#!/usr/bin/env perl
#Kamin Whitehouse Oct 17 2004
#This script keeps a local working copy in synch with a subversion
#repository, only updating directories with changed files (for efficiency).  
#It should be called by your subversion post-commit script.
#
#The script takes two parametrs: the path to the repos and the
#revision number of which changes need to be synched.
#
#$reposdirectory is the directory in the repos we are trying to synch with
#$exporteddirectory is the path to the local working copy
#$username is the owner of the local working copy (who this script should be run as)
#$dirperms is the permissions that all directories in the working copy should have
#$fileperms is the permissions that all files in the working copy should have
#
#The dirperms and fileperms is most useful if you are trying to keep a
#www directory in synch with a svn repos.  They are set to 755 and 644
#by default so that all files in the working copy are world readable.
#
#The username is most useful if you are using apache to access your
#repository.  The post-commit scripts are run as the "apache" user, so
#you either need to let apache run as the owner of the repository or
#you need to let that user sudo to the owner of the repository for
#"svn up" commands.  
#
#This script is a modification of the standard commit-access-control.pl file that comes with the
#subversion distribution.  
#

# ====================================================================
# synchWithSvnRepos.pl: keep a local working copy in synch with a svn repos
#
# derived from:
# $HeadURL: http://svn.collab.net/repos/svn/branches/1.0.5/tools/hook-scripts/commit-access-control.pl.in $
# $LastChangedDate: 2004-02-12 05:07:35 -0500 (Thu, 12 Feb 2004) $
# $LastChangedBy: dlr $
# $LastChangedRevision: 8621 $
#
# Usage: synchWithSvnRepos.pl REPOS REV_NUM
#    
# ====================================================================
# Copyright (c) 2000-2004 CollabNet.  All rights reserved.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution.  The terms
# are also available at http://subversion.tigris.org/license-1.html.
# If newer versions of this license are posted there, you may use a
# newer version instead, at your option.
#
# This software consists of voluntary contributions made by many
# individuals.  For exact contribution history, see the revision
# history and logs, available at http://subversion.tigris.org/.
# ====================================================================

# The warning switch is set here and not in the shebang line above
# with /usr/bin/env because env will try to find the binary named
# 'perl -w', which won't work.
BEGIN
  {
    $^W = 1;
  }

use strict;
use Carp;
#use Config::IniFiles 2.27;

######################################################################
# Configuration section.

# web directory in repository
my $reposdirectory = "html/public_html/";

# exported web directory
my $exporteddirectory = "/mnt/coeus/public_html/";
#my $exporteddirectory = "/home/kamin/argus_html/";

# Svnlook path.
my $svnlook = "/usr/local/bin/svnlook";

# debug file name
my $debugFile = "/tmp/webUpdateDebug";

#directory perms: set updated dirs to these permissions
my $dirperms = "775";

#file perms: set updated files to these permissions
my $fileperms = "664";

# make sure the script is run as the following user:
my $username = "kamin";

# if the script is being run as a different user than specified above,
# that user must be able to sudo to the user above
my $sudoprefix = "";
if($username ne $ENV{"USER"}){
    $sudoprefix = "sudo -u $username";
}

# Since the path to svnlook depends upon the local installation
# preferences, check that the required program exists to insure that
# the administrator has set up the script properly.
{
  my $ok = 1;
  foreach my $program ($svnlook)
    {
      if (-e $program)
        {
          unless (-x $program)
            {
              warn "$0: required program `$program' is not executable, ",
                   "edit $0.\n";
              $ok = 0;
            }
        }
      else
        {
          warn "$0: required program `$program' does not exist, edit $0.\n";
          $ok = 0;
        }
    }
  exit 1 unless $ok;
}

######################################################################
# Initial setup/command-line handling.

&usage unless @ARGV == 2;

my $repos        = shift;
my $rev          = shift;

unless (-e $repos)
  {
    &usage("$0: repository directory `$repos' does not exist.");
  }
unless (-d $repos)
  {
    &usage("$0: repository directory `$repos' is not a directory.");
  }

# Define two constant subroutines to stand for read-only or read-write
# access to the repository.
sub ACCESS_READ_ONLY  () { 'read-only' }
sub ACCESS_READ_WRITE () { 'read-write' }

######################################################################
# Harvest data using svnlook.

# Change into /tmp so that svnlook diff can create its .svnlook
# directory.
my $tmp_dir = '/tmp';
chdir($tmp_dir)
  or die "$0: cannot chdir `$tmp_dir': $!\n";

open(FIL,">$debugFile");
print(FIL "repos $repos, revision $rev, sudoprefix = $sudoprefix\n");
close(FIL);

# Get the author from svnlook.
my @svnlooklines = &read_from_process($svnlook, 'author', $repos, '-r', $rev);
my $author = shift @svnlooklines;
unless (length $author)
  {
    die "$0: rev `$rev' has no author.\n";
  }

open(FIL,">>$debugFile");
print(FIL "author $author", "\n");
close(FIL);

# Figure out what directories have changed using svnlook..
my @dirs_changed = &read_from_process($svnlook, 'dirs-changed', $repos,
                                      '-r', $rev);
open(FIL,">>$debugFile");
print(FIL @dirs_changed,"\n");
close(FIL);

# Lose the trailing slash in the directory names if one exists, except
# in the case of '/'.
my $rootchanged = 0;
for (my $i=0; $i<@dirs_changed; ++$i)
  {
    if ($dirs_changed[$i] eq '/')
      {
        $rootchanged = 1;
      }
    else
      {
#	  print "Tried to strip slash but couldn't";
#        $dirs_changed[$i] =~ s#^(.+)[/\\]$#$1#;
      }
  }

# Figure out what files have changed using svnlook.
my @files_changed;
foreach my $line (&read_from_process($svnlook, 'changed', $repos, '-r', $rev))
  {
    # Split the line up into the modification code and path, ignoring
    # property modifications.
    if ($line =~ /^..  (.*)$/)
      {
        push(@files_changed, $1);
      }
  }

open(FIL,">>$debugFile");
print(FIL @files_changed,"\n");
close(FIL);

# Create the list of all modified paths.
my @changed = (@dirs_changed, @files_changed);

# There should always be at least one changed path.  If there are
# none, then there maybe something fishy going on, so just exit now
# indicating that the commit should not proceed.
unless (@changed)
  {
    die "$0: no changed paths found in rev `$rev'.\n";
  }

# Go through all the modified directories and see if any of them are in
# exporteddirectory.   If so, update that directory

foreach my $path (@dirs_changed)
  {
     if ( $path =~ s/^$reposdirectory/$exporteddirectory/)
     {
         #don't check to see if the directory exists because we might be adding a new directory
	 open(FIL,">>$debugFile");
	 print(FIL "> svn up -N $path\n");
	 if(system("$sudoprefix /usr/local/bin/svn up -N $path")!=0){
	     print(FIL "$!\n");
	 }
	 close(FIL);
     }
 }

#assuming the umask of the caller sets the correct permissions, you
#don't need the following code.  Otherwise, uncomment this code to
#change the permissions for each file/directory
# foreach my $path (@changed)
#   {
#      if ( $path =~ s/^$reposdirectory/$exporteddirectory/)
#      {
# 	 if ( -e $path)
# 	 {
# 	     if ($path =~ /.*\/$/) #this is a directory
# 	     {
# 		 open(FIL,">>$debugFile");
# 		 print(FIL "> chmod $dirperms $path\n");
# 		 if(system("$sudoprefix /bin/chmod 775 $path")!=0){
# 		     print(FIL "$!\n");
# 		 }
# 		 close(FIL);
# 	     }
# 	     else #this is a file
# 	     {
# 		 open(FIL,">>$debugFile");
# 		 print(FIL "> chmod $fileperms $path\n");
# 		 if(system("$sudoprefix /bin/chmod 664 $path")!=0){
# 		     print(FIL "$!\n");
# 		 }
# 		 close(FIL);
# 	     }
# 	 }
# 	 else
# 	 {
# 	     open(FIL,">>$debugFile");
# 	     print(FIL "> ERROR: no such directory \"chmod $path\n\"");
# 	     close(FIL);
# 	 }

#      }
#  }

#not the right thing to do
# 	  system "svn up $exporteddirectory";
# 	  system "find $exporteddirectory -type d  -exec chmod 755 '{}' \;";
# 	  system "find $exporteddirectory -type f  -exec chmod 644 '{}' \;";

# 	  system "find $exporteddirectory -type d -path '*.svn*' -exec chmod 750 '{}' \;";
# 	  system "find $exporteddirectory -type f -path '*.svn*' -exec chmod 640 '{}' \;";

sub usage
{
  warn "@_\n" if @_;
  die "usage: $0 REPOS REV-NUM\n";
}

sub safe_read_from_pipe
{
  unless (@_)
    {
      croak "$0: safe_read_from_pipe passed no arguments.\n";
    }
  print "Running @_\n";
  my $pid = open(SAFE_READ, '-|');
  unless (defined $pid)
    {
      die "$0: cannot fork: $!\n";
    }
  unless ($pid)
    {
      open(STDERR, ">&STDOUT")
        or die "$0: cannot dup STDOUT: $!\n";
      exec(@_)
        or die "$0: cannot exec `@_': $!\n";
    }
  my @output;
  while (<SAFE_READ>)
    {
      chomp;
      push(@output, $_);
    }
  close(SAFE_READ);
  my $result = $?;
  my $exit   = $result >> 8;
  my $signal = $result & 127;
  my $cd     = $result & 128 ? "with core dump" : "";
  if ($signal or $cd)
    {
      warn "$0: pipe from `@_' failed $cd: exit=$exit signal=$signal\n";
    }
  if (wantarray)
    {
      return ($result, @output);
    }
  else
    {
      return $result;
    }
}

sub read_from_process
  {
  unless (@_)
    {
      croak "$0: read_from_process passed no arguments.\n";
    }
  my ($status, @output) = &safe_read_from_pipe(@_);
  if ($status)
    {
      if (@output)
        {
          die "$0: `@_' failed with this output:\n", join("\n", @output), "\n";
        }
      else
        {
          die "$0: `@_' failed with no output.\n";
        }
    }
  else
    {
      return @output;
    }
}