#!/usr/bin/perl

# Date   : 4-20-2000
# Author : James Dean Palmer
#
# Description :
#
# This script performs file renaming / renumbering / copying tasks based
# on a silly grammar that I made up.  Type "renumber --help" for more
# information.

use Getopt::Long;

sub in_and_out {
  if (!(defined $in)) { $in = $_[0]; }
  elsif (!(defined $out)) { $out = $_[0]; }
  else {
    $opt_help = 1;
  }
};

&GetOptions("debug", "preview", "copy", "help", "<>", \&in_and_out);

if ((!defined $in) || (!defined $out)) { $opt_help = 1; }

if ($opt_help) {
  print "Usage: renumber [OPTION] \"SOURCE\" \"DEST\"\n";
  print "Rename SOURCE to DEST using renumber rules.\n\n";
  print "  --help           This message\n";
  print "  --copy           Copy the file instead of moving it\n";
  print "  --preview        Preview what is about to happen\n";
  print "\n";
  print "Renumber rules:\n\n";
  print "  (\#)\n";
  print "  (\#,N)\n";
  print "  (\#,N,START)\n";
  print "  (\#,N,START,END)\n";
  print "\n";
  print "Any of the above forms is valid where,\n";
  print "\n";
  print "  N = The number of digits to match when used in SOURCE.  If this \n";
  print "      is set to 0, any number of digits is matched.  N is the\n";
  print "      number of digits to print in DEST.  If the number to be \n";
  print "      printed in DEST is longer than N, it will be longer than N.\n";
  print "\n";
  print "  START = The number to start the match at in SOURCE.  START is the\n";
  print "      number to start renumbering at in DEST.\n";
  print "\n";
  print "  END = The number to end the match at in SOURCE.  END is the number\n";
  print "      to stop at in DEST.\n";
  print "\n";
  print "Caveats:\n\n";
  print "  Re-numbering takes place based on the sorted file order when using\n";
  print "  START and/or END.\n\n";
  print "  Wild cards may be used in both SOURCE and DEST.\n\n";
  print "  SOURCE and DEST must be quoted, otherwise your shell tries to \n";
  print "  interpret the wild cards and parans.\n\n";
  print "Examples:\n\n";
  print "  Renumber frames.##.tga to frames.#####.tga:\n";
  print "    renumber \"frames.(\#,2).tga\" \"frames.(\#,5).tga\"\n\n";
  print "  Renumber frames.???.tga to frames.#####.tga, where ??? is an\n";
  print "  unknown number of digits:\n";
  print "    renumber \"frames.(\#).tga\" \"frames.(\#,5).tga\"\n\n";
  print "  Use wild cards in the name:\n";
  print "    renumber \"*.(\#).tga\" \"*.(\#,5).tga\"\n\n";
  print "  Use multiple wild cards in the name:\n";
  print "    renumber \"*.(\#).*\" \"*.(\#,5).*\"\n\n";
  print "  Renumber frames 22-46 to 0093+:\n";
  print "    renumber \"frames.(\#,0,22,46).tga\" \"frames.(\#,4,93).tga\"\n\n";
  print "Report bugs to James Dean Palmer <james\@tiger-marmalade.com>\n";
  exit (0);
}

# $in                            The input file expression.
$in_path = "";                 # The input file path.
# $out                           The output file expression.
$out_path = "";                # The output file path.
# $wild_in                       The input file expression with wild cards.
$digits         = "";          # The expression to match digits.
$renumber       = 0;           # Should renumbering be done?
$renumber_start = 0;           # start point for renumbering.
$renumber_end   = 1000000000;  # end point for renumbering.

# First lets list all the files in IN, and see what matches.

while ($in =~ m/\//) {
  $in =~ s/(.*\/)//;
  $in_path .= $1;
}

while ($out =~ m/\//) {
  $out =~ s/(.*\/)//;
  $out_path .= $1;
}

if (!($in_path)) { $dir = "."; }
else { $dir = $in_path; }

if (!(opendir INDIR, "$dir")) {
  print STDERR "Could not open input directory, \"$dir\".\n";
  exit (0);
}

# Skip . and ..
readdir INDIR;
readdir INDIR;

# Get the sorted directory list.
@files = readdir INDIR;
closedir INDIR;
@files = sort @files;

# Escape out escapes.
$in =~ s/\\/\\\\/g;
$wild_in = $in;

# Build a regular expression based on $in.
if ($in =~ m/\(\#\s*\)/) {
  $digits = "\\d+";
} 
elsif ($in =~ m/\(\#\s*\,\s*(\d+)\s*\)/) {
  my ($cnt) = $1;
  for ($i=0; $i<$cnt; $i++) { $digits .= "\\d"; }
  if ($cnt == 0) { $digits = "\\d+"; }
}
elsif ($in =~ m/\(\#\s*\,\s*(\d+)\s*,\s*(\d+)\s*\)/) {
  my ($cnt) = $1;
  $start_match = $2;
  for ($i=0; $i<$cnt; $i++) { $digits .= "\\d"; }
  if ($cnt == 0) { $digits = "\\d+"; }
}
elsif ($in =~ m/\(\#\s*\,\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*\)/) {
  my ($cnt) = $1;
  $start_match = $2;
  $end_match = $3;
  for ($i=0; $i<$cnt; $i++) { $digits .= "\\d"; }
  if ($cnt == 0) { $digits = "\\d+"; }
}

# Match a renumber rule:
$in      =~ s/\(\#[ \,\d]*\)/\($digits\)/;
$wild_in =~ s/\(\#[ \,\d]*\)/$digits/;

# Match wild cards:
$in =~ s/\*/\\D\*/g;
$wild_cnt = ($wild_in =~ s/\*/\(\\D\*\)/g);

# Build a format based on $out.
if ($out =~ s/\(\#\s*\,\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*\)/__replace__/) {
  $digit_cnt = $1;
  $renumber_start = $2;
  $renumber_end = $3;
  $renumber = 1;
} 
elsif ($out =~ s/\(\#\s*\,\s*(\d+)\s*,\s*(\d+)\s*\)/__replace__/) {
  $digit_cnt = $1;
  $renumber_start = $2;
  $renumber = 1;
}
elsif ($out =~ s/\(\#\s*\,\s*(\d+)\s*\)/__replace__/) {
  $digit_cnt = $1;
}
elsif ($out =~ s/\(\#\s*\)/__replace__/) {
  $digit_cnt = 0;
}

if ($opt_debug) {
  print "in       =\"$in\"\n";
  print "out      =\"$out\"\n";
  print "wild_in  =\"$wild_in\"\n";
  print "in_path  =\"$in_path\"\n";
  print "out_path =\"$out_path\"\n";
}

$renumber_next = $renumber_start;
foreach $file (@files) {
  if ($file =~ m/$in/) {
    my ($number) = "";
    $number = $1;
    if ((!defined $start_match) || (int ($number) >= int ($start_match))) {
      if ((!defined $end_match) || (int ($number) <= int ($end_match))) {
        if ($renumber_next > $renumber_end) {
          print STDERR "Reached end count ($renumber_end).\n";
          exit (0);
        }
        if ($renumber) { $number = $renumber_next; }
        $renumber_next++;
        if ($digits) { 
          $number = sprintf ("%0." . $digit_cnt . "d", int ($number));
        }
        $newfile = $out;
        $newfile =~ s/__replace__/$number/;
        for ($i=0; $i<$wild_cnt; $i++) {
          my ($r);
          $file =~ m/$wild_in/;
          $r = ${$i+1};
          $newfile =~ s/\*/$r/;
        }
        $xxx = "$in_path$file $out_path$newfile";
        if ($opt_preview) {
          if ($opt_copy) {
            print "cp $xxx\n";
          } else {
            print "mv $xxx\n";
          }
        } else {
          if ($opt_copy) {
            print "cp $xxx\n";
	    print `cp $xxx`;
          } else {
            print "mv $xxx\n";
	    print `mv $xxx`;
          }    
        }
      }
    }
  }
}