/*
Copyright 2018-2019 Intel Corporation

Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0

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.
*/

function parseServiceStatus(token)
{
    var j = {};
    var serviceType = token.Deref(0, 4).IntVal;
    j.isFileSystemDriver = ((serviceType & 0x00000002) == 0x00000002);
    j.isKernelDriver = ((serviceType & 0x00000001) == 0x00000001);
    j.isSharedProcess = ((serviceType & 0x00000020) == 0x00000020);
    j.isOwnProcess = ((serviceType & 0x00000010) == 0x00000010);
    j.isInteractive = ((serviceType & 0x00000100) == 0x00000100);
    switch (token.Deref((1 * 4), 4).toBuffer().readUInt32LE())
    {
        case 0x00000005:
            j.state = 'CONTINUE_PENDING';
            break;
        case 0x00000006:
            j.state = 'PAUSE_PENDING';
            break;
        case 0x00000007:
            j.state = 'PAUSED';
            break;
        case 0x00000004:
            j.state = 'RUNNING';
            break;
        case 0x00000002:
            j.state = 'START_PENDING';
            break;
        case 0x00000003:
            j.state = 'STOP_PENDING';
            break;
        case 0x00000001:
            j.state = 'STOPPED';
            break;
        default:
            // Unknown service state
            break;
    }
    var controlsAccepted = token.Deref((2 * 4), 4).toBuffer().readUInt32LE();
    j.controlsAccepted = [];
    if ((controlsAccepted & 0x00000010) == 0x00000010)
    {
        j.controlsAccepted.push('SERVICE_CONTROL_NETBINDADD');
        j.controlsAccepted.push('SERVICE_CONTROL_NETBINDREMOVE');
        j.controlsAccepted.push('SERVICE_CONTROL_NETBINDENABLE');
        j.controlsAccepted.push('SERVICE_CONTROL_NETBINDDISABLE');
    }
    if ((controlsAccepted & 0x00000008) == 0x00000008) { j.controlsAccepted.push('SERVICE_CONTROL_PARAMCHANGE'); }
    if ((controlsAccepted & 0x00000002) == 0x00000002) { j.controlsAccepted.push('SERVICE_CONTROL_PAUSE'); j.controlsAccepted.push('SERVICE_CONTROL_CONTINUE'); }
    if ((controlsAccepted & 0x00000100) == 0x00000100) { j.controlsAccepted.push('SERVICE_CONTROL_PRESHUTDOWN'); }
    if ((controlsAccepted & 0x00000004) == 0x00000004) { j.controlsAccepted.push('SERVICE_CONTROL_SHUTDOWN'); }
    if ((controlsAccepted & 0x00000001) == 0x00000001) { j.controlsAccepted.push('SERVICE_CONTROL_STOP'); }
    if ((controlsAccepted & 0x00000020) == 0x00000020) { j.controlsAccepted.push('SERVICE_CONTROL_HARDWAREPROFILECHANGE'); }
    if ((controlsAccepted & 0x00000040) == 0x00000040) { j.controlsAccepted.push('SERVICE_CONTROL_POWEREVENT'); }
    if ((controlsAccepted & 0x00000080) == 0x00000080) { j.controlsAccepted.push('SERVICE_CONTROL_SESSIONCHANGE'); }
    j.pid = token.Deref((7 * 4), 4).toBuffer().readUInt32LE();
    return (j);
}

function serviceManager()
{
    this._ObjectID = 'service-manager';
    if (process.platform == 'win32') 
    {
        this.GM = require('_GenericMarshal');
        this.proxy = this.GM.CreateNativeProxy('Advapi32.dll');
        this.proxy.CreateMethod('OpenSCManagerA');
        this.proxy.CreateMethod('EnumServicesStatusExA');
        this.proxy.CreateMethod('OpenServiceA');
        this.proxy.CreateMethod('QueryServiceStatusEx');
        this.proxy.CreateMethod('ControlService');
        this.proxy.CreateMethod('StartServiceA');
        this.proxy.CreateMethod('CloseServiceHandle');
        this.proxy.CreateMethod('CreateServiceA');
        this.proxy.CreateMethod('ChangeServiceConfig2A');
        this.proxy.CreateMethod('DeleteService');
        this.proxy.CreateMethod('AllocateAndInitializeSid');
        this.proxy.CreateMethod('CheckTokenMembership');
        this.proxy.CreateMethod('FreeSid');

        this.proxy2 = this.GM.CreateNativeProxy('Kernel32.dll');
        this.proxy2.CreateMethod('GetLastError');

        this.isAdmin = function isAdmin() {
            var NTAuthority = this.GM.CreateVariable(6);
            NTAuthority.toBuffer().writeInt8(5, 5);
            var AdministratorsGroup = this.GM.CreatePointer();
            var admin = false;

            if (this.proxy.AllocateAndInitializeSid(NTAuthority, 2, 32, 544, 0, 0, 0, 0, 0, 0, AdministratorsGroup).Val != 0)
            {
                var member = this.GM.CreateInteger();
                if (this.proxy.CheckTokenMembership(0, AdministratorsGroup.Deref(), member).Val != 0)
                {
                    if (member.toBuffer().readUInt32LE() != 0) { admin = true; }
                }
                this.proxy.FreeSid(AdministratorsGroup.Deref());
            }
            return admin;
        };
        this.getProgramFolder = function getProgramFolder()
        {
            if (require('os').arch() == 'x64')
            {
                // 64 bit Windows
                if (this.GM.PointerSize == 4)
                {
                    return process.env['ProgramFiles(x86)'];    // 32 Bit App
                } 
                return process.env['ProgramFiles'];             // 64 bit App
            }

            // 32 bit Windows
            return process.env['ProgramFiles'];                 
        };
        this.getServiceFolder = function getServiceFolder() { return this.getProgramFolder() + '\\mesh'; };

        this.enumerateService = function () {
            var machineName = this.GM.CreatePointer();
            var dbName = this.GM.CreatePointer();
            var handle = this.proxy.OpenSCManagerA(0x00, 0x00, 0x0001 | 0x0004);

            var bytesNeeded = this.GM.CreatePointer();
            var servicesReturned = this.GM.CreatePointer();
            var resumeHandle = this.GM.CreatePointer();
            //var services = this.proxy.CreateVariable(262144);
            var success = this.proxy.EnumServicesStatusExA(handle, 0, 0x00000030, 0x00000003, 0x00, 0x00, bytesNeeded, servicesReturned, resumeHandle, 0x00);
            if (bytesNeeded.IntVal <= 0) {
                throw ('error enumerating services');
            }
            var sz = bytesNeeded.IntVal;
            var services = this.GM.CreateVariable(sz);
            this.proxy.EnumServicesStatusExA(handle, 0, 0x00000030, 0x00000003, services, sz, bytesNeeded, servicesReturned, resumeHandle, 0x00);
            console.log("servicesReturned", servicesReturned.IntVal);

            var ptrSize = dbName._size;
            var blockSize = 36 + (2 * ptrSize);
            blockSize += ((ptrSize - (blockSize % ptrSize)) % ptrSize);
            var retVal = [];
            for (var i = 0; i < servicesReturned.IntVal; ++i) {
                var token = services.Deref(i * blockSize, blockSize);
                var j = {};
                j.name = token.Deref(0, ptrSize).Deref().String;
                j.displayName = token.Deref(ptrSize, ptrSize).Deref().String;
                j.status = parseServiceStatus(token.Deref(2 * ptrSize, 36));
                retVal.push(j);
            }
            this.proxy.CloseServiceHandle(handle);
            return (retVal);
        }
        this.getService = function (name) {
            var serviceName = this.GM.CreateVariable(name);
            var ptr = this.GM.CreatePointer();
            var bytesNeeded = this.GM.CreateVariable(ptr._size);
            var handle = this.proxy.OpenSCManagerA(0x00, 0x00, 0x0001 | 0x0004 | 0x0020 | 0x0010);
            if (handle.Val == 0) { throw ('could not open ServiceManager'); }
            var h = this.proxy.OpenServiceA(handle, serviceName, 0x0004 | 0x0020 | 0x0010 | 0x00010000);
            if (h.Val != 0) {
                var success = this.proxy.QueryServiceStatusEx(h, 0, 0, 0, bytesNeeded);
                var status = this.GM.CreateVariable(bytesNeeded.toBuffer().readUInt32LE());
                success = this.proxy.QueryServiceStatusEx(h, 0, status, status._size, bytesNeeded);
                if (success != 0) {
                    retVal = {};
                    retVal.status = parseServiceStatus(status);
                    retVal._scm = handle;
                    retVal._service = h;
                    retVal._GM = this.GM;
                    retVal._proxy = this.proxy;
                    require('events').inherits(retVal);
                    retVal.on('~', function () { this._proxy.CloseServiceHandle(this); this._proxy.CloseServiceHandle(this._scm); });
                    retVal.name = name;
                    retVal.stop = function () {
                        if (this.status.state == 'RUNNING') {
                            var newstate = this._GM.CreateVariable(36);
                            var success = this._proxy.ControlService(this._service, 0x00000001, newstate);
                            if (success == 0) {
                                throw (this.name + '.stop() failed');
                            }
                        }
                        else {
                            throw ('cannot call ' + this.name + '.stop(), when current state is: ' + this.status.state);
                        }
                    }
                    retVal.start = function () {
                        if (this.status.state == 'STOPPED') {
                            var success = this._proxy.StartServiceA(this._service, 0, 0);
                            if (success == 0) {
                                throw (this.name + '.start() failed');
                            }
                        }
                        else {
                            throw ('cannot call ' + this.name + '.start(), when current state is: ' + this.status.state);
                        }
                    }
                    return (retVal);
                }
                else {

                }
            }

            this.proxy.CloseServiceHandle(handle);
            throw ('could not find service: ' + name);
        }
    }
    else
    {
        this.isAdmin = function isAdmin() 
        {
            return (require('user-sessions').isRoot());
        }
    }
    this.installService = function installService(options)
    {
        if (process.platform == 'win32')
        {
            if (!this.isAdmin()) { throw ('Installing as Service, requires admin'); }

            // Before we start, we need to copy the binary to the right place
            var folder = this.getServiceFolder();
            if (!require('fs').existsSync(folder)) { require('fs').mkdirSync(folder); }
            require('fs').copyFileSync(options.servicePath, folder + '\\' + options.name + '.exe');
            options.servicePath = folder + '\\' + options.name + '.exe';

            var servicePath = this.GM.CreateVariable('"' + options.servicePath + '"');
            var handle = this.proxy.OpenSCManagerA(0x00, 0x00, 0x0002);
            if (handle.Val == 0) { throw ('error opening SCManager'); }
            var serviceName = this.GM.CreateVariable(options.name);
            var displayName = this.GM.CreateVariable(options.name);
            var allAccess = 0x000F01FF;
            var serviceType;
            

            switch (options.startType) {
                case 'BOOT_START':
                    serviceType = 0x00;
                    break;
                case 'SYSTEM_START':
                    serviceType = 0x01;
                    break;
                case 'AUTO_START':
                    serviceType = 0x02;
                    break;
                case 'DEMAND_START':
                    serviceType = 0x03;
                    break;
                default:
                    serviceType = 0x04; // Disabled
                    break;
            }

            var h = this.proxy.CreateServiceA(handle, serviceName, displayName, allAccess, 0x10 | 0x100, serviceType, 0, servicePath, 0, 0, 0, 0, 0);
            if (h.Val == 0) { this.proxy.CloseServiceHandle(handle); throw ('Error Creating Service: ' + this.proxy2.GetLastError().Val); }
            if (options.description) {
                console.log(options.description);

                var dscPtr = this.GM.CreatePointer();
                dscPtr.Val = this.GM.CreateVariable(options.description);

                if (this.proxy.ChangeServiceConfig2A(h, 1, dscPtr) == 0) {
                    this.proxy.CloseServiceHandle(h);
                    this.proxy.CloseServiceHandle(handle);
                    throw ('Unable to set description');
                }
            }
            this.proxy.CloseServiceHandle(h);
            this.proxy.CloseServiceHandle(handle);
            return (this.getService(options.name));
        }
        if(process.platform == 'linux')
        {
            if (!this.isAdmin()) { throw ('Installing as Service, requires root'); }

            switch (this.getServiceType())
            {
                case 'init':
                    require('fs').copyFileSync(options.servicePath, '/etc/init.d/' + options.name);
                    console.log('copying ' + options.servicePath);
                    var m = require('fs').statSync('/etc/init.d/' + options.name).mode;
                    m |= (require('fs').CHMOD_MODES.S_IXUSR | require('fs').CHMOD_MODES.S_IXGRP);
                    require('fs').chmodSync('/etc/init.d/' + options.name, m);
                    this._update = require('child_process').execFile('/bin/sh', ['sh'], { type: require('child_process').SpawnTypes.TERM });
                    this._update._moduleName = options.name;
                    this._update.on('exit', function onUpdateRC_d() { console.log(this._moduleName + ' installed'); process.exit(); });
                    this._update.stdout.on('data', function (chunk) { });
                    this._update.stdin.write('update-rc.d ' + options.name + ' defaults\n');
                    this._update.stdin.write('exit\n');
                    //update-rc.d meshagent defaults # creates symlinks for rc.d
                    //service meshagent start

                    break;
                case 'systemd':
                    var serviceDescription = options.description ? options.description : 'MeshCentral Agent';
                    if (!require('fs').existsSync('/usr/local/mesh')) { require('fs').mkdirSync('/usr/local/mesh'); }
                    require('fs').copyFileSync(options.servicePath, '/usr/local/mesh/' + options.name);
                    var m = require('fs').statSync('/usr/local/mesh/' + options.name).mode;
                    m |= (require('fs').CHMOD_MODES.S_IXUSR | require('fs').CHMOD_MODES.S_IXGRP);
                    require('fs').chmodSync('/usr/local/mesh/' + options.name, m);
                    require('fs').writeFileSync('/lib/systemd/system/' + options.name + '.service', '[Unit]\nDescription=' + serviceDescription + '\n[Service]\nExecStart=/usr/local/mesh/' + options.name + '\nStandardOutput=null\nRestart=always\nRestartSec=3\n[Install]\nWantedBy=multi-user.target\nAlias=' + options.name + '.service\n', { flags: 'w' });
                    this._update = require('child_process').execFile('/bin/sh', ['sh'], { type: require('child_process').SpawnTypes.TERM });
                    this._update._moduleName = options.name;
                    this._update.on('exit', function onUpdateRC_d() { console.log(this._moduleName + ' installed'); process.exit(); });
                    this._update.stdout.on('data', function (chunk) { });
                    this._update.stdin.write('systemctl enable ' + options.name + '.service\n');
                    this._update.stdin.write('exit\n');

                    break;
                default: // unknown platform service type
                    break;
            }
        }
        if(process.platform == 'darwin')
        {
            if (!this.isAdmin()) { throw ('Installing as Service, requires root'); }

            // Mac OS
            var stdoutpath = (options.stdout ? ('<key>StandardOutPath</key>\n<string>' + options.stdout + '</string>') : '');
            var autoStart = (options.startType == 'AUTO_START' ? '<true/>' : '<false/>');
            var params =  '     <key>ProgramArguments</key>\n';
            params += '     <array>\n';
            params += ('         <string>/usr/local/mesh_services/' + options.name + '/' + options.name + '</string>\n');
            if(options.parameters)
            {
                for(var itm in options.parameters)
                {
                    params += ('         <string>' + options.parameters[itm] + '</string>\n');
                }
            }        
            params += '     </array>\n';
            
            var plist = '<?xml version="1.0" encoding="UTF-8"?>\n';
            plist += '<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">\n';
            plist += '<plist version="1.0">\n';
            plist += '  <dict>\n';
            plist += '      <key>Label</key>\n';
            plist += ('     <string>' + options.name + '</string>\n');
            plist += (params + '\n');
            plist += '      <key>WorkingDirectory</key>\n';
            plist += ('     <string>/usr/local/mesh_services/' + options.name + '</string>\n');
            plist += (stdoutpath + '\n');
            plist += '      <key>RunAtLoad</key>\n';
            plist += (autoStart + '\n');
            plist += '  </dict>\n';
            plist += '</plist>';

            if (!require('fs').existsSync('/usr/local/mesh_services')) { require('fs').mkdirSync('/usr/local/mesh_services'); }
            if (!require('fs').existsSync('/Library/LaunchDaemons/' + options.name + '.plist'))
            {
                if (!require('fs').existsSync('/usr/local/mesh_services/' + options.name)) { require('fs').mkdirSync('/usr/local/mesh_services/' + options.name); }
                if (options.binary)
                {
                    require('fs').writeFileSync('/usr/local/mesh_services/' + options.name + '/' + options.name, options.binary);
                }
                else
                {
                    require('fs').copyFileSync(options.servicePath, '/usr/local/mesh_services/' + options.name + '/' + options.name);
                }
                require('fs').writeFileSync('/Library/LaunchDaemons/' + options.name + '.plist', plist);
                var m = require('fs').statSync('/usr/local/mesh_services/' + options.name + '/' + options.name).mode;
                m |= (require('fs').CHMOD_MODES.S_IXUSR | require('fs').CHMOD_MODES.S_IXGRP);
                require('fs').chmodSync('/usr/local/mesh_services/' + options.name + '/' + options.name, m);
            }
            else
            {
                throw ('Service: ' + options.name + ' already exists');
            }
        }
    }
    this.uninstallService = function uninstallService(name)
    {
        if (!this.isAdmin()) { throw ('Uninstalling a service, requires admin'); }

        if (typeof (name) == 'object') { name = name.name; }
        if (process.platform == 'win32')
        {
            var service = this.getService(name);
            if (service.status.state == undefined || service.status.state == 'STOPPED')
            {
                if (this.proxy.DeleteService(service._service) == 0)
                {
                    throw ('Uninstall Service for: ' + name + ', failed with error: ' + this.proxy2.GetLastError());
                }
                else
                {
                    try
                    {
                        require('fs').unlinkSync(this.getServiceFolder() + '\\' + name + '.exe');
                    }
                    catch(e)
                    {
                    }
                }
            }
            else
            {
                throw ('Cannot uninstall service: ' + name + ', because it is: ' + service.status.state);
            }
        }
        else if(process.platform == 'linux')
        {
            switch (this.getServiceType())
            {
                case 'init':
                    this._update = require('child_process').execFile('/bin/sh', ['sh'], { type: require('child_process').SpawnTypes.TERM });
                    this._update._svcname = name;
                    this._update.on('exit', function onUninstallExit() {
                        try {
                            require('fs').unlinkSync('/etc/init.d/' + this._svcname);
                            console.log(this._svcname + ' uninstalled');

                        }
                        catch (e) {
                            console.log(this._svcname + ' could not be uninstalled')
                        }
                        process.exit();
                    });
                    this._update.stdout.on('data', function (chunk) { });
                    this._update.stdin.write('service ' + name + ' stop\n');
                    this._update.stdin.write('update-rc.d -f ' + name + ' remove\n');
                    this._update.stdin.write('exit\n');
                    break;
                case 'systemd':
                    this._update = require('child_process').execFile('/bin/sh', ['sh'], { type: require('child_process').SpawnTypes.TERM });
                    this._update._svcname = name;
                    this._update.on('exit', function onUninstallExit() {
                        try {
                            require('fs').unlinkSync('/usr/local/mesh/' + this._svcname);
                            require('fs').unlinkSync('/lib/systemd/system/' + this._svcname + '.service');
                            console.log(this._svcname + ' uninstalled');
                        }
                        catch (e) {
                            console.log(this._svcname + ' could not be uninstalled')
                        }
                        process.exit();
                    });
                    this._update.stdout.on('data', function (chunk) { });
                    this._update.stdin.write('systemctl stop ' + name + '.service\n');
                    this._update.stdin.write('systemctl disable ' + name + '.service\n');
                    this._update.stdin.write('exit\n');
                    break;
                default: // unknown platform service type
                    break;
            }
        }
        else if(process.platform == 'darwin')
        {
            if (require('fs').existsSync('/Library/LaunchDaemons/' + name + '.plist'))
            {
                var child = require('child_process').execFile('/bin/sh', ['sh']);
                child.stdout.on('data', function (chunk) { });
                child.stdin.write('launchctl stop ' + name + '\n');
                child.stdin.write('launchctl unload /Library/LaunchDaemons/' + name + '.plist\n');
                child.stdin.write('exit\n');
                child.waitExit();

                try
                {
                    require('fs').unlinkSync('/usr/local/mesh_services/' + name + '/' + name);
                    require('fs').unlinkSync('/Library/LaunchDaemons/' + name + '.plist');
                }
                catch(e)
                {
                    throw ('Error uninstalling service: ' + name + ' => ' + e);
                }

                try
                {
                    require('fs').rmdirSync('/usr/local/mesh_services/' + name);
                }
                catch(e)
                {}
            }
            else
            {
                throw ('Service: ' + name + ' does not exist');
            }
        }
    }
    if(process.platform == 'linux')
    {
        this.getServiceType = function getServiceType()
        {
            return (require('process-manager').getProcessInfo(1).Name);
        };
    }
}

module.exports = serviceManager;