# Copyright (c) 2010, Panos Louridas, GRNET S.A.
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
# list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# * Neither the name of GRNET S.A, nor the names of its contributors may be
# used to endorse or promote products derived from this software without
# specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

use strict;

use Prefixes qw(%other_namespaces %namespaces %languages);

my %redirect;

open(REDIRECT_FILE, "< $ARGV[0]");

while (my $line = <REDIRECT_FILE>) {
  chomp $line;
  my ($from , $to, $anchor) = $line =~ /(.+) #REDIRECT ([^#]+)(#.*)?/;
  $redirect{$from} = $to if $from ne $to; # makes sure we do not redirect to self
}

close(REDIRECT_FILE);

open(LINKS_FILE, "< $ARGV[1]");

while (my $line = <LINKS_FILE>) {
    chomp $line;
    my ($from, $to, $anchor) = $line =~ /(.+) => ([^#]+)(#.*)?/;
    next unless $from && $to;
    next if $to =~ /^:/;
    my $prefix = substr($to, 0, 1 + index($to, ":"));
    if ($prefix ne "" && ($other_namespaces{$prefix} || $namespaces{$prefix}
                          || $languages{$prefix})) {
      next;
    }
    my $new_target = $to;
    my %seen = ();
    while ($new_target && !exists($seen{$new_target})) {
      $seen{$new_target} = 1;
      $to = $new_target;
      $new_target = $redirect{$to};
    }
    $from = $from;
    if (index("$from => $to\n", "#") >= 0) {
      die "line: $line from: $from to: $to\n";
    }
    print "$from => $to\n";
}

close(LINKS_FILE);
