#!/usr/bin/perl

#man{{{

=head1 NAME

mr - a Multiple Repository management tool

=head1 SYNOPSIS

B<mr> [options] checkout

B<mr> [options] update

B<mr> [options] status

B<mr> [options] commit [-m "message"]

B<mr> [options] diff

B<mr> [options] log

B<mr> [options] register [repository]

B<mr> [options] config section [parameter=[value] ...]

B<mr> [options] action [params ...]

=head1 DESCRIPTION

B<mr> is a Multiple Repository management tool. It
can checkout, update, or perform other actions on
a set of repositories as if they were one combined respository. It
supports any combination of subversion, git, cvs, and bzr repositories, 
and support for other revision control systems can easily be added.

B<mr> cds into and operates on all registered repsitories at or below your
working directory. Or, if you are in a subdirectory of a repository that
contains no other registered repositories, it will stay in that directory,
and work on only that repository,

These predefined commands should be fairly familiar to users of any revision
control system:

=over 4

=item checkout (or co)

Checks out any repositories that are not already checked out.

=item update

Updates each repository from its configured remote repository.

If a repository isn't checked out yet, it will first check it out.

=item status

Displays a status report for each repository, showing what
uncommitted changes are present in the repository.

=item commit (or ci)

Commits changes to each repository. (By default, changes are pushed to the
remote repository too, when using distributed systems like git.)

The optional -m parameter allows specifying a commit message.

=item diff

Show a diff of uncommitted changes.

=item log

Show the commit log.

=back

These commands are also available:

=over 4

=item list (or ls)

List the repositories that mr will act on.

=item register

Register an existing repository in the mrconfig file. By default, the
epository in the current directory is registered, or you can specify a
directory to register.

=item config

Adds, modifies, removes, or prints a value from the mrconfig file. The next
parameter is the name of the section the value is in. To add or modify
values, use one or more instances of "parameter=value". Use "parameter=" to
remove a parameter. Use just "parameter" to get the value of a parameter.

For example, to add (or edit) a repository in src/foo:

  mr config src/foo checkout="svn co svn://example.com/foo/trunk foo"

To show the command that mr uses to update the repository in src/foo:

  mr config src/foo update

=item help

Displays this help.

=back

Actions can be abbreviated to any unambiguous subsctring, so
"mr st" is equivilant to "mr status", and "mr up" is equivilant to "mr
update"

Additional parameters can be passed to most commands, and are passed on
unchanged to the underlying revision control system. This is mostly useful
if the repositories mr will act on all use the same revision control
system.

=head1 OPTIONS

=over 4

=item -d directory

Specifies the topmost directory that B<mr> should work in. The default is
the current working directory.

=item -c mrconfig

Use the specified mrconfig file, instead of looking for one in your home
directory.

=item -v

Be verbose.

=item -s

Expand the statistics line displayed at the end to include information
about exactly which repositories failed and were skipped, if any.

=back

=head1 FILES

B<mr> is configured by .mrconfig files. It starts by reading the .mrconfig
file in your home directory, and this can in turn chain load .mrconfig files
from repositories.

Here is an example .mrconfig file:

  [src]
  checkout = svn co svn://svn.example.com/src/trunk src
  chain = true

  [src/linux-2.6]
  checkout = git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git &&
  	cd linux-2.6 &&
  	git checkout -b mybranch origin/master

The .mrconfig file uses a variant of the INI file format. Lines starting with
"#" are comments. Values can be continued to the following line by
indenting the line with whitespace.

The "DEFAULT" section allows setting default values for the sections that
come after it.

The "ALIAS" section allows adding aliases for actions. Each parameter
is an alias, and its value is the action to use.

All other sections add repositories. The section header specifies the
directory where the repository is located. This is relative to the directory
that contains the mrconfig file, but you can also choose to use absolute
paths.

Within a section, each parameter defines a shell command to run to handle a
given action. mr contains default handlers for the "update", "status", and
"commit" actions, so normally you only need to specify what to do for
"checkout".

Note that these shell commands are run in a "set -e" shell
environment, where any additional parameters you pass are available in
"$@". The "checkout" command is run in the parent of the repository
directory, since the repository isn't checked out yet. All other commands
are run inside the repository, though not necessarily at the top of it.
The "MR_REPO" environment variable is set to the path to the top of the
repository.

A few parameters have special meanings:

=over 4

=item skip

If the "skip" parameter is set and its command returns nonzero, then B<mr>
will skip acting on that repository. The command is passed the action
name in $1.

Here are two examples. The first skips the repo unless
mr is run by joey. The second uses the hours_since function
(included in mr's built-in library) to skip updating the repo unless it's
been at least 12 hours since the last update.

  skip = test $(whoami) != joey
  skip = [ "$1" = update ] && [ $(hours_since "$1") -lt 12 ]

=item chain

If the "chain" parameter is set and its command returns nonzero, then B<mr>
will try to load a .mrconfig file from the root of the repository. (You
should avoid chaining from repositories with untrusted committers.)

=item deleted

If the "deleted" parameter is set and its command returns nonzero, then
B<mr> will treat the repository as deleted. It won't ever actually delete
the repository, but it will warn if it sees the repsoitory's directory.
This is useful when one mrconfig file is shared amoung multiple machines,
to keep track of and remember to delete old repositories.

=item lib

The "lib" parameter can specify some shell code that will be run before each
command, this can be a useful way to define shell functions for other commands
to use.

=back

=head1 AUTHOR

Copyright 2007 Joey Hess <joey@kitenet.net>

Licensed under the GNU GPL version 2 or higher.

http://kitenet.net/~joey/code/mr/

=cut

#}}}

use warnings;
use strict;
use Getopt::Long;
use Cwd qw(getcwd abs_path);

my $directory=getcwd();
my $config="$ENV{HOME}/.mrconfig";
my $verbose=0;
my $stats=0;
my %config;
my %knownactions;
my %alias;

Getopt::Long::Configure("no_permute");
my $result=GetOptions(
	"d|directory=s" => sub { $directory=abs_path($_[1]) },
	"c|config=s" => \$config,
	"v|verbose" => \$verbose,
	"s|stats" => \$stats,
);
if (! $result || @ARGV < 1) {
	die("Usage: mr [-d directory] action [params ...]\n".
	    "(Use mr help for man page.)\n");

}

loadconfig(\*DATA);
loadconfig($config);
#use Data::Dumper;
#print Dumper(\%config);

eval {
	use FindBin qw($Bin $Script);
	$ENV{MR_PATH}=$Bin."/".$Script;
};

# alias expansion and command stemming
my $action=shift @ARGV;
if (exists $alias{$action}) {
	$action=$alias{$action};
}
if (! exists $knownactions{$action}) {
	my @matches = grep { /^\Q$action\E/ }
		keys %knownactions, keys %alias;
	if (@matches == 1) {
		$action=$matches[0];
	}
	elsif (@matches == 0) {
		die "mr: unknown action \"$action\" (known actions: ".
			join(", ", sort keys %knownactions).")\n";
	}
	else {
		die "mr: ambiguous action \"$action\" (matches: ".
			join(", ", @matches).")\n";
	}
}

if ($action eq 'help') {
	exec($config{''}{DEFAULT}{$action}) || die "exec: $!";
}
elsif ($action eq 'config') {
	if (@ARGV < 2) {
		die "mr config: not enough parameters\n";
	}
	my $section=shift;
	if ($section=~/^\//) {
		# try to convert to a path relative to $config's dir
		my ($dir)=$config=~/^(.*\/)[^\/]+$/;
		if ($section=~/^\Q$dir\E(.*)/) {
			$section=$1;
		}
	}
	my %changefields;
	foreach (@ARGV) {
		if (/^([^=]+)=(.*)$/) {
			$changefields{$1}=$2;
		}
		else {
			my $found=0;
			foreach my $topdir (sort keys %config) {
				if (exists $config{$topdir}{$section} &&
				    exists $config{$topdir}{$section}{$_}) {
					print $config{$topdir}{$section}{$_}."\n";
					$found=1;
				}
			}
			if (! $found) {
				die "mr $action: $section $_ not set\n";
			}
		}
	}
	modifyconfig($config, $section, %changefields) if %changefields;
	exit 0;
}
elsif ($action eq 'register') {
	my $command="set -e; ".$config{''}{DEFAULT}{lib}."\n".
		"my_action(){ $config{''}{DEFAULT}{$action}\n }; my_action ".
		join(" ", map { s/\//\/\//g; s/"/\"/g; '"'.$_.'"' } @ARGV);
	print STDERR "mr $action: running >>$command<<\n" if $verbose;
	exec($command) || die "exec: $!";
}

# work out what repos to act on
my @repos;
my $nochdir=0;
foreach my $topdir (sort keys %config) {
	foreach my $subdir (sort keys %{$config{$topdir}}) {
		next if $subdir eq 'DEFAULT';
		my $dir=($subdir =~/^\//) ? $subdir : $topdir.$subdir;
		my $d=$directory;
		$dir.="/" unless $dir=~/\/$/;
		$d.="/" unless $d=~/\/$/;
		next if $dir ne $directory && $dir !~ /^\Q$directory\E/;
		push @repos, [$dir, $topdir, $subdir];
	}
}
if (! @repos) {
	# fallback to find a leaf repo
	LEAF: foreach my $topdir (reverse sort keys %config) {
		foreach my $subdir (reverse sort keys %{$config{$topdir}}) {
			next if $subdir eq 'DEFAULT';
			my $dir=($subdir =~/^\//) ? $subdir : $topdir.$subdir;
			my $d=$directory;
			$dir.="/" unless $dir=~/\/$/;
			$d.="/" unless $d=~/\/$/;
			if ($d=~/^\Q$dir\E/) {
				push @repos, [$dir, $topdir, $subdir];
				last LEAF;
			}
		}
	}
	$nochdir=1;
}

my (@failed, @ok, @skipped);
foreach my $repo (@repos) {
	action($action, @$repo);
}

sub action { #{{{
	my ($action, $dir, $topdir, $subdir) = @_;
	
	my $lib= exists $config{$topdir}{$subdir}{lib} ?
	                $config{$topdir}{$subdir}{lib}."\n" : "";

	if (exists $config{$topdir}{$subdir}{deleted}) {
		if (! -d $dir) {
			return;
		}
		else {
			my $test="set -e;".$lib.$config{$topdir}{$subdir}{deleted};
			print "mr $action: running deleted test >>$test<<\n" if $verbose;
			my $ret=system($test);
			if ($ret >> 8 == 0) {
				print STDERR "mr error: $dir should be deleted yet still exists\n\n";
				push @failed, $dir;
				return;
			}
		}
	}

	if ($action eq 'checkout') {
		if (-d $dir) {
			print "mr $action: $dir already exists, skipping checkout\n" if $verbose;
			push @skipped, $dir;
			return;
		}
		$dir=~s/^(.*)\/[^\/]+\/?$/$1/;
	}
	elsif ($action eq 'update') {
		if (! -d $dir) {
			return action("checkout", $dir, $topdir, $subdir);
		}
	}
	
	$ENV{MR_REPO}=$dir;

	if (exists $config{$topdir}{$subdir}{skip}) {
		my $test="set -e;".$lib.
			"my_action(){ $config{$topdir}{$subdir}{skip}\n }; my_action '$action'";
		print "mr $action: running skip test >>$test<<\n" if $verbose;
		my $ret=system($test);
		if ($ret >> 8 == 0) {
			print "mr $action: $dir skipped per config file\n" if $verbose;
			push @skipped, $dir;
			return;
		}
	}
	
	if (! $nochdir && ! chdir($dir)) {
		print STDERR "mr $action: failed to chdir to $dir: $!\n";
		push @failed, $dir;
	}
	elsif (! exists $config{$topdir}{$subdir}{$action}) {
		print STDERR "mr $action: no defined $action command for $topdir$subdir, skipping\n";
		push @skipped, $dir;
	}
	else {
		if (! $nochdir) {
			print "mr $action: $topdir$subdir\n";
		}
		else {
			print "mr $action: $topdir$subdir (in subdir $directory)\n";
		}
		my $command="set -e; ".$lib.
			"my_action(){ $config{$topdir}{$subdir}{$action}\n }; my_action ".
			join(" ", map { s/\//\/\//g; s/"/\"/g; '"'.$_.'"' } @ARGV);
		print STDERR "mr $action: running >>$command<<\n" if $verbose;
		my $ret=system($command);
		if ($ret != 0) {
			print STDERR "mr $action: failed ($ret)\n" if $verbose;
			push @failed, $dir;
			if ($ret >> 8 != 0) {
				print STDERR "mr $action: command failed\n";
			}
			elsif ($ret != 0) {
				print STDERR "mr $action: command died ($ret)\n";
			}
		}
		else {
			if ($action eq 'checkout' && ! -d $dir) {
				print STDERR "mr $action: $dir missing after checkout\n";;
				push @failed, $dir;
				return;
			}

			push @ok, $dir;
		}

		print "\n";
	}
} #}}}

sub showstat { #{{{
	my $count=shift;
	my $singular=shift;
	my $plural=shift;
	if ($count) {
		return "$count ".($count > 1 ? $plural : $singular);
	}
	return;
} #}}}
if (! @ok && ! @failed && ! @skipped) {
	die "mr $action: no repositories found to work on\n";
}
print "mr $action: finished (".join("; ",
	showstat($#ok+1, "ok", "ok"),
	showstat($#failed+1, "failed", "failed"),
	showstat($#skipped+1, "skipped", "skipped"),
).")\n";
if ($stats) {
	if (@skipped) {
		print "mr $action: (skipped: ".join(" ", @skipped).")\n";
	}
	if (@failed) {
		print "mr $action: (failed: ".join(" ", @failed).")\n";
	}
}
if (@failed) {
	exit 1;
}
elsif (! @ok && @skipped) {
	exit 1;
}
exit 0;

my %loaded;
sub loadconfig { #{{{
	my $f=shift;

	my @toload;

	my $in;
	my $dir;
	if (ref $f eq 'GLOB') {
		$dir="";
		$in=$f;	
	}
	else {
		if (! -e $f) {
			return;
		}

		my $absf=abs_path($f);
		if ($loaded{$absf}) {
			return;
		}
		$loaded{$absf}=1;

		($dir)=$f=~/^(.*\/)[^\/]+$/;
		if (! defined $dir) {
			$dir=".";
		}
		$dir=abs_path($dir)."/";

		# copy in defaults from first parent
		my $parent=$dir;
		while ($parent=~s/^(.*\/)[^\/]+\/?$/$1/) {
			if ($parent eq '/') {
				$parent="";
			}
			if (exists $config{$parent} &&
			    exists $config{$parent}{DEFAULT}) {
				$config{$dir}{DEFAULT}={ %{$config{$parent}{DEFAULT}} };
				last;
			}
		}
		
		print "mr: loading config $f\n" if $verbose;
		open($in, "<", $f) || die "mr: open $f: $!\n";
	}
	my @lines=<$in>;
	close $in;

	my $section;
	my $line=0;
	while (@lines) {
		$_=shift @lines;
		$line++;
		chomp;
		next if /^\s*\#/ || /^\s*$/;
		if (/^\[([^\]]*)\]\s*$/) {
			$section=$1;
		}
		elsif (/^(\w+)\s*=\s*(.*)/) {
			my $parameter=$1;
			my $value=$2;

			# continued value
			while (@lines && $lines[0]=~/^\s(.+)/) {
				shift(@lines);
				$line++;
				$value.="\n$1";
				chomp $value;
			}

			if (! defined $section) {
				die "$f line $.: parameter ($parameter) not in section\n";
			}
			if ($section ne 'ALIAS' &&
			    ! exists $config{$dir}{$section} &&
			    exists $config{$dir}{DEFAULT}) {
				# copy in defaults
				$config{$dir}{$section}={ %{$config{$dir}{DEFAULT}} };
			}
			if ($section eq 'ALIAS') {
				$alias{$parameter}=$value;
			}
			elsif ($parameter eq 'lib') {
				$config{$dir}{$section}{lib}.=$value."\n";
			}
			else {
				$config{$dir}{$section}{$parameter}=$value;
				$knownactions{$parameter}=1;
				if ($parameter eq 'chain' &&
				    length $dir && $section ne "DEFAULT" &&
				    -e $dir.$section."/.mrconfig" &&
			    	    system($value) >> 8 == 0) {
					push @toload, $dir.$section."/.mrconfig";
			        }
			}
		}
		else {
			die "$f line $line: parse error\n";
		}
	}

	foreach (@toload) {
		loadconfig($_);
	}
} #}}}

sub modifyconfig { #{{{
	my $f=shift;
	# the section to modify or add
	my $targetsection=shift;
	# fields to change in the section
	# To remove a field, set its value to "".
	my %changefields=@_;

	my @lines;
	my @out;

	if (-e $f) {
		open(my $in, "<", $f) || die "mr: open $f: $!\n";
		@lines=<$in>;
		close $in;
	}

	my $formatfield=sub {
		my $field=shift;
		my @value=split(/\n/, shift);

		return "$field = ".shift(@value)."\n".
			join("", map { "\t$_\n" } @value);
	};
	my $addfields=sub {
		my @blanks;
		while ($out[$#out] =~ /^\s*$/) {
			unshift @blanks, pop @out;
		}
		foreach my $field (sort keys %changefields) {
			if (length $changefields{$field}) {
				push @out, "$field = $changefields{$field}\n";
				delete $changefields{$field};
			}
		}
		push @out, @blanks;
	};

	my $section;
	while (@lines) {
		$_=shift(@lines);

		if (/^\s*\#/ || /^\s*$/) {
			push @out, $_;
		}
		elsif (/^\[([^\]]*)\]\s*$/) {
			if (defined $section && 
			    $section eq $targetsection) {
				$addfields->();
			}

			$section=$1;

			push @out, $_;
		}
		elsif (/^(\w+)\s*=\s(.*)/) {
			my $parameter=$1;
			my $value=$2;

			# continued value
			while (@lines && $lines[0]=~/^\s(.+)/) {
				shift(@lines);
				$value.="\n$1";
				chomp $value;
			}

			if ($section eq $targetsection) {
				if (exists $changefields{$parameter}) {
					if (length $changefields{$parameter}) {
						$value=$changefields{$parameter};
					}
					delete $changefields{$parameter};
				}
			}

			push @out, $formatfield->($parameter, $value);
		}
	}

	if (defined $section && 
	    $section eq $targetsection) {
		$addfields->();
	}
	elsif (%changefields) {
		push @out, "\n[$targetsection]\n";
		foreach my $field (sort keys %changefields) {
			if (length $changefields{$field}) {
				push @out, $formatfield->($field, $changefields{$field});
			}
		}
	}

	open(my $out, ">", $f) || die "mr: write $f: $!\n";
	print $out @out;
	close $out;	
} #}}}

# Finally, some useful actions that mr knows about by default.
# These can be overridden in ~/.mrconfig.
#DATA{{{
__DATA__
[ALIAS]
co = checkout
ci = commit
ls = list

[DEFAULT]
lib =
	error() {
		echo "mr: $@" >&2
		exit 1
	}
	hours_since() {
		for dir in .git .svn .bzr CVS; do
			if [ -e "$MR_REPO/$dir" ]; then
				flagfile="$MR_REPO/$dir/.mr_last$1"
				break
			fi
		done
		if [ -z "$flagfile" ]; then
			error "cannot determine flag filename"
		fi
		perl -wle 'print -f shift() ? int((-M _) * 24) : 9999' "$flagfile"
		touch "$flagfile"
	}

update =
	if [ -d "$MR_REPO"/.svn ]; then
		svn update "$@"
	elif [ -d "$MR_REPO"/.git ]; then
		git pull origin master "$@"
	elif [ -d "$MR_REPO"/.bzr ]; then
		bzr merge "$@"
	elif [ -d "$MR_REPO"/CVS ]; then
		cvs update "$@"
	else
		error "unknown repo type"
	fi
status =
	if [ -d "$MR_REPO"/.svn ]; then
		svn status "$@"
	elif [ -d "$MR_REPO"/.git ]; then
		git status "$@" || true
	elif [ -d "$MR_REPO"/.bzr ]; then
		bzr status "$@"
	elif [ -d "$MR_REPO"/CVS ]; then
		cvs status "$@"
	else
		error "unknown repo type"
	fi
commit =
	if [ -d "$MR_REPO"/.svn ]; then
		svn commit "$@"
	elif [ -d "$MR_REPO"/.git ]; then
		git commit -a "$@" && git push --all
	elif [ -d "$MR_REPO"/.bzr ]; then
		bzr commit "$@" && bzr push
	elif [ -d "$MR_REPO"/CVS ]; then
		cvs commit "$@"
	else
		error "unknown repo type"
	fi
diff =
	if [ -d "$MR_REPO"/.svn ]; then
		svn diff "$@"
	elif [ -d "$MR_REPO"/.git ]; then
		git diff "$@"
	elif [ -d "$MR_REPO"/.bzr ]; then
		bzr diff "$@"
	elif [ -d "$MR_REPO"/CVS ]; then
		cvs diff "$@"
	else
		error "unknown repo type"
	fi
log =
	if [ -d "$MR_REPO"/.svn ]; then
		svn log"$@"
	elif [ -d "$MR_REPO"/.git ]; then
		git log "$@"
	elif [ -d "$MR_REPO"/.bzr ]; then
		bzr log "$@"
	elif [ -d "$MR_REPO"/CVS ]; then
		cvs log "$@"
	else
		error "unknown repo type"
	fi
register =
	if [ -n "$1" ]; then
		cd "$1"
	fi
	basedir="$(basename $(pwd))"
	if [ -d .svn ]; then
		url=$(LANG=C svn info . | grep -i ^URL: | cut -d ' ' -f 2)
		if [ -z "$url" ]; then
			error "cannot determine svn url"
		fi
		echo "Registering svn url: $url"
		mr config "$(pwd)" checkout="svn co $url $basedir"
	elif [ -d .git ]; then
		url=$(LANG=C git-config --get remote.origin.url)
		if [ -z "$url" ]; then
			error "cannot determine git url"
		fi
		echo "Registering git url: $url"
		mr config "$(pwd)" checkout="git clone $url $basedir"
	elif [ -d .bzr ]; then
		url=$(cat .bzr/branch/parent)
		if [ -z "$url" ]; then
			error "cannot determine bzr url"
		fi
		echo "Registering bzr url: $url"
		mr config "$(pwd)" checkout="bzr clone $url $basedir"
	else
		error "unable to register this repo type"
	fi
help =
	if [ ! -e "$MR_PATH" ]; then
		error "cannot find program path"
	fi
	(pod2man -c mr "$MR_PATH" | man -l -) || error "pod2man or man failed"
list = true
config = 

ed = echo "A horse is a horse, of course, of course.."
T = echo "I pity the fool."
right = echo "Not found."
#}}}