#!/usr/bin/perl

use strict;
use vars qw/ $CFG %SEEN /;
use Symbol;

$CFG = {
    gphoto_fpath => "/media/mmc1/pocket/bin/gphoto2",
    process_cmd => "echo Fetched {}",
    save_path => "/media/mmc1",
    poll_delay => 5,
};

main();

sub main {
# --------------------------------------------------
    my $files = camera_files();

# So that we can score the images in the right directory
    chdir $CFG->{save_path};

    while (1) {
        photos_seen_mark( $files );
        $files = camera_files();
        if ( my $not_seen = photos_seen_filter($files) ) {
            camera_file_fetch( $not_seen );
            photos_post_action( $not_seen );
        }
        sleep $CFG->{poll_delay};
    }
}

sub photos_post_action {
# --------------------------------------------------
# Execute a script or do something for each photo
# that has been fetched
#
    my $files = shift or return;
    for ( @$files ) {
        my $fpath = $CFG->{save_path}? "$CFG->{save_path}/$_->{fname}" : $_->{fname};
        my $process_cmd = $CFG->{process_cmd};
        $process_cmd =~ s/\{\}/"$fpath"/g;
        system $process_cmd;
    }
}

sub photos_seen_mark {
# --------------------------------------------------
# Mark all the photos passed via array as "seen"
#
    my $files = shift;    
    for ( @$files ) {
        $SEEN{$_->{fname}} = 1;
    }
}

sub photos_seen_filter {
# --------------------------------------------------
# Returns an array of all the photos that have 
# not been seen by the system
#
    my $files = shift;    
    my @filtered = grep {not $SEEN{$_->{fname}}} @$files or return;
    return \@filtered;
}

sub camera_file_fetch {
# --------------------------------------------------
# Fetches the files in the list passed in
#
    my $files = shift or return;
    my $range = join ",",map {$_->{id}} @$files;
    my $fh = Symbol->gensym;
    open $fh, "$CFG->{gphoto_fpath} --get-file=$range --force-overwrite 2> /dev/null |" or die $!;
    my @saved;
    while ( my $l = <$fh> ) {
        next unless $l =~ /Saving file as (.*)/;
        push @saved, $1;
    }
    close $fh;
}

sub camera_files {
# --------------------------------------------------
# Returns an array of hashrefs describing what files
# are available on the target camera
#
    my $fh = Symbol->gensym;
    open $fh, "$CFG->{gphoto_fpath} -L 2> /dev/null |" or die $!;
    my @files;
    my @headers = qw( id fname u size unit mime );
    while ( my $l = <$fh> ) {
        my @e = split /\s+/, $l;
        next unless $l =~ /^\#\d+/;
        my @e = split /\s+/, $l;
        my $rec = {};
        @$rec{@headers} = @e;
        $rec->{id} =~ s/^#//;
        push @files, $rec;
    }
    close $fh;

    return \@files;
}