#!/usr/bin/perl

# uncomment flock
# chmod files
# delete error output

# tritz.cgi

# SOME OPTIONS
#	'no' or incorrect password prevents removal of word/meaning entries
	$subtract = 'yes';
	$passwd = 'fireicebolt';

# database.txt will be a plain text file containing words and their meanings stored thus:
#	"word\n
#	 definition\n\n"

# The following are the expected form inputs:
#
# $FORM{'do'}				# tells script what action to perform
#						# will redirect to tritz.cgi if omitted
#	eq 'search'
#		$FORM{'pattern'} 		# this is the pattern to look for
#		$FORM{'match_what'}
#			eq 'words'		# look in words
#			eq 'meanings'	# look in meanings
#			eq 'quotes'		# look in quotes
#	eq 'alphabet'
#		$FORM{'letter'} 		# look for all words beginning with this letter
#						  or all non-letters if !~ /[a-zA-Z]/
#	eq 'add'
# 		$FORM{'word'} 		# add this word to database
# 		$FORM{'meaning'} 		# add this meaning
# 		$FORM{'quote'} 		# add this quote
#	eq 'subtract'
#		$FORM{'word'} 		# delete this word from the database
#		$FORM{'meaning'}		# optional meaning to specify which word
# 		$FORM{'password'}		# password for deleting a word from the database
#	eq 'last10'

require "read_in.cgi";

%FORM = &read_input;

unless (defined($FORM{'do'})) {
	print "URI: tritz.html\n";
	print "Location: tritz.html\n\n";
	exit;
}

$do =			$FORM{'do'};
$pattern = 		$FORM{'pattern'};
$match_what = 	$FORM{'match_what'};
$letter = 		$FORM{'letter'};
$word = 		$FORM{'word'};
$meaning = 		$FORM{'meaning'};
$quote = 		$FORM{'quote'};
$password =		$FORM{'password'};

print "Content-type: text/html\n\n";

if (defined($FORM{'out'})) {
	open(OUTFILE, ">$FORM{'out'}") || die "Couldn't open file $FORM{'out'}: $!";
	select(OUTFILE);
}

# What should the script do?
# Add, subtract, search?
if ($do eq 'search') {
	&search;
} elsif ($do eq 'alphabet') {
	&alphabet;
} elsif ($do eq 'last10') {
	&last10;
} elsif ($do eq 'add') {
	&add;
} elsif ($do eq 'subtract') {
	&subtract;
} else {
	&write_error("Undefined action do=$do");
}

sub search {
	$pattern =~ s/([\^\(\)\{\}\*\+\?\.\[\]\|\\\$])/\\$1/g;
	$pattern =~ s/</&lt;/g;
	open(DATABASE, '<database.txt') || die "Couldn't open database.txt for reading: $!";
	$/ = "\n\n";
	@database = <DATABASE>;
	close(DATABASE);
	if ($match_what =~ /words/) {
		push(@data, grep(/$pattern.*\n.+\n.+/i, @database));
		push(@match, 'words');
	} 
	if ($match_what =~ /meanings/) {
		push(@data, grep(/.+\n.*$pattern.*\n.+/i, @database));
		push(@match, 'meanings');
	} 
	if ($match_what =~ /quotes/) {
		push(@data, grep(/.+\n.+\n.*$pattern/i, @database));
		push(@match, 'quotes');
	} 
	if ($match_what !~ /words|meanings|quotes/) {
		@data = grep(/$pattern/i, @database);
		push(@match, 'words, meanings, quotes');
	}
	@data = grep(($Last eq $_ ? 0 : ($Last = $_, 1)),sort @data);
	$match = join(', ', @match);
	&write_search;
}

sub alphabet {
	open(DATABASE, '<database.txt') || die "Couldn't open database.txt for reading: $!";
	$/ = "\n\n";
	@database = <DATABASE>;
	close(DATABASE);
	if ($letter =~ /^[a-zA-Z]$/) {
		@data = grep(/^$letter/i, @database);
	} else {
		@data = grep(/^[^a-zA-Z]/, @database);
	}
	@data = grep(($Last eq $_ ? 0 : ($Last = $_, 1)),sort @data);
	&write_alphabet;
}

sub last10 {
	open(DATABASE, '<database.txt') || die "Couldn't open database.txt for reading: $!";
	$/ = "\n\n";
	@database = <DATABASE>;
	close(DATABASE);
	@database = reverse (@database);
	@data = @database[0..9];
	&write_last10;
}

sub add {
	&write_error('Please make sure both a word and its meaning were included in the form.') if ($word eq '' || $meaning eq '');
# replaces such things as carriage returns, etc... with a single space
	$word =~ s/\s+/ /g;
	$meaning =~ s/\s+/ /g;
	$quote =~ s/\s+/ /g;
# strips beginning and trailing white space
	$word =~ s/^\s+//;
	$word =~ s/\s+$//;
	$meaning =~ s/^\s+//;
	$meaning =~ s/\s+$//;
	if ($quote eq '') {
		$quote = ' ';
	} else {
		$quote =~ s/^\s+//;
		$quote =~ s/\s+$//;
	}
	$quote =~ s/</&lt;/g; # prevents html as input...
	open(DATABASE, '>>database.txt') || die "Couldn't open database.txt for appending: $!";
#	flock(DATABASE, 2);
	print DATABASE "$word\n$meaning\n$quote\n\n";
#	flock(DATABASE, 8);
	close(DATABASE);
	&write_add;
}

sub subtract {
	&write_error('Incorrect password') unless ($password eq $passwd);
	&write_error('Cannot delete entry.  Option not available.') unless ($subtract eq 'yes');
	&write_error('Please make sure a word was included for deletion -- an accompanying definition is not required.') if ($word eq '');
	open(OLD_DATA, '<database.txt') || die "Couldn't open database.txt for reading: $!";
	open(BACK_DATA, '>databack.txt') || die "Couldn't open databack.txt for writing: $!";
	open(TEMP_DATA, '>datatemp.txt') || die "Couldn't open datatemp.txt for writing: $!";
	$/ = "\n\n";
	while ($line = <OLD_DATA>) {
		print BACK_DATA $line;
		if ($line =~ /^$word\n$meaning/o) {
			push(@data,$line);
			next;
		}
		print TEMP_DATA $line;
	}
	close(TEMP_DATA);
	close(BACK_DATA);
	close(OLD_DATA);
	open(TEMP_DATA, '<datatemp.txt') || die "Couldn't open datatemp.txt for reading: $!";
	open(NEW_DATA, '>database.txt') || die "Couldn't open database.txt for writing: $!";
	flock(NEW_DATA, 2);
	undef $/;
	$line = <TEMP_DATA>;
	print NEW_DATA $line;
	flock(NEW_DATA, 8);
	close(NEW_DATA);
	close(TEMP_DATA);
	@data = grep(($Last eq $_ ? 0 : ($Last = $_, 1)),sort @data);
	&write_subtract;
}

sub write_search {
print <<END_SEARCH;
<HTML>
<HEAD><TITLE>Search results</TITLE>
</HEAD>

<body bgcolor=000000 text=ffffff link=FF00AA vlink=d9d919>

Searched for <i>$match</i> 
<br> which matched the following pattern:  <b>$FORM{'pattern'}</b>

END_SEARCH
	&write_list;
	print "<P><A HREF=\"tritz.html\">Back to the MainPage</A>\n\n";
	print "</BODY>\n</HTML>";
}

sub write_alphabet {
print <<END_ALPHABET;
<HTML>
<HEAD><TITLE>Tritz was brought to you by the letter $letter</TITLE>
</HEAD>

<body bgcolor=000000 text=ffffff link=FF00AA vlink=d9d919>

Searched for words beginning with the letter <b>$letter</b>

END_ALPHABET
	&write_list;
	print "<P><A HREF=\"tritz.html\">Back to the MainPage</A>\n\n";
	print "</BODY>\n</HTML>";
}

sub write_last10 {
print <<END_LAST10;
<HTML>
<HEAD><TITLE>Last 10 entries</TITLE>
</HEAD>

<body bgcolor=000000 text=ffffff link=FF00AA vlink=d9d919>

These are the last 10 entries:

END_LAST10
	&write_list;
	print "<P><A HREF=\"tritz.html\">Back to the MainPage</A>\n\n";
	print "</BODY>\n</HTML>";
}

sub write_add {
print <<END_ADD;
<HTML>
<HEAD><TITLE>Add results</TITLE>
</HEAD>

<body bgcolor=000000 text=ffffff link=FF00AA vlink=d9d919>

The following entry has been successfully added:
<P>
<B>$word</B>
<BR>$meaning
<BR><I>$quote</I>

<P><A HREF="tritz.html">Back to the MainPage</A>

</BODY>
</HTML>
END_ADD
}

sub write_subtract {
print <<END_SUBTRACT;
<HTML>
<HEAD><TITLE>Subtract results</TITLE>
</HEAD>

<body bgcolor=000000 text=ffffff link=FF00AA vlink=d9d919>

This word was searched for:
<P>
<B>$word</B>
<BR>$meaning
<P>
The following words have been deleted from the database:

END_SUBTRACT
	&write_list;
	print "<P><A HREF=\"tritz.html\">Back to the MainPage</A>\n\n";
	print "</BODY>\n</HTML>";
}

sub write_list {
	foreach $dat (@data) {
		($word,$meaning,$quote) = split(/\n/,$dat,3);
		print "<P><B>$word</B>\n";
		print "<BR>$meaning\n";
		print "<BR><I>$quote</I>\n\n";
	}
}

sub write_error {
	$message = shift;
print <<END_ERROR;
<HTML>
<HEAD><TITLE>Error!</TITLE>
</HEAD>

<body bgcolor=000000 text=ffffff link=FF00AA vlink=d9d919>

<h2>An error has occurred.</h2>
<P>$message

<P><A HREF="tritz.html">Back to the MainPage</A>

</BODY>
</HTML>
END_ERROR
	exit;
}

select(STDOUT);
close(OUTFILE);
exit;