/*
 * This file is part of mpv.
 *
 * mpv is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * mpv is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <windows.h>
#include <shlobj.h>
#include <knownfolders.h>

#include "options/path.h"
#include "osdep/io.h"
#include "osdep/path.h"
#include "osdep/threads.h"

static mp_once path_init_once = MP_STATIC_ONCE_INITIALIZER;

static char *portable_path;

static char *mp_get_win_exe_dir(void *talloc_ctx)
{
    wchar_t *w_exedir = talloc_array(NULL, wchar_t, MP_PATH_MAX);

    int len = (int)GetModuleFileNameW(NULL, w_exedir, MP_PATH_MAX);
    int imax = 0;
    for (int i = 0; i < len; i++) {
        if (w_exedir[i] == '\\') {
            w_exedir[i] = '/';
            imax = i;
        }
    }
    w_exedir[imax] = '\0';

    char *ret = mp_to_utf8(talloc_ctx, w_exedir);
    talloc_free(w_exedir);
    return ret;
}

static char *mp_get_win_exe_subdir(void *ta_ctx, const char *name)
{
    return talloc_asprintf(ta_ctx, "%s/%s", mp_get_win_exe_dir(ta_ctx), name);
}

static char *mp_get_win_shell_dir(void *talloc_ctx, REFKNOWNFOLDERID folder)
{
    wchar_t *w_appdir = NULL;

    if (FAILED(SHGetKnownFolderPath(folder, KF_FLAG_CREATE, NULL, &w_appdir)))
        return NULL;

    char *appdir = mp_to_utf8(talloc_ctx, w_appdir);
    CoTaskMemFree(w_appdir);
    return appdir;
}

static char *mp_get_win_app_dir(void *talloc_ctx)
{
    char *path = mp_get_win_shell_dir(talloc_ctx, &FOLDERID_RoamingAppData);
    return path ? mp_path_join(talloc_ctx, path, "mpv") : NULL;
}

static char *mp_get_win_local_app_dir(void *talloc_ctx)
{
    char *path = mp_get_win_shell_dir(talloc_ctx, &FOLDERID_LocalAppData);
    return path ? mp_path_join(talloc_ctx, path, "mpv") : NULL;
}

static void path_uninit(void)
{
    TA_FREEP(&portable_path);
}

static void path_init(void)
{
    void *tmp = talloc_new(NULL);
    char *path = mp_get_win_exe_subdir(tmp, "portable_config");
    if (path && mp_path_exists(path)) {
        portable_path = talloc_strdup(NULL, path);
        atexit(path_uninit);
    }
    talloc_free(tmp);
}

const char *mp_get_platform_path_win(void *talloc_ctx, const char *type)
{
    mp_exec_once(&path_init_once, path_init);
    if (portable_path) {
        if (strcmp(type, "home") == 0)
            return portable_path;
        if (strcmp(type, "cache") == 0)
            return mp_path_join(talloc_ctx, portable_path, "cache");
    } else {
        if (strcmp(type, "home") == 0)
            return mp_get_win_app_dir(talloc_ctx);
        if (strcmp(type, "cache") == 0)
            return mp_path_join(talloc_ctx, mp_get_win_local_app_dir(talloc_ctx), "cache");
        if (strcmp(type, "state") == 0)
            return mp_get_win_local_app_dir(talloc_ctx);
        if (strcmp(type, "exe_dir") == 0)
            return mp_get_win_exe_dir(talloc_ctx);
        // Not really true, but serves as a way to return a lowest-priority dir.
        if (strcmp(type, "global") == 0)
            return mp_get_win_exe_subdir(talloc_ctx, "mpv");
    }
    if (strcmp(type, "desktop") == 0)
        return mp_get_win_shell_dir(talloc_ctx, &FOLDERID_Desktop);
    return NULL;
}