#!/usr/bin/env perl

# ifuse-photos-to-tmp -- import photos from iPhone/iPad/etc. using ifuse

# Copyright (C) 2019 Sean Whitton
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or (at
# your option) any later version.
#
# 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.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

use 5.028;
use strict;
use warnings;

use Const::Fast;
use DateTime;
use DateTime::TimeZone::Local;
use DateTime::Format::Epoch;
use File::Copy;
use File::Find;
use File::Path qw(make_path remove_tree);
use File::Spec::Functions;
use File::stat qw(stat);
use Image::ExifTool qw(ImageInfo);
use Syntax::Keyword::Try;
use File::Basename "basename";

# should be absolute paths
const my $mount => "$ENV{HOME}/mnt/hermes";
const my $dest  => "$ENV{HOME}/tmp";

try {
    make_path($mount, $dest);
}
catch {
    die "could not mkdir $mount and/or $dest";
}

unless (grep { /ifuse on $mount/ } `mount`) {
    system "ifuse $mount";
    die "could not mount $mount with ifuse" unless ($? == 0);
}

my $epoch = DateTime->new(year => 1970, month => 1, day => 1);
my $epoch_formatter = DateTime::Format::Epoch->new(epoch => $epoch, );
find(sub {
         # defend against ImageInfo changing $_ (which obeys dynamic,
         # not lexical, scoping rules)
         my $file = $_;
         # we handle any file, images or not, falling back to mtime if
         # we can't extract EXIF data
         return unless (-f $file);
         my $info = ImageInfo($file, 'FileType', 'CreateDate', 'DateCreated');

         my $ext; my $dt;
         my $no_exif = 0;
         # a closure, in particular over $info and $dt
         my $try_apple_exif = sub {
             my $key = shift;

             if ($info->{$key} =~
                 /([0-9]+):([0-9]+):([0-9]+) ([0-9]+):([0-9]+):([0-9]+)/) {
                 $dt = DateTime->new(year => $1, month => $2, day => $3,
                                     hour => $4, minute => $5, second => $6);
             }
         };
         if (exists $info->{FileType} && exists $info->{CreateDate}
	     && $info->{CreateDate} ne "0000:00:00 00:00:00"
             && $info->{FileType} eq "JPEG") {
             $ext = "jpg";
             $try_apple_exif->("CreateDate");
         } elsif (exists $info->{FileType} && exists $info->{DateCreated}
		  && $info->{DateCreated} ne "0000:00:00 00:00:00"
                  && $info->{FileType} eq "PNG") {
             $ext = "png";
             $try_apple_exif->("DateCreated");
         } elsif (exists $info->{FileType} && exists $info->{MediaCreateDate}
		  && $info->{MediaCreateDate} ne "0000:00:00 00:00:00"
                  && $info->{FileType} eq "MOV") {
             $ext = "mov";
             $try_apple_exif->("MediaCreateDate");
         } elsif (exists $info->{FileType} && exists $info->{CreateDate}
		  && $info->{CreateDate} ne "0000:00:00 00:00:00"
                  && $info->{FileType} eq "MOV") {
             $ext = "mov";
             $try_apple_exif->("CreateDate");
         } else {
             $no_exif = 1;
             $file =~ /\.([^.]+\z)/;
             $ext = lc($1) if defined $1;
             $dt = $epoch_formatter->parse_datetime(stat($file)->mtime);
             $dt->set_time_zone(DateTime::TimeZone::Local->TimeZone());
         }

         if (defined $ext && defined $dt) {
             # TODO factor out Local::Rename::suffix_until_unique()
             my $target =
               catfile($dest,
                       $dt->strftime('%Y-%m-%d %H.%M.%S') . "." . $ext);

             my $counter = 1;
             $target =~ s/\.$ext\z/-1.$ext/ if -e $target;
             while (-e $target) {
                 $counter++;
                 $target =~ s/-[0-9]+\.$ext\z/-$counter.$ext/;
             }

             move($file, $target);
             say STDERR "fell back to mtime for $file $target" if $no_exif;
         } else {
             warn "not touching $file because could not determine target name";
         }
     }, catfile($mount, "DCIM"));

# this causes the device to regenerate its knowledge of what photos it
# has; otherwise they'll still appear despite the files having been moved
unlink glob "$mount/PhotoData/Photos*";
unlink "$mount/PhotoData/com.apple.photos.caches_metadata.plist";

# iOS 13 additionally seems to require us to clear these:
unlink glob "$mount/PhotoData/Thumbnails/*.ithmb";
remove_tree(glob("$mount/PhotoData/Thumbnails/V2/DCIM/10*"),
            "$mount/PhotoData/MISC");
# (source: https://ubuntuforums.org/archive/index.php/t-2203298.html)

say "attempting unmount of photos";
patient_unmount($mount);

system "ifuse --documents org.videolan.vlc-ios $mount";
die "could not mount $mount with ifuse" unless ($? == 0);

foreach my $file (glob qq<"${mount}/Apple CoreAudio format*.caf" "${mount}/Audio Message*.caf">) {
    my $target = catfile $dest, basename $file;
    my $counter = 1;
    my $dir = catfile $ENV{HOME}, qw(annex chats),
      lc DateTime->now->strftime('%Y/%b');
    my $eventual_dest = catfile $dir, basename $target;
    $target =~ s/\.caf\z/-1.caf/ if -e $target or -e $eventual_dest;
    $eventual_dest = catfile $dir, basename $target;
    while (-e $target or -e $eventual_dest) {
	$counter++;
	$target =~ s/-[0-9]+\.caf\z/-$counter.caf/;
	$eventual_dest = catfile $dir, basename $target;
    }
    move $file, $target;
}

say "attempting unmount of voice notes";
patient_unmount($mount);

if (fork) {
    exit;
} else {
    exec "xdg-open", $dest;
}

sub patient_unmount {
    my $mount = shift;
    my $count = 0;
    while ($count < 3) {
	system "fusermount -u $mount";
	if ($? == 0) {
	    say " unmounted.";
	    last;
	} else {
	    print "\n" if $count > 0;
	    print "unmount failed; waiting a few seconds ..";
	    sleep 2;
	    $count++;
	}
    }
    die "failed to unmount $mount" unless $? == 0;
}