use strict;
use lib './';
use functs_skeleton;

# create a hash of functions--see asmt sheet
my %function = ( '1' => \&add_user, '2' => \&edit_user, '3' => \&delete_user, '4' => \&print_list);
#global var declarations go here
my $fh;
my $fn;
my %hash;
#Open file for reading
# prompt user for filename & store in variable:"$fn"  : print, <>, chomp
print "Enter Filename: ";
$fn = <>;
chomp($fn);

open ($fh, "<", $fn);
# if file does not exist, create it by opening an empty file for writing
if (!$fh) {
	open ($fh, ">", $fn);
}
#transfer file line by line into hash with a while loop, splitting the username and password by the delimiter character ":"
while (my $line = <$fh>) {
	my @line_array = split(/:/,$line);
	my $username = $line_array[0];
	my $password = $line_array[1];
	chomp($password);
	$hash{$username} = $password;
}
# outer loop until user quits
outer:{
while(1) {
	#inner loop until user enters correct option
	my $func = "UNSET";
	my $choice;
	inner:{
		while(1) {
		# print menu & prompt/chomp for user input: $choice
		print "\n\nChoose an option:\n\t1. Add user account\n\t2. Edit existing user account\n\t3. Delete existing user account\n\t4. Print list of user accounts\n\t5. Save and quit\n\nEnter choice: ";
		$choice = <>;
		chomp($choice);
		if ($choice eq '5') {last outer;}
		# if the user enters a valid choice, exit inner loop
		# if ($choice eq '1') {$func=\&add_user;last;}
		# if ($choice eq '2') {$func=\&edit_user;last;}
		# if ($choice eq '3') {$func=\&delete_user;last;}
		# if ($choice eq '4') {$func=\&print_list;last;}
		#print"choice='".$choice."', val='".$function{$choice}."'\n";
		if (exists($function{$choice})) {last;}
		print "Unknown choice\n";
	} #end of the inner loop
	}
	# set local variable to appropriate function references in hash by user's choice & call appropriate function by passing in the hash as a parameter
	# and assigning the function result to the hash to update it
	# print"choice=".$choice."\n";
	%hash = $function{$choice}->(\%hash);

} # end of outer loop
}

#Close the file for reading
close($fh);
# prompt user to save changes, if so, then print the entire contents of the hash to the file & close the file for writing
print "Save (y/n)?";
my $saveit = <>;
chomp($saveit);
if ($saveit eq 'y') {
	open( $fh, ">", $fn);
	#for every entry in the hash, write it to the file
	foreach my $key (keys %hash) {
		print $fh $key . ":" . $hash{$key} . "\n";
	}
	close($fh);
} # if