use warnings;
use strict;
use Scalar::Util 'looks_like_number';
print "Welcome to an interactive Perl program. Enter either q or Q to terminate the program or c to continue. Enter your key now: "; #prompts the user to enter either q Q or c
my $input; #declares the variable input
$input = <STDIN>; #the user input will be stored in the variable called input
chomp $input; #the value in the variable called input will be chomped
while (($input ne "q") && ($input ne "Q") && ($input ne "c")) #this conditional is for checking if the user inputted anything other than q Q or c
{
	print "Welcome to an interactive Perl program. Enter either q or Q to terminate the program or c to continue. Enter your key now: "; #if the user inputted anything other than q Q or c then they will be prompted again
	$input = <STDIN>; #the new user input will be stored in the variable called input
	chomp $input; #the new value in the variable called input will be chomped
}
if (($input eq "q") || ($input eq "Q")) #this conditional is for checking if the user inputed either q or Q
{
	exit; #if they inputted either q or Q then the program will stop running
}
else
{
	my %patientinfo = do {
	open my $patientinfo, '<', 'Patient_Info.txt';
	map {
	my ($first, $second, @info) = split;
	"$first $second" => \@info;
	} <$patientinfo>;
	}; #this is for creating the hash that stores the info inside the text file
	my @patientinfo = <%patientinfo>; #I also store the info from the hash inside an array
	print "Would you like to change the information? (y/n): "; #prompts the user
	my $inp; #declares variable
	$inp = <STDIN>; #takes the users input
	chomp $inp; #chomps the users input
	while (($inp ne "y") && ($inp ne "n")) #conditional loop to check and see if the users input doesn't equal y or n
	{
		print "Would you like to change the information? (y/n): "; #prompts the user again 
		my $inp; #declares variable again
		$inp = <STDIN>; #takes the users input again
		chomp $inp;  #chomps the users input again
	}
	if ($inp eq "y") #checks to see if the users input equals y
	{
		print "Give Patient's Name: "; #prompts the user
		my $inpname; #declares variable
		$inpname = <STDIN>; #takes the users input
		chomp $inpname; #chomps the users input
		if (exists $patientinfo{$inpname}) #checks to see if patient name exists in hash
		{
			print "Enter 1 to change the gender, 2 to change the DOB, or 3 to change the disease: "; #prompts the user
			my $inpnum; #declares variable
			$inpnum = <STDIN>; #takes the users input
			chomp $inpnum; #chomps the users input
			while (($inpnum != 1) && ($inpnum != 2) && ($inpnum != 3)) #conditional loop to check and see if the users input doesn't equal to 1 2 or 3
			{
				print "Enter 1 to change the gender, 2 to change the DOB, or 3 to change the disease: "; #prompts the user
                        	my $inpnum; #declares variable
                        	$inpnum = <STDIN>; #takes the users input
                        	chomp $inpnum; #chomps the users input
			}
			if ($inpnum == 1) #checks to see if user input equals to 1
			{
				print "Please enter (M/F): "; #prompts the user
				my $gender; #declares variable
				$gender = <STDIN>; #takes the users input
				chomp $gender; #chomps the users input
				while (($gender ne "M") && ($gender ne "F")) #checks to see if the user input doesn't equal to either M or F
				{
					print "Please enter (M/F): "; #prompts the user again
					my $gender; #declares variable again
					$gender = <STDIN>; #takes the users input again
					chomp $gender; #chomps the users input again
				}
				if (($gender eq "M") || ($gender eq "F"))
				{
					$patientinfo[1] = $gender; #changes the value inside the array
				}
				else
				{
					;
				}
			}
			elsif ($inpnum == 2) #checks to see if user input equals to 2
			{
				print "Please enter (xx/xx/xx): "; #prompts the user
				my $dob; #declares variable
				$dob = <STDIN>; #takes the users input
				chomp $dob; #chomps the users input
				$patientinfo[2] = $dob; #changes the value inside the array
			}
			else
			{
				print "Please enter a disease: "; #prompts the user
				my $disease; #declares variable
				$disease = <STDIN>; #takes the users input
				chomp $disease; #chomps the users input
				while ($disease !~ /^-?0/ && looks_like_number($disease)) #checks to see if the user input was a number
				{
					print "Please enter a disease: "; #prompts the user again
					my $disease; #declares variable again
					$disease = <STDIN>; #takes the users input again
					chomp $disease; #chomps the users input again
				} 
					$patientinfo[3] = $disease; #changes the value insude the array
				}
			}
			print "Would you like to print patient information to a file? (n/y): "; #prompts the user
                        my $print; #declares variable
                        $print = <STDIN>; #takes the users input
                        chomp $print; #chomps the users input
                        while (($print ne "n") && ($print ne "y")) #checks to see if user input doesn't equal to either n or y
                        {
                                print "Would you like to print patient information to a file? (n/y): "; #prompts the user
                                my $print; #declares variable
                                $print = <STDIN>; #takes the users input
                                chomp $print; #chomps the users input
                        }
                        if ($print eq "n") #checks to see if user input equals n
                        {
                                exit; #exits the script
                        }
                        else
                        {
                                print "Give Patient name: "; #prompts the user
                                my $names1 = <STDIN>; #declares a variable and takes the users input
                                chomp $names1; #chomps the users input
                                if (exists $patientinfo{$names1}) #checks to see if the users input exists in the hash
                                {
                                        open(my $patientinfo, '>', 'Info_Accessed.txt');
                                        print "Name: $patientinfo[0]";
                                        print "Gender: $patientinfo[1]";
                                        print "DOB: $patientinfo[2]";
                                        print "Disease: $patientinfo[3]";
                                        close $patientinfo; #writes all the info to a new text file called Info_Accessed.txt
                                }
                                else
                                {
                                        print "Error, name not found."; #displays an error message for the user
                                        exit; #exits the script
                                }
                        }
		}
		else
		{
			print "Error, name not found. Moving on to part 2."; #displays an error message for the user
			print "Would you like to print patient information to a file? (n/y): "; #prompts the user
			my $print1; #declare a variable
			$print1 = <STDIN>; #takes the users input
			chomp $print1; #chomps the users input
			while (($print1 ne "n") && ($print1 ne "y")) #checks to see if the users input doesn't equal to either n or y
			{
				print "Would you like to print patient information to a file? (n/y): "; #prompts the user
                        	my $print1; #declares variable
                        	$print1 = <STDIN>; #takes the users input
                        	chomp $print1; #chomps the users input
			}
			if ($print1 eq "n") #checks to see if the users input equals n
			{
				exit; #exits the script
			}
			else
			{
				print "Give Patient name: "; #prompts the user
				my $na = <STDIN>; #declares a variable and takes the users input
				chomp $na; #chomps the users input
				if (exists $patientinfo{$na}) #checks to see if the users input exists in the hash
				{
					open(my $patientinfo, '>', 'Info_Accessed.txt'); 
					print "Name: $patientinfo[0]";
					print "Gender: $patientinfo[1]";
					print "DOB: $patientinfo[2]";
					print "Disease: $patientinfo[3]";
					close $patientinfo; #writes all the info to a new text file called Info_Accessed.txt
				}
				else
				{
					print "Error, name not found."; #displays an error message for the user
					exit; #exits the script
				}
			}
		}
	***else***
	{
		print "Would you like to print patient information to a file? (n/y): "; #prompts the user
        	my $print; #declares variable
        	$print = <STDIN>; #tales the users input
        	chomp $print; #chomps the users input
        	while (($print ne "n") && ($print ne "y")) #checks to see if the users input doesn't equal n and y
        	{
                	print "Would you like to print patient information to a file? (n/y): "; #prompts the user again
                	my $print; #declares variable again
                	$print = <STDIN>; #takes the users input again
                	chomp $print; #chomps the users input again
        	}
        	if ($print eq "n") #checks to see if the user input equals n
        	{
                	exit; #exits the script
        	}
        	else
        	{
                	print "Give Patient name: "; #prompts the user
                	my $na1 = <STDIN>; #declares a variable and takes the users input
                	chomp $na1; #chomps the users input
                	if (exists $patientinfo{$na1}) #checks to see if the users input exists in the hash
                	{
                		open(my $patientinfo, '>', 'Info_Accessed.txt');
                        	print "Name: $patientinfo[0]";
                        	print "Gender: $patientinfo[1]";
                        	print "DOB: $patientinfo[2]";
                        	print "Disease: $patientinfo[3]";
                        	close $patientinfo; #writes all the info to a new text file called Info_Accessed.txt
			}
                	else
                	{
                        	print "Error, name not found."; #displays an error message for the user
                        	exit; #exits the script
                	}
		}
	}
***}***