#!/usr/local/bin/perl

# simtrade.pl. This program simulates fluctuating 
# stock prices for the WWWS system. 

$historySize = 30;

$dataPath = "/home/boutell/wwwws";

$iterations = 1;

srand();

if (int(@ARGV) == 1) {
	$iterations = $ARGV[0];
} elsif (int(@ARGV) == 0) {
	# OK, assume 1 iteration 
} else {
	die "Usage: simtrade [# of iterations]\n";
}
for ($iter = 0; ($iter < $iterations); $iter++) {
	$stocks = 0;
	$s = $dataPath . "/database";
	$snew = $dataPath . "/database.new";
	open(IN, $s) || die "Can't open database file " . $s . "for reading.\n";
	open(OUT, ">" . $snew) || 
		die "Can't open temporary file " . $s . " for writing.\n"; 
	while(<IN>) {
		#Remove any trailing space
		s/\s+$//g;
		@fields = split(/ /);
		$symbol = $fields[0];
		if ($symbol eq "") {
			break;
		}
		$historyTotal = int(@fields) - 1;
		if ($historyTotal == $historySize) {
			for ($i = 0; ($i < ($historySize - 1)); $i++) {
				$fields[$i + 1] = $fields[$i + 2];
			}
			$#fields -= 1;
			$historyTotal--;
		}
		# Generate a price fluctuation at random. Some would say this
		# method is quite realistic. 
		if ($historyTotal) {
			$fields[$historyTotal + 1] = 
				$fields[$historyTotal] + 
				(int(rand(40)) - 19.5) * .125;
			if ($fields[$historyTotal + 1] < 0.0) {
				$fields[$historyTotal + 1] = 0.125;
			}	
		} else {
			$fields[$historyTotal + 1] = 
				(int(rand(80)) + 80) / 2.0;
		}
		$historyTotal++;
		# Write the updated record. 
		print OUT join(' ', @fields), "\n";
		$stocks++;
	} 
	print $stocks, " stocks updated.\n";
	close(IN);
	close(OUT);
	rename($snew, $s);
}
exit 0;