title: Which hook for Woocommerce single product thumbnail src link replacement
body: <p>Is there any hook to change the single product thumbnail? I did search a lot on SO as well as over the internet but no luck.</p>
  
  <p>With 'thumbnail' I don't mean changing the size of the current image but I want to completely change/replace the product image (thumbnail) with a new image based on some scenario.</p>
  
  <pre><code>public function pn_change_product_image_link( $html, $post_id ){
  
      $url =  get_post_meta( $post_id );
      $alt = get_post_field( 'post_title', $post_id ) . ' ' .  __( 'thumbnail', 'txtdomain' );
      $attr = array( 'alt' =&gt; $alt );
      $attr = apply_filters( 'wp_get_attachment_image_attributes', $attr, NULL );
      $attr = array_map( 'esc_attr', $attr );
      $html = sprintf( '&lt;img src="https://upload.wikimedia.org/wikipedia/commons/thumb/3/38/WP_Suspension_logo.svg/2000px-WP_Suspension_logo.svg.png"', esc_url($url) );
      foreach ( $attr as $name =&gt; $value ) {
          $html .= " $name=" . '"' . $value . '"';
      }
      $html .= ' /&gt;';
      return $html;
  }
  </code></pre>
  
  <p>This is what I'm doing now but it's throwing an error.</p>
  
  <p>Filter, Hook:</p>
  
  <pre><code>post_thumbnail_html
  </code></pre>