woo_remove_product_category_slug_from_link.php

<?php
/**
 * Shop Custom Permalinks
 * Remove 'product' slug from Product permalink
 * Remove 'product-category' slug from Product Category term link
 * @author vovadevelopenko
 */
defined( 'ABSPATH' ) || exit;

/**
 * Remove "product_cat" from product category term link
 */
function vd_remove_product_category_link( $termlink, $term, $taxonomy ) {
    if ( 'product_cat' != $taxonomy ) {
        return $termlink;
    }

    $termlink = str_replace( '/product-category/', '/', $termlink );

    return $termlink;
}

add_filter( 'term_link', 'vd_remove_product_category_link', 10, 3 );

/**
 * remove "product" from product permalink
 */
function vd_remove_product_slug( $post_link, $post, $leavename ) {

    if ( 'product' != $post->post_type || 'publish' != $post->post_status ) {
        return $post_link;
    }

    $post_link = str_replace( '/product/', '/', $post_link );

    return $post_link;
}

add_filter( 'post_type_link', 'vd_remove_product_slug', 10, 3 );

/**
 * Fix request when removed products_cat slug
 */
function vd_filter_the_request( $vars ) {

    if ( !empty( $vars[ 'pagename' ] ) || !empty( $vars[ 'category_name' ] ) || !empty( $vars[ 'name' ] ) || !empty( $vars[ 'attachment' ] ) ) {
        $slug = !empty( $vars[ 'pagename' ] ) ? $vars[ 'pagename' ] : (!empty( $vars[ 'name' ] ) ? $vars[ 'name' ] : (!empty( $vars[ 'category_name' ] ) ? $vars[ 'category_name' ] : $vars[ 'attachment' ] ) );

        // try to find shop Category/Product by existing slug
        if ( !empty( $pcat_vars = vd_maybe_get_prod_category_var( $slug ) ) ) {
            $old_vars = $vars;
            $vars = $pcat_vars;
        }

        if ( !empty( $old_vars[ 'paged' ] ) || !empty( $old_vars[ 'page' ] ) ) {
            $vars[ 'paged' ] = !empty( $old_vars[ 'paged' ] ) ? $old_vars[ 'paged' ] : $old_vars[ 'page' ];
        }
    } elseif ( isset( $vars[ 'error' ] ) ) {

        // try to find shop Category/Product if none slug is found
        if ( !empty( $pcat_vars = vd_maybe_get_prod_category_var() ) ) {
            $vars = $pcat_vars;
        }
    }

    return $vars;
}

add_filter( 'request', 'vd_filter_the_request', 20, 1 );

/**
 * Try to find product category by Request URI / slug
 */
function vd_maybe_get_prod_category_var( $slug = null ) {
    global $wpdb;

    if ( empty( $slug ) && empty( $slug_arr = vd_request_uri_slug() ) )
        return false;

    if ( is_array( $slug_arr ) ) {
        $slug = $slug_arr[ 'slug' ];
    }

    // try to find category
    $sql = "SELECT t.term_id FROM $wpdb->terms t
                LEFT JOIN $wpdb->term_taxonomy tt ON tt.term_id = t.term_id
                WHERE tt.taxonomy = 'product_cat' AND t.slug = '$slug'";
    $cat = $wpdb->get_var( $sql );

    if ( $cat ) {
        return array(
            'product_cat' => $slug,
            'paged' => isset( $slug_arr ) ? $slug_arr[ 'page' ] : '',
        );
    }

    // try to find product
    $sql = "SELECT ID FROM $wpdb->posts WHERE post_status = 'publish' AND post_type = 'product' AND post_name = '$slug'";
    $prod = $wpdb->get_var( $sql );

    if ( $prod ) {
        return array(
            'product' => $slug,
            'name' => $slug,
            'post_type' => 'product',
            'page' => '',
        );
    }

    return false;
}

/**
 * Get slug from request URI
 * @return array
 */
function vd_request_uri_slug() {
    $page = $slug = '';
    $uri_parts = parse_url( $_SERVER[ 'REQUEST_URI' ] );

    if ( empty( $uri_parts[ 'path' ] ) || empty( $uri = trim( $uri_parts[ 'path' ], '/' ) ) )
        return false;

    if ( strpos( $uri, '/page/' ) !== false ) {
        $uri_arr = explode( '/page/', $uri );
        $uri = $uri_arr[ 0 ];
        $page = intval( $uri_arr[ 1 ] );
    }

    $slug_arr = explode( '/', $uri );
    $slug = $slug_arr[ count( $slug_arr ) - 1 ];

    return array(
        'slug' => $slug,
        'page' => $page,
    );
}