#!/usr/bin/perl
#
# Pre-commit hook for running checkstyle on changed Java sources
#
# To use this you need:
# 1. checkstyle's jar file somewhere
# 2. a checkstyle XML check file somewhere
# 3. To configure git:
#   * git config --add checkstyle.jar <location of jar>
#   * git config --add checkstyle.checkfile <location of checkfile>
#   * git config --add checkstyle.basedir <project's basedir>
#   * git config --add checkstyle.defaultseverity <default severity level>
#   * git config --add checkstyle.configloc <Path on the config file>
#   * git config --add java.command <path to java executale> [optional
#     defaults to assuming it's in your path]
# 4. Put this in your .git/hooks directory as pre-commit
#
# Now, when you commit, you will be disallowed from doing so
# until you pass your checkstyle checks.

# Get files names located in index
$command = "git diff-index --cached --name-only HEAD";
#open (FILES,$command . "|") || die "Cannot run '$command': $!\n";
open (FILES,$command . "|") || die "Cannot run '$command': $!\n";

$CONFIG_CHECK_FILE = "checkstyle.checkfile";
$CONFIG_JAR = "checkstyle.jar";
$CONFIG_JAVA = "java.command";
$CONFIG_BASEDIR ="checkstyle.basedir";
$CONFIG_DEFAULT_SEVERITY ="checkstyle.defaultseverity";
$CONFIG_CONFIG_LOC ="checkstyle.configloc";

$check_file = `git config --get $CONFIG_CHECK_FILE`;
$checkstyle_jar = `git config --get $CONFIG_JAR`;
$java_command = `git config --get $CONFIG_JAVA`;
$basedir = `git config --get $CONFIG_BASEDIR`;
$defaultseverity = `git config --get $CONFIG_DEFAULT_SEVERITY`;
$configloc = `git config --get $CONFIG_CONFIG_LOC`;


if (!$check_file || !$checkstyle_jar)
{
   die "You must configure checkstyle in your git config:\n"
   . "\t$CONFIG_CHECK_FILE - path to your checkstyle.xml file\n"
   . "\t$CONFIG_JAR - path to your checkstyle jar file\n"
   . "\t$CONFIG_JAVA - path to your java executable (optional)\n"
   ;
}

# Stash files to have only check indexed files
$command = "git stash --keep-index -m'WIP pre-commit hook'";
@stashCommand = qx/$command/;
print "stashCommand: @stashCommand\n";

$java_command = "java" if (!$java_command);

chomp $check_file;
chomp $checkstyle_jar;
chomp $java_command;
chomp $basedir;
chomp $defaultseverity;
chomp $configloc;

$command = "$java_command -Dbasedir=$basedir -Ddefault_severity=$defaultseverity -Dconfig_loc=$configloc -jar $checkstyle_jar -c $check_file ";

@java_files = ();

foreach  (<FILES>)
{
   chomp;
   next if (!(/\.java$/));
   push @java_files,$_;
   $command .= " ";
   $command .= $_;
}


my $javaFileSize = @java_files;

if ($javaFileSize >= 1)
{
   print "[Checkstyle] List of Java files (" . $javaFileSize . "):\n[Checkstyle]\t" . join("\n[Checkstyle]\t", @java_files) . "\n[Checkstyle]\n";

   if (&run_and_log_system ($command))
   {
     $command = "git stash pop";
     @stashPopCommand = qx/$command/;
     print "stashPopCommand 1 : @stashPopCommand\n";
     print "[Checkstyle] GIT COMMIT ABORTED.\n";
     exit -1;
   }
}
else
{
    print "[Checkstyle] No Java file in index, checkstyle verifications ignored.\n";
    exit 0;
}

     $command = "git stash pop";
     @stashPopCommand = qx/$command/;
     print "stashPopCommand 2 : @stashPopCommand\n";


exit 0;

sub run_and_log_system
{
   ($cmd) = @_;
   @result = qx/$cmd/;
   my $size = $#result;
   print "[Checkstyle] " . join("[Checkstyle]\t", @result[0..$size-1]);
   print "[Checkstyle] " . @result[$size] . "[Checkstyle]\n";
   print "[Checkstyle] Violations: " . ($size - 1) . "\n[Checkstyle]\n";
   return $#result > 1 ? -1 : 0;
}