#! /usr/bin/perl -w
# Migrate an old-style database to the new hashed (db-h) form.

use strict;
use File::Copy;

if (@ARGV != 2) {
    print <<EOF;
Usage: $0 old-db-directory new-db-directory

debbugs-dbhash converts an old-style flat debbugs database into a
new-style hashed-directory debbugs database.

The old database is simply copied, and otherwise left untouched.
The directory given for the new database must not already exist.

EOF
    exit 0;
}

my ($db, $dbh) = @ARGV[0, 1];
opendir DB, $db or die "Can't opendir $db: $!";
mkdir $dbh or die "Can't mkdir $dbh: $!";
for my $i (0 .. 99) {
    my $dir = sprintf '%s/%02d', $dbh, $i;
    mkdir $dir or die "Can't mkdir $dir: $!";
}

while (defined(my $file = readdir DB)) {
    next if $file =~ /^\.\.?$/;
    my $oldfile = "$db/$file";
    my $newfile;
    if ($file =~ /(\d*)(\d\d)\.(.*)/) {
	$newfile = "$dbh/$2/$1$2.$3";
    } else {
	warn "Not hashing $file.\n";
	$newfile = "$dbh/$file";
    }
    copy $oldfile, $newfile or warn "Can't copy $oldfile to $newfile: $!";
}

closedir DB;