class Deploy {
   constructor(S3, SSH, FS) {
      this.s3 = S3;
      this.SSH = SSH;
      this.fs = FS;
      this.msgString = null;
      this.zip_extract_path = '/home/golfmds/deploy/thriv-golfnow';
      this.deploy_base_path = '/home/golfmds/thriv-golfnow';
      this.deploy_base_path_suffix = '/view-applet_golfnow';
      this.envs = {
         golfnow: {
            environment: 'golfnow',
            hosts: ['ip-10-42-52-50.ec2.internal'],
            symlink: '/home/golfmds/golfnow/golfmds/templates/view-applet_golfnow',
            user: 'ec2-user'
         },
         dev: {
            environment: 'dev',
            hosts: ['ip-10-42-52-50.ec2.internal'],
            symlink: '/home/golfmds/ga/templates/view-applet_golfnow',
            user: 'ec2-user'
         },
         qa: {
            environment: 'qa',
            hosts: ['ip-10-42-52-50.ec2.internal'],
            symlink: '/home/golfmds/qa/golfmds/templates/view-applet_golfnow',
            user: 'ec2-user'
         },
         // stage: {
         //    environment: 'stage',
         //    hosts: ['ip-10-44-63-82.ec2.internal', 'ip-10-44-59-35.ec2.internal'],
         //    symlink: '/home/golfmds/ga/templates/view-applet_golfnow'
         // }
      };
      this.deploy_package = null;
      this.pkey = this.fs.readFileSync("keys/thriv-dev.pem");
      this.snsMsgObject = null;
      this.srcBucket = null;
      this.srcKey = null;
      this.srcEnvPrefix = null;
      this.srcFileName = null;
      this.connectionConfig = {
         host: null,
         user: null,
         key: this.pkey
      };
      this.ssh_connection = null;
   }

   startDeploymentProcess(event, callback) {
      console.log(event);
      this.msgString = JSON.stringify(event.Records[0].Sns.Message);
      this.callback = callback;
      this.processSNSEvent
         .then(this.getDeployPackage(result))
         .then(this.setConnectionConfig(result))
         .then(this.establishSshConnection(result))
         .then(this.deployPackageToEc2(result))
      ;
   }

   processSNSEvent = new Promise(function (resolve, reject) {
      this.snsMsgObject = this.extractSNSMessageObject(this.msgString);
      this.srcBucket = this.snsMsgObject.Records[0].s3.bucket.name;
      this.srcKey = this.snsMsgObject.Records[0].s3.object.key;
      this.srcEnvPrefix = this.srcKey.substring(0, this.srcKey.indexOf("/"));
      this.srcFileName = this.srcKey.substring(this.srcKey.indexOf('/') + 1, this.srcKey.length);
      console.log('SRC Bucket: ' + this.srcBucket);
      console.log('SRC Key: ' + this.srcKey);
      console.log('SRC Prefix: ' + this.srcEnvPrefix);
      resolve('SNS event processed');
   });

   extractSNSMessageObject(msgString) {
      var x = msgString.replace(/\\/g, '');
      var y = x.substring(1, x.length - 1);
      var z = JSON.parse(y);

      return z;
   }

   getDeployPackage() {
      console.log("grabbing deployment package from s3");
      let params = {
         Bucket: this.srcBucket,
         Key: this.srcKey
      };
      this.s3.getObject(params, function (err, data) {
         if (err) {
            console.log(err, err.stack);
            let message = `Error getting object ${params.Key} from bucket ${params.Bucket}. Make sure they exist and your bucket is in the same region as this function.`;
            console.log(message);
            this.callback(message);
         } else {
            this.deploy_package = data;
            let message = 'got deployment package';
            console.log(message);
            return (message);
         }
      });
   }

   setConnectionConfig() {
      if (this.srcEnvPrefix && this.srcEnvPrefix !== null && this.srcEnvPrefix !== '') {
         this.connectionConfig.host = this.envs[this.srcEnvPrefix].hosts[0];
         this.connectionConfig.user = this.envs[this.srcEnvPrefix].user;
         let message = 'Connection configuration set.';
         console.log(message);
         return message;
      } else {
         let message = 'Error: missing environment prefix.';
         console.log(message);
         return message;
      }
   }

   establishSshConnection() {
      this.ssh_connection = new this.SSH(this.connectionConfig);
      let m = 'ssh connection established';
      console.log(m);
      return m;
   }

   deployPackageToEc2() {
      let fullzipfilepath = `${this.zip_extract_path}/${this.srcEnvPrefix}/${this.srcFileName}`;
      let fulldeploypath = `${this.zip_extract_path}/${this.srcEnvPrefix}/  ${this.deploy_base_path}/${this.srcEnvPrefix}/${this.deploy_base_path_suffix}`;
      /* -- execute SSH command -- */
      this.ssh_connection.exec('sudo su - golfmds')
         .exec(`mkdir -p ${fulldeploypath}`, {
            out: function (stdout) {
               console.log('mkdir for deploy env');
               console.log(stdout);
            }
         })
         .exec(`mkdir -p ${this.zip_extract_path}/${this.srcEnvPrefix}`, {
            out: function (stdout) {
               console.log('mkdir for zip extract env');
               console.log(stdout);
            }
         })
         .exec(`cd ${this.zip_extract_path}/${this.srcEnvPrefix}`)
         .exec('ls -al', {
            out: function (stdout) {
               console.log('change directory to zip extract path');
               console.log(stdout);
            }
         })
         .exec(`cat > ${fullzipfilepath}`, {
            in: this.fs.readFileStream(this.deploy_package.Body)
         })
         .exec('ls -al', {
            out: function (stdout) {
               console.log('push zip file to deploy zip extract location ');
               console.log(stdout);
            }
         })
         .exec(`unzip -o ${fullzipfilepath}`)
         .exec('ls -al', {
            out: function (stdout) {
               console.log('extract zip, overwriting all files');
               console.log(stdout);
            }
         })
         .exec(`rsync -r --delete-before ${this.zip_extract_path}/${this.srcEnvPrefix}/  ${fulldeploypath}`)
         .exec('ls -al', {
            out: function (stdout) {
               console.log('rsync files over from extraction location to running location');
               console.log(stdout);
            }
         })
         .exec(`ln -sfn ${fulldeploypath}  ${this.envs[this.srcEnvPrefix].symlink}`)
         .exec('ls -al', {
            out: function (stdout) {
               console.log('setup symlink');
               console.log(stdout);
            },
            exit: function (code, stdout, stderr) {
               console.log('operation exited with code: ' + code);
               console.log('STDOUT from EC2:\n' + stdout);
               console.log('STDERR from EC2:\n' + stderr);
               context.succeed('Success!');
            }
         }).start();

   }
}

module.exports = Deploy;