<?php
function main_code($unique_id,$event,$nr_args,$args)
{
	$event=$args[0];
	if($unique_id==0&&$event!=1&&$event!=2)
	{
		send_data_to_player($unique_id,[2,0]);//force log in
	}else{
	
	if($event==1)
			{
				//REGISTER ACCOUNT  
				//INPUT:arg1-username  arg2-password
				//OUTPUT:arg1- state  arg2 -unique id
				if(isset($args[1])&&isset($args[2]))
				{
					$username=$args[1];
					$password=$args[2];
					if(check_string($username) and check_string($password) and !(is_numeric($password)) and !(is_numeric($username)))
					{
						if(file_exists("accounts/".$username.".txt"))
						{
							send_data_to_player($unique_id,[1,0]);//the account already exists
						}else{
							$last_unique_id=read_file("server_vars/player.txt") + 1;
							write_file("server_vars/player.txt",$last_unique_id);
							
							write_file("username_id/".$username.".txt",$last_unique_id);
							write_file("accounts/".$username.".txt",$password);
							
							make_dir('players/'.$last_unique_id.'/');//create the id directory
							init_player($last_unique_id,$username);
							
							send_data_to_player($unique_id,[1,1,$last_unique_id]);//succesfull created account
						}
					}else{
						send_data_to_player($unique_id,[1,4]);//invalid characters used
					}
				}
			}
		else if($event==2)
			{
			//LOG IN
			//INPUT:arg1-username  arg2-password
			//OUTPUT:arg1- state  arg2 -unique id arg3- local id
				if(isset($args[1])&&isset($args[2]))
				{
					$username=$args[1];
					$password=$args[2];
					if(check_string($username) and check_string($password) and !(is_numeric($password)) and !(is_numeric($username)))
					{
						if(file_exists("accounts/".$username.".txt"))
						{
							$real_password=read_file("accounts/".$username.".txt");
							if($real_password==$password)
							{
								$local_id_slot=find_local_id(0);
								if($local_id_slot!=0)
								{
									if(file_exists("ip_login/".get_player_ip().".txt"))
									{
										$unique_id_real = get_unique_id_by_username($username);
										send_data_to_player($unique_id,[2,2,$unique_id_real,get_local_id_by_ip()]);//succesfull log in	
										send_initial_players($unique_id_real);
									}else{
										$unique_id_real =get_unique_id_by_username($username);
										write_file("ip_login/".get_player_ip().".txt",$local_id_slot);
										write_file("local_id/".$local_id_slot.".txt",$unique_id_real);
										write_file("players/".$unique_id_real."/active.txt",1);
										write_file("players/".$unique_id_real."/last_time_active.txt",time());
										write_file("players/".$unique_id_real."/ip.txt",get_player_ip());
										write_file("players/".$unique_id_real."/local_id.txt",$local_id_slot);
										write_file("players/".$unique_id_real."/ping.txt",0);
										write_file("players/".$unique_id_real."/ping_var.txt",0);
										send_data_to_player($unique_id,[2,2,$unique_id_real,$local_id_slot]);//succesfull log in	
										send_initial_players($unique_id);
										
										ti_on_player_connect($unique_id_real);
										
										}
								}else{
									send_data_to_player($unique_id,[2,3]);//the server is full	
								}
							}else{
								send_data_to_player($unique_id,[2,1]);//invalid user or pass
							}
						}else{
							send_data_to_player($unique_id,[2,1]);//invalid user or pass
						}
					}else{
						send_data_to_player($unique_id,[2,4]);//invalid characters used
					}
				}
			}
		else if($event==3)
			{
				//CHAT
				//Input arg1 - message
				if(isset($args[1]))
				{
					$message = $args[1];
					if($message=='')
					{
					}else{
						if(is_numeric($message))
						{
							$message = $message.' ';
						}
						$username=get_player_username($unique_id);
						for($i=1;$i<=10;$i++)
						{
							$u_id = get_unique_id_by_local($i);
							if($u_id!=0)
							{
								send_data_to_player($u_id,[3,$message,$username],2);
							}
						}
					}
					
				}
			}
		else if($event==4)
			{
				//SAVE PLAYER POSITION
				//Input: arg1-x arg2-y arg3-rotation
				//output:none
				if(isset($args[1]) and isset($args[2]) and isset($args[3]))
				{
					$x=$args[1];
					$y=$args[2];
					$rot=$args[3];
					global $allow_teleport;
					
					if($allow_teleport)
					{
						set_position($unique_id,$x,$y,$rot);	
					}else{
						$position=get_position($unique_id);
						$old_x=$position[0];
						$old_y=$position[1];
						$old_rot=$position[2];
						$distance=sqrt( pow($old_x - $x , 2)  +  pow($old_y - $y , 2) );
						if($distance < 1000)
							{
								set_position($unique_id,$x,$y,$rot);
							}
						else
							{
								$to_send[0]=5;
								$to_send[1]=$old_x;
								$to_send[2]=$old_y;
								$to_send[3]=$old_rot;
								
								send_data_to_player($unique_id,$to_send);
								// send_data_to_player($unique_id,[15," ".$distance,0xFF0000],1);
							}
					}
				}
			}
		else if($event==6)
		{
				//SEND PLAYERS POSITION
				//Input:none
				//Output:arg1 - number of players  arg2 - local player id arg3 - x arg4- y arg5 - rot arg6 -local player id ....
				$number_of_players=0;
				$to_send[0]=6;
				$c=2;
				for($i=1;$i<=10;$i++)
				{
					$u_id=get_unique_id_by_local($i);
					if($u_id!=0 and $u_id!=$unique_id)
					{
						$number_of_players++;
						$to_send[$c]=$i;
						$c++;
						
						$position=get_position($u_id);
						$x=$position[0];
						$y=$position[1];
						$rot=$position[2];
						
						$to_send[$c]=$x;
						$c++;
						$to_send[$c]=$y;
						$c++;
						$to_send[$c]=$rot;
						$c++;
					}
				}
				$c--;
				$to_send[1]=$number_of_players;
				
				send_data_to_player($unique_id,$to_send);
		}
		else if($event==9)
			{
				//PING
				if(isset($args[1]))
				{
					if($args[1]==0)
					{
						write_file("players/".$unique_id."/ping_var.txt",round(microtime_float(), 2));
						send_data_to_player($unique_id,[9,1]);
					}else{
						$time=read_file("players/".$unique_id."/ping_var.txt");
						$ping=round(round(round(microtime_float(), 2) - round($time,2),2)*100);
						write_file("players/".$unique_id."/ping.txt",$ping);
						write_file("players/".$unique_id."/ping_var.txt",0);
						
						$c=2;
						$data[0]=9;
						$data[1]=0;
						for($i=1;$i<=10;$i++)
						{
							$u_id=get_unique_id_by_local($i);
							if($u_id!=0)
							{
								$data[$c]=read_file("players/".$u_id."/ping.txt");
								$c++;
							}else{
								$data[$c]=0;
								$c++;
							}
						}
						
						send_data_to_player($unique_id,$data);
					}
				}
			}
		else if($event==10)
			{
				//SEND PLAYER INVENTORY
				$inv=read_file("players/".$unique_id."/inventory.txt");
				$inv=explode("|",$inv);
				$inv[0]=10;
				send_data_to_player($unique_id,$inv);
			}
		else if($event==11)
			{
				//SEND PLAYER GOLD
				send_data_to_player($unique_id,[11,get_gold($unique_id)]);
			}
		else if($event==14)
			{
				//SEND PLAYER TROOPS
				$troops=read_file("players/".$unique_id."/troops.txt");
				$troops=explode("|",$troops);
				$nr=0;
				foreach ($a as $troops) 
				{
					if($a!=-1)
						$nr++;
				}
				$troops[0]=14;
				$troops[1]=$nr+2;//incrementing here, so we will not have to increment in the game
				send_data_to_player($unique_id,$troops);
			}
		}
	}

?>

I want to use username without password. Rework the code so that you can successfully log in using username only