#!/usr/bin/perl
use strict;
use warnings;

my $BARSIZE = 40; # Size of the progress bar
my @statuses = qw(A U D);

my $repo = shift();
my $outfile = shift() || "./svnloc.txt";
my $revision = shift();
my $latest_rev;
my %rev_users;
my %rev_dates;
my %rev_changes;
my %rev_diff;

if (not defined $repo or not -e $repo) {
        print <<END_USAGE;
Usage: svnloc repo [outfile [revision]]
        repo      the path to the svn repository
        outfile   the path for the output file, defaults to "./svnloc.txt"
        revision  if specified, will append data for that revision to the output
                  if not specified, all data for all revisions is obtained and the file
                  is generated from scratch, overwriting the old file if it exists.
END_USAGE
        exit(1);
}

my $bl_filename = "svnloc.blacklist";
my @blacklist; # Don't count these revisions
if (-e "svnloc.blacklist") {
        open BL, $bl_filename;
        chomp( @blacklist = <BL> );
        close BL;
}

if (defined $revision) {  #get info for our revision and append to output file
        get_info($revision);
        open OUTPUT, ">>$outfile";
        output_line($revision);
        close OUTPUT;
} else { # generate output file from scratch
        my $history = `svnlook history $repo`;
        ($latest_rev) = $history =~ /(\d+)/s;
        print "Latest revision: $latest_rev\n";

        rev_loop("Obtaining revision information...",\&get_info);

        open OUTPUT, ">$outfile";
        printf OUTPUT ("%-20s%-18s%6s%7s%7s%5s%5s\n","Date","Username","Rev","Add","Mod","Chrn","Del",@statuses);

        rev_loop("Generating outputfile ($outfile)...",\&output_line);

        close OUTPUT;
}
print "Finished.\n";

sub get_info {
        my $rev = shift;

        my $info = `svnlook info -r $rev $repo`;
        my ($user, $date) = split(/\n/,$info);
        $rev_users{$rev} = $user;
        $rev_dates{$rev} = $date;

        my $changed = `svnlook changed -r $rev $repo`;
        for my $s (split(/\n/,$changed)) {
                my ($status) = substr($s,0,1);
                $rev_changes{$rev}->{$status}++;
        }

        my $diff = `svnlook diff -r $rev $repo`;

        my ($added,$modified,$deleted,$temp_deleted) = (0)x4;
        for my $line (split(/\n/,$diff)) {
            my $c2 = substr($line,0,2);
            my ($c) = substr($line,0,1);
            next if ($c2 eq '--' || $c2 eq '++'); # ignore header lines
            if ($c eq '-') {
                $temp_deleted++;
            } elsif ($c eq '+') {
                if ($temp_deleted) {
                    $temp_deleted--;
                    $modified++;
                } else {
                    $added++;
                }
            } else {
                $deleted += $temp_deleted;
                $temp_deleted = 0;
            }
        }
        $rev_diff{$rev}->{added} = $added;
        $rev_diff{$rev}->{modified} = $modified;
        $rev_diff{$rev}->{churn} = $added + $modified;
        $rev_diff{$rev}->{removed} = $deleted;

}

sub output_line {
        my $rev = shift;
        no warnings 'uninitialized';
        printf OUTPUT ("%20s%-18s%6d%7d%7d%7d%7d%5d%5d%5d\n",
                substr($rev_dates{$rev},0,20),
                $rev_users{$rev},
                $rev,
                $rev_diff{$rev}->{added},
                $rev_diff{$rev}->{modified},
                $rev_diff{$rev}->{churn},
                $rev_diff{$rev}->{removed},
                map { $rev_changes{$rev}->{$_} } @statuses);
}

sub rev_loop {
        my ($msg, $code) = @_;
        my $progress;
        print "$msg\n";
        start_progress(\$progress);
        for (1..$latest_rev) {
                tick_progress(\$progress,$latest_rev);
                next if (is_in($_,@blacklist));
                $code->($_);
        }
        end_progress();
}

sub start_progress {
        my $progress = shift();
        $$progress=0;
        print "[" . (" " x $BARSIZE) . "]\r";
}

sub tick_progress {
        my $progress = shift();
        my $max = shift();
        my $ticks  = int(($$progress++/$max) * $BARSIZE);
        my $spaces = $BARSIZE - $ticks;

        printf "[" . ("=" x $ticks)
                          . (" " x $spaces)
                          . "] %-10s\r",$_;
}

sub end_progress {
        print "[" . ("=" x $BARSIZE) . "]\n\n";
}

sub is_in {
        my $item = shift;
        my @list = @_;
        my %seen;
        @seen{@list} = (1) x scalar @list;
        return $seen{$item};
}