hpr-tools/InternetArchive/view_derivatives

#!/usr/bin/env perl
#===============================================================================
#
#         FILE: view_derivatives
#
#        USAGE: ./view_derivatives metadata_file
#
#  DESCRIPTION: Experimental!
#               Reads a JSON file containing IA metadata for an item (HPR
#               show) and processes 'derived' files from the IA. Their
#               relationships are usually simple, but sometimes can be rather
#               weird, so building a representation of the hierarchy might be
#               a way to understand what's there and maybe make a list for the
#               'ia delete' command to work on!
#               Each 'original' file may be accompanied by 'derived' files. So
#               an image file might generate a thumbnail for example. The
#               image will be marked in the JSON metadata as "original" and
#               the derived file as a "derivative" with the file it was built
#               from being its "parent". There can also be "derivative" files
#               built from other "derivative"s in rare cases. This has been
#               seen when an EPUB file is used to build a PDF "derivative",
#               and then other versions of the PDF are generated as
#               "derivatives" with the PDF as the "parent".
#               The point is that we do not want the "derivatives". We (HPR)
#               generate all of the versions of a given file we require:
#               audio types and thumbnails, for example. The tools we use can
#               disable the generation of "derivatives", so it has been rare
#               to see them in recent times. However, with older shows we
#               either couldn't stop the "derive" process, or some IA servers
#               ignored our '--no-derive' options. Now (August 2024) we are
#               cleaning up the HPR collection, and thus this script has been
#               developed.
#               Special note: any cleaning up of IA items needs to be done
#               before files are moved around. The parental relationships are
#               stored in the metadata, and do not track file movements. This
#               script cannot analyse metadata from after such rearrangements!
#               [It may be possible to adjust these metadata fields, but it
#               does not seem to be necessary if the correct sequence of
#               changes is adhered to - find derivatives, delete derivatives,
#               move files]
#
#      OPTIONS: ---
# REQUIREMENTS: ---
#         BUGS: ---
#        NOTES: ---
#       AUTHOR: Dave Morriss (djm), Dave.Morriss@gmail.com
#      VERSION: 0.0.2
#      CREATED: 2024-08-12 16:26:29
#     REVISION: 2024-08-17 13:44:44
#
#===============================================================================

use v5.36;
use strict;
use warnings;
use feature qw{ postderef say signatures state try };
no warnings
    qw{ experimental::postderef experimental::signatures experimental::try };

use open ':std', ':encoding(UTF-8)'; # Make all IO UTF-8

use Carp;
use Getopt::Long;
use Pod::Usage;

use File::Slurper qw{ read_text read_lines };
use JSON;

use Data::Dumper;

#
# Version number (Incremented by Vim)
#
our $VERSION = '0.0.2';

#
# Script and directory names
#
( my $PROG = $0 ) =~ s|.*/||mx;
( my $DIR  = $0 ) =~ s|/?[^/]*$||mx;
$DIR = '.' unless $DIR;

#-------------------------------------------------------------------------------
# Declarations
#-------------------------------------------------------------------------------
#
# Constants and other declarations
#
my $basedir    = "$ENV{HOME}/HPR/InternetArchive";
my $outputfile = "$basedir/$PROG.svg";
my $logfile    = "$basedir/$PROG.log";

my ( $file, $filebuffer, $json, @jsonbuffer );
my ( %filetree, @original, @derived );

#-------------------------------------------------------------------------------
# Options
#-------------------------------------------------------------------------------
#
# Option defaults
#
my $DEFDEBUG = 0;

#
# Options and arguments
#
my %options;
Options( \%options );

#
# Default help shows minimal information
#
pod2usage( -msg => "$PROG version $VERSION\n", -exitval => 1, -verbose => 0 )
    if ( $options{'help'} );

#
# The -documentation or -man option shows the full POD documentation through
# a pager for convenience
#
pod2usage( -msg => "$PROG version $VERSION\n", -exitval => 1, -verbose => 2 )
    if ( $options{'documentation'} );

my $DEBUG   = ( defined( $options{debug} ) ? $options{debug} : $DEFDEBUG );
my $dry_run = ( defined( $options{'dry-run'} ) ? $options{'dry-run'} : 0 );
my $verbose = ( defined( $options{verbose} )   ? $options{verbose}   : 0 );

my $list_derived
    = ( defined( $options{list_derived} ) ? $options{list_derived} : 0 );

#
# Get the filename argument (metadata in JSON format)
#
$file = shift;
die "File of IA metadata is required\n" unless ($file);

#
# Read the entire JSON file into a buffer
#
try {
    $filebuffer = read_text($file);
}

catch ($e) {
    die "Failed to read JSON file $file\n";
}

#
# Parse the JSON from the buffer
#
try {
    $json = JSON->new;
    @jsonbuffer = $json->incr_parse($filebuffer);
}

catch ($e) {
    die "Failed to parse JSON\n";
}

_debug($DEBUG > 3, '@jsonbuffer: ' . Dumper(\@jsonbuffer));

#
# Check that this is the type of JSON we need
#
die "Empty JSON?\n" unless (@jsonbuffer);

#
# We got an array of one element from 'ia metadata <item>'. Use $md to
# reference that one element
#
my $md = $jsonbuffer[0];

#
# Collect the identifier from the parsed JSON and define the one derived file
# we don't want to delete.
#
my $identifier = $md->{metadata}->{identifier};
my $item_png = "${identifier}.png";

#
# Build a hash from the original and derived files referenced in the metadata.
# The hash will contain all but a number of files which are not of interest
# when sorting out which file came from which. At the end of the loop the
# structure will contain back links with child files pointing to parents. The
# forward child links get added later.
#
# The original names of files are also kept in an array to help with
# traversing the main hash.
#
foreach my $file ( @{ $md->{files} } ) {
    my $fname = $file->{name};

    printf "%-40s %-10s %s\n", $fname, $file->{source},
        coalesce( $file->{original}, 'null' )
        if ($verbose > 1);

    unless ( $file->{source} =~ /[Mm]etadata/
        || $file->{format}
        =~ /[Mm]etadata|Item Tile|Columbia Peaks|Spectrogram/ )
    {
        $filetree{$fname} = {
            source   => $file->{source},
            parent   => $file->{original},
            format   => $file->{format},
            children => [],
        };

        if ( $file->{source} eq 'original' ) {
            push( @original, $fname );
        }
        elsif ( $file->{source} eq 'derivative' ) {
            push( @derived, $fname );
        }
    }

}

#
# Visit all the nodes for derived files. They point to their parent node, so
# we can visit this node and add the children to an internal array.
#
foreach my $file (@derived) {
    if ( defined( $filetree{$file}->{parent} ) ) {
        push(
            @{ $filetree{ $filetree{$file}->{parent} }->{children} },
            $file
        );
    }
}

#
# The trees are built, so we can dump the final result
#
_debug(
   $DEBUG > 2,
   '%filetree'
       . sprintf( '[%d]: ', scalar( keys(%filetree) ) )
       . Dumper( \%filetree )
);

_debug($DEBUG > 2, '@original: ' . Dumper(\@original));
_debug($DEBUG > 2, '@derived: ' . Dumper(\@derived));

#
# If the verbosity level is greater than 0 scan all the 'original' files in
# the '$filetree' hash. For each one walk its 'children' array if there's
# anything in it, and recurse into each node it points to. It's possible to
# have further levels than the one below the parent, but very little seems to
# be set up this way so far.
#
if ($verbose > 0) {
    foreach my $file ( sort(@original) ) {
        #
        # Print the top level node and recurse into any children and print them
        #
        display_nodes( \%filetree, 0, $file );
    }
    say '-' x 10;
}

if ($list_derived) {
    foreach my $file ( sort(@derived) ) {
        say "$file" unless ($file eq $item_png);
    }
}

exit;

#===  FUNCTION  ================================================================
#         NAME: display_nodes
#      PURPOSE: Walks a tree of original and derived files in the IA metadata
#   PARAMETERS: $tree           Hashref pointing to the file tree
#               $level          The current level within the tree
#               $key            Hash key for the current node
#      RETURNS: Nothing
#  DESCRIPTION: Recurses through a tree
#       THROWS: No exceptions
#     COMMENTS: None
#     SEE ALSO: N/A
#===============================================================================
sub display_nodes {
    my ($tree, $level, $key) = @_;

    #
    # Report this node
    #
    printf "%s%d: %s\n", "\t" x $level, $level, $key;

    #
    # If there are children we use each to recurse to a lower level
    #
    if (scalar(@{$tree->{$key}->{children}}) > 0) {
        $level++;

        foreach my $child (@{$tree->{$key}->{children}}) {
            display_nodes($tree, $level, $child);
        }
    }

    return;
}

#===  FUNCTION  ================================================================
#         NAME: coalesce
#      PURPOSE: To find the first defined argument and return it
#   PARAMETERS: Arbitrary number of arguments
#      RETURNS: The first defined argument or undef if there are none
#  DESCRIPTION: Just a simple way of ensuring an 'undef' value is never
#               returned when doing so might be a problem.
#       THROWS: No exceptions
#     COMMENTS: None
#     SEE ALSO: N/A
#===============================================================================
sub coalesce {
    foreach (@_) {
        return $_ if defined($_);
    }
    return undef;    ## no critic
}

#===  FUNCTION  ================================================================
#         NAME: _debug
#      PURPOSE: Prints debug reports
#   PARAMETERS: $active         Boolean: 1 for print, 0 for no print
#               $message        Message to print
#      RETURNS: Nothing
#  DESCRIPTION: Outputs a message if $active is true. It removes any trailing
#               newline and then adds one in the 'print' to the caller doesn't
#               have to bother. Prepends the message with 'D> ' to show it's
#               a debug message.
#       THROWS: No exceptions
#     COMMENTS: None
#     SEE ALSO: N/A
#===============================================================================
sub _debug {
    my ( $active, $message ) = @_;

    chomp($message);
    print "D> $message\n" if $active;
}

#===  FUNCTION  ================================================================
#         NAME: Options
#      PURPOSE: Processes command-line options
#   PARAMETERS: $optref     Hash reference to hold the options
#      RETURNS: Undef
#  DESCRIPTION: Process the options we want to offer. See the documentation
#               for details
#       THROWS: no exceptions
#     COMMENTS: none
#     SEE ALSO: n/a
#===============================================================================
sub Options {
    my ($optref) = @_;

    my @options = (
        "help",     "documentation|man", "debug=i", "dry-run!",
        "verbose+", "list_derived!"
    );

    if ( !GetOptions( $optref, @options ) ) {
        pod2usage(
            -msg     => "$PROG version $VERSION\n",
            -exitval => 1,
            -verbose => 0
        );
    }

    return;
}

__END__

#%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
#  Application Documentation
#%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
#{{{

=head1 NAME

view_derivatives - <One line description of application's purpose>

=head1 VERSION

The initial template usually just has:

This documentation refers to view_derivatives version 0.0.2


=head1 USAGE

    # Brief working invocation example(s) here showing the most common usage(s)

    # This section will be as far as many users ever read
    # so make it as educational and exemplary as possible.


=head1 REQUIRED ARGUMENTS

A complete list of every argument that must appear on the command line.
when the application  is invoked, explaining what each of them does, any
restrictions on where each one may appear (i.e. flags that must appear
before or after filenames), and how the various arguments and options
may interact (e.g. mutual exclusions, required combinations, etc.)

If all of the application's arguments are optional this section
may be omitted entirely.


=head1 OPTIONS

A complete list of every available option with which the application
can be invoked, explaining what each does, and listing any restrictions,
or interactions.

If the application has no options this section may be omitted entirely.


=head1 DESCRIPTION

A full description of the application and its features.
May include numerous subsections (i.e. =head2, =head3, etc.)


=head1 DIAGNOSTICS

A list of every error and warning message that the application can generate
(even the ones that will "never happen"), with a full explanation of each
problem, one or more likely causes, and any suggested remedies. If the
application generates exit status codes (e.g. under Unix) then list the exit
status associated with each error.


=head1 CONFIGURATION AND ENVIRONMENT

A full explanation of any configuration system(s) used by the application,
including the names and locations of any configuration files, and the
meaning of any environment variables or properties that can be set. These
descriptions must also include details of any configuration language used


=head1 DEPENDENCIES

A list of all the other modules that this module relies upon, including any
restrictions on versions, and an indication whether these required modules are
part of the standard Perl distribution, part of the module's distribution,
or must be installed separately.


=head1 INCOMPATIBILITIES

A list of any modules that this module cannot be used in conjunction with.
This may be due to name conflicts in the interface, or competition for
system or program resources, or due to internal limitations of Perl
(for example, many modules that use source code filters are mutually
incompatible).


=head1 BUGS AND LIMITATIONS

A list of known problems with the module, together with some indication
whether they are likely to be fixed in an upcoming release.

Also a list of restrictions on the features the module does provide:
data types that cannot be handled, performance issues and the circumstances
in which they may arise, practical limitations on the size of data sets,
special cases that are not (yet) handled, etc.

The initial template usually just has:

There are no known bugs in this module.
Please report problems to <Maintainer name(s)>  (<contact address>)
Patches are welcome.

=head1 AUTHOR

<Author name(s)>  (<contact address>)


=head1 LICENCE AND COPYRIGHT

Copyright (c) <year> <copyright holder> (<contact address>). All rights reserved.

Followed by whatever licence you wish to release it under.
For Perl code that is often just:

This module is free software; you can redistribute it and/or
modify it under the same terms as Perl itself. See perldoc perlartistic.

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.

=cut

#}}}

# [zo to open fold, zc to close]

# vim: syntax=perl:ts=8:sw=4:et:ai:tw=78:fo=tcrqn21:fdm=marker