#!/usr/athena/bin/perl

use File::Spec::Functions;
use Data::Dumper;
use Getopt::Long;
use Cwd;

my ($redodelete, $redoadd, $redoreplace, $redodiff) = (0,0,0,0);

my $scriptsdev = "";

GetOptions("redo-delete" => \$redodelete,
	   "redo-add" => \$redoadd,
	   "redo-replace" => \$redoreplace,
	   "redo-diff" => \$redodiff,
	   "redo-all" => sub {$redodelete = $redoadd = $redoreplace = $redodiff = 1;},
	   "dev" => sub {$scriptsdev = "dev";},
		  );

if (@ARGV < 3) {
  print STDERR "Usage: $0 [--redo-{delete,add,replace,diff,all}] package oldversion newversion\n";
  exit(1);
}

my ($package, $oldversion, $newversion) = @ARGV;
my ($old, $new, $updatename) = ($package.'-'.$oldversion, $package.'-'.$newversion, $package.'-'.$oldversion.'-to-'.$newversion);

my $outdir = $updatename.".proposal";

(-d $outdir || mkdir($outdir)) or die "mkdir($outdir) failed: $!";

my $olddir = catdir($outdir,$old);
my $newdir = catdir($outdir,$new);

unpackPackage($old, $olddir);
unpackPackage($new, $newdir);

sub unpackPackage($$) {
  my ($package, $dir) = @_;
  print STDERR "Extracting $package to $dir... ";
  if (-d $dir) {
    warn "$dir already exists; assuming unpacking was successful";
    return;
  }
  mkdir($dir) or die "mkdir($dir) failed: $!";
  my $cwd = cwd();
  chdir($dir) or die $!;
  `athrun scripts gtar zxf "/mit/scripts/deploy$scriptsdev/$package/$package.tar.gz"`;
  if ($?) { chdir($cwd); system("rmdir", "$dir"); die "Failed to unpack $package.tar.gz: $?"; }
  my @files=`athrun scripts gfind . -mindepth 1 -maxdepth 1 | grep -v .admin`;
  if (@files <= 1) {
    `athrun scripts gfind . -mindepth 2 -maxdepth 2 | xargs -i mv \{} .`;
    rmdir($files[0]);
  }
  chdir($cwd) or die "Couldn't return to $cwd";
  print "done.\n";
}

my @oldfiles = sort { $a->[1] cmp $b->[1] } map { chomp; s|$olddir\/?||g; [split(' ', $_, 2)] } `athrun scripts gfind $olddir -type f | xargs -i md5sum \{}`;
#print Dumper(\@oldfiles);
my @newfiles = sort { $a->[1] cmp $b->[1] } map { chomp; s|$newdir\/?||g; [split(' ', $_, 2)] } `athrun scripts gfind $newdir -type f | xargs -i md5sum \{}`;
#print Dumper(\@newfiles);

sub compareDirectories($$) {
  my ($alist, $blist) = @_;
  my @a = @$alist;
  my @b = @$blist;
  my @aonly, @bonly, @both;
  $a = $b = 0;
  my $debug = 0;
  local $Data::Dumper::Indent = 0;
  while ($a <= $#a || $b <= $#a) {
    my $fa = $a[$a];
    my $fb = $b[$b];
    print STDERR "Comparing ".Dumper($fa, $fb)."\n" if $debug;
    if ($fa->[1] eq $fb->[1]) { # Same file exists on both
      print STDERR "Same file\n" if $debug;
      if ($fa->[0] ne $fb->[0]) { # File has changed in some way
	print STDERR "Different md5, pushing on \@both\n" if $debug;
	push(@both, [$fa->[1], $fa, $fb]);
      }
      $a++; $b++; # increment both counters
    } else {
      my $a2 = $a;
      while ($a2 <= $#a && $a[$a2]->[1] lt $fb->[1]) {
	$a2++;
      }
      if ($a2 <= $#a && $a[$a2]->[1] eq $fb->[1]) {
	for my $i ($a..$a2-1) {
	  push @aonly, $a[$i];
	}
	$a = $a2;
      } else {
	my $b2 = $b;
	while ($b2 <= $#b && $b[$b2]->[1] lt $fa->[1]) {
	  $b2++;
	}
	if ($b2 <= $#b && $b[$b2]->[1] eq $fa->[1]) {
	  for my $i ($b..$b2-1) {
	    push @bonly, $b[$i];
	  }
	  $b = $b2;
	} else {
	  push @aonly, $a[$a];
	  push @bonly, $b[$b];
	  $a++; $b++;
	}
      }
    }
  }
  return (\@aonly, \@bonly, \@both);
}

my (@todelete, @toadd, @changed);
my @comp = compareDirectories(\@oldfiles, \@newfiles);
open(DIFF, ">", catfile($outdir, "diff.pl"));
print DIFF Dumper(@comp);
close(DIFF);
@todelete = @{$comp[0]};
@toadd = @{$comp[1]};
@changed = @{$comp[2]};

if ($redodelete or ! -e catfile($outdir, "files.delete")) {
	open(TODELETE, ">", catfile($outdir, "files.delete")) or die "Can't open files.delete: $!";
	foreach my $file (@todelete) {
	  printf TODELETE "%s %s\n", $file->[0], $file->[1];
	}
	close(TODELETE);
	printf "Wrote %d filenames to files.delete\n", scalar(@todelete);
} else { printf "Not overwriting existing files.delete\n"; }

if ($redoadd or ! -e catfile($outdir, "files.add")) {
	open(TOADD, ">", catfile($outdir, "files.add")) or die "Can't open files.add: $!";
	foreach my $file (@toadd) {
	  printf TOADD "%s %s\n", $file->[0], $file->[1];
	}
	close(TOADD);
	printf "Wrote %d filenames to files.add\n", scalar(@toadd);
} else { printf "Not overwriting existing files.add\n"; }

my @toreplace;
my @topatch;

foreach my $file (@changed) {
	if (-B catdir($newdir, $file->[0])) {
		push (@toreplace, $file);
	} else {
		push (@topatch, $file);
	}
}

if ($redoreplace or ! -e catfile($outdir, "files.replace")) {
	open(TOREPLACE, ">", catfile($outdir, "files.replace")) or die "Can't open files.replace: $!";
	foreach my $file (@toreplace) {
		printf TOREPLACE "%s %s\n", $file->[1][0], $file->[0];
	}
	close(TOREPLACE);
	printf "Wrote %d filenames to files.replace\n", scalar(@toreplace);
} else { printf "Not overwriting existing files.replace\n"; }

if ($redodiff or ! -e catfile($outdir, "update.diff")) {
    open(DIFF, ">", catfile($outdir, "update.diff")) or die "Can't open update.diff: $!";
    foreach my $file (@topatch) {
	my $filename = $file->[0];
	my $oldfile = catfile($olddir, $file->[1][1]);
	my $newfile = catfile($newdir, $file->[2][1]);
	my $cmd = "diff -urN $oldfile $newfile";
	print DIFF "$cmd\n";
	print DIFF `$cmd`;
    }
    close(DIFF);
    printf "Wrote %d diffs to update.diff\n", scalar(@topatch);
} else { printf "Not overwriting existing update.patch\n"; }