Woocommerce: Show stock amounts for a product depending on the local and wholesale stock

show_stock.php

<?php
/**
 * Echo stock amounts for a product depending on the local and wholesale stock
 * quantities and possibly add wholesale information.
 *
 * @param int $product_id Product ID (optional)
 */
function show_stock( $product_id = 0 ) {
  $product_id = $product_id ? $product_id : get_the_ID();

  // Bail out if we don't have product id
  if ( ! $product_id ) {
    return;
  }

  // Get the local and wholesale stock quantities and convert to integer
  $stock = intval( get_post_meta( $product_id, '_stock', true ) );
  $wholesale_stock = intval( get_post_meta( $product_id, 'wholesaleqty', true ) );

  // Set the estimates if available for wholesale
  $estimates = [
    'Supplier 1' => '1-3',
    'Supplier 2' => '4-6',
    'Supplier 3' => '1-3',
  ];

  // Prepare the string to be outputted
  $output = '';

  if ( 0 === $stock && $wholesale_stock ) {
    // Set wholesale stock
    if ( $wholesale_stock > 10 ) {
      $output .= sprintf( esc_html__( 'Yli %s kpl maahantuojalla', 'my-text-domain' ), $wholesale_stock );
    } else {
      $output .= sprintf( esc_html__( '%s kpl maahantuojalla', 'my-text-domain' ), $wholesale_stock );
    }

    // Get estimate time by supplier if they have product in stock
    $supplier = get_post_meta( $product_id, 'maahantuoja', true );
    if ( $wholesale_stock && $supplier && ! empty( $estimates[ $supplier ] ) ) {
      $output .= sprintf( esc_html__( '(arvio %s pv)', 'my-text-domain' ), $estimates[ $supplier ] );
    }
  } elseif ( $stock <= 3 ) {
    $output .= sprintf( esc_html__( 'Vain %s kpl varastossa', 'my-text-domain' ), $stock );
  } elseif ( $stock > 3 ) {
    $output .= sprintf( esc_html__( '%s kpl varastossa', 'my-text-domain' ), $stock );
  } else {
    $output .= sprintf( esc_html__( '%s kpl jälkitoimituksessa', 'my-text-domain' ), $stock );
  }

  if ( ! empty( $output ) ) {
    // Wrap output to div element
    $output = '<div class="remaining">' . $output . '</div>';
    // Escape and echo output
    echo wp_kses_post( $output );
  }
}