your threshold setting of %2$d%%', 'classifai' ), $caption['confidence'] * 100, $threshold ) );
+
 				/**
 				 * Fires if there were no captions returned.
 				 *