#!/usr/bin/perl
# extract_license
# Determine the license of a program, given 2 parameters:
# (1) the directory containing the program's source code.
# (2) the RPM spec file (which may be /dev/null)

# This "regularizes" license names.  For example,
# BSD-style, BSDish, and BSD-like all become "BSD-like".
# License names "sentence capitalization", e.g., "Freely distributable".
# It also fixes a lot of errors in Red Hat spec files.

# 
# This is part of SLOCCount, a toolsuite that counts
# source lines of code (SLOC).
# Copyright (C) 2001-2004 David A. Wheeler.
# 
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
# 
# To contact David A. Wheeler, see his website at:
#  http://www.dwheeler.com.
# 
# 

$program_dir = shift;
$rpm_spec = shift;

$license = $copyright = "";

%all_licenses = ();


sub read_license_file() {
 my $filename = shift(@_);
 my $license = "";
 if ((-s $filename) && open(LICENSE_FILE, "<$filename")) {
    # TODO: detect even more licenses automatically.
    # It'd hard to detect BSD/MIT licenses,
    # because these licenses make changes in the MIDDLE of their text.
    # Thus, it's hard to avoid falsely detecting "almost" licenses.
    # For example, ipf has license text that looks like a BSD/MIT license,
    # but it's not even open source.
    # However, we CAN detect many other kinds, so let's at least do that.
    for ($i=1; $i < 9; $i++) {
      $line = <LICENSE_FILE>;
      if ($line =~ m/GNU GENERAL PUBLIC LICENSE/i) {$license = "GPL";}
      elsif ($line =~ m/GNU LIBRARY GENERAL PUBLIC LICENSE/i) {$license = "LGPL";}
      elsif ($line =~ m/GNU LESSER GENERAL PUBLIC LICENSE/i) {$license = "LGPL";}
      elsif ($line =~ m/Mozilla PUBLIC LICENSE/i) {$license = "MPL";}
      elsif ($line =~ m/Netscape PUBLIC LICENSE/i) {$license = "NPL";}
      elsif ($line =~ m/IBM PUBLIC LICENSE/i) {$license = "IBM Public License";}
      elsif ($line =~ m/\bApache Software License\b/i) {$license = "Apache";}
      elsif ($line =~ m/\bThe "Artistic License"/i) {$license = "Artistic";}
    }
    close(LICENSE_FILE);
  }
  return $license;
}

sub add_license() {
 # Add to license list "all_licenses" the license in the given file, if one.
 my $filename = shift(@_);
 my $license = &read_license_file($filename);
 if ($license) { $all_licenses{$license} = 1; }
}

open(RPM_SPEC, "<$rpm_spec");

while (<RPM_SPEC>) {
 if (/^Copyright:(.*)/i) {$copyright=$1;}
 if (/^License:(.*)/i)       {$license=$1;}
}
close(RPM_SPEC);

if (! $license) {
  $license = $copyright;
}

# print "GOT: $license\n";

if ( $license ) {
  $_ = $license;

  # Remove extraneous material in the middile of the license text.
  s/ \(see: [^)]*\)//;  # Delete parenthetical see: references.
  s/, ?no warranties//;  # "No warranties" not important for our purposes.
  s/See COPYRIGHT file//i;
  s/\b,?URW holds copyright\b//i;

  # Clean up front and back.
  s/^\s*//;
  s/[ \t\.]*$//;  # Delete trailing periods and blanks.

  $_ = ucfirst($_);  # Uppercase first character. Remove this line if need to.

  if (/^GPL2?$/i || /^GNU$/ || /^GNU ?GPL *(Version 2)?$/i) {$_ = "GPL"};
  if (/^Apache ?Group License$/i) {$_ = "Apache"};
  if (/^Apacheish$/i || /^Apache-style$/i) {$_ = "Apache-like"};
  if (/^Artistic$/i) {$_ = "Artistic"};
  if (/^BSD$/i) {$_ = "BSD"};
  if (/^BSDish$/i || /^BSD-style$/i || /^BSD-like$/) {$_ = "BSD-like"};
  if (/^Distributable$/i) {$_ = "Distributable"};
  if (/^Distributable ?\(BSD-like\)$/i) {$_ = "BSD-like"};
  if (/^Freely ?Distributable$/i) {$_ = "Freely distributable"};
  if (/^Free,no warranties.?$/i) {$_ = "Free"};
  if (/^freeware. See COPYRIGHT file.?$/i) {$_ = "Free"};
  if (/^freeware.?$/i) {$_ = "Free"};
  if (/^GPLand Artistic$/i) {$_ = "GPL and Artistic"};
  if (/^GPL ?or BSD$/i) {$_ = "GPL or BSD"};
  if (/^GPL\/XFree86$/i) {$_ = "GPL/MIT"};
  if (/^distributable- most of it GPL$/i) {$_ = "Distributable - mostly GPL"};
  if (/^IBM ?Public License Version 1.0 -/i) {$_ = "IBM Public License"};
  if (/^IBM ?Public License$/i) {$_ = "IBM Public License"};
  if (/^MIT, ?freely distributable/i) {$_ = "MIT"};
  if (/^MIT\/X ?Consortium$/i) {$_ = "MIT"};
  if (/^Non[- ]commercial[- ]use[- ]only$/i) {$_ = "Non-commercial use only"};
  if (/^Proprietary$/i) {$_ = "Proprietary"};
  if (/^Public ?domain$/i) {$_ = "Public domain"};
  if (/^Universityof Washington's Free-Fork License$/i)
         {$_ = "U of Washington's Free-Fork License"};
  if (/^W3CCopyright \(BSD like\)$/i) {$_ = "BSD-like"};
  if (/^X ?Consortium[ -]?like$/i) {$_ = "MIT-like"};
  if (/^XFree86$/i) {$_ = "MIT"};
  if (/^W3C Copyright \(BSD[- ]like\)$/i) {$_ = "BSD-like"};

  # Eliminate license if it isn't really a license.
  if (/^2000Red Hat, Inc.?$/i) {$_ = ""};
  if (/^OMRON ?Corporation, OMRON Software Co., Ltd.?$/i) {$_ = ""};
  if (/^Copyright\s?.?\s?[1-9][0-9][0-9][0-9]/i) {$_ = ""}; # Not a license.
  if (/^\(C\)\s?[1-9][0-9][0-9][0-9]/i) {$_ = ""}; # Not a license.
  if (/^[1-9][0-9][0-9][0-9]\s/i) {$_ = ""}; # A date, not a license.

  $license = $_;
}

if ($license) {
  print $license;
} else {
  # The spec file didn't tell us anything.  Let's look for files that tell us.
  &add_license("${program_dir}/LICENSE");
  &add_license("${program_dir}/COPYING");
  &add_license("${program_dir}/COPYING.LIB");
  &add_license("${program_dir}/Artistic");
  &add_license("${program_dir}/COPYING-2.0");
  &add_license("${program_dir}/COPYING.WTFPL");
  &add_license("${program_dir}/COPYING.GPL");
  &add_license("${program_dir}/COPYING.NEWLIB");
  &add_license("${program_dir}/COPYING.kdb");
  if (-s "${program_dir}/COPYING.BSD") {  # Assume there's a BSD license.
     $all_licenses{"BSD"} = 1;
  }
  if (-s "${program_dir}/COPYING.MIT") {  # Assume there's an MIT license.
     $all_licenses{"MIT"} = 1;
  }

  if (%all_licenses) {
     $license = "";
     foreach $license_fragment (sort(keys(%all_licenses))) {
       $license .= "${license_fragment}, "
     }
     $license =~ s/, $//;
     print $license;
  }

}
print "\n";