io.github.jwharm.javagi.interop.Platform Maven / Gradle / Ivy

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/* Java-GI - Java language bindings for GObject-Introspection-based libraries
 * Copyright (C) 2022-2024 Jan-Willem Harmannij
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 *
 * This library 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.
 *
 * This library 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 this library; if not, see .
 */

package io.github.jwharm.javagi.interop;

import io.github.jwharm.javagi.base.UnsupportedPlatformException;

import java.util.StringJoiner;

/**
 * The Platform class provides utility functions to retrieve the runtime
 * platform and and check if a function is supported on the runtime platform.
 */
public class Platform {

    private static String runtimePlatform = null;

    /**
     * Determine the runtime platform
     * @return the runtime platform: "windows", "linux" or "macos"
     */
    public static String getRuntimePlatform() {
        if (runtimePlatform == null) {
            String osName = System.getProperty("os.name").toLowerCase();
            if (osName.contains("windows"))
                runtimePlatform = "windows";
            else if (osName.contains("linux"))
                runtimePlatform = "linux";
            else
                runtimePlatform = "macos";
        }
        return runtimePlatform;
    }

    /**
     * Check if the runtime platform is in the list of provided platforms; if
     * not, throws UnsupportedPlatformException.
     *
     * @param  supportedPlatforms the platforms on which the api call is
     *                            supported
     * @throws UnsupportedPlatformException when the runtime platform does not
     *                                      support this api call
     */
    public static void checkSupportedPlatform(String... supportedPlatforms)
            throws UnsupportedPlatformException {

        /*
         * Check if the runtime platform is in the list of platforms where this
         * function is available.
         */
        for (var platform : supportedPlatforms) {
            if (platform.equals(getRuntimePlatform()))
                return;
        }

        /*
         * Runtime platform is not in list of supported platforms: throw
         * UnsupportedPlatformException.
         */
        StringJoiner joiner = new StringJoiner(" and ",
                "Unsupported API call (only available on ", ".");

        for (var platform : supportedPlatforms) {
            joiner.add(platform);
        }

        throw new UnsupportedPlatformException(joiner.toString());
    }
}