wordpress simple post multi rating with post_meta and user_meta

Question

I am trying to create a multi criteria post rating function with simple form and post_meta and user meta.

The Goal

when users submits their ratings 2 things should happen:

1.the ratings is stored in the post_meta called 'wpd_rating' like this:

array(user id => array(
          field1 => 5
          field2 => 3
          field3 => 4
          ),
      another user id => array(
          field1 => 2
          field2 => 5
          field3 => 4
          )

) 

2.the ratings is stored in the user_meta called 'plgn_rating' like this:

array(post id => array(
          field1 => 5
          field2 => 3
          field3 => 4
          ),
      another rated post id => array(
          field1 => 2
          field2 => 5
          field3 => 4
          )

) 

The Code (Not working Obviously)

In single.php:

the header part:

<?php // top of page
if ( isset( $_POST['drw_inventory'] ) && wp_verify_nonce($_POST['drw_inventory'],'update_drw_postmeta') )
    { //if nonce check succeeds.
        global $post;
        $postid = $post->ID;
        $data = $_POST['wpd_function_rating'];
        $data2 = $_POST['wpd_feature_rating'];
        $data3 = $_POST['wpd_support_rating'];
        $currentusr = get_current_user_id();

        //*******************The post meta field Part****************************
        //Get the Existing user ratings of this post
        $ls_up_votes = get_post_meta($postid, 'wpd_rating');

        //if the current user already rated, unset the rating
        foreach ( $ls_up_votes as $key => $value )
          {
            if ( $key == $currentusr )
              {
                unset( $ls_up_votes[$key] );
              }
          }

    //Add post meta 'wpd_rating' with this structure: 
    //array(userid => array('wpd_function_rating' => '3','wpd_feature_rating' => '5','wpd_support_rating' => '4',))
        $up_vote = array($currentusr => array('wpd_function_rating' => $data,'wpd_feature_rating' => $data2,'wpd_support_rating' => $data3));

        //appending new user ratings after one another
        $ls_up_voted = array_merge($ls_up_votes, $up_vote);
        update_post_meta($postid,'wpd_rating',$ls_up_voted);



        //*******************The user field Part****************************
        //Get the Current user ratings of this post
        $user_rated_posts = get_user_meta($currentusr, 'plgn_rating',true);
        foreach ( $user_rated_posts as $key => $value )
          {
            if ( $key == $postid )
              {
                unset( $user_rated_posts[$key] );
              }
          }
        //add a user field 'plgn_rating' with this structure
        //(postid => array('wpd_function_rating' => '3','wpd_feature_rating' => '5','wpd_support_rating' => '4',))
        $usr_vote = array($postid => array('wpd_function_rating' => $data,'wpd_feature_rating' => $data2,'wpd_support_rating' => $data3));
        //appending new user ratings after one another
        $ls_up_voted = array_merge($user_rated_posts, $usr_vote);
        update_user_meta($currentusr,'plgn_rating',$ls_up_voted);

    }

?>

The Form:

<form method="post" action="">
   <?php wp_nonce_field('update_drw_postmeta','drw_inventory'); ?>
   <label>This is label</label>
   <input type='text' name='wpd_function_rating' value='' />
   <input type='text' name='wpd_feature_rating' value='' />
   <input type='text' name='wpd_support_rating' value='' />
   <input type='submit' value='save' />
</form>

Issues with the current code

1. The array is not saving as I structured. I am pretty sure I am using the array_merge wrong. or the calling the get_post_meta wrong.

2. The code is not checking for the existing user rating and replacing the old ratings with the new one.

Update

as s_ha_dum suggested tried this with no avail:

foreach ( $ls_up_votes as $key => $value ){ 
var_dump($key,$value);

   if ( $key == $currentusr ){ 
      unset( $ls_up_votes[$key] );
   }
} 

When I add the user input 2 times, the unset commands should remove the previous array that was added by the same user and add the new one, instead its adding all 2 times.Here is what I am getting:

Array ( [0] => Array ( [0] => [1] => Array ( [wpd_function_rating] => 33 [wpd_feature_rating] => 23 [wpd_support_rating] => 66 ) ) [1] => Array ( [wpd_function_rating] => 44 [wpd_feature_rating] => 11 [wpd_support_rating] => 32 ) ) 

Answer 1

Based on this:

Array ( 
  [0] => Array ( 
    [wpd_function_rating] => 33 
    [wpd_feature_rating] => 12 
    [wpd_support_rating] => 66 
  ) 
)

I can spot at least one problem. You have a nested array but are only looping over the top level. Here:

foreach ( $ls_up_votes as $key => $value )
      {
        if ( $key == $currentusr )
          {
            unset( $ls_up_votes[$key] );
      }
 }

Try var_dump($key,$value) inside that foreach.

I think that your solution is going to be to pass the third parameter to get_post_meta so that it returns "single" and not an array. It is a bit weird but works somewhat counter-intuitively with serialized arrays like I think you have.

$ls_up_votes = get_post_meta($postid, 'wpd_rating');