/*
 * Copyright (C) 2013 RoboVM AB
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/gpl-2.0.html>.
 */
package org.robovm.libimobiledevice;

import java.io.BufferedOutputStream;
import java.io.Closeable;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * 
 */
public class NativeLibrary {
    private static boolean loaded = false;
    public static final boolean supportedPlatform;
    private static final String os;
    private static final String arch;
    private static final String libName;

    static {
        String osProp = System.getProperty("os.name").toLowerCase();
        String archProp = System.getProperty("os.arch").toLowerCase();
        String ext = null;
        if (osProp.startsWith("mac") || osProp.startsWith("darwin")) {
            os = "macosx";
            ext = ".dylib";
        } else {
            os = null;
        }
        if (archProp.matches("amd64|x86[-_]64")) {
            arch = "x86_64";
        } else {
            arch = null;
        }
        
        supportedPlatform = os != null && arch != null;
        if (supportedPlatform) {
            libName = "librobovm-libimobiledevice" + ext;
        } else {
            libName = null;
        }
    }
    
    public static synchronized void load() {
        if (loaded) {
            return;
        }
        if (!supportedPlatform) {
            return;
        }
        
        String prefix = libName.substring(0, libName.lastIndexOf('.'));
        String ext = libName.substring(libName.lastIndexOf('.'));
        
        InputStream in = NativeLibrary.class.getResourceAsStream("binding/" + os + "/" + arch + "/" + libName);
        if (in == null) {
            throw new UnsatisfiedLinkError("Native library for " + os + "-" + arch + " not found");
        }
        OutputStream out = null;
        File tmpLibFile = null;
        try {
            tmpLibFile = File.createTempFile(prefix, ext);
            tmpLibFile.deleteOnExit();
            out = new BufferedOutputStream(new FileOutputStream(tmpLibFile));
            copy(in, out);
        } catch (IOException e) {
            throw (Error) new UnsatisfiedLinkError(e.getMessage()).initCause(e);
        } finally {
            closeQuietly(in);
            closeQuietly(out);
        }
        
        Runtime.getRuntime().load(tmpLibFile.getAbsolutePath());
    }
    
    private static void copy(InputStream in, OutputStream out) throws IOException {
        byte[] buffer = new byte[4096];
        int n = 0;
        while ((n = in.read(buffer)) != -1) {
            out.write(buffer, 0, n);
        }
    }
    
    private static void closeQuietly(Closeable in) {
        try {
            if (in != null) {
                in.close();
            }
        } catch (IOException ioe) {
        }
    }
}