#!/usr/bin/perl -w
use strict;

###############################################################################
# wsr2csv.pl - Converts Wi-Spy Recordings to comma-separated value (csv) files
# Copyright (C) 2006 MetaGeek, LLC
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
# http://www.gnu.org/copyleft/gpl.html
#
###############################################################################


my($HEADER_SIZE) = 8816;
my($NUM_FREQUENCIES) = 85;
my($inputFileName);
my($outputFileName);

# Set the input and output file names
my($numArgs) = $#ARGV + 1;
if ($numArgs >= 1)
{
    $inputFileName = $ARGV[0];
}
else
{
    &Dienice("Please specify input file as first parameter");
}
if ($numArgs >= 2)
{
    $outputFileName = $ARGV[1];
}
else
{
    (my($fileName), my($ext)) = split(/\./, $inputFileName);		

    $outputFileName = "$fileName.csv";
}

# Open the input file
open(INPUT, "$inputFileName") or &Dienice("Couldn't open $inputFileName for reading");

# Set input file I/O mode to binary
binmode(INPUT);

# Open the output file
open(OUTPUT, ">$outputFileName") or &Dienice("Couldn't open $outputFileName for writing");

# Read the header from input file
my($readcount) = read(INPUT, my($inputData), $HEADER_SIZE);

print "Converting $inputFileName\n";

print OUTPUT "Timestamp,Seconds,";

# Print header row
for (my($frequency) = 2400; $frequency < $NUM_FREQUENCIES + 2400; $frequency++)
{
    print OUTPUT "$frequency";
    if ($frequency != $NUM_FREQUENCIES + 2400 - 1)
    {
        print OUTPUT ",";
    }
}
print OUTPUT "\n";

my($moreData) = 1;
while ($moreData == 1)
{
    # Read timestamp
    $readcount = read(INPUT, my($timestamp), 4);
    my($output) = unpack('N', $timestamp);
    print OUTPUT "$output,";
    
    $readcount = read(INPUT, $timestamp, 4);
    $output = unpack('N', $timestamp);
    print OUTPUT "$output,";

    if ($readcount == 4)
    {
        for (my($frequency) = 0; $frequency < $NUM_FREQUENCIES; $frequency++)
        {
            # Read amplitude of frequency
            $readcount = read(INPUT, my($amplitude), 1);
            if ($readcount == 1)
            {
                # Interpret $amplitude as signed char
                my($output) = unpack('c', $amplitude);
                
                # Print amplitude to output file
                print OUTPUT "$output";
                if ($frequency != $NUM_FREQUENCIES - 1)
                {
                    print OUTPUT ",";
                }
                else
                {
                    print OUTPUT "\n";
                }
            }
            else
            {
                $moreData = 0;
            }
        }
    }
    else
    {
        $moreData = 0;
    }
}

close(INPUT);
close(OUTPUT);

print "Successfully converted $inputFileName to $outputFileName";

###########################################
sub Dienice
{
	my($errmsg) = @_;
	print "Error: $errmsg\n";
	exit;
}