/*
Plugin Name: Bulk Update Post meta
Version: 0.1
Plugin URI: https://amirhosseinhpv.ir/news/echo-on-loop-pure-php/
Description:
Author: Amirhosseinhpv
Author URI: https://hpv.im/
*/

/**
 * check if we are receiving request in admin area
 * e.g. https://yoursite.com/wp-admin/?bulk_update_post_meta
 */
if ( is_blog_admin() && isset($_GET["bulk_update_post_meta"])){
  bulk_update_post_meta_proccess();
}

/**
 * Bulk update post meta function
 */
function bulk_update_post_meta_proccess()
{
  // first get all posts ids as array
  $array_posts_ids = get_posts(
    array(
      "post_type" => "post",
      "posts_per_page" => -1,
      "fields" => "ids",
    )
  );

  // declare variables
  $i = 0;
  $success_items = 0;
  $current_progress = 0;
  $total_posts = count($array_posts_ids);

  // we are going to sent js to frontend as we want to update frontend dom elements
  // so what happens here is if we have 12000 item, we will output js for 12000 times,
  // which may cause browser crash, so we output js only for 300 times
  $steps = floor($total_posts / 300);

  // Implicit flushing will result in a flush operation after every output call,
  // so that explicit calls to flush() will no longer be needed
	ob_implicit_flush(true);

  // turn output buffering on
	ob_start();

  // let user know we started process
  echo "<h1>Updating Meta in progress, press ESC to cancel.</h1>";

	foreach( $array_posts_ids as $post) {

    // set current loop item position
    $i++;

    // get post meta
    $views = get_post_meta( $post, "views", true);

    // set post meta
		$update = update_post_meta($post, "views", $views*7 );
    if (true === $update){
      $success_items++;
    }

    // calculate current progress percentage, output be like 48.78%
    $_precent = min(100, 100 * $i / $total_posts);
    $current_precent = sprintf("%'05.2f%%", );

    // now output loop information
    // output be like: 50.00% ~~ 500 / 1000 ~~ Post ID #7896 meta updated!
    printf("<p>%s ~~ %02d / %02d ~~ Post ID #%s meta updated!</p>", $current_precent, $i, $total_posts, $post);

    // we only update progressbar or page title precentage 300 times, no matter how many items are in loop
    if ($i % $steps == 0 ){
      echo "<script>

        /* update page title */
        document.title = 'Updating $current_precent';

        /* make a large progressbar with body background */
        document.querySelector('body').style.backgroundImage = 'linear-gradient(to right, rgba(0, 223, 56, 0.18) {$_precent}%, white {$_precent}%)';

        /* scroll to bottom */
        window.scrollTo(0, document.body.scrollHeight);

      </script>";
    }
    ob_end_flush();
    ob_flush();
    flush();
    ob_start();
	}

  echo "<h1><strong>$success_items</strong> items of total <strong>$total_posts</strong> posts meta updated successfully.</h1>";

	ob_end_flush();
	exit;
}

/*
Plugin Name: Bulk Update Post meta
Version: 0.1
Plugin URI: https://amirhosseinhpv.ir/news/echo-on-loop-pure-php/
Description:
Author: Amirhosseinhpv
Author URI: https://hpv.im/
*/

/* usage: https://yoursite.com/wp-admin/?bulk_update_post_meta */
if ( is_blog_admin() && isset($_GET["bulk_update_post_meta"])){
  $array_posts_ids = get_posts( array( "post_type" => "post", "posts_per_page" => -1, "fields" => "ids", ) );
  $i = 0; $success_items = 0; $current_progress = 0; $total_posts = count($array_posts_ids);
  $steps = floor($total_posts / 300);
  ob_implicit_flush(true);  ob_start();
  echo "<h1>Updating Meta in progress, press ESC to cancel.</h1>";
  foreach( $array_posts_ids as $post) {
    $i++;
    $views = get_post_meta( $post, "views", true);
    $update = update_post_meta($post, "views", $views*7 );
    if (true === $update){ $success_items++; }
    $_precent = min(100, 100 * $i / $total_posts);
    $current_precent = sprintf("%'05.2f%%", );
    printf("<p>%s ~~ %02d / %02d ~~ Post ID #%s meta updated!</p>", $current_precent, $i, $total_posts, $post);
    if ($i % $steps == 0 ){
      echo "<script>document.title = 'Updating $current_precent';
      document.querySelector('body').style.backgroundImage = 'linear-gradient(to right, rgba(0, 223, 56, 0.18) {$_precent}%, white {$_precent}%)';
      window.scrollTo(0, document.body.scrollHeight);</script>";
    }
    ob_end_flush(); ob_flush(); flush(); ob_start();
  }
  echo "<h1><strong>$success_items</strong> items of total <strong>$total_posts</strong> posts meta updated successfully.</h1>";
  ob_end_flush(); exit;
}