<?php

namespace App\Classes;

use Illuminate\Support\Facades\Log;
use Illuminate\Database\Eloquent\ModelNotFoundException;

use Sock\{SocketClient,SocketException};

use App\User;
use App\Classes\Frame as FrameClass;
use App\Models\Frame as FrameModel;
use App\Models\Mode;

abstract class Server {
	private $mo = NULL;     // Our Mode object
	private $co = NULL;
	protected $blp = 0;     // Size of Bottom Line Pollution
	protected $baseline = ''; // Whats on the baseline currently
	protected $pid = NULL;  // Client PID

	public function __construct(Mode $o)
	{
		$this->mo = $o;

		define('MODE_BL',           1); // Typing a * command on the baseline
		define('MODE_FIELD',        2);	// typing into an input field
		define('MODE_WARPTO',       3);	// awaiting selection of a timewarp
		define('MODE_COMPLETE',     4);	// Entry of data is complete ..
		define('MODE_SUBMITRF',     5);	// asking if should send or not.
		define('MODE_RFSENT',       6);
		define('MODE_RFERROR',      7);
		define('MODE_RFNOTSENT',    8);

		define('ACTION_RELOAD',     1);
		define('ACTION_GOTO',       2);
		define('ACTION_BACKUP',     3);
		define('ACTION_NEXT',       4);
		define('ACTION_INFO',       5);
		define('ACTION_TERMINATE',  6);
		define('ACTION_SUBMITRF',   7); // Offer to submit a response frame
		define('ACTION_STAR',       8);

		define('CONTROL_TELNET',    1); // Telnet session control
		define('CONTROL_METHOD',    2); // Send input to an external method

		// Keyboard presses
		define('KEY_DELETE',    chr(8));
		define('KEY_LEFT',      chr(136));
		define('KEY_RIGHT',     chr(137));
		define('KEY_DOWN',      chr(138));
		define('KEY_UP',        chr(139));

		define('TCP_IAC',       chr(255));
		define('TCP_DONT',      chr(254));
		define('TCP_DO',        chr(253));
		define('TCP_WONT',      chr(252));
		define('TCP_WILL',      chr(251));
		define('TCP_SB',        chr(250));
		define('TCP_AYT',       chr(246));
		define('TCP_SE',        chr(240));

		define('TCP_BINARY',            chr(0));
		define('TCP_OPT_ECHO',          chr(1));
		define('TCP_OPT_SUP_GOAHEAD',   chr(3));
		define('TCP_OPT_TERMTYPE',      chr(24));
		define('TCP_OPT_WINDOWSIZE',    chr(31));
		define('TCP_OPT_LINEMODE',      chr(34));

		define('MSG_SENDORNOT', GREEN.'KEY 1 TO SEND, 2 NOT TO SEND');
		define('MSG_SENT',      GREEN.'MESSAGE SENT - KEY '.HASH.' TO CONTINUE');
		define('MSG_NOTSENT',   GREEN.'MESSAGE NOT SENT - KEY '.HASH.' TO CONTINUE');

		define('ERR_DATABASE',  RED.'UNAVAILABLE AT PRESENT - PLSE TRY LATER');
		define('ERR_NOTSENT',   WHITE.'MESSAGE NOT SENT DUE TO AN ERROR');
		define('ERR_PRIVATE',   WHITE.'PRIVATE PAGE'.GREEN.'- FOR EXPLANATION *37'.HASH.'..');
		define('ERR_ROUTE',     WHITE.'MISTAKE?'.GREEN.'TRY AGAIN OR TELL US ON *08');
		define('ERR_PAGE',ERR_ROUTE);
		define('ERR_USER_ALREADYMEMBER',    RED.'ALREADY MEMBER OF CUG');

		define('MSG_TIMEWARP_ON',   WHITE.'TIMEWARP ON'.GREEN.'VIEW INFO WITH *02');
		define('MSG_TIMEWARP_OFF',  WHITE.'TIMEWARP OFF'.GREEN.'VIEWING DATE IS FIXED');
		define('MSG_TIMEWARP_TO',   GREEN.'TIMEWARP TO %s');
		define('MSG_TIMEWARP',      WHITE.'OTHER VERSIONS EXIST'.GREEN.'KEY *02 TO VIEW');
	}

	public function client()
	{
		return $this->co;
	}

	public function log(string $mode,string $message,array $data=[])
	{
		Log::$mode(sprintf('%s: %s',$this->pid,$message),$data);
	}

	/**
	 * Connection handler
	 *
	 * @param SocketClient $client
	 * @return bool|void
	 * @throws SocketException
	 */
	function onConnect(SocketClient $client) {
		$pid = pcntl_fork();

		if ($pid == -1)
			throw new SocketException(SocketException::CANT_ACCEPT,'Could not fork process');

		// Parent return ready for next connection
		elseif ($pid)
			return;

		$fo = NULL;
		$this->co = $client;
		$this->pid = getmypid();
		$this->log('info','Connection from: ',['client'=>$client->getAddress(),'server'=>$this->mo->name]);

		// We are now the child.
		try {
			$session = NULL;            // TCP Session Details

			$client->send(TCP_IAC.TCP_DO.TCP_OPT_SUP_GOAHEAD);     // DO SUPPRES GO AHEAD
			$client->send(TCP_IAC.TCP_WONT.TCP_OPT_LINEMODE);      // WONT LINEMODE
			$client->send(TCP_IAC.TCP_DO.TCP_OPT_ECHO);            // DO ECHO
//		    $client->send(TCP_IAC.TCP_AYT); // AYT
			$client->send(TCP_IAC.TCP_DO.TCP_OPT_TERMTYPE.TCP_IAC.TCP_SB.TCP_OPT_TERMTYPE.TCP_OPT_ECHO.TCP_IAC.TCP_SE); // Request Term Type

			$client->send(CLS.COFF);
			$client->send('Press a key...');

			// Setup VARS
			$timewarp = FALSE;          // Is timewarp active.
			$timewarpalt = FALSE;       // Alternative timewarp frame to get
			$history = collect();       // Page history for going backwards
			$action = ACTION_GOTO;      // Initial action.
			$control = FALSE;           // Logic in control
			$mode = FALSE;              // Current mode.
			$save = FALSE;              //
			$cmd = '';                  // Current *command being typed in
			$user = new User;           // The logged in user
			$method = collect();        // Method in control for CONTROL_METHOD

			$current = [];              // Attributes about the current page
			// field/fieldnum indexes are for fields on the active page
			$current['fieldreset'] = FALSE;          // Flag to reset position (used in fields)
			$current['fieldpos'] = 0;                // For current field, position within.
			$current['prevmode'] = FALSE;            // Previous mode - in case we need to go back to MODE_FIELD

			// @todo Get the login/start page, and if it is not available, throw the ERR_DATEBASE error.
			if (isset($config['loginpage'])) {
				$page = ['frame'=>$config['loginpage']];
			} else if (!empty($service['start_page'])) {
				$page = ['frame'=>$service['start_page']];
			} else {
				$page = ['frame'=>'980'];            // next page
			}

			while ($action != ACTION_TERMINATE) {
				// Read a character from the client session
				$read = $client->read(1);
				printf(". Got: %s (%s): Mode: [%s], Action: [%s], Control: [%s]\n",$read,ord($read),$mode,$action,$control);

				// It appears that read will return '' instead of false when a disconnect has occurred.
				// We'll set it to NULL so its caught later
				if ($read === '')
					$read = NULL;

				if ($read != '') {
					if ($read == TCP_IAC) {

						// If we are not already in a TELNET LOOP
						if ($control !== CONTROL_TELNET) {
							$control = CONTROL_TELNET;

							// Remember our Telnet Session Object
							// @todo We might need to clear out the old mode/action states
							if (! $session) {
								$session = Control::factory('telnet',$this);
							}

							$method->push($session);
						}
					}

					if ($control AND $method->count()) {
						printf("= Control going to method: %s\n", get_class($method->last()));

						// Capture our state when we enter this method.
						if (! array_key_exists('control',$method->last()->state)) {
							$method->last()->state['control'] = $control;
							$method->last()->state['action'] = $action;
						}

						$method->last()->state['mode'] = $mode;
						$action = FALSE;

						// Pass Control to Method
						$read = $method->last()->handle($read,$current);
						$mode = $method->last()->state['mode'];

						if ($method->last()->complete()) {
							printf("- Control complete: %s\n",get_class($method->last()));
							$save = $method->pop();

							if ($method->count()) {
								$control = $method->last()->state['control'];

							} else {
								$mode = $save->state['mode'];
								$action = $save->state['action'];
								$control = FALSE;
							}

							dump(sprintf('End: Control is now: %s: Method Count: %s',is_object($control) ? get_class($control) : serialize($control),$method->count()));
						}
					}

					printf("- End Control: Read %s (%s): Mode: [%s], Action: [%s], Control: [%s]\n",$read,ord($read),$mode,$action,$control);

					switch ($mode) {
						// Key presses during field input.
						case MODE_FIELD:
							$cmd = '';
							$action = FALSE;

							switch ($fo->type()) {
								// Login frame.
								case Frame::FRAMETYPE_LOGIN:
									switch ($read) {
										case HASH:
											// If we are the main login screen, see if it is a new user
											if ($fo->isCUG(0))
											{
												if ($current['field']->type == 't' AND array_get($fielddata,$current['fieldnum']) == 'NEW')
												{
													$action = ACTION_GOTO;
													$page = ['frame'=>'981']; // @todo This should be in the DB.

													break 2;
												}
											}

											break;
									}

								// Response frame.
								case Frame::FRAMETYPE_ACTION:
									switch ($read) {
										// End of field entry.
										case LF:
										case HASH:
											// Next Field
											$current['fieldnum']++;
											$current['fieldpos'] = 0;

											if ($current['fieldnum'] < $fo->fields->count()) {
												$current['fieldnum'] = $fo->getFieldId('edit',$current['fieldnum']);

												if ($current['fieldnum'] !== FALSE) {
													$current['field'] = $fo->getField($current['fieldnum']);

													$client->send($this->outputPosition($current['field']->x,$current['field']->y).CON);
													$mode = MODE_FIELD;

												// There were no (more) editable fields.
												} else {
													$action = ACTION_SUBMITRF;
												}

											} else {
												// Finished all editable fields.
												$action = ACTION_SUBMITRF;
											}

											break;

										case STAR:
											$current['prevmode'] = MODE_FIELD;
											$action = ACTION_STAR;
											$current['fieldpos'] = 0;
											$fielddata[$current['fieldnum']] = '';
											$current['fielddata'][$current['fieldnum']] = '';

											break;

										case KEY_DELETE:
											if ($current['fieldpos'])
											{
												$current['fieldpos']--;
												$client->send(LEFT.$fo::$if_filler.LEFT);
												$fielddata[$current['fieldnum']] = substr($fielddata[$current['fieldnum']],0,-1);
												$current['fielddata'][$current['fieldnum']] = substr($current['fielddata'][$current['fieldnum']],0,-1);
											}

											break;

										case KEY_LEFT:
											if ($current['fieldpos']) {
												$current['fieldpos']--;
												$client->send(LEFT);
											}

											break;

										case KEY_RIGHT:
											if ($current['fieldpos']++ < $current['field']->length)
												$client->send(RIGHT);

											break;

										case KEY_DOWN:
											if ($current['fieldpos'] + 40 < $current['field']->length) {
												$client->send(DOWN);
												$current['fieldpos'] = $current['fieldpos'] + 40;
											};

											break;

										case KEY_UP:
											if ($current['fieldpos'] - 40 >= 0) {
												$client->send($read);
												$current['fieldpos'] = $current['fieldpos'] - 40;
											};

											break;

										case CR:
											// On second or later line of a field
											if ($current['fieldpos'] + $current['field']->x > 40) {
												$client->send($read);
												$current['fieldpos'] = (($current['fieldpos'] + $current['field']->x) % 40) * 40;

											} else {
												$client->send($this->outputPosition($current['field']->x,$current['field']->y).CON);
												$current['fieldpos'] = 0;
											}

											break;

										case ESC:
											break;

										// Record Data Entry
										default:
											if (ord($read) > 31 && $current['fieldpos'] < $current['field']->length) {
												if (! array_key_exists($current['fieldnum'],$current['fielddata'])) {
													$current['fielddata'][$current['fieldnum']] = '';
													$fielddata[$current['fieldnum']] = '';
												}

												$fielddata[$current['fieldnum']]{$current['fieldpos']} = $read; // @todo delete
												$current['fielddata'][$current['fieldnum']]{$current['fieldpos']} = $read;

												$current['fieldpos']++;

												$client->send($fo->isFieldMasked($current['field']->type) ?: $read);
											}
									}

									break;

								// Other Frame Types - Shouldnt get here.
								default:
									$client->close();

									throw new \Exception('Shouldnt get here', 500);
							}

							break;

						// Form submission: 1 to send, 2 not to send.
						case MODE_SUBMITRF:
							switch ($read) {
								// @todo Input received, process it.
								case '1':
									$route = $fo->route(1);

									// If we are in a control method, complete it
									if ($control AND $method->count()) {
										$method->last()->process();

									} elseif ($route == '*' OR is_numeric($route)) {
										$this->sendBaseline($client,RED.'NO ACTION PERFORMED');
										$mode = MODE_RFSENT;

									} elseif ($ao = FrameClass\Action::factory($fo->route(1),$this,$user,$action,$mode)) {
										$ao->handle($fielddata);
										$mode = $ao->mode;
										$action = $ao->action;
										$user = $ao->uo;

										if ($ao->page)
											$page = $ao->page;

									} else {
										$this->sendBaseline($client, RED.'NO method exists...');

										$mode = MODE_RFSENT;
									}

									break;

								case '2':
									$this->sendBaseline($client,MSG_NOTSENT);
									$mode = MODE_RFNOTSENT;

									// If a Control method was rejected, we can clear it
									if ($control AND $method->count()) {
										$save = $method->pop();

										if ($method->count()) {
											$control = $method->last()->state['control'];

										} else {
											$mode = $save->state['mode'];
											$action = $save->state['action'];
											$control = FALSE;
										}
									}

									break;

								case STAR:
									$action = ACTION_STAR;

									break;
							}

							break;

						// Response form after Sent processing
						case MODE_RFSENT:
							$client->send(COFF);

							if ($read == HASH) {
								if ($route = $fo->route(2) AND $route !== '*' AND is_numeric($route)) {
									$page = ['frame'=>$route];

								} elseif (FrameModel::where('frame',$fo->frame())->where('index',$fo->index_next())->exists()) {
									$page = ['frame'=>$fo->frame(),'index'=>$fo->index_next()];

								} elseif ($route = $fo->route(0) AND $route !== '*' AND is_numeric($route)) {
									$page = ['frame'=>$route];

								// No further routes defined, go home.
								} else {
									$page = ['frame'=>0];
								}

								$action = ACTION_GOTO;

							} elseif ($read == STAR) {
								$action = ACTION_STAR;

								break;
							}

							break;

						// Response form after NOT sending
						case MODE_RFNOTSENT:

							// Response form ERROR
						case MODE_RFERROR:
							$client->send(COFF);

							if ($read == HASH) {
								if ($route = $fo->route(2) AND $route !== '*' AND is_numeric($route)) {
									$page = ['frame'=>$route];

								} elseif (FrameModel::where('frame',$fo->frame())->where('index',$fo->index_next())->exists()) {
									$page = ['frame'=>$fo->frame(),'index'=>$fo->index_next()];

								} elseif ($route = $fo->route(0) AND $route !== '*' AND is_numeric($route)) {
									$page = ['frame'=>$route];

								// No further routes defined, go home.
								} else {
									$page = ['frame'=>0];
								}

								$action = ACTION_GOTO;

							} elseif ($read == STAR) {
								$action = ACTION_STAR;

								break;
							}

							break;

						// List of alternate frames has been presented
						case MODE_WARPTO:
							if (is_numeric($read) AND $read) {
								$timewarpalt = $alts->get($read-1)->id;
								$action = ACTION_GOTO;

							} elseif ($read === '0') {
								$action = ACTION_RELOAD;
							}

							break;

						// Not doing anything in particular.
						case MODE_COMPLETE:
						case FALSE:
							$this->log('debug','Idle');
							$cmd = '';

							switch ($read) {
								case HASH:
									$action = ACTION_NEXT;
									break;

								case STAR:
									$action = ACTION_STAR;
									break;

								// Frame Routing
								case '0':
								case '1':
								case '2':
								case '3':
								case '4':
								case '5':
								case '6':
								case '7':
								case '8':
								case '9':
									if (is_numeric($fo->route($read))) {
										$page = ['frame'=>$fo->route($read),'index'=>'a'];

										$action = ACTION_GOTO;

									} else {
										$this->sendBaseline($client,ERR_ROUTE);
										$mode = $action = FALSE;
									}

									break;
							}

							break;

						// Currently accepting baseline input after a * was received
						case MODE_BL:
							echo "- Waiting for Page Number\n";

							// if it's a number, continue entry
							if (strpos('0123456789', $read) !== FALSE) {
								$cmd .= $read;
								$client->send($read);
								$this->blp++;
							}

							// if we hit a special numeric command, deal with it.
							// Refresh page
							if ($cmd === '00') {
								$client->send(COFF);
								$action = ACTION_RELOAD;
								$cmd = '';

								break;
							}

							// Toggle Timewarp Mode
							// @todo in forms, the cursor is in the wrong location for ANSI
							if ($cmd === '01') {
								$client->send(COFF);
								$timewarp = !$timewarp;
								$this->sendBaseline($client, ($timewarp ? MSG_TIMEWARP_ON : MSG_TIMEWARP_OFF));
								$cmd = '';
								$action = $mode = FALSE;

								break;
							}

							// Present Timewarp Frames
							// @todo in forms, the cursor is in the wrong location for ANSI
							if ($cmd === '02') {
								$client->send(COFF);
								$action = ACTION_INFO;
								$cmd = '';

								break;
							}

							// Bookmark page
							if ($cmd === '05') {
								$this->sendBaseline($client, RED.'NOT IMPLEMENTED YET?');
								$mode = FALSE;

								break;
							}

							// Report a problem
							if ($cmd === '08') {
								$this->sendBaseline($client, RED.'NOT IMPLEMENTED YET?');
								$mode = FALSE;

								break;
							}

							// Reload page
							if ($cmd === '09') {
								$client->send(COFF);
								$action = ACTION_GOTO;
								$cmd = '';

								break;
							}

							// Another star aborts the command.
							if ($read === STAR) {
								$action = FALSE;
								$this->sendBaseline($client,array_get($current,'baseline',''));
								$cmd = '';

								if ($current['prevmode'] == MODE_FIELD) {
									$mode = $current['prevmode'];
									$current['prevmode'] = FALSE;

									// @todo The cursor color could be wrong
									$client->send($this->outputPosition($current['field']->x,$current['field']->y).CON);
									$client->send(str_repeat($fo::$if_filler, $current['field']->length));
									$current['fieldreset'] = TRUE;

								} else {
									$mode = FALSE;
								}

								break;
							}

							// Complete request
							if ($read === HASH or $read === LF) {
								$client->send(COFF);
								$timewarpalt = FALSE;

								// Nothing typed between * and #
								// *# means go back
								if ($cmd === '') {
									$action = ACTION_BACKUP;

								} elseif ($cmd === '0') {
									$page = $user->exists ? ['frame'=>1,'index'=>'a'] : ['frame'=>980,'index'=>'a']; // @todo Get from DB.
									$action = ACTION_GOTO;

								} else {
									$page['frame'] = $cmd;
									$page['index'] = 'a';
									$action = ACTION_GOTO;
								}

								// Clear the command, we are finished processing
								$cmd = '';

								break;
							}

							break;

						default:
							$this->log('debug','Not sure what we were doing?');
					}
				}

				printf("- End Mode: Read %s (%s): Mode: [%s], Action: [%s], Control: [%s]\n",$read,ord($read),$mode,$action,$control);

				// This section performs some action if it is deemed necessary
				if ($action) {
					printf("+ Performing action: %s\n",$action);
				}

				switch ($action) {
					case ACTION_STAR:
						echo "+ Star command...\n";

						// If there is something on the baseline, lets preserve it
						if ($this->blp)
							$current['baseline'] = $this->baseline;

						$this->sendBaseline($client,GREEN.STAR,TRUE);
						$client->send(CON);
						$action = FALSE;
						$mode = MODE_BL;

						break;

					case ACTION_SUBMITRF:
						$action = FALSE;
						$client->send(COFF);
						$this->sendBaseline($client,MSG_SENDORNOT);
						$mode = MODE_SUBMITRF;

						break;

					// GO Backwards
					case ACTION_BACKUP:
						// Do we have anywhere to go, drop the current page from the history.
						if ($history->count() > 1)
							$history->pop();

						if ($control AND $method->count()) {
							$save = $method->pop();

							// Do we still have more nested methods to complete
							if ($method->count()) {
								$control = $method->last()->state['control'];

							} else {
								$mode = $save->state['mode'];
								$action = $save->state['action'];
								$control = FALSE;
							}
						}

						$page = $history->last();

						$this->log('debug','Backing up to:',$page);

					// Go to next index frame.
					case ACTION_NEXT:
						// We need this extra test in case we come from ACTION_BACKUP
						if ($action == ACTION_NEXT)
						{
							$current['page']['index'] = $fo->index();
							$page['index'] = $fo->index_next();
						}

					// Look for requested page
					case ACTION_GOTO:
						$current['frame'] = $fo;

						// If we wanted a "Searching..." message, this is where to put it.
						try {
							$fo = $timewarpalt
								? $this->mo->frame(FrameModel::findOrFail($timewarpalt))
								: $this->mo->frameLoad($page['frame'],array_get($page,'index','a'),$this);

							$this->log('debug',sprintf('Fetched frame: %s (%s)',$fo->id(),$fo->page()));

						} catch (ModelNotFoundException $e) {
							$this->sendBaseline($client,ERR_PAGE);
							$mode = $action = FALSE;

							$fo = $current['frame'] ?: $this->mo->frame($this->testFrame());

							break;
						}

						// Is there a user logged in
						if ($user)
						{
							if ($fo->isFramePublic() AND $fo->isAccessible())
							{
								if ($fo->type() == Frame::FRAMETYPE_LOGIN AND $user->isMemberCUG($fo->getCUG()))
								{
									$this->sendBaseline($client,ERR_USER_ALREADYMEMBER);
									$fo = $current['frame'];
									$page = $history->last();
									$mode = $action = FALSE;
									$this->log('debug',sprintf('Frame Denied - Already Member: %s (%s)',$fo->id(),$fo->page()));

									break;
								}

							// If this is a login frame and the user is already a member.
							} else {

								if (! $fo->isOwner($user))
								{
									if (! $fo->isAccessible())
									{
										$this->sendBaseline($client,ERR_PAGE);
										$fo = $current['frame'];
										$page = $history->last();
										$mode = $action = FALSE;
										$this->log('debug',sprintf('Frame Denied - In Accessible: %s (%s)',$fo->id(),$fo->page()));

										break;
									}

									if (! $user->isMemberCUG($fo->getCUG()))
									{
										$this->sendBaseline($client, ERR_PRIVATE);
										$fo = $current['frame'];
										$page = $history->last();
										$mode = $action = FALSE;
										$this->log('debug',sprintf('Frame Denied - Not in CUG [%s]: %s (%s)',$fo->getCUG()->id,$fo->id(),$fo->page()));

										break;
									}
								}
							}

						} else {
							// Is this a public frame in CUG 0?
							if (! $fo->isCUG(0) OR ! $fo->isFramePublic())
							{
								$this->sendBaseline($client,ERR_PAGE);
								$mode = $action = FALSE;

								break;
							}
						}

						$current['page'] = $fo->page(TRUE);
						$current['fieldpos'] = 0;

						// Only if new location, not going backwards
						if (($history->last() != $page) AND ($action == ACTION_GOTO || $action == ACTION_NEXT)) {
							$history->push($page);
						}

						printf("+ Mode is: %s\n",$mode);

					// drop into
					case ACTION_RELOAD:
						$this->sendBaseline($client,'');
						$output = (string)$fo;

						if ($timewarpalt) {
							$this->sendBaseline($client,sprintf(MSG_TIMEWARP_TO,$fo->created() ? $fo->created()->format('Y-m-d H:i:s') : 'UNKNOWN'));
						}

						switch ($fo->type()) {
							default:
							// Standard Frame
							case Frame::FRAMETYPE_INFO:
								$client->send($output);
								$mode = $action = FALSE;

								break;

							// Login Frame.
							case Frame::FRAMETYPE_LOGIN:
								$client->send($output);
								$action = FALSE;
								$output = '';

								// If this is the registration page
								// @todo Should be evaluated out of the DB
								if ($fo->page() == '981a') {
									$control = CONTROL_METHOD;
									$method->push(Control::factory('register',$this));
									$method->last()->state['control'] = $control;
									$method->last()->state['action'] = FALSE;
									$method->last()->state['mode'] = MODE_FIELD;
								}

							// Active Frame. Prestel uses this for a Response Frame.
							case Frame::FRAMETYPE_ACTION:
								$client->send($output);
								// holds data entered by user.
								$fielddata = [];
								$current['fielddata'] = [];

								if (count($fo->fields)) {
									// Get our first editable field.
									$current['fieldnum'] = $fo->getFieldId('edit',0);
									$current['field'] = $fo->getField($current['fieldnum']);
									$current['fieldreset'] = TRUE;

									if ($current['fieldnum'] !== FALSE) {
										$mode = MODE_FIELD;

										// There were no editable fields.
									} else {
										$mode = MODE_COMPLETE;
										$client->send(COFF);
									}

									$current['fieldpos'] = 0;

								} else {
									$mode = FALSE;
								}

								break;

							// Terminate Frame
							case Frame::FRAMETYPE_TERMINATE:
								$client->send($output);
								$action = ACTION_TERMINATE;

								break;
						}

						break;

					// Timewarp Mode
					case ACTION_INFO:
						$mode = $action = FALSE;
						$cmd = '';
						$y = 0;

						$output = $this->outputPosition(0, $y++) . WHITE . NEWBG . RED . 'TIMEWARP INFO FOR Pg.' . BLUE . $fo->page(). WHITE;
						//$output .= $this->outputPosition(0, $y++) . WHITE . NEWBG . BLUE . 'Service : ' . substr($service['service_name'] . str_repeat(' ', 27), 0, 27);
						//$output .= $this->outputPosition(0, $y++) . WHITE . NEWBG . BLUE . 'Varient : ' . substr($varient['varient_name'] . str_repeat(' ', 27), 0, 27);
						$output .= $this->outputPosition(0, $y++) . WHITE . NEWBG . BLUE . 'Dated   : ' .substr(($fo->created() ? $fo->created()->format('j F Y') : 'Unknown').str_repeat(' ', 27), 0, 27);

						$alts = $fo->alts($this->mo)->get();

						if (count($alts)) {
							$n = 1;

							$output .= $this->outputPosition(0, $y++) . WHITE . NEWBG . RED . 'ALTERNATIVE VERSIONS:' . str_repeat(' ', 16);

							foreach ($alts as $o) {
								$date = $o->created_at->format('d M Y');

								$line = WHITE.NEWBG;

								if ($timewarp) {
									$line .= RED.$n++;
								}

								$line .= BLUE.$date.' '.$o->note;

								$output .= $this->outputPosition(0,$y++).$line.str_repeat(' ',40-$this->strlenv($line)); // @todo should use frame::page_length
							}

							if ($timewarp) {
								$mode = MODE_WARPTO;
							}

						}

						$client->send($output);

						break;
				}

				printf("- End Action: Read %s (%s): Mode: [%s], Action: [%s], Control: [%s]\n",$read,ord($read),$mode,$action,$control);

				// We need to reposition the cursor to the current field.
				if ($current['fieldreset'] !== FALSE) {
					$client->send($this->outputPosition($current['field']->x,$current['field']->y).CON);
					$current['fieldreset'] = FALSE;
				}

				// Did the client disconnect
				if ($read === NULL || socket_last_error()) {
					$client->close();
					$this->log('debug',sprintf('Client Disconnected: %s',$client->getaddress()));

					return;
				}
			}

			// Something bad happened. We'll log it and then disconnect.
		} catch (\Exception $e) {
			Log::emergency($e->getMessage(),['line'=>$e->getLine(),'file'=>$e->getFile()]);
		}

		$client->close();
		$this->log('debug',sprintf('Disconnected: %s',$client->getaddress()));
	}

	/**
	 * Move the cursor via the shortest path.
	 */
	abstract function outputPosition($x,$y);

	/**
	 * Send a message to the base line
	 *
	 * @note "$this->blp" remembers how many chars are there, so that they can be replace with next call
	 * @param $client
	 * @param $text
	 * @param bool $reposition
	 */
	abstract function sendBaseline($client,$text,$reposition=FALSE);

	/**
	 * Calculate the length of text
	 *
	 * ESC characters are two chars, and need to be counted as one.
	 *
	 * @param $text
	 * @return int
	 */
	abstract function strlenv($text):int;

	/**
	 * Return a test frame appropriate for this server.
	 * @return mixed
	 */
	abstract public function testFrame();
}