/****************************************************************************
 Copyright (c) 2021-2022 Xiamen Yaji Software Co., Ltd.

 http://www.cocos.com

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated engine source code (the "Software"), a limited,
 worldwide, royalty-free, non-assignable, revocable and non-exclusive license
 to use Cocos Creator solely to develop games on your target platforms. You shall
 not use Cocos Creator software for developing other software or tools that's
 used for developing games. You are not granted to publish, distribute,
 sublicense, and/or sell copies of Cocos Creator.

 The software or tools in this License Agreement are licensed, not sold.
 Xiamen Yaji Software Co., Ltd. reserves all rights not expressly granted to you.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
****************************************************************************/

#include "FileUtils-linux.h"
#include <errno.h>
#include <stdio.h>
#include <sys/stat.h>
#include <unistd.h>
#include "base/Log.h"

#define DECLARE_GUARD std::lock_guard<std::recursive_mutex> mutexGuard(_mutex)
#ifndef CC_RESOURCE_FOLDER_LINUX
    #define CC_RESOURCE_FOLDER_LINUX ("/Resources/")
#endif

namespace cc {

FileUtils *FileUtils::getInstance() {
    if (FileUtils::sharedFileUtils == nullptr) {
        FileUtils::sharedFileUtils = new FileUtilsLinux();
        if (!FileUtils::sharedFileUtils->init()) {
            delete FileUtils::sharedFileUtils;
            FileUtils::sharedFileUtils = nullptr;
            CC_LOG_DEBUG("ERROR: Could not init CCFileUtilsLinux");
        }
    }
    return FileUtils::sharedFileUtils;
}

bool FileUtilsLinux::init() {
    // get application path
    char    fullpath[256] = {0};
    ssize_t length        = readlink("/proc/self/exe", fullpath, sizeof(fullpath) - 1);

    if (length <= 0) {
        return false;
    }

    fullpath[length]    = '\0';
    std::string appPath = fullpath;
    _defaultResRootPath = appPath.substr(0, appPath.find_last_of('/'));
    _defaultResRootPath.append(CC_RESOURCE_FOLDER_LINUX);

    // Set writable path to $XDG_CONFIG_HOME or ~/.config/<app name>/ if $XDG_CONFIG_HOME not exists.
    const char *xdg_config_path = getenv("XDG_CONFIG_HOME");
    std::string xdgConfigPath;
    if (xdg_config_path == nullptr) {
        xdgConfigPath = getenv("HOME");
        xdgConfigPath.append("/.config");
    } else {
        xdgConfigPath = xdg_config_path;
    }
    _writablePath = xdgConfigPath;
    _writablePath.append(appPath.substr(appPath.find_last_of('/')));
    _writablePath.append("/");

    return FileUtils::init();
}

bool FileUtilsLinux::isFileExistInternal(const std::string &filename) const {
    if (filename.empty()) {
        return false;
    }

    std::string strPath = filename;
    if (!isAbsolutePath(strPath)) { // Not absolute path, add the default root path at the beginning.
        strPath.insert(0, _defaultResRootPath);
    }

    struct stat sts;
    return (stat(strPath.c_str(), &sts) == 0) && S_ISREG(sts.st_mode);
}

std::string FileUtilsLinux::getWritablePath() const {
    struct stat st;
    stat(_writablePath.c_str(), &st);
    if (!S_ISDIR(st.st_mode)) {
        mkdir(_writablePath.c_str(), 0744);
    }

    return _writablePath;
}

} // namespace cc