#!/usr/bin/perl -w

# bload - easy upload for web files
# by Eiki Martinson

# Makes a checksum file (using MD5) of all files in the directory. Each time bload is
# run, it will compare current checksums against this file; any differences indicate
# the file has been changed and needs to be uploaded again. This it will do using scp
# with parameters provided by constants.

use strict;

use Digest::MD5 qw(md5_hex);
use System2;

use constant CHECK_FILE => ".blcheck";
use constant SERVERNAME => "foo.bar.baz";
use constant SERVERPATH => "www/"; #something like "web/" or "files/"
use constant SERVERUSER => "myname"; #your username

my $file;
my $contents;
my @line;
my @null = split(/\//, `pwd`);
my $localdir = pop(@null);
chop($localdir);
my $allfiles = `ls -R1Bp | grep -v .*\\/\$`;
my @dirs = split(/\s+\.\//, $allfiles);
foreach(@dirs) {

    my %oldchecksums;
    my %newchecksums;
    my ($path, @files) = split(/\n/);
    if($path eq '.:') {
	$path = '';
    }
    else {
	$path =~ s/(.*):$/$1\//;
    }
    my $remotepath = $localdir."/".$path;

    #if checksum file already exists, compare checksums and update as necessary
    if(-e $path.CHECK_FILE) {

	#get old checksums from the file
	open(CHECK, "<$path".CHECK_FILE);
	while(<CHECK>) {
	    chomp;
	    @line = split(/\s/);
            #filename as hash key, digest as value
	    $oldchecksums{$line[0]} = $line[1]; 
	}
	close(CHECK);

	#make new md5 digests from actual files, compare, and upload if different
	foreach $file (@files) {	    
	    my $newsum = file_md5($path, $file);
	    
	    if(!($oldchecksums{$file}) || $newsum ne $oldchecksums{$file}) {
		update($path, $file, $remotepath);		
		$newchecksums{$file} = $newsum;
	    }
	    else {
		$newchecksums{$file} = $oldchecksums{$file};
	    }
	}

	#write new checksums to file
	open(CHECK, ">$path".CHECK_FILE);
	while(@line = each %newchecksums) {
	    print CHECK "$line[0] $line[1]\n";
	}
	close(CHECK);	

    }

    #otherwise generate the checksum file from scratch
    else {
	open(CHECK, ">$path".CHECK_FILE);
	foreach $file (@files) {	    
	    update($remotepath, $file);
	    print CHECK "$file ".file_md5($path, $file)."\n";
	}
	close(CHECK);
    }

}

#make md5 digest from file contents.
sub file_md5 {
    open(FILE, $_[0].$_[1]);
    my @lines = <FILE>;
    close(FILE);
    my $contents;
    foreach(@lines) {
	$contents = $contents.$_;
    }
    return md5_hex($contents);
}

#upload file
sub update {
    print "Uploading $_[0]"."$_[1]\n";
    my ($out, $err) = system2('scp', $_[0].$_[1],
			      SERVERUSER.'@'.SERVERNAME.':'.SERVERPATH.$_[2].$_[1]);
    if($err) {
	die "$err File $file was not uploaded. Please try again.\n";
    }
}