#!/usr/bin/perl

# RPM (and it's source code) is covered under two separate licenses. 

# The entire code base may be distributed under the terms of the GNU
# General Public License (GPL), which appears immediately below.
# Alternatively, all of the source code in the lib subdirectory of the
# RPM source code distribution as well as any code derived from that
# code may instead be distributed under the GNU Library General Public
# License (LGPL), at the choice of the distributor. The complete text
# of the LGPL appears at the bottom of this file.

# This alternatively is allowed to enable applications to be linked
# against the RPM library (commonly called librpm) without forcing
# such applications to be distributed under the GPL.

# Any questions regarding the licensing of RPM should be addressed to
# Erik Troan <ewt@redhat.com>.

# a simple makedepends like script for perl.
 
# To save development time I do not parse the perl grammmar but
# instead just lex it looking for what I want.  I take special care to
# ignore comments and pod's.

# It would be much better if perl could tell us the dependencies of a
# given script.

# The filenames to scan are either passed on the command line or if
# that is empty they are passed via stdin.

# If there are strings in the file which match the pattern
#     m/^\s*\$RPM_Requires\s*=\s*["'](.*)['"]/i
# then these are treated as additional names which are required by the
# file and are printed as well.

# I plan to rewrite this in C so that perl is not required by RPM at
# build time.

# by Ken Estes Mail.com kestes@staff.mail.com
# modified by Mikhail Zabaluev <mookid@mu.ru>
# modified by Alexey Tourbin <at@turbinal.org>

use 5.005; # qr
use Getopt::Long;
use File::Spec;

GetOptions("debug" => \my $debug, "method=s" => \my $method);
sub debug ($) {
	my $msg = shift;
	warn "$msg\n" if $debug;
}
if ($debug) {
	require IO::Handle;
	STDOUT->autoflush(1);
	STDERR->autoflush(1);
	debug "debug mode enabled";
}
$method ||= $ENV{RPM_PERL_REQ_METHOD};
$method =~ s/\s+//g;
$method eq "strict" || $method eq "normal" || $method eq "relaxed"
	|| die "$0: strcit, normal, relaxed methods supported\n";
debug "method = $method";

my @ignore_files = (
	qr(/usr/share/doc/),
	qr(/[Dd]emos?/),
	qr(/examples?/),
);
my @ignore_reqs = (
	qr(^Makefile\b),
# OS-specific
	qr(^machine/ansi\b),
	qr(^sys/systeminfo\b),
	qr(^vmsish\b),
	qr(^MacPerl\b),
	qr(^VMS/),
	qr(^OS2/),
	qr(^Mac/),
	qr(^ExtUtils/XSSymSet\b),
	qr(^Convert/EBCDIC\b),
# old names
	qr(^Digest/Perl/MD5\b),
	qr(^Pod/PlainText\b),
# wrong names
	qr(/\.),
	qr(\$),
# MDK: skip if the phrase was "use of" -- shows up in gimp-perl, et al
	qr(^of$),
);

if (@ARGV) {
  foreach (@ARGV) {
    process_file($_);
  }
} else {
  
  # notice we are passed a list of filenames NOT as common in unix the
  # contents of the file.
  
  foreach (<>) {
    process_file($_);
  }
}

MODULE:
foreach $module (sort keys %require) {
  unless ($method eq "strict") {
	for my $re (@ignore_reqs) {
		if ($module =~ $re) {
			debug "module $module matches $re; skip";
			next MODULE;
		}
	}
  }
  if (length($require{$module}) == 0) {
    print "perl($module)\n";
  } else {
    print "perl($module) >= $require{$module}\n";
  }
}

exit 0;



sub process_file {
  
  my ($file) = @_;
  chomp($file);

  return if $file eq '';

  unless ($method eq "strict") {
	foreach my $re (@ignore_files) {
		if ($file =~ $re) {
			debug "file: $file matches: $re; skip";
			return;
		}
	}
  }

  open(FILE, "<$file")||
    die("$0: Could not open file: '$file' : $!\n");
  
  while (<FILE>) {
    
    # skip the documentation

    # we should not need to have item in this if statement (it
    # properly belongs in the over/back section) but people do not
    # read the perldoc.

    if ((m/^=(head[12]|pod|over|item|for|begin)/) .. (m/^=(cut)/)) {
      next;
    }
    
    if ( (m/^=(over)/) .. (m/^=(back)/) ) {
      next;
    }
    
    # skip the data section
    # AT: but what about AutoLoader and SelfLoader? (TODO)
    if (m/^__(DATA|END)__$/) {
      last;
    }

    # Each keyword can appear multiple times.  Don't
    #  bother with datastructures to store these strings,
    #  if we need to print it print it now.
    
    if ( m/^\s*\$RPM_Requires\s*=\s*["'](.*)['"]/i) {
      foreach (split(/\s+/, $1)) {
	print "$_\n";
      }
      next;
    }

	chomp;
	s/#.*//;
	next unless /\b(use|require|do)\b/; # do not want 'do {' loops
	next if /\bdo\s*{/; # do not want 'do {' loops
	next if /^\s*["']/;
	# print "just use it";
	if (/^\s*(?:(?!use|require|do|eval|if|unless)[\w:$->]+\s*)+\(/) {
		debug "skip: $_";
		next;
	}
	if (/^\s*(?:(?!use|require|do|eval|if|unless)[\w:]+\s*)+\(?(['"]).*\1/) {
		debug "skip: $_";
		next;
	}
	next unless /^(.*?)\b(use|do|require)\s+(['"]?)([.:\w\/]+)\3\s*(.*)/;
	my ($indent, $statement, $quote, $module, $rest) = ($1, $2, $3, $4, $5);
	debug "line: $_";
	next if $module =~ m/\$/;
	next if $module !~ m/\w/;

	# conditional statements
	if (/\b(if|unless|eval)\b/ && $method eq "relaxed") {
		debug "file: $file requires: $module (conditional); skip";
		next;
	}

	# indent is somewhat unclear
	if ($indent =~ /[^\w\s{}();:]/ && $method ne "strict") {
		debug "file: $file requires: $module (indent unclear); skip";
		next;
	}
		
	# statement requires a particular version of Perl
	if ($module =~ m/^v?[0-9._]+$/ && $rest =~ /^;|\s*$/) {
		print "perl-base >= " . package_version($module, '%.5f') . "\n";
		next;
	}

	if ($statement eq "require") {
		if ($indent =~ /^\s+$/ && $method eq "relaxed") {
			debug "file: $file <require>s: $module (whitespace); skip";
			next;
		}
		if ($indent =~ /\S/ && $method ne "strict") {
			debug "file: $file <require>s: $module (inside); skip";
			next;
		}
	}

	if ($statement eq "do") {
		if ($indent =~ /^\s+$/ && $method eq "relaxed") {
			debug "file: $file <do>es: $module (whitespace); skip";
			next;
		}
		if ($indent =~ /\S/ && $method ne "strict") {
			debug "file: $file <do>es: $module (inside); skip";
			next;
		}
	}

	if ($statement eq "use") {
		if ($indent =~ /\S/ && $method ne "strict") {
			debug "file: $file <use>s: $module (inside); skip";
			next;
		}
	}

	# filename
	if ($quote && $module =~ /^\w+(\/\w+)*\.p[lmh]$/ && $rest =~ /^$|;/ &&
		($statement eq "do" || $statement eq "require"))
	{
		$require{$module} = undef;
		debug "\$require{$module} = yes";
		next;
	}

	# modules, variables, lists
	my $m = qr/[:\w]+/;
	my $v = qr/[\$\%\@]$m/;
	my $s = qr/(?:[\s\t,]|=>)/;
	my $ml = qr/^\s*(?:qw)?[\/('"]?\s*($m(?:$s$m)*)/;
	my $fl = qr/^\s*(?:qw)?[\/('"]?\s*($m(?:$s$m)*)/;
	my $vl = qr/^\s*(?:qw)?[\/('"]?\s*($v(?:$s$v)*)/;
	
	# special pragma (vars, subs)
	if (($module eq "vars" || $module eq "subs") && $rest =~ $vl) {
		my $mod = module_filename($module);
		$require{$mod} = undef;
		debug "$module: \$requires{$mod} = yes";
		next;
	}

	# special pragma (constant)
	if ($module eq "constant" && $rest =~ $ml) {
		my $mod = module_filename($module);
		$require{$mod} = undef;
		debug "$module: \$requires{$mod} = yes";
		next;
	}

	# special pragma (base, autouse)
	if (($module eq "base" || $module eq "autouse") && $rest =~ $vl) {
		my $modules = $1;
		my @modules = split $s, $modules;
		foreach my $mod (@modules, $module) {
			if ($mod =~ /^\w+(::\w+)*$/) {
				$mod = module_filename($mod);
				$require{$mod} = undef;
				debug "$module: \$requires{$mod} = yes";
			}
		}
		next;
	}

	# special pragma (overload)
	if ($statement eq "use" && $module eq "overload" && $rest =~ /'|"|=>|,/) {
		my $mod = module_filename($module);
		$require{$mod} = undef;
		debug "\$requires{$mod} = yes";
		next;
	}

	# perl module
	if ($module && $module =~ /^\w+(::\w+)*$/ &&
		($rest =~ /^$|^[;}"']|\b(if|unless|eval)\b|\(|^v?\d|qw|$fl/ &&
		$indent =~ /^\s*$|[^\w\s]\s*$/) &&
		($statement eq "use" || $statement eq "require")) 
	{
		$module = module_filename($module);
		my ($version) = $rest =~ /^(v?[0-9._]+)\b/;
		if ($version) {
			$version = package_version($version);
			debug "\$require{$module} >= $version";
			$require{$module} = $version
				unless $require{$module} && $require{$module} >= $version;
		} else {
			$require{$module} = undef;
			debug "\$require{$module} = yes";
		}
		next;
	}
	debug "untrapped: $_";
  }

  close(FILE)||
    die("$0: Could not close file: '$file' : $!\n");
  
  return ; 
}


# module_filename($name) -
# converts module name to relative file path

sub module_filename {
  my $name = shift;
  $name =~ s{::|'}{/}g;
  return $name . '.pm'; 	#'
}


# package_version($version[, $oldformat]) -
# converts Perl version constant to RPM package version.
# New style 'vN.N.N' numbers are converted to epoch 1 versions,
# whereas old-style floating point versions are given epoch 0 and
# optionally formatted by sprintf() using supplied format.
# Parameters:
#   $version - version number in 'vN.N.N' or 'N.NNN_NN' format
#   $oldformat - format specifier for sprintf() used to format old-style
#       floating-point version number

sub package_version {
  my $version = shift;
  if ($version =~ s/^v// || $version =~ /\.[\d_]+\./) {
    return "1:$version";
  }
  else {
    my $format = shift;
    $format = '%s' unless defined $format;
    return '0:' . sprintf($format, $version);
  }
}