/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "apr_arch_dso.h"
#include "apr_strings.h"
#include "apr_private.h"
#include "apr_arch_file_io.h"
#include "apr_arch_utf8.h"

#if APR_HAS_DSO

APR_DECLARE(apr_status_t) apr_os_dso_handle_put(apr_dso_handle_t **aprdso,
                                                apr_os_dso_handle_t osdso,
                                                apr_pool_t *pool)
{
    *aprdso = apr_pcalloc(pool, sizeof **aprdso);
    (*aprdso)->handle = osdso;
    (*aprdso)->cont = pool;
    return APR_SUCCESS;
}

APR_DECLARE(apr_status_t) apr_os_dso_handle_get(apr_os_dso_handle_t *osdso,
                                                apr_dso_handle_t *aprdso)
{
    *osdso = aprdso->handle;
    return APR_SUCCESS;
}

static apr_status_t dso_cleanup(void *thedso)
{
    apr_dso_handle_t *dso = thedso;

    if (dso->handle != NULL && !FreeLibrary(dso->handle)) {
        return apr_get_os_error();
    }
    dso->handle = NULL;

    return APR_SUCCESS;
}

APR_DECLARE(apr_status_t) apr_dso_load(struct apr_dso_handle_t **res_handle,
                                       const char *path, apr_pool_t *ctx)
{
    HINSTANCE os_handle;
    apr_status_t rv;
    DWORD em;

    apr_wchar_t wpath[APR_PATH_MAX];
    if ((rv = utf8_to_unicode_path(wpath, sizeof(wpath)
                                        / sizeof(apr_wchar_t), path))
            != APR_SUCCESS) {
        *res_handle = apr_pcalloc(ctx, sizeof(**res_handle));
        return ((*res_handle)->load_error = rv);
    }
    /* Prevent ugly popups from killing our app */
    if (!SetThreadErrorMode(SEM_FAILCRITICALERRORS, &em)) {
        *res_handle = apr_pcalloc(ctx, sizeof(**res_handle));
        return ((*res_handle)->load_error = apr_get_os_error());
    }
    os_handle = LoadLibraryExW(wpath, NULL, 0);
    if (!os_handle)
        os_handle = LoadLibraryExW(wpath, NULL, LOAD_WITH_ALTERED_SEARCH_PATH);
    if (!os_handle) {
        rv = apr_get_os_error();

        os_handle = LoadLibraryExW(wpath, NULL, LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR);
        if (os_handle) {
            rv = APR_SUCCESS;
        }
    }
    SetThreadErrorMode(em, NULL);

    *res_handle = apr_pcalloc(ctx, sizeof(**res_handle));
    (*res_handle)->cont = ctx;

    if (rv) {
        return ((*res_handle)->load_error = rv);
    }

    (*res_handle)->handle = (void*)os_handle;
    (*res_handle)->load_error = APR_SUCCESS;

    apr_pool_cleanup_register(ctx, *res_handle, dso_cleanup, apr_pool_cleanup_null);

    return APR_SUCCESS;
}

APR_DECLARE(apr_status_t) apr_dso_unload(struct apr_dso_handle_t *handle)
{
    return apr_pool_cleanup_run(handle->cont, handle, dso_cleanup);
}

APR_DECLARE(apr_status_t) apr_dso_sym(apr_dso_handle_sym_t *ressym,
                         struct apr_dso_handle_t *handle,
                         const char *symname)
{
    *ressym = (apr_dso_handle_sym_t)GetProcAddress(handle->handle, symname);
    if (!*ressym) {
        return apr_get_os_error();
    }
    return APR_SUCCESS;
}

APR_DECLARE(const char *) apr_dso_error(apr_dso_handle_t *dso, char *buf, apr_size_t bufsize)
{
    return apr_strerror(dso->load_error, buf, bufsize);
}

#endif