Do a useful thing with Google Photos backups

# fixdates.pl (pwtenny AT the place where google mail goes)
# 2021-12-30
# Extract time/date stamps from JSON files in Google Photos backups/exports and set them
# for all the archived photos and videos on the local file system. Or something.

# Where to start looking for photos. Everything in this directory is searched recursively.
# $start shouldn't have ANY photos in it, if it does, they aren't going to get got.
$start = "D:/Documents/Downloads/takeout-20211229T132532Z-001/Takeout/Google Photos/";

opendir($dh, $start) || die "The \$start var isn't a valid directory. It's not my fault. IT'S NOT MY FAULT.\n";

# Iterate through every file/folder in $start
while(readdir $dh)
{
    # Trying to open ".." will briefly read the parent directory of $start, and "." will make us read $start twice.
    next if($_ eq '..' || $_ eq '.');

    if(-d $_)
    {
        search_directory($start.$_);
    }
}

# Iterate through everything in a sub-directory of $start, ignoring .JSON files.
sub search_directory
{
    $where = shift;
    opendir($ldh, $where);

    # This is not a recursive search. AFAIK Google Photo exports everything in one-layer-deep directories
    # and that's it. No sub-directories in any of them. (Perhaps that's possible?)
    while(readdir $ldh)
    {
        next if($_ eq '..' || $_ eq '.');
        next if($_ =~ /\.json/);  # Don't want these.

        print "$where: ".$_."\n"; # Delete this if you don't want a bunch of console spam. But you should. Spam is delicious.
        set_datetime($where.'/'.$_);
    }
    print "\n";
}

# Open a .JSON file and DIRTY parse out a timestamp, then set the file attributes accordingly.
# I honestly don't know if every JSON file has both a photoTakenTime and a creationTime,
# but I do know that we want photoTakenTime if it exists, since creationTime is *always* when the file
# was uploaded to Google Photos.
sub set_datetime
{
    $file = shift;
    $json = $file.".json";
    $ts = "";

    open(fh,$json);
    $json_data = join("", <fh>);
    close fh;

    if($json_data =~ /photoTakenTime/)
    {
        ($photoTakenTime) = $json_data =~ /"photoTakenTime": \{(.*?)\}/gs;
        ($ts) = $photoTakenTime =~ /"timestamp": "(.*?)",/gs;
    }
    else
    {
        ($ts) = $json_data =~ /"timestamp": "(.*?)",/gs;
    }

    use Win32API::File::Time qw{:win};
    $truefalse = SetFileTime($file, $ts, $ts, $ts);
    # Notice how I didn't check the return code to see if it worked?
}

#   Code Monkey get up get coffee
#   Code Monkey go to job
#   Code Monkey have boring meeting
#   With boring manager Rob
#   Rob say Code Monkey very dilligent
#   But his output stink
#   His code not “functional” or “elegant”
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#   Code Monkey not say it out loud
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