/******************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of Qt for Device Creation.
**
** $QT_BEGIN_LICENSE:COMM$
**
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see http://www.qt.io/terms-conditions. For further
** information use the contact form at http://www.qt.io/contact-us.
**
** $QT_END_LICENSE$
**
******************************************************************************/

#include "process.h"
#include "portlist.h"
#include "perfprocesshandler.h"
#include <QCoreApplication>
#include <QDir>
#include <QLocalSocket>
#include <QTcpServer>
#include <QProcess>
#include <errno.h>
#include <QStringList>
#include <QSocketNotifier>
#include <QFile>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/wait.h>

#define PID_FILE "/data/user/.appcontroller"
#define FEATURES "restart perf eglresize qmldebugservices explicitdebugports"

#define B2QT_PREFIX "/usr/bin/b2qt"

static int serverSocket = -1;

static const char socketPath[] = "#Boot2Qt_appcontroller";

static void usage()
{
    printf("appcontroller [--debug-gdb]  [--debug-gdb-port <port>]"
           " [--debug-qml] [--debug-qml-port <port>] [--qml-debug-services <services>]"
           " [--profile-perf <params>] [--port-range <range>] [--stop] [--launch] [--show-platfrom]"
           " [--make-default] [--remove-default] [--print-debug] [--version] [--detach]"
           " [executable] [arguments]\n"
           "\n"
           "--port-range <range>            Port range to use for debugging connections\n"
           "--debug-gdb                     Start GDB debugging\n"
           "--debug-gdb-port <port>         Port to be used for GDB debugging\n"
           "--debug-qml                     Start QML debugging or profiling\n"
           "--debug-qml-port <port>         Port to be used for QML debugging\n"
           "--qml-debug-services <services> Specify services to use for QML debugging/profiling\n"
           "--profile-perf <params>         Start perf profiling\n"
           "--stop                          Stop already running application\n"
           "--stop-for-restart              Stop already running application and prepare to\n"
           "                                restart it\n"
           "--launch                        Start application without stopping already running\n"
           "                                application\n"
           "--show-platform                 Show platform information\n"
           "--make-default                  Make this application the default on boot\n"
           "--remove-default                Restore the default application\n"
           "--version                       Print version information\n"
           "--detach                        Start application as usual, then go into background\n"
           "--restart                       Restart the current running application or an\n"
           "                                application stopped with --stop-for-restart\n"
           "--help, -h, -help               Show this help\n"
          );
}

static void setupAddressStruct(struct sockaddr_un &address)
{
    address.sun_family = AF_UNIX;
    memset(address.sun_path, 0, sizeof(address.sun_path));
    strncpy(address.sun_path, socketPath, sizeof(address.sun_path)-1);
    address.sun_path[0] = 0;
}

static int connectSocket(const QByteArray &command)
{
    int fd = 0;
    struct sockaddr_un address;

    if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
        perror("Could not create socket");
        return -1;
    }

    if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
        perror("Unable to set CLOEXEC");

    setupAddressStruct(address);

    if (connect(fd, (struct sockaddr *) &address, sizeof (address)) != 0) {
        perror("Could not connect");
        return -1;
    }

    QLocalSocket localSocket;
    if (!localSocket.setSocketDescriptor(fd)) {
        fprintf(stderr, "Unable to initialize local socket from descriptor.\n");
        close(fd);
        return -1;
    }

    if (localSocket.write(command) != command.size()) {
        fprintf(stderr, "Could not send command");
        return -1;
    }
    localSocket.waitForBytesWritten();
    return 0;
}

static int createServerSocket()
{
  struct sockaddr_un address;

  if ((serverSocket = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
      perror("Could not create socket");
      return -1;
  }

  if (fcntl(serverSocket, F_SETFD, FD_CLOEXEC) == -1) {
      perror("Unable to set CLOEXEC");
  }

  setupAddressStruct(address);

  unsigned int tries = 20;

  while (tries > 0) {
      --tries;
      if (bind(serverSocket, (struct sockaddr *) &address, sizeof (address)) != 0) {
          if (errno != EADDRINUSE) {
              perror("Could not bind socket: App is still running");
              return -1;
          }

          if (connectSocket("stop") != 0) {
              fprintf(stderr, "Failed to connect to process\n");
          }

          usleep(500000);
          continue;
      }

      if (listen(serverSocket, 5) != 0) {
          perror("Could not listen");
          return -1;
      }
      else
          return 0;
  }

  return -1;
}

static void stop()
{
    connectSocket("stop");
}

static void restart()
{
    connectSocket("restart");
}

static void stopForRestart()
{
    connectSocket("stopForRestart");
}

static int openServer(QTcpServer *s, Utils::PortList &range)
{
    while (range.hasMore()) {
        if (s->listen(QHostAddress::Any, range.getNext()))
            return s->serverPort();
    }
    return -1;
}

static int findFirstFreePort(Utils::PortList &range)
{
    QTcpServer s;
    return openServer(&s, range);
}

bool parseConfigFile(Config *config, const QString &fileName)
{
    QFile f(fileName);

    if (!f.open(QFile::ReadOnly)) {
        fprintf(stderr, "Could not read config file: %s\n", qPrintable(fileName));
        return false;
    }

    while (!f.atEnd()) {
        QString line = f.readLine();
        if (line.startsWith("env=")) {
                QString sub = line.mid(4).simplified();
                int index = sub.indexOf('=');
                if (index < 2) {
                    // ignore
                } else
                    config->env[sub.left(index)] = sub.mid(index+1);
        } else if (line.startsWith("append=")) {
              config->args += line.mid(7).simplified();
        } else if (line.startsWith("base=")) {
              config->base = line.mid(5).simplified();
        } else if (line.startsWith("platform=")) {
              config->platform = line.mid(9).simplified();
        } else if (line.startsWith("debugInterface=")) {
              const QString value = line.mid(15).simplified();
              if (value == "local")
                  config->debugInterface = Config::LocalDebugInterface;
              else if (value == "public")
                  config->debugInterface = Config::PublicDebugInterface;
              else
                  qWarning() << "Unkonwn value for debuginterface:" << value;
        }
    }
    f.close();
    return true;
}

bool parseConfigFileDirectory(Config *config, const QString &dirName)
{
    QDir d(dirName);
    if (d.exists()) {
        foreach (const QString &fileName, d.entryList(QDir::Files)) {
            const QString file(d.absoluteFilePath(fileName));

            if (!parseConfigFile(config, file)) {
                fprintf(stderr, "Failed to parse config file: %s\n", qPrintable(file));
                return false;
            }
        }
    }
    return true;
}

static bool removeDefault()
{
    QFileInfo fi(B2QT_PREFIX);

    if (fi.isSymLink()) {
        if (!QFile::remove(B2QT_PREFIX)) {
            fprintf(stderr, "Could not remove default application.\n");
            return false;
        }
        sync();
        return true;
    }

    if (fi.isDir()) {
        fprintf(stderr, "Could not remove default application because '" B2QT_PREFIX "' is a directory. It should be a symlink.\n");
        return false;
    }

    if (fi.isFile()) {
        fprintf(stderr, "Could not remove default application because '" B2QT_PREFIX "' is a file. It should be a symlink.\n");
        return false;
    }

    if (!fi.exists()) {
        return true;
    }

    return false;
}

static bool makeDefault(const QString &filepath)
{
    QFile executable(filepath);

    if (!executable.exists()) {
        fprintf(stderr, "File %s does not exist.\n", executable.fileName().toLocal8Bit().constData());
        return false;
    }

    if (!removeDefault())
        return false;

    if (!executable.link(B2QT_PREFIX)) {
        fprintf(stderr, "Could not link default application.\n");
        return false;
    }
    sync();
    return true;
}

static QStringList extractPerfParams(QString s)
{
    QStringList lst;
    int h = 0;
    int i = 0;
    for (;;) {
        i = s.indexOf(QLatin1Char(','), i);
        if (i >= 0) {
            if (i + 1 < s.length() && s.at(i + 1) == QLatin1Char(',')) {
                s.remove(i, 1);
                i++;
                continue;
            }
            lst << s.mid(h, i - h);
            i++;
            h = i;
        } else {
            lst << s.mid(h);
            break;
        }
    }
    return lst;
}

int main(int argc, char **argv)
{
    // Save arguments before QCoreApplication handles them
    QStringList args;
    for (int i = 1; i < argc; i++)
        args.append(argv[i]);

    QStringList defaultArgs;
    quint16 gdbDebugPort = 0;
    quint16 qmlDebugPort = 0;
    bool useGDB = false;
    bool useQML = false;
    QString qmlDebugServices;
    QStringList perfParams;
    bool fireAndForget = false;
    bool detach = false;
    Utils::PortList range;

    if (args.isEmpty()) {
        fprintf(stderr, "No arguments given.\n");
        return 1;
    }

    Config config;
    if (!parseConfigFile(&config, "/etc/appcontroller.conf"))
        fprintf(stderr, "Failed to parse config file.\n");

    while (!args.isEmpty()) {
        const QString arg(args.takeFirst());

        if (arg == "--port-range") {
            if (args.isEmpty()) {
                fprintf(stderr, "--port-range requires a range specification\n");
                return 1;
            }
            range = Utils::PortList::fromString(args.takeFirst());
            if (!range.hasMore()) {
                fprintf(stderr, "Invalid port range\n");
                return 1;
            }
        } else if (arg == "--debug-gdb") {
            useGDB = true;
            setpgid(0,0); // must be called before setsid()
            setsid();
        } else if (arg == "--debug-gdb-port") {
            if (args.isEmpty()) {
                fprintf(stderr, "--debug-gdb-port requires a port number\n");
                return 1;
            }
            gdbDebugPort = args.takeFirst().toUInt();
            if (gdbDebugPort < 1) {
                fprintf(stderr, "--debug-gdb-port has invalid port number\n");
                return 1;
            }
        } else if (arg == "--debug-qml") {
            useQML = true;
        } else if (arg == "--debug-qml-port") {
            if (args.isEmpty()) {
                fprintf(stderr, "--debug-qml-port requires a port number\n");
                return 1;
            }
            qmlDebugPort = args.takeFirst().toUInt();
            if (qmlDebugPort < 1) {
                fprintf(stderr, "--debug-qml-port has invalid port number\n");
                return 1;
            }
        } else if (arg == "--qml-debug-services") {
            if (args.isEmpty()) {
                fprintf(stderr, "--qml-debug-services requires a list of comma-separated service "
                                "names.\n");
                return 1;
            }
            qmlDebugServices = args.takeFirst();
        } else if (arg == "--profile-perf") {
            if (args.isEmpty()) {
                fprintf(stderr, "--profile-perf requires comma-separated list of parameters that\n"
                                "get passed to \"perf record\". Arguments \"-o -\" are\n"
                                "automatically appended to capture the output as stream.\n"
                                "Escape commas by doubling them.\n");
                return 1;
            }
            perfParams = extractPerfParams(args.takeFirst());
        } else if (arg == "--stop") {
            stop();
            return 0;
        } else if (arg == "--launch") {
            fireAndForget = true;
        } else if (arg == "--show-platform") {
            printf("base:%s\nplatform:%s\n",
                config.base.toLocal8Bit().constData(),
                config.platform.toLocal8Bit().constData());
            return 0;
        } else if (arg == "--make-default") {
              if (args.isEmpty()) {
                  fprintf(stderr, "--make-default requires an argument\n");
                  return 1;
              }
              if (!makeDefault(args.takeFirst()))
                  return 1;
              return 0;
        } else if (arg == "--remove-default") {
              if (removeDefault())
                  return 0;
              else
                  return 1;
        } else if (arg == "--version") {
            printf("Appcontroller version: " GIT_VERSION "\nGit revision: " GIT_HASH "\nFeatures: " FEATURES "\n");
            return 0;
        } else if (arg == "--detach") {
            detach = true;
        } else if (arg == "--restart") {
            restart();
            return 0;
        } else if (arg == "--stop-for-restart") {
            stopForRestart();
            return 0;
        } else if (arg == "--help" || arg == "-help" || arg == "-h") {
            usage();
            return 0;
        } else {
            args.prepend(arg);
            break;
        }
    }

    if (args.isEmpty()) {
        fprintf(stderr, "No binary to execute.\n");
        return 1;
    }

    if (useGDB && !(gdbDebugPort || range.hasMore())) {
        fprintf(stderr, "--debug-gdb requires --port-range or --debug-gdb-port\n");
        return 1;
    }

    if (useQML && !(qmlDebugPort || range.hasMore())) {
        fprintf(stderr, "--debug-qml requires --port-range or --debug-qml-port\n");
        return 1;
    }

    if (detach && (useGDB || useQML)) {
        fprintf(stderr, "Detached debugging not possible. --detach and one of --debug-gdb, --debug-qml must not be used together.\n");
        return 1;
    }

    if (gdbDebugPort && !useGDB)
        gdbDebugPort = 0;

    if (useGDB && !gdbDebugPort) {
        int port = findFirstFreePort(range);
        if (port < 0) {
            fprintf(stderr, "Could not find an unused port in range\n");
            return 1;
        }
        gdbDebugPort = port;
    }
    if (useQML) {
        if (!qmlDebugPort) {
            int port = findFirstFreePort(range);
            if (port < 0) {
                fprintf(stderr, "Could not find an unused port in range\n");
                return 1;
            }
            qmlDebugPort = port;
        }
        defaultArgs.push_front("-qmljsdebugger=port:" + QString::number(qmlDebugPort) + ",block" +
                               (qmlDebugServices.isEmpty() ?
                                    "" : (",services:" + qmlDebugServices)));
        printf("QML Debugger: Going to wait for connection on port %d...\n", qmlDebugPort);
    }

    defaultArgs.push_front(args.takeFirst());
    defaultArgs.append(args);

    if (useGDB) {
        QString interface;
        if (config.debugInterface == Config::LocalDebugInterface)
            interface = QLatin1String("localhost");

        defaultArgs.push_front(interface + ":" + QString::number(gdbDebugPort));
        defaultArgs.push_front("gdbserver");
    }

    if (!fireAndForget && createServerSocket() != 0) {
        fprintf(stderr, "Could not create serversocket\n");
        return 1;
    }

    // daemonize
    if (detach) {
        pid_t rc = fork();
        if (rc == -1) {
            printf("fork failed\n");
            return -1;
        } else if (rc > 0) {
            // parent
            ::wait(NULL); // wait for the child to exit
            return 0;
        }

        setsid();
        if (chdir("/") != 0)
            return -1;
        signal(SIGHUP, SIG_IGN);

        // child
        int devnull = open("/dev/null", O_RDWR);
        if (devnull < 0)
            return -1;
        dup2(devnull, 0); // Replace file descriptors
        dup2(devnull, 1);
        dup2(devnull, 2);
        rc = fork();
        if (rc == -1)
            return -1;
        else if (rc > 0)
            return 0;

        // child
    }

    // Create QCoreApplication after parameter parsing to prevent printing evaluation
    // message to terminal before QtCreator has parsed the output.
    QCoreApplication app(argc, argv);
    Process process;
    process.setConfig(config);
    if (gdbDebugPort)
        process.setDebug();
    process.setSocketNotifier(new QSocketNotifier(serverSocket, QSocketNotifier::Read, &process));

    if (!perfParams.isEmpty()) {
        QStringList allArgs;
        allArgs << QLatin1String("perf") << QLatin1String("record")
                << perfParams << QLatin1String("-o") << QLatin1String("-")
                << QLatin1String("--") << defaultArgs;

        PerfProcessHandler *server = new PerfProcessHandler(&process, allArgs);
        int port = openServer(server->server(), range);
        if (port < 0) {
            fprintf(stderr, "Could not find an unused port in range\n");
            return 1;
        }
        printf("AppController: Going to wait for perf connection on port %d...\n", port);
    } else {
        process.start(defaultArgs);
    }

    app.exec();
    if (!fireAndForget)
        close(serverSocket);
    return 0;
}