#!/usr/bin/perl

use strict;
use warnings;
use Getopt::Long;
use Pod::Usage;
use File::Spec;
use FindBin;
use lib "$FindBin::Bin/../lib";

use Crypt::TSD;

# Command line options
my $help = 0;
my $version = 0;
my $output_file;
my $extract_timestamps = 0;
my $timestamp_dir = "timestamps";
my $verbose = 0;

# Parse command line options
GetOptions(
    'help|h' => \$help,
    'version' => \$version,
    'output|o=s' => \$output_file,
    'timestamps|t' => \$extract_timestamps,
    'timestamp-dir|d=s' => \$timestamp_dir,
    'verbose|v' => \$verbose,
) or pod2usage(2);

# Show help
if ($help) {
    pod2usage(-verbose => 2);
    exit 0;
}

# Show version
if ($version) {
    print "tsd-extract version $Crypt::TSD::VERSION\n";
    exit 0;
}

# Get input file from command line
my $input_file = shift @ARGV;
if (!$input_file) {
    print "Error: Input TSD file required\n";
    pod2usage(1);
}

# Check if input file exists
unless (-f $input_file) {
    die "Error: Input file '$input_file' not found\n";
}

print "Extracting from TSD file...\n" if $verbose;
print "Input file: $input_file\n" if $verbose;

# Read TSD file
my $tsd_data;
eval {
    $tsd_data = Crypt::TSD->read_file($input_file);
};
if ($@) {
    die "Error reading TSD file: $@\n";
}

print "TSD file read successfully\n" if $verbose;
print "Version: " . $tsd_data->{version} . "\n" if $verbose;

# Extract content
my $content = Crypt::TSD->extract_content_der($tsd_data);
if (defined $content) {
    # Generate output filename if not provided
    unless ($output_file) {
        $output_file = $input_file;
        $output_file =~ s/\.tsd$/.extracted/;
    }
    
    print "Extracting content to: $output_file\n" if $verbose;
    
    # Write content to file
    open my $fh, '>:raw', $output_file or die "Cannot create output file '$output_file': $!\n";
    print $fh $content;
    close $fh;
    
    print "Content extracted successfully: $output_file\n";
    print "Content size: " . length($content) . " bytes\n" if $verbose;
} else {
    print "No embedded content found in TSD file\n";
}

# Extract timestamps if requested
if ($extract_timestamps) {
    print "Extracting timestamps...\n" if $verbose;
    
    # Create timestamp directory
    unless (-d $timestamp_dir) {
        mkdir $timestamp_dir or die "Cannot create timestamp directory '$timestamp_dir': $!\n";
    }
    
    my $token_count = Crypt::TSD->write_tst_files($tsd_data, $timestamp_dir);
    if ($token_count > 0) {
        print "Extracted $token_count timestamp(s) to directory: $timestamp_dir\n";
    } else {
        print "No timestamps found in TSD file\n";
    }
}

print "Done!\n";

__END__

=head1 NAME

tsd-extract - Extract content and timestamps from a TimeStampedData (.tsd) file

=head1 SYNOPSIS

tsd-extract [options] input_file.tsd

Options:
    -o, --output FILE       Output file for extracted content
    -t, --timestamps        Extract timestamp tokens to files
    -d, --timestamp-dir DIR Directory for timestamp files (default: timestamps)
    -v, --verbose           Verbose output
    -h, --help              Show this help
    --version               Show version

=head1 DESCRIPTION

Extracts the embedded content and optionally timestamp tokens from a
TimeStampedData (.tsd) file. The extracted content is saved to a file,
and timestamp tokens can be saved as separate .tsr files.

=head1 EXAMPLES

    # Extract content only
    tsd-extract document.tsd

    # Extract content to specific file
    tsd-extract -o original.pdf document.tsd

    # Extract content and timestamps
    tsd-extract -t document.tsd

    # Extract with custom timestamp directory
    tsd-extract -t -d my_timestamps document.tsd

    # Verbose output
    tsd-extract -v -t document.tsd

=head1 SEE ALSO

L<Crypt::TSD>, L<Crypt::TimestampedData>

=cut