<?php
add_filter( 'forminator_poll_handle_form_user_can_vote', 'my_limit_forminator_vote_once_per_wp_user', 10, 2 );

function my_limit_forminator_vote_once_per_wp_user( $can_vote, $poll_id ) {
	$POLL_ID_TO_LIMIT = 381;

	// if not our poll, leave it
	if ( $POLL_ID_TO_LIMIT !== (int) $poll_id ) {
		return $can_vote;
	}

	$user = wp_get_current_user();

	// its not logged in
	if ( ! $user instanceof WP_User || empty( $user->ID ) ) {
		return false;
	}

	// check if already vote
	$voters_post_meta = get_post_meta( $POLL_ID_TO_LIMIT, 'my_forminator_poll_voters', true );
	if ( empty( $voters_post_meta ) ) {
		$voters_post_meta = array();
	}

	if ( in_array( $user->ID, $voters_post_meta ) ) {
		return false;
	}

	return $can_vote;
}

add_filter( 'forminator_polls_submit_response', 'my_limit_forminator_vote_once_per_wp_user_error_response', 10, 2 );
add_filter( 'forminator_polls_ajax_submit_response', 'my_limit_forminator_vote_once_per_wp_user_error_response', 10, 2 );
function my_limit_forminator_vote_once_per_wp_user_error_response( $response, $poll_id ) {
	$POLL_ID_TO_LIMIT = 381;

	// if not our poll, leave it
	if ( $POLL_ID_TO_LIMIT !== (int) $poll_id ) {
		return $response;
	}

	if ( ! $response['success'] ) {
		$response['message'] = 'Make sure you are logged in before vote, and not voted this poll yet.';
	}

	return $response;
}

add_filter( 'forminator_polls_submit_field_data', 'my_limit_forminator_vote_once_per_wp_user_save_wp_user_on_entry', 10, 2 );
function my_limit_forminator_vote_once_per_wp_user_save_wp_user_on_entry( $field_data_array, $poll_id ) {
	$POLL_ID_TO_LIMIT = 381;

	// if not our poll, leave it
	if ( $POLL_ID_TO_LIMIT !== (int) $poll_id ) {
		return $field_data_array;
	}

	$user = wp_get_current_user();

	$field_data_array[] = array(
		'name'  => 'my_forminator_wp_user_id',
		'value' => $user->ID,
	);

	return $field_data_array;
}

add_action( 'forminator_polls_after_handle_submit', 'my_limit_forminator_vote_once_per_wp_user_save_user_on_post_meta', 10, 2 );
add_action( 'forminator_polls_after_save_entry', 'my_limit_forminator_vote_once_per_wp_user_save_user_on_post_meta', 10, 2 );
function my_limit_forminator_vote_once_per_wp_user_save_user_on_post_meta( $poll_id, $response ) {
	$POLL_ID_TO_LIMIT = 381;

	// if not our poll, leave it
	if ( $POLL_ID_TO_LIMIT === (int) $poll_id ) {
		$user = wp_get_current_user();
		// its success
		if ( $response['success'] ) {
			$voters_post_meta = get_post_meta( $POLL_ID_TO_LIMIT, 'my_forminator_poll_voters', true );
			if ( empty( $voters_post_meta ) ) {
				$voters_post_meta = array();
			}
			$voters_post_meta[] = $user->ID;
			sort( $voters_post_meta );
			update_post_meta( $POLL_ID_TO_LIMIT, 'my_forminator_poll_voters', $voters_post_meta );
		}
	}
}