#!/usr/bin/perl

use strict;

my %config = (
		"confFiles"=> ["config/*php.dist","config/conf.xml"]
	);

my $debug = 1;

unless($#ARGV == 1) {
	DEBUG(1,"usage: $0 sourceDir destinationDir");
	exit;
}

unless (-e $ARGV[0] && -e $ARGV[1]) {
	DEBUG(0,"sourceDir $ARGV[0] or destinationDir $ARGV[1] not exist");
	exit(1);
}

unless (&farmer($ARGV[0],$ARGV[1])) {
	DEBUG(0,"Cloning failed");
}


sub farmer {

	my $from = shift;
	my $to = shift;
	my %FROM = ();
	
	unless ( -d $from ) {
		&DEBUG($from." not exist or not directory");
		return undef;
	}
	
	if (! -e $to ) {
		unless ($config{"confFiles"}) {
			symlink $from,$to;
			return "true";
		} else {
			mkdir $to,0755;
		}
	} elsif (! -d $to) {
		DEBUG(0,"$to exist but not directory");
		return undef;
	}

	foreach my $conf (@{$config{confFiles}}) {
		$conf =~ s/\*/[^\/]*/g;
		$conf =~ s/(\.|\?)/\\$1/g;
		$conf =~ s/^\///;
		$conf =~ s/\/$//;
	}

	my $dir = "";
	my %cdir = ();
	my @dirs = ();
	
	do {
		unless ( opendir(DIR,$from."/".$dir) ){
			DEBUG(0, "Can not open dir $from.$dir: $!");
			return undef;
		}
		foreach ( grep {! /\.{1,2}$/ } readdir(DIR)) {
			if ( -f $from."/".$dir."/".$_ ){
				$FROM{$dir."/".$_} = "f". &checkCf($dir."/".$_,\%cdir);
			} elsif ( -d $from."/".$dir."/".$_ ) {
				$FROM{$dir."/".$_} = "d". &checkCf($dir."/".$_,\%cdir);
				push @dirs,$dir."/".$_;
			} else {
				DEBUG(1, "$_ not file or directory. Skip it.");
			}
		}
		close(DIR);
		$dir = shift @dirs;
	} while ($dir);

	my @list = sort keys %FROM;

	foreach my $file (@list) {

		if (exists $cdir{$file} || $FROM{$file} eq "dc"){
			if ( -e $to.$file ) {
				if ( -l $to.$file ) {
					unlink $to.$file;
				} elsif (! -d $to.$file) {
					DEBUG(1,"$file is not a dir. Something wrong. Try to backUp");
					unless (&backUp($to.$file)) {
						return undef;
					};
				}
			}
			my ($mode,$uid,$gid) = (stat($from.$file))[2,4,5];
			mkdir $to.$file, $mode;
			chown $uid,$gid,$to.$file;
		} elsif ($FROM{$file} eq "fc") {
			if ( -l $to.$file ) {
				unlink $to.$file;
			} elsif ( -e $to.$file ) {
				next;
			}
			system("cp","-p",$from.$file,$to.$file);
		} elsif ($FROM{$file} eq "d") {
			if ( -l $to.$file ) {
				unlink $to.$file;
			} elsif ( -d $to.$file ) {
				DEBUG(1, "$file is a dir. Can not link it. Try to backUp");
				next unless (&backUp($to.$file));
			} elsif (-e $to.$file ) {
				DEBUG(1,"$file not dir. Try to backUp");
				unless (&backUp($to.$file)) {
					return undef;
				}
			}
			symlink($from.$file,$to.$file);
			foreach my $empty ( grep { /^$file\/.+/ } @list ){
				$FROM{$empty} = "empty";
			}

		} elsif ($FROM{$file} eq "f") {
			if (-l $to.$file) {
				unlink($from.$to);
			} elsif ( -e $to.$file) {
				next unless (&backUp($to.$file));
			}
			symlink($from.$file,$to.$file);
		}
	}

	return "ok";

}

sub checkCf {
	my $file = shift;
	my $dir = shift;
	my $ret = undef;
	my @tmp = ();
	foreach my $cnf (@{$config{confFiles}}) {
		next unless ($file =~ /^\/$cnf$/ || $file =~ /^\/$cnf\/.+$/ );
		$ret = "c";
		@tmp = split(/\//, $file);
		shift @tmp; pop @tmp;
		foreach (@tmp) {
			next if (exists ${$dir}{"/".$_});
			${$dir}{"/".$_} = "c";
		}
	}
	return $ret;
}

sub DEBUG {
	my $level = shift;
	my $message = shift;

        if ($level == 0) {
		print STDERR $message."\n";
	} elsif ($level <= $debug) {
		print $message."\n";
	}
}

sub backUp {
	my $file = shift;
	my $backup = $file.".farmer-save";
	
	if (-d $backup) {
		system("rm","-rf",$backup);
	} elsif ( -f $backup || -l $backup) {
		unlink $backup;
	} elsif ( -e $backup) {
		return undef;	
	}

	system("mv",$file,$backup);

	return "ok";	
}