#!/usr/bin/env perl

use strict;

my ($arg, $i, $j, $targ);

my @targets = qw/sjcl aes bitArray codecString codecHex codecBase32 codecBase64 codecBytes codecZ85 sha256 sha512 sha1 ccm ctr cbc ocb2 ocb2progressive gcm hmac pbkdf2 scrypt random convenience bn ecc srp ccmArrayBuffer codecArrayBuffer ripemd160/;
my %deps = ('aes'=>'sjcl',
            'bitArray'=>'sjcl',
            'codecString'=>'bitArray',
            'codecHex'=>'bitArray',
            'codecBase64'=>'bitArray',
            'codecBase32'=>'bitArray',
            'codecBytes'=>'bitArray',
            'codecZ85'=>'bitArray',
            'sha256'=>'codecString',
            'sha512'=>'codecString',
            'sha1'=>'codecString',
            'ripemd160' => 'codecString',
            'ccm'=>'bitArray,aes',
            'ctr'=>'bitArray,aes',
            'ocb2'=>'bitArray,aes',
            'ocb2progressive'=>'ocb2',
            'gcm'=>'bitArray,aes',
            'hmac'=>'sha256',
            'pbkdf2'=>'hmac',
            'scrypt'=>'pbkdf2,codecBytes',
            'srp'=>'sha1,bn,bitArray',
            'bn'=>'bitArray,random',
            'ecc'=>'bn',
            'cbc'=>'bitArray,aes',
            'random'=>'sha256,aes',
            'convenience'=>'ccm,pbkdf2,random,codecBase64',
            'ccmArrayBuffer'=>'bitArray,codecArrayBuffer',
            'codecArrayBuffer'=>'bitArray');

my $compress = "closure";
my $exported = 1;

my %enabled = ();
$enabled{$_} = 0 foreach (@targets);

# by default, all but codecBytes, codecZ85, srp, bn
$enabled{$_} = 1 foreach (qw/aes bitArray codecString codecHex codecBase32 codecBase64 sha256 ccm ocb2 gcm hmac pbkdf2 random convenience/);

# argument parsing
while (my $arg = shift @ARGV) {
  if ($arg =~ /^--?with-all$/) {
    foreach (@targets) {
      if ($enabled{$_} == 0) {
        $enabled{$_} = 1;
      }
    }
  } elsif ($arg =~ /^--?without-all$/) {
    foreach (@targets) {
      if ($enabled{$_} == 1) {
        $enabled{$_} = 0;
      }
    }
  } elsif ($arg =~ /^--?with-(.*)$/) {
    $targ = $1;
    $targ =~ s/-(.)/uc $1/ge;
    if (!defined $deps{$targ}) {
      print STDERR "No such target $targ\n";
      exit 1;
    }
    $enabled{$targ} = 2;
  } elsif ($arg =~ /^--?without-(.*)$/) {
    $targ = $1;
    $targ =~ s/-(.)/uc $1/ge;
    if (!defined $deps{$targ}) {
      print STDERR "No such target $targ\n";
      exit 1;
    }
    $enabled{$targ} = -1;
  } elsif ($arg =~ /^--?compress(?:or|ion)?=(none|closure|yui)$/) {
    $compress = $1;
  } elsif ($arg =~ /^--?no-export$/) {
    $exported = 0;
  } else {
    my $targets = join " ", @targets;
    $targets =~ s/sjcl //;
    $targets =~ s/(.{50})\s+/$1\n    /g;
    print STDERR <<EOT;
Usage: $0 arguments...

Valid arguments are:
  --with-all: by default, include all targets
  --without-all: by default, include no targets

  --compress=none|closure|yui

  --with-TARGET: require TARGET
  --without-TARGET: forbid TARGET

  --no-export: do not export sjcl

  --help: show this message

  Valid targets are:
    $targets

EOT
    exit 1 unless $arg =~ /^--?help$/;
    exit 0;
  }
}

my $config = '';
my $pconfig;

# dependency analysis: forbidden
foreach my $i (@targets) {
  if ($enabled{$i} > 0) {
    foreach $j (split /,/, $deps{$i}) {
      if ($enabled{$j} == -1) {
        if ($enabled{$i} == 2) {
          print STDERR "Conflicting options: $i depends on $j\n";
          exit 1;
        } else {
          $enabled{$i} = -1;
          last;
        }
      }
    }
  }
}

$config = "exports $config" if $exported;

# reverse
foreach my $i (reverse @targets) {
  if ($enabled{$i} > 0) {
    foreach $j (split /,/, $deps{$i}) {
      if ($enabled{$j} < $enabled{$i}) {
        $enabled{$j} = $enabled{$i};
      }
    }
    $config = "$i $config";
  }
}

open CONFIG, "> config.mk" or die "$!";


($pconfig = $config) =~ s/^sjcl //;
$pconfig =~ s/ /\n  /g;
print "Enabled components:\n  $pconfig\n";
print "Compression: $compress\n";

$config =~ s=\S+=core/$&.js=g;
print CONFIG "SOURCES= $config\n";

$compress = "core_$compress.js";
$compress = 'core.js' if ($compress eq 'core_none.js');

print CONFIG "COMPRESS= $compress\n";