#!/usr/bin/perl -w

####################################################################################################
#
# Program:         getpapers
#
# Function:        Extracts the local-url lines from a BibTeX library file exported by Papers
#                  and copies PDF files to the current directory
#
# Author:          Benjamin Bulheller
#
# Website:         www.bulheller.com
#
# Mail address:    webmaster.-at-.bulheller.com
#
# Version:         $Revision: 3076 $, $Date: 2008-07-03 17:20:33 +0100 (Thu, 03 Jul 2008) $
#
####################################################################################################

use strict;                          # always use this!!!
use Data::Dumper;                    # for easy printout of arrays and hashes
use FindBin qw/$Bin/;                # sets $Bin to the directory of the script
use File::Copy;                      # to copy and move files
# use lib $Bin;                      # add the script's directory to the library path
# use lib "$ENV{HOME}/bin/perllib/"; # adds ~/bin/perllib to the library path
# use DebugPrint;                    # handy during debugging

my ($File, @Lines, $Line, $Start, $End);

if (not @ARGV) {
	print "\n";
	print "Usage:   getpapers  library.bib\n\n";
	print "library.bib must be a BibTeX library exported by Papers. All local-url fields are\n";
	print "extracted and the file://localhost prefix is removed in order to copy all files to\n";
	print "the current directory.\n\n";
	exit 1;
}

while (@ARGV) {                                  # while command line parameters are still available
	$File = shift;                                # read the next given filename
	
	if (not -f $File) {
		print "\nERROR: File $File not found\n\n";
		next;
	}
	
	@Lines = `grep local-url $File`;              # get all lines containing "local-url"
	chomp @Lines;                                 # remove line feeds

	foreach $Line ( @Lines ) {
		$Start =  index $Line, "{";                # determine the position of the first "{"
		$End   = rindex $Line, "}";                # determine the position of the last "}"
		$End   = $End - $Start - 1;                # for substr, $End needs to be the length from $Start
		$Line  = substr $Line, $Start + 1, $End;   # cut out the filename
		
		$Line =~ s!file://localhost!!;             # remove the URL prefix
		$Line =~ s/%20/ /g;                        # replace "%20" with a space (Perl automatically escapes it)
		
		if (not -f $Line) {
			print "WARNING: File $Line not found.\n";
		}
		else {
			copy $Line, ".";
		}
	}
}