/*******************************************************************************
 * Copyright (c) 2006, 2007 Intel Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 * Intel Corporation - Initial API and implementation
 *******************************************************************************/
package org.eclipse.cdt.managedbuilder.internal.buildmodel;

import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.eclipse.cdt.core.CommandLauncher;
import org.eclipse.cdt.managedbuilder.buildmodel.IBuildCommand;
import org.eclipse.cdt.managedbuilder.internal.core.ManagedMakeMessages;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.SubProgressMonitor;

/**
 * 
 * This class implements the IBuildCommand building
 * To build the given command, create an instance of this class
 * and invoke the build method
 *
 * NOTE: This class is subject to change and discuss, 
 * and is currently available in experimental mode only
 *  
 */
public class CommandBuilder implements IBuildModelBuilder {
	private static final String PATH_ENV = "PATH"; //$NON-NLS-1$
	private static final String PROPERTY_DELIMITER = "path.separator"; //$NON-NLS-1$
	private static final String PROPERTY_OS_NAME    = "os.name"; //$NON-NLS-1$
	private static final String PROPERTY_OS_VALUE = "windows";//$NON-NLS-1$
	static final String DELIMITER_UNIX = ":";    //$NON-NLS-1$
	static final String DELIMITER_WINDOWS = ";";    //$NON-NLS-1$

	private IBuildCommand fCmd;
	private Process fProcess;
	private String fErrMsg;
	
	private static final String BUILDER_MSG_HEADER = "InternalBuilder.msg.header"; //$NON-NLS-1$ 
	private static final String LINE_SEPARATOR = System.getProperty("line.separator", "\n"); //$NON-NLS-1$ //$NON-NLS-2$ 

/*
 * no need in this for now, Spawner is always used
 * 
	protected class SpawnerfreeLauncher extends CommandLauncher{

		public Process execute(IPath commandPath, String[] args, String[] env, IPath changeToDirectory) {
			try {
				// add platform specific arguments (shell invocation)
				fCommandArgs = constructCommandArray(commandPath.toOSString(), args);
				fProcess = Runtime.getRuntime().exec(fCommandArgs, env, changeToDirectory.toFile()); 
//					ProcessFactory.getFactory().exec(fCommandArgs, env, changeToDirectory.toFile());
				fErrorMessage = ""; //$NON-NLS-1$
			} catch (IOException e) {
				setErrorMessage(e.getMessage());
				fProcess = null;
			}
			return fProcess;
		}
	}
*/
	/*
	 * a temporary work-around to resolve the bug#145099
	 * (https://bugs.eclipse.org/bugs/show_bug.cgi?id=145099)
	 * 
	 * this will be removed after fixing the bug#145737
	 * (https://bugs.eclipse.org/bugs/show_bug.cgi?id=145737) 
	 */
	private class CommandSearchLauncher extends CommandLauncher{

		protected String[] constructCommandArray(String command, String[] commandArgs) {
			String[] args = new String[1 + commandArgs.length];
			if(!isWindows()){
				//find a full path to an executable
				String cmd = getExecutable(command, fCmd.getEnvironment());
				if(cmd != null)
					command = cmd;
				//if not found, continue with the command passed as an argument
			}

			args[0] = command;
			System.arraycopy(commandArgs, 0, args, 1, commandArgs.length);
			return args;
		}

		
		protected void printCommandLine(OutputStream os) {
			if (os != null) {
				String cmd = CommandBuilder.this.getCommandLine();
				try {
					os.write(cmd.getBytes());
					os.flush();
				} catch (IOException e) {
					// ignore;
				}
			}
		}
	}
	
	protected class OutputStreamWrapper extends OutputStream {
		private OutputStream fOut;
		
		public OutputStreamWrapper(OutputStream out){
			fOut = out;
		}
		
	    public void write(int b) throws IOException {
	    	fOut.write(b);
	    }

	    public void write(byte b[]) throws IOException {
	    	fOut.write(b);
	    }

	    public void write(byte b[], int off, int len) throws IOException {
	    	fOut.write(b, off, len);
	    }

	    public void flush() throws IOException {
	    	fOut.flush();
	    }

	    public void close() throws IOException {
	    }
	    
	}

	public CommandBuilder(IBuildCommand cmd, IResourceRebuildStateContainer cr){
		fCmd = cmd;
	}
	
	protected OutputStream wrap(OutputStream out){
		return new OutputStreamWrapper(out);
	}

	/* (non-Javadoc)
	 * @see org.eclipse.cdt.managedbuilder.internal.builddescription.IBuildDescriptionBuilder#build(java.io.OutputStream, java.io.OutputStream, org.eclipse.core.runtime.IProgressMonitor)
	 */
	public int build(OutputStream out, OutputStream err,
			IProgressMonitor monitor){
		
		//TODO: should we display the command line here?
		monitor.beginTask("", getNumCommands());	//$NON-NLS-1$
		monitor.subTask(""/*getCommandLine()*/);	//$NON-NLS-1$
		
		CommandLauncher launcher = createLauncher();
		int status = STATUS_OK;

		launcher.showCommand(true);

		fProcess = launcher.execute(fCmd.getCommand(), fCmd.getArgs(), mapToStringArray(fCmd.getEnvironment()), fCmd.getCWD());
		
		if (fProcess != null) {
			try {
				// Close the input of the process since we will never write to it
				fProcess.getOutputStream().close();
			} catch (IOException e) {
			}
		}
		
		//wrapping out and err streams to avoid their closure
		int st = launcher.waitAndRead(wrap(out), wrap(err),
				new SubProgressMonitor(monitor,	getNumCommands()));
		switch(st){
		case CommandLauncher.OK:
			if(fProcess.exitValue() != 0)
				status = STATUS_ERROR_BUILD;
			break;
		case CommandLauncher.COMMAND_CANCELED:
			status = STATUS_CANCELLED;
			fErrMsg = launcher.getErrorMessage(); 
			if(DbgUtil.DEBUG)
				DbgUtil.trace("command cancelled: " + fErrMsg);	//$NON-NLS-1$
			
			printMessage(fErrMsg, out);
			break;
		case CommandLauncher.ILLEGAL_COMMAND:
		default:
			status = STATUS_ERROR_LAUNCH;
			fErrMsg = launcher.getErrorMessage(); 
			if(DbgUtil.DEBUG)
				DbgUtil.trace("error launching the command: " + fErrMsg);	//$NON-NLS-1$
			
			printMessage(fErrMsg, out);
			break;
		}
		
		monitor.done();
		return status;
	}
	
	protected CommandLauncher createLauncher() {
//		if(isWindows())
//			return new CommandLauncher();
		return new CommandSearchLauncher();
	}
	
	public String getErrMsg(){
		return fErrMsg;
	}
	
	private String[] mapToStringArray(Map map){
		if(map == null)
			return null;
		
		List list = new ArrayList();
		
		for(Iterator iter = map.entrySet().iterator(); iter.hasNext();){
			Map.Entry entry = (Map.Entry)iter.next();
			list.add((String)entry.getKey() + "=" + (String)entry.getValue());	//$NON-NLS-1$
		}
		
		return (String[])list.toArray(new String[list.size()]);
	}

	protected void printMessage(String msg, OutputStream os){
		if (os != null) {
			msg = ManagedMakeMessages.getFormattedString(BUILDER_MSG_HEADER, msg) + LINE_SEPARATOR;
			try {
				os.write(msg.getBytes());
				os.flush();
			} catch (IOException e) {
				// ignore;
			}
		}
		
	}

	public int getNumCommands() {
		return 1;
	}
	
	protected String getCommandLine() {
		StringBuffer buf = new StringBuffer();
		if (fCmd != null) {
			buf.append(fCmd.getCommand().toOSString());
			String args[] = fCmd.getArgs();
			for (int i = 0; i < args.length; i++) {
				buf.append(' ');
				buf.append(args[i]);
			}
			buf.append(LINE_SEPARATOR);
		}
		return buf.toString();
	}

	private String getExecutable(String command, Map environment){
		if(new Path(command).isAbsolute())
			return command;
		return searchExecutable(command, getPaths(environment));
	}
	
	private String[] getPaths(Map env){
		String pathsStr = (String)env.get(PATH_ENV);
		if(pathsStr == null){
			for(Iterator iter = env.entrySet().iterator(); iter.hasNext();){
				Map.Entry entry = (Map.Entry)iter.next();
				if(PATH_ENV.equalsIgnoreCase((String)entry.getKey())){
					pathsStr = (String)entry.getValue();
					break;
				}
			}
		}
		if(pathsStr != null){
			String delimiter = getDelimiter();
			
			return pathsStr.split(delimiter);
		}
		return null;
	}
	
	private String getDelimiter(){
		String delimiter = System.getProperty(PROPERTY_DELIMITER);
		if(delimiter == null)
			delimiter = isWindows() ? DELIMITER_WINDOWS : DELIMITER_UNIX;
		return delimiter;
	}
	
	private String searchExecutable(String command, String paths[]){
		if(paths == null)
			return null;
		
		for(int i = 0; i < paths.length; i++){
			File file = new File(paths[i], command.toString());
			if(file.isFile())
				return file.toString();
		}
		return null;
	}
	
	private boolean isWindows() {
		String prop = System.getProperty(PROPERTY_OS_NAME);
		return prop != null ? prop.toLowerCase().startsWith(PROPERTY_OS_VALUE) : false;
	}
}
