/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2015, Red Hat, Inc., and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This 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 software 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 software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.jboss.as.cli.embedded;

import java.io.File;
import java.io.PrintStream;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;

import org.jboss.as.cli.CliEvent;
import org.jboss.as.cli.CliEventListener;
import org.jboss.as.cli.CommandContext;
import org.jboss.as.cli.CommandFormatException;
import org.jboss.as.cli.CommandLineException;
import org.jboss.as.cli.Util;
import org.jboss.as.cli.handlers.CommandHandlerWithHelp;
import org.jboss.as.cli.handlers.FilenameTabCompleter;
import org.jboss.as.cli.handlers.SimpleTabCompleter;
import org.jboss.as.cli.impl.ArgumentWithValue;
import org.jboss.as.cli.impl.ArgumentWithoutValue;
import org.jboss.as.cli.impl.FileSystemPathArgument;
import org.jboss.as.cli.operation.ParsedCommandLine;
import org.jboss.as.controller.client.ModelControllerClient;
import org.jboss.as.controller.client.helpers.ClientConstants;
import org.jboss.dmr.ModelNode;
import org.jboss.logmanager.LogContext;
import org.jboss.modules.ModuleLoader;
import org.jboss.stdio.NullOutputStream;
import org.jboss.stdio.StdioContext;
import org.wildfly.core.embedded.Configuration;
import org.wildfly.core.embedded.EmbeddedManagedProcess;
import org.wildfly.core.embedded.EmbeddedProcessFactory;
import org.wildfly.core.embedded.EmbeddedProcessStartException;
import org.wildfly.security.manager.WildFlySecurityManager;

/**
 * Handler for the "embed-host-controller" command.
 *
 * @author Ken Wills <kwills@redhat.com> (c) 2015 Red Hat Inc.
 */
class EmbedHostControllerHandler extends CommandHandlerWithHelp {

    private static final String ECHO = "echo";
    private static final String DISCARD_STDOUT = "discard";
    private static final String DOMAIN_CONFIG = "--domain-config";
    private static final String HOST_CONFIG = "--host-config";
    private static final String EMPTY_HOST_CONFIG = "--empty-host-config";
    private static final String REMOVE_EXISTING_HOST_CONFIG = "--remove-existing-host-config";
    private static final String EMPTY_DOMAIN_CONFIG = "--empty-domain-config";
    private static final String REMOVE_EXISTING_DOMAIN_CONFIG = "--remove-existing-domain-config";

    private static final String JBOSS_DOMAIN_BASE_DIR = "jboss.domain.base.dir";
    private static final String JBOSS_DOMAIN_CONFIG_DIR = "jboss.domain.config.dir";
    private static final String JBOSS_DOMAIN_LOG_DIR = "jboss.domain.log.dir";

    private final AtomicReference<EmbeddedProcessLaunch> hostControllerReference;
    private ArgumentWithValue jbossHome;
    private ArgumentWithValue stdOutHandling;
    private ArgumentWithValue domainConfig;
    private ArgumentWithValue hostConfig;
    private ArgumentWithValue dashC;
    private ArgumentWithValue timeout;
    private ArgumentWithoutValue emptyDomainConfig;
    private ArgumentWithoutValue removeExistingDomainConfig;
    private ArgumentWithoutValue emptyHostConfig;
    private ArgumentWithoutValue removeExistingHostConfig;

    static EmbedHostControllerHandler create(final AtomicReference<EmbeddedProcessLaunch> hostControllerReference, final CommandContext ctx, final boolean modular) {
        EmbedHostControllerHandler result = new EmbedHostControllerHandler(hostControllerReference);
        final FilenameTabCompleter pathCompleter = FilenameTabCompleter.newCompleter(ctx);
        if (!modular) {
            result.jbossHome = new FileSystemPathArgument(result, pathCompleter, "--jboss-home");
        }
        result.stdOutHandling = new ArgumentWithValue(result, new SimpleTabCompleter(new String[]{ECHO, DISCARD_STDOUT}), "--std-out");
        result.domainConfig = new ArgumentWithValue(result, DOMAIN_CONFIG);
        result.hostConfig = new ArgumentWithValue(result, HOST_CONFIG);
        result.dashC = new ArgumentWithValue(result, "-c");
        result.dashC.addCantAppearAfter(result.domainConfig);
        result.domainConfig.addCantAppearAfter(result.dashC);
        result.timeout = new ArgumentWithValue(result, "--timeout");
        result.emptyDomainConfig = new ArgumentWithoutValue(result, EMPTY_DOMAIN_CONFIG);
        result.removeExistingDomainConfig = new ArgumentWithoutValue(result, REMOVE_EXISTING_DOMAIN_CONFIG);
        result.emptyHostConfig = new ArgumentWithoutValue(result, EMPTY_HOST_CONFIG);
        result.removeExistingHostConfig = new ArgumentWithoutValue(result, REMOVE_EXISTING_HOST_CONFIG);
        return result;
    }

    private EmbedHostControllerHandler(final AtomicReference<EmbeddedProcessLaunch> hostControllerReference) {
        super("embed-host-controller", false);
        assert hostControllerReference != null;
        this.hostControllerReference = hostControllerReference;
    }

    @Override
    public boolean isAvailable(CommandContext ctx) {
       return ctx.getModelControllerClient() == null;
    }

    @Override
    protected void doHandle(CommandContext ctx) throws CommandLineException {

        final ParsedCommandLine parsedCmd = ctx.getParsedCommandLine();
        final File jbossHome = getJBossHome(parsedCmd);

        // set up the expected properties, default to JBOSS_HOME/standalone
        final String baseDir = WildFlySecurityManager.getPropertyPrivileged(JBOSS_DOMAIN_BASE_DIR, jbossHome + File.separator + "domain");

        String domainXml = domainConfig.getValue(parsedCmd);
        if (domainXml == null) {
            domainXml = dashC.getValue(parsedCmd);
        }

        if ((domainConfig.isPresent(parsedCmd) || dashC.isPresent(parsedCmd)) && (domainXml == null || domainXml.isEmpty())) {
            throw new CommandFormatException("The --domain-config (or -c) parameter requires a value.");
        }

        String hostXml = hostConfig.getValue(parsedCmd);
        if (hostConfig.isPresent(parsedCmd) && (hostXml == null || hostXml.isEmpty())) {
            throw new CommandFormatException("The --host-config parameter requires a value.");
        }

        Long bootTimeout = null;
        String timeoutString = timeout.getValue(parsedCmd);
        if (timeout.isPresent(parsedCmd) && (timeoutString == null || timeoutString.isEmpty())) {
            throw new CommandFormatException("The --timeout parameter requires a value.");
        }

        if (timeoutString != null) {
            bootTimeout = TimeUnit.SECONDS.toNanos(Long.parseLong(timeoutString));
        }

        String stdOutString = stdOutHandling.getValue(parsedCmd);
        if (stdOutHandling.isPresent(parsedCmd)) {
            if (stdOutString == null || stdOutString.isEmpty()) {
                throw new CommandFormatException("The --std-out parameter requires a value { echo, discard }.");
            }
            if (! (stdOutString.equals(ECHO) || stdOutString.equals(DISCARD_STDOUT))) {
                throw new CommandFormatException("The --std-out parameter should be one of { echo, discard }.");
            }
        }

        final List<String> args = parsedCmd.getOtherProperties();
        if (!args.isEmpty()) {
                throw new CommandFormatException("The command accepts 0 unnamed argument(s) but received: " + args);
        }

        final EnvironmentRestorer restorer = new EnvironmentRestorer(JBOSS_DOMAIN_LOG_DIR);
        boolean ok = false;
        ThreadLocalContextSelector contextSelector = null;
        try {

            Contexts defaultContexts = restorer.getDefaultContexts();

            StdioContext discardStdoutContext = null;
            if (!ECHO.equalsIgnoreCase(stdOutHandling.getValue(parsedCmd))) {
                PrintStream nullStream = new UncloseablePrintStream(NullOutputStream.getInstance());
                StdioContext currentContext = defaultContexts.getStdioContext();
                discardStdoutContext = StdioContext.create(currentContext.getIn(), nullStream, currentContext.getErr());
            }

            // Configure and get the log context
            String controllerLogDir = WildFlySecurityManager.getPropertyPrivileged(JBOSS_DOMAIN_LOG_DIR, null);
            if (controllerLogDir == null) {
                controllerLogDir = baseDir + File.separator + "log";
                WildFlySecurityManager.setPropertyPrivileged(JBOSS_DOMAIN_LOG_DIR, controllerLogDir);
            }
            final String controllerCfgDir = WildFlySecurityManager.getPropertyPrivileged(JBOSS_DOMAIN_CONFIG_DIR, baseDir + File.separator + "configuration");

            final LogContext embeddedLogContext = EmbeddedLogContext.configureLogContext(new File(controllerLogDir), new File(controllerCfgDir), "host-controller.log", ctx);

            Contexts localContexts = new Contexts(embeddedLogContext, discardStdoutContext);
            contextSelector = new ThreadLocalContextSelector(localContexts, defaultContexts);
            contextSelector.pushLocal();

            StdioContext.setStdioContextSelector(contextSelector);
            LogContext.setLogContextSelector(contextSelector);

            List<String> cmdsList = new ArrayList<>();
            if (domainXml != null && domainXml.trim().length() > 0) {
                cmdsList.add(DOMAIN_CONFIG);
                cmdsList.add(domainXml.trim());
            }

            if (hostXml != null && hostXml.trim().length() > 0) {
                cmdsList.add(HOST_CONFIG);
                cmdsList.add(hostXml.trim());
            }

            boolean emptyDomain = emptyDomainConfig.isPresent(parsedCmd);
            boolean removeDomain = removeExistingDomainConfig.isPresent(parsedCmd);
            if (emptyDomain) {
                cmdsList.add(EMPTY_DOMAIN_CONFIG);
            }
            if (removeDomain) {
                cmdsList.add(REMOVE_EXISTING_DOMAIN_CONFIG);
            }

            File domainXmlCfgFile = new File(controllerCfgDir + File.separator + (domainConfig.isPresent(parsedCmd) ? domainXml : "domain.xml"));
            if (emptyDomain && !removeDomain && domainXmlCfgFile.exists() && domainXmlCfgFile.length() != 0) {
                throw new CommandFormatException("The specified domain configuration file already exists and has size > 0 and may not be overwritten unless --remove-existing-domain-config is also specified.");
            }

            boolean emptyHost = emptyHostConfig.isPresent(parsedCmd);
            boolean removeHost = removeExistingHostConfig.isPresent(parsedCmd);
            if (emptyHost) {
                cmdsList.add(EMPTY_HOST_CONFIG);
            }

            if (removeHost) {
                cmdsList.add(REMOVE_EXISTING_HOST_CONFIG);
            }

            File hostXmlCfgFile = new File(controllerCfgDir + File.separator + (hostConfig.isPresent(parsedCmd) ? hostXml : "host.xml"));
            if (emptyHost && !removeHost && hostXmlCfgFile.exists() && hostXmlCfgFile.length() != 0) {
                throw new CommandFormatException("The specified host configuration file already exists and has size > 0 and may not be overwritten unless --remove-existing-host-config is also specified.");
            }

            String[] cmds = cmdsList.toArray(new String[cmdsList.size()]);

            final Configuration.Builder configBuilder;
            if (this.jbossHome == null) {
                // Modular environment, note that the jbossHome here is resolved from the JBOSS_HOME environment
                // variable and should never be null according to the getJBossHome() method.
                configBuilder = Configuration.Builder.of(jbossHome)
                        .setModuleLoader(ModuleLoader.forClass(getClass()))
                        .setCommandArguments(cmds);
            } else {
                configBuilder = Configuration.Builder.of(jbossHome.getAbsoluteFile())
                        .addSystemPackages(EmbeddedControllerHandlerRegistrar.EXTENDED_SYSTEM_PKGS)
                        .setCommandArguments(cmds);
            }
            // Disables the logging subsystem from registering an embedded log context if the subsystem is present
            WildFlySecurityManager.setPropertyPrivileged("org.wildfly.logging.embedded", "false");
            final EmbeddedManagedProcess hostController = EmbeddedProcessFactory.createHostController(configBuilder.build());
            hostController.start();

            hostControllerReference.set(new EmbeddedProcessLaunch(hostController, restorer, true));
            ModelControllerClient mcc = new ThreadContextsModelControllerClient(hostController.getModelControllerClient(), contextSelector);

            if (hostController.canQueryProcessState()) {
                // If we can check the process state, then use this method instead of using management operations to verify
                // the process state and wait for it even if we are on EMPTY_HOST_CONFIG scenario.
                if (bootTimeout == null || bootTimeout > 0) {
                    long expired = bootTimeout == null ? Long.MAX_VALUE : System.nanoTime() + bootTimeout;

                    String status;

                    do {
                        status = hostController.getProcessState();

                        if (status == null || "starting".equals(status)) {
                            try {
                                Thread.sleep(50);
                            } catch (InterruptedException e) {
                                Thread.currentThread().interrupt();
                                throw new CommandLineException("Interrupted while waiting for embedded server to start");
                            }
                        } else {
                            break;
                        }
                    } while (System.nanoTime() < expired);

                    if (status == null || "starting".equals(status)) {
                        assert bootTimeout != null; // we'll assume the loop didn't run for decades
                        // Stop server and restore environment
                        StopEmbeddedHostControllerHandler.cleanup(hostControllerReference);
                        throw new CommandLineException("Embedded host controller did not exit 'starting' status within " +
                                TimeUnit.NANOSECONDS.toSeconds(bootTimeout) + " seconds");
                    }
                }
            } else {
                // Fallback to management operations. This could be problematic when we are using an empty host configuration
                // file because, in this case, there is no way to wait for the embedded process before returning the control
                // to the client. We need the host name to query for its state.
                // In specific cases, it could return the client when the managed process is still starting, which is problematic
                // when we are using the embedded server programmatically.
                // See https://issues.redhat.com/browse/WFLY-13276 for some context.
                if (!emptyHost && (bootTimeout == null || bootTimeout > 0)) {
                    long expired = bootTimeout == null ? Long.MAX_VALUE : System.nanoTime() + bootTimeout;

                    String status = "starting";

                    // read out the host controller name
                    final ModelNode getNameOp = new ModelNode();
                    getNameOp.get(ClientConstants.OP).set(ClientConstants.READ_ATTRIBUTE_OPERATION);
                    getNameOp.get(ClientConstants.NAME).set(Util.LOCAL_HOST_NAME);

                    final ModelNode getStateOp = new ModelNode();
                    getStateOp.get(ClientConstants.OP).set(ClientConstants.READ_ATTRIBUTE_OPERATION);
                    ModelNode address = getStateOp.get(ClientConstants.ADDRESS);
                    getStateOp.get(ClientConstants.NAME).set(ClientConstants.HOST_STATE);
                    do {
                        try {
                            final ModelNode nameResponse = mcc.execute(getNameOp);
                            if (Util.isSuccess(nameResponse)) {
                                // read out the connected HC name
                                final String localName = nameResponse.get(ClientConstants.RESULT).asString();
                                address.set(ClientConstants.HOST, localName);
                                final ModelNode stateResponse = mcc.execute(getStateOp);
                                if (Util.isSuccess(stateResponse)) {
                                    status = stateResponse.get(ClientConstants.RESULT).asString();
                                }
                            }
                        } catch (Exception e) {
                            // ignore and try again
                        }

                        if ("starting".equals(status)) {
                            try {
                                Thread.sleep(50);
                            } catch (InterruptedException e) {
                                Thread.currentThread().interrupt();
                                throw new CommandLineException("Interrupted while waiting for embedded server to start");
                            }
                        } else {
                            break;
                        }
                    } while (System.nanoTime() < expired);

                    if ("starting".equals(status)) {
                        assert bootTimeout != null; // we'll assume the loop didn't run for decades
                        // Stop server and restore environment
                        StopEmbeddedHostControllerHandler.cleanup(hostControllerReference);
                        throw new CommandLineException("Embedded host controller did not exit 'starting' status within " +
                                TimeUnit.NANOSECONDS.toSeconds(bootTimeout) + " seconds");
                    }
                }
            }
            // Expose the client to the rest of the CLI last so nothing can be done with
            // it until we're ready
            ctx.bindClient(mcc);
            // Stop the server on any disconnect event
            ctx.addEventListener(new CliEventListener() {
                @Override
                public void cliEvent(CliEvent event, CommandContext ctx) {
                    if (event == CliEvent.DISCONNECTED) {
                        StopEmbeddedHostControllerHandler.cleanup(hostControllerReference);
                    }
                }
            });
            ok = true;
        } catch (RuntimeException | EmbeddedProcessStartException e) {
            throw new CommandLineException("Cannot start embedded Host Controller", e);
        } finally {
            if (!ok) {
                ctx.disconnectController();
                restorer.restoreEnvironment();
            } else if (contextSelector != null) {
                contextSelector.restore(null);
            }
        }
    }

    private File getJBossHome(final ParsedCommandLine parsedCmd) throws CommandLineException {
        String jbossHome = this.jbossHome == null ? null : this.jbossHome.getValue(parsedCmd);
        if (jbossHome == null || jbossHome.length() == 0) {
            jbossHome = WildFlySecurityManager.getEnvPropertyPrivileged("JBOSS_HOME", null);
            if (jbossHome == null || jbossHome.length() == 0) {
                if (this.jbossHome != null) {
                    throw new CommandLineException("Missing configuration value for --jboss-home and environment variable JBOSS_HOME is not set");
                } else {
                    throw new CommandLineException("Environment variable JBOSS_HOME is not set");
                }
            }
            return validateJBossHome(jbossHome, "environment variable JBOSS_HOME");
        } else {
            return validateJBossHome(jbossHome, "argument --jboss-home");
        }
    }

    private static File validateJBossHome(String jbossHome, String source) throws CommandLineException {
        File f = new File(jbossHome);
        if (!f.exists()) {
            throw new CommandLineException(String.format("File %s specified by %s does not exist", jbossHome, source));
        } else if (!f.isDirectory()) {
            throw new CommandLineException(String.format("File %s specified by %s is not a directory", jbossHome, source));
        }
        return f;
    }

}
