/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Eclipse Public License, Version 1.0 (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.eclipse.org/org/documents/epl-v10.php
 *
 * 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.
 */

package com.android.ide.eclipse.ndk.internal.build;

import com.android.ide.eclipse.adt.AdtPlugin;
import com.android.ide.eclipse.ndk.internal.NdkManager;

import org.eclipse.cdt.core.CommandLauncher;
import org.eclipse.cdt.utils.CygPath;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.Platform;

import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

@SuppressWarnings("restriction") // for AdtPlugin internal classes
public class NdkCommandLauncher extends CommandLauncher {
    private static CygPath sCygPath = null;

    private static final List<String> WINDOWS_NATIVE_EXECUTABLES = Arrays.asList(
            "exe",      //$NON-NLS-1$
            "cmd",      //$NON-NLS-1$
            "bat"       //$NON-NLS-1$
            );

    static {
        if (Platform.OS_WIN32.equals(Platform.getOS())) {
            try {
                sCygPath = new CygPath();
            } catch (IOException e) {
                AdtPlugin.printErrorToConsole("Unable to launch cygpath. Is Cygwin on the path?",
                        e);
            }
        }
    }

    @Override
    public Process execute(IPath commandPath, String[] args, String[] env, IPath changeToDirectory,
            IProgressMonitor monitor)
            throws CoreException {
        if (!commandPath.isAbsolute())
            commandPath = new Path(NdkManager.getNdkLocation()).append(commandPath);

        if (Platform.getOS().equals(Platform.OS_WIN32)) {
            // convert cygwin paths to standard paths
            if (sCygPath != null && commandPath.toString().startsWith("/cygdrive")) { //$NON-NLS-1$
                try {
                    String path = sCygPath.getFileName(commandPath.toString());
                    commandPath = new Path(path);
                } catch (IOException e) {
                    AdtPlugin.printErrorToConsole(
                            "Unexpected error while transforming cygwin path.", e);
                }
            }

            if (isWindowsExecutable(commandPath)) {
                // append necessary extension
                commandPath = appendExecutableExtension(commandPath);
            } else {
                // Invoke using Cygwin shell if this is not a native windows executable
                String[] newargs = new String[args.length + 1];
                newargs[0] = commandPath.toOSString();
                System.arraycopy(args, 0, newargs, 1, args.length);

                commandPath = new Path("sh"); //$NON-NLS-1$
                args = newargs;
            }
        }

        return super.execute(commandPath, args, env, changeToDirectory, monitor);
    }

    private boolean isWindowsExecutable(IPath commandPath) {
        String ext = commandPath.getFileExtension();
        if (isWindowsExecutableExtension(ext)) {
            return true;
        }

        ext = findWindowsExecutableExtension(commandPath);
        if (ext != null) {
            return true;
        }

        return false;
    }

    private IPath appendExecutableExtension(IPath commandPath) {
        if (isWindowsExecutableExtension(commandPath.getFileExtension())) {
            return commandPath;
        }

        String ext = findWindowsExecutableExtension(commandPath);
        if (ext != null) {
            return commandPath.addFileExtension(ext);
        }

        return commandPath;
    }

    private String findWindowsExecutableExtension(IPath command) {
        for (String e: WINDOWS_NATIVE_EXECUTABLES) {
            File exeFile = command.addFileExtension(e).toFile();
            if (exeFile.exists()) {
                return e;
            }
        }

        return null;
    }

    private boolean isWindowsExecutableExtension(String extension) {
        return extension != null && WINDOWS_NATIVE_EXECUTABLES.contains(extension);
    }
}