/*=============================================================================#
 # Copyright (c) 2007, 2020 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.internal.r.cmd.ui.launching;

import static org.eclipse.statet.jcommons.lang.ObjectUtils.nonNullAssert;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.eclipse.core.filesystem.EFS;
import org.eclipse.core.filesystem.IFileStore;
import org.eclipse.core.filesystem.URIUtil;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.SubMonitor;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.ILaunch;
import org.eclipse.debug.core.ILaunchConfiguration;
import org.eclipse.debug.core.model.IProcess;
import org.eclipse.debug.core.model.LaunchConfigurationDelegate;
import org.eclipse.debug.ui.CommonTab;
import org.eclipse.debug.ui.DebugUITools;
import org.eclipse.ui.console.IConsole;
import org.eclipse.ui.console.TextConsole;

import org.eclipse.statet.jcommons.lang.NonNullByDefault;
import org.eclipse.statet.jcommons.lang.Nullable;

import org.eclipse.statet.ecommons.debug.core.util.LaunchUtils;
import org.eclipse.statet.ecommons.debug.ui.config.LaunchConfigUtils;
import org.eclipse.statet.ecommons.debug.ui.util.UnterminatedLaunchAlerter;
import org.eclipse.statet.ecommons.io.FileUtil;

import org.eclipse.statet.internal.r.console.ui.RConsoleUIPlugin;
import org.eclipse.statet.r.cmd.ui.launching.RCmdLaunching;
import org.eclipse.statet.r.core.renv.IREnvConfiguration;
import org.eclipse.statet.r.core.renv.IREnvConfiguration.Exec;
import org.eclipse.statet.r.launching.core.RLaunching;
import org.eclipse.statet.r.launching.ui.REnvTab;
import org.eclipse.statet.r.launching.ui.RErrorLineTracker;


@NonNullByDefault
public class RCmdLaunchDelegate extends LaunchConfigurationDelegate {
	
	
	private static class RunData {
		
		private final IREnvConfiguration rEnvConfig;
		
		private final String cmd;
		
		private final List<String> command;
		
		private final IFileStore workingDirectory;

		private final @Nullable IPath resourcePathAbsolute;
		
		public RunData(final IREnvConfiguration rEnvConfig, final String cmd, final List<String> command,
				final IFileStore workingDirectory, final @Nullable IPath resourcePathAbsolute) {
			this.rEnvConfig= rEnvConfig;
			this.cmd= cmd;
			this.command= command;
			this.workingDirectory= workingDirectory;
			this.resourcePathAbsolute= resourcePathAbsolute;
		}
		
	}
	
	
	public RCmdLaunchDelegate() {
	}
	
	
	@Override
	public String showCommandLine(final ILaunchConfiguration configuration, final String mode,
			final @Nullable ILaunch launch,
			final @Nullable IProgressMonitor monitor) throws CoreException {
		final SubMonitor m= SubMonitor.convert(monitor, 5);
		try {
			final RunData data= getLaunchCommandData(configuration, m);
			return (data != null) ?
					LaunchUtils.generateCommandLine(data.command) :
					""; //$NON-NLS-1$
		}
		finally {
			m.done();
		}
	}
	
	@Override
	public void launch(final ILaunchConfiguration configuration, final String mode,
			final ILaunch launch,
			final @Nullable IProgressMonitor monitor) throws CoreException {
		final SubMonitor m= LaunchUtils.initProgressMonitor(configuration, monitor, 25);
		final long timestamp= System.currentTimeMillis();
		try {
			if (m.isCanceled()) {
				return;
			}
			
			final RunData data= getLaunchCommandData(configuration, m);
			if (data == null || m.isCanceled()) {
				return;
			}
			
			final ProcessBuilder builder= new ProcessBuilder(data.command);
			builder.directory(data.workingDirectory.toLocalFile(EFS.NONE, null));
			builder.redirectErrorStream(
					configuration.getAttribute(DebugPlugin.ATTR_MERGE_OUTPUT, false) );
			
			// environment
			final Map<String, String> envp= builder.environment();
			LaunchUtils.configureEnvironment(envp, configuration,
					data.rEnvConfig.getEnvironmentsVariables() );
			
			// exec process
			UnterminatedLaunchAlerter.registerLaunchType(RCmdLaunching.R_CMD_CONFIGURATION_TYPE_ID);
			Process p;
			try {
				p= builder.start();
			} catch (final IOException e) {
				throw new CoreException(new Status(IStatus.ERROR, RConsoleUIPlugin.BUNDLE_ID, 0,
						Messages.RCmd_LaunchDelegate_error_StartingExec, e ));
			}
			m.worked(10);
			
			// register process
			final Map<String, String> processAttributes= new HashMap<>();
			processAttributes.put(IProcess.ATTR_PROCESS_TYPE, RCmdLaunching.R_CMD_PROCESS_TYPE);
			final String processName= data.command.get(0) + ' ' + LaunchUtils.createProcessTimestamp(timestamp);
			final String label;
			{
				final StringBuilder sb= new StringBuilder(200);
				sb.append(LaunchUtils.createLaunchPrefix(configuration));
				sb.append(' ').append(data.rEnvConfig.getName());
				sb.append(" : R ").append(data.cmd); //$NON-NLS-1$
				if (data.resourcePathAbsolute != null) {
					sb.append(' ').append(data.resourcePathAbsolute.toOSString());
				}
				sb.append(" ~ ").append(processName); //$NON-NLS-1$
				label= sb.toString();
			}
			
			final IProcess process= DebugPlugin.newProcess(launch, p, processName, processAttributes);
			if (process == null) {
				p.destroy();
				throw new CoreException(new Status(IStatus.ERROR, RConsoleUIPlugin.BUNDLE_ID, 0,
						Messages.RCmd_LaunchDelegate_error_ProcessHandle, null ));
			}
			process.setAttribute(IProcess.ATTR_CMDLINE, LaunchUtils.generateCommandLine(data.command));
			process.setAttribute(IProcess.ATTR_PROCESS_LABEL, label);
			
			m.worked(5);
			if (!process.isTerminated() && !CommonTab.isLaunchInBackground(configuration)) {
				m.subTask(Messages.RCmd_LaunchDelegate_Running_label);
			}
			
			final IConsole console= DebugUITools.getConsole(process);
			if (console instanceof TextConsole) {
				final RErrorLineTracker lineMatcher= new RErrorLineTracker(data.workingDirectory);
				((TextConsole) console).addPatternMatchListener(lineMatcher);
			}
			
			LaunchConfigUtils.launchResourceRefresh(configuration, process, m.newChild(5));
		}
		finally {
			m.done();
		}
	}
	
	private @Nullable RunData getLaunchCommandData(final ILaunchConfiguration configuration,
			final SubMonitor m) throws CoreException {
		final List<String> command= new ArrayList<>();
		
		// r env
		final IREnvConfiguration rEnvConfig= RLaunching.getREnvConfig(configuration, true);
//		renv.validate();
		
		final String cmd= configuration.getAttribute(RCmdLaunching.R_CMD_COMMAND_ATTR_NAME, "").trim(); //$NON-NLS-1$
		if (!cmd.isEmpty()) {
			command.addAll(Arrays.asList(cmd.split(" "))); //$NON-NLS-1$
		}
		String arg1= null;
		if (command.size() > 0) {
			arg1= command.remove(0);
		}
		command.addAll(0, rEnvConfig.getExecCommand(arg1, EnumSet.of(Exec.CMD, Exec.TERM)));
		
		m.worked(1);
		if (m.isCanceled()) {
			return null;
		}
		
		// working directory
		final IFileStore workingDirectory= REnvTab.getWorkingDirectory(configuration);
		
		m.worked(1);
		if (m.isCanceled()) {
			return null;
		}
		
		// arguments
		command.addAll(Arrays.asList(
				LaunchUtils.getProcessArguments(configuration, RCmdLaunching.R_CMD_OPTIONS_ATTR_NAME) ));
		
		final String resourceValue= configuration.getAttribute(RCmdLaunching.R_CMD_RESOURCE_ATTR_NAME, ""); //$NON-NLS-1$
		IFileStore resource= null;
		IPath resourcePathAbsolute= null;
		IPath resourcePathAuto= null;
		if (resourceValue.length() > 0) {
			resource= FileUtil.expandToLocalFileStore(resourceValue, workingDirectory, null);
			final IPath workingDirectoryPath= nonNullAssert(URIUtil.toPath(workingDirectory.toURI()));
			resourcePathAuto= resourcePathAbsolute= nonNullAssert(URIUtil.toPath(resource.toURI()));
			if (workingDirectoryPath.isPrefixOf(resourcePathAuto)) {
				resourcePathAuto= resourcePathAuto.setDevice(null);
				resourcePathAuto= resourcePathAuto.removeFirstSegments(workingDirectoryPath.segmentCount());
			}
			command.add(resourcePathAuto.toString());
		}
		
		m.worked(1);
		
		return new RunData(rEnvConfig, cmd, command, workingDirectory, resourcePathAbsolute);
	}
	
}