package App::FatPacker;

use strict;
use warnings FATAL => 'all';
use 5.008001;
use Getopt::Long;
use Cwd qw(cwd);
use File::Find qw(find);
use File::Spec::Functions qw(
  catdir splitpath splitdir catpath rel2abs abs2rel
);
use File::Copy qw(copy);
use File::Path qw(make_path remove_tree);
use B qw(perlstring);

our $VERSION = '0.009003'; # 0.9.3

$VERSION = eval $VERSION;

my $option_parser = Getopt::Long::Parser->new(
  config => [ qw(require_order pass_through bundling no_auto_abbrev) ]
);

sub call_parser {
  local *ARGV = [ @{$_[0]} ];
  $option_parser->getoptions(@{$_[1]});
  [ @ARGV ];
}

sub lines_of {
  map +(chomp,$_)[1], do { local @ARGV = ($_[0]); <> };
}

sub stripspace {
  my ($text) = @_;
  $text =~ /^(\s+)/ && $text =~ s/^$1//mg;
  $text;
}

sub import {
  $_[1] eq '-run_script'
    and return shift->new->run_script;
}

sub new { bless({}, $_[0]) }

sub run_script {
  my ($self, $args) = @_;
  my @args = $args ? @$args : @ARGV;
  (my $cmd = shift @args || 'help') =~ s/-/_/g;
  if (my $meth = $self->can("script_command_${cmd}")) {
    $self->$meth(\@args);
  } else {
    die "No such command ${cmd}";
  }
}

sub script_command_help {
  print "Try `perldoc fatpack` for how to use me\n";
}

sub script_command_trace {
  my ($self, $args) = @_;
  
  $args = call_parser $args => [
    'to=s' => \my $file,
    'to-stderr' => \my $to_stderr,
  ];

  die "Can't use to and to-stderr on same call" if $file && $to_stderr;

  (my $use_file = $file) ||= 'fatpacker.trace';
  if (!$to_stderr and -e $use_file) {
    unlink $use_file or die "Couldn't remove old trace file: $!";
  }
  my $arg = do {
    if ($file) {
      "=>>${file}"
    } elsif ($to_stderr) {
      "=>&STDERR"
    } else {
      ""
    }
  };
  {
    local $ENV{PERL5OPT} = '-MApp::FatPacker::Trace'.$arg;
    system $^X, @$args;
  }
}

sub script_command_packlists_for {
  my ($self, $args) = @_;
  foreach my $pl ($self->packlists_containing($args)) {
    print "${pl}\n";
  }
}

sub packlists_containing {
  my ($self, $targets) = @_;
  my @targets = @$targets;
  require $_ for @targets;
  my @search = grep -d $_, map catdir($_, 'auto'), @INC;
  my %pack_rev;
  my $cwd = cwd;
  find(sub {
    return unless $_ eq '.packlist' && -f $_;
    $pack_rev{$_} = $File::Find::name for lines_of $File::Find::name;
  }, @search);
  chdir($cwd) or die "Couldn't chdir back to ${cwd} after find: $!";
  my %found; @found{map +($pack_rev{$INC{$_}}||()), @targets} = ();
  sort keys %found;
}

sub script_command_tree {
  my ($self, $args) = @_;
  my $base = catdir(cwd,'fatlib');
  $self->packlists_to_tree($base, $args);
}

sub packlists_to_tree {
  my ($self, $where, $packlists) = @_;
  remove_tree $where;
  make_path $where;
  foreach my $pl (@$packlists) {
    my ($vol, $dirs, $file) = splitpath $pl;
    my @dir_parts = splitdir $dirs;
    my $pack_base;
    PART: foreach my $p (0 .. $#dir_parts) {
      if ($dir_parts[$p] eq 'auto') {
        # $p-2 since it's <wanted path>/$Config{archname}/auto
        $pack_base = catpath $vol, catdir @dir_parts[0..$p-2];
        last PART;
      }
    }
    die "Couldn't figure out base path of packlist ${pl}" unless $pack_base;
    foreach my $source (lines_of $pl) {
      # there is presumably a better way to do "is this under this base?"
      # but if so, it's not obvious to me in File::Spec
      next unless substr($source,0,length $pack_base) eq $pack_base;
      my $target = rel2abs( abs2rel($source, $pack_base), $where );
      my $target_dir = catpath((splitpath $target)[0,1]);
      make_path $target_dir;
      copy $source => $target;
    }
  }
}

sub script_command_file {
  my ($self, $args) = @_;
  my $file = shift @$args;
  my $cwd = cwd;
  my @dirs = map rel2abs($_, $cwd), ('lib','fatlib');
  my %files;
  foreach my $dir (@dirs) {
    find(sub {
      return unless -f $_;
      !/\.pm$/ and warn "File ${File::Find::name} isn't a .pm file - can't pack this and if you hoped we were going to things may not be what you expected later\n" and return;
      $files{abs2rel($File::Find::name,$dir)} = do {
        local (@ARGV, $/) = ($File::Find::name); <>
      };
    }, $dir);
  }
  my $start = stripspace <<'  END_START';
    # This chunk of stuff was generated by App::FatPacker. To find the original
    # file's code, look for the end of this BEGIN block or the string 'FATPACK'
    BEGIN {
    my %fatpacked;
  END_START
  my $end = stripspace <<'  END_END';
    s/^  //mg for values %fatpacked;

    unshift @INC, sub {
      if (my $fat = $fatpacked{$_[1]}) {
        open my $fh, '<', \$fat;
        return $fh;
      }
      return
    };

    } # END OF FATPACK CODE
  END_END
  my @segments = map {
    (my $stub = $_) =~ s/\.pm$//;
    my $name = uc join '_', split '/', $stub;
    my $data = $files{$_}; $data =~ s/^/  /mg; $data =~ s/(?<!\n)\z/\n/;
    '$fatpacked{'.perlstring($_).qq!} = <<'${name}';\n!
    .qq!${data}${name}\n!;
  } sort keys %files;
  print join "\n", $start, @segments, $end;
}

=head1 NAME

App::FatPacker - pack your dependencies onto your script file

=head1 SYNOPSIS

  $ fatpack trace myscript.pl
  $ fatpack packlists-for `cat fatpacker.trace` >packlists
  $ fatpack tree `cat packlists`
  $ (fatpack file; cat myscript.pl) >myscript.packed.pl

See the documentation for the L<fatpack> script itself for more information.

The programmatic API for this code is not yet fully decided, hence the 0.9.1
release version. Expect that to be cleaned up for 1.0.

=head1 SUPPORT

Your current best avenue is to come annoy annoy mst on #toolchain on
irc.perl.org. There should be a non-IRC means of support by 1.0.

=head1 AUTHOR

Matt S. Trout (mst) <mst@shadowcat.co.uk>

=head2 CONTRIBUTORS

None as yet, though I probably owe lots of people thanks for ideas. Yet
another doc nit to fix.

=head1 COPYRIGHT

Copyright (c) 2010 the App::FatPacker L</AUTHOR> and L</CONTRIBUTORS>
as listed above.

=head1 LICENSE

This library is free software and may be distributed under the same terms
as perl itself.

=cut

1;
