#!/usr/bin/perl
use strict;
use warnings;
use threads;
use threads::shared;
use Fuse;
use LWP::UserAgent;
use LWP::Simple;
use List::MoreUtils qw(uniq);
use MogileFS::Client;
use Path::Class;
use POSIX qw(ENOENT EISDIR EINVAL);
my $DEBUG = 0;
our (%FILE_CACHE, $CACHE_SIZE, $CACHE_AGE) = (('/' => {size => 0, age => 0}));
 
# create client object w/ server-configured namespace and IPs of trackers
my $ua = LWP::UserAgent->new;
my $class = 'default';
my $mogilefs = MogileFS::Client->new(
  domain => 'ifap',
  hosts  => [ '10.10.0.100:6001', '10.10.0.101:6001' ],
);
 
my ($mountpoint) = "";
$mountpoint = shift(@ARGV) if @ARGV;
Fuse::main(
    debug      => $DEBUG,
    mountpoint => $mountpoint,
    threaded   => 1,
 
    getattr    => "main::e_getattr",
    getdir     => "main::e_getdir",
    mknod      => "main::e_mknod",
    open       => "main::e_open",
    read       => "main::e_read",
    rename     => "main::e_rename",
    statfs     => "main::e_statfs",
    unlink     => "main::e_unlink",
    write      => "main::e_write",
);
 
sub e_getattr {
    my $filename = shift;
    $filename =~ s#^.*/##;
    warn "main::e_getattr $filename\n" if $DEBUG;
 
    my ( $size, $modes );
    my ( $dev, $ino, $rdev, $blocks, $gid, $uid, $nlink, $blksize )
        = ( 0, 0, 0, 1, 0, 0, 1, 1024 );
    my ( $atime, $ctime, $mtime ) = ( time, time, time );
 
    if ( $filename !~ m{\.} ) {
        #        warn "directory!";
        $size  = 0;
        $modes = ( 0040 << 9 ) + 0755;
    } else {
        #        warn "file!";
        $size  = 123;
        $modes = ( 0100 << 9 ) + 0644;
 
        my @paths = $mogilefs->get_paths( $filename, { noverify => 1 } );
        my ( $content_type, $document_length, $modified_time, $expires, $server );
 
        if ( scalar( @paths ) ) {
            ( $content_type, $document_length, $modified_time, $expires, $server ) = head( $paths[0] );
            $size = $document_length;
            ( $atime, $ctime, $mtime ) = ($modified_time) x 3;
        }
        else {
            @paths = $mogilefs->get_paths( '_big_info:' . $filename, { noverify => 1 } );
            if ( scalar( @paths ) ) {
                my $data = $mogilefs->get_file_data( '_big_info:' . $filename );
                my ( $_des, $_type, $_compress, $_filename, $_chunks, $_size, undef, @_parts ) = split /\n/, $$data;
                ( $size ) = $_size =~ m#^size (\d+)$#;
                OUTER: foreach my $_part ( @_parts ) {
                    $_part =~ m#paths: (.+?)$#;
                    my @_paths = split ', ', $_part;
                    foreach my $_path ( @_paths ) {
                        ( $content_type, $document_length, $modified_time, $expires, $server ) = head( $paths[0] );
                        ( $atime, $ctime, $mtime ) = ($modified_time) x 3;
                        last OUTER if $server;
                    }
                }
            }
        }
        return -ENOENT() unless @paths;
    }
 
    warn(
        join(
            ",",
            (   $dev,   $ino,     $modes, $nlink, $uid,
                $gid,   $rdev,    $size,  $atime, $mtime,
                $ctime, $blksize, $blocks
            )
        ),
        "\n"
    ) if $DEBUG;
 
    return (
        $dev,  $ino,   $modes, $nlink, $uid,     $gid, $rdev,
        $size, $atime, $mtime, $ctime, $blksize, $blocks
    );
}
 
sub e_getdir {
    my $prefix = shift;
    warn "main::e_getdir $prefix\n" if $DEBUG;
    my @filenames;
    $mogilefs->foreach_key(
#        prefix => $prefix,
        sub {
          my $filename = shift;
          push @filenames, $filename;
          push @filenames, file( $filename )->parent();
        }
    );
 
    @filenames = uniq @filenames;
    warn "returning: @filenames\n" if $DEBUG;
    return ( @filenames, 0 );
}
 
sub e_mknod {
    my $filename = shift;
    $filename =~ s#.*/##;
 
    warn "main::e_mknod $filename\n" if $DEBUG;
 
    my $fh = $mogilefs->new_file($filename, undef);
    if ( $fh ) {
        print $fh "\n";
 
        unless ($fh->close) {
            my ($code, $str) = ($mogilefs->errcode || -1, $mogilefs->errstr || '');
            warn "Error creating file:$code: $str" if $DEBUG;
            $! = $str;
            $? = $code;
            return -1;
        }
        return 0;
    }
    else {
        return -1;
    }
}
 
sub e_open {
    my $filename = shift;
    $filename =~ s#.*/##;
    warn "main::e_open $filename\n" if $DEBUG;
 
    return -EISDIR() unless $filename =~ m{\.};
    my @paths = $mogilefs->get_paths( $filename, { noverify => 1 } );
    if ( ! scalar( @paths ) ) {
        @paths = $mogilefs->get_paths( '_big_info:' . $filename, { noverify => 1 } );
    }
    return -ENOENT() unless @paths;
    return 0;
}
 
sub e_read {
    my ( $filename, $length, $offset ) = @_;
    $filename =~ s#.*/##;
    warn "main::e_read $filename $length $offset\n" if $DEBUG;
 
    return -EISDIR() if $filename =~ m{/$};
 
 
 
    my $maxoff = $offset + ( $length - 1 );
warn "requested offset=$offset length=$length bytes=$maxoff" if $DEBUG;
    my @paths = $mogilefs->get_paths( $filename, { noverify => 1 } );
    my $size;
    my ( $content_type, $document_length, $modified_time, $expires, $server );
 
    if ( scalar( @paths ) ) {
warn "it's a small file" if $DEBUG;
        ( $content_type, $document_length, $modified_time, $expires, $server ) = head( $paths[0] );
        $size = $document_length;
        return 0 if $offset == $document_length;
 
        $maxoff = $document_length if $maxoff > $document_length;
        my $range = $offset . "-" . $maxoff;
        warn "  Range: bytes=$range\n" if $DEBUG;
        my $response = $ua->get( $paths[0], "Range" => "bytes=$range" );
        if ( $response->is_success ) {
            return $response->content;
        } else {
            warn $response->as_string if $DEBUG;
        }
    }
    else {
        @paths = $mogilefs->get_paths( '_big_info:' . $filename, { noverify => 1 } );
        return -ENOENT() unless @paths;
warn "it's a big file" if $DEBUG;
 
        my $data = $mogilefs->get_file_data( '_big_info:' . $filename );
        my ( $_des, $_type, $_compress, $_filename, $_chunks, $_size, undef, @_parts ) = split /\n/, $$data;
        ( $size ) = $_size =~ m#^size (\d+)$#;
        return 0 if $offset == $size;
 
        $maxoff = $size if $maxoff > $size;
 
        my $part_min = -1;
        my $part_max = -1;
#part 2 bytes=23080964 md5=af45f7ac80ca34328db3c90de1db1ab0 paths: http://10.10.0.100:7500/dev8/0/000/119/0000119969.fid, http://10.10.0.101:7500/dev2/0/000/119/0000119969.fid
 
        my $buf = '';
        foreach my $_part ( @_parts ) {
            my ( $_bytes, $_paths ) = $_part =~ m#bytes=(\d+) .+? paths: (.+?)$#;
 
            $part_min = $part_max > 0 ? $part_max + 1 : 0;
            $part_max += $_bytes;
 
 
warn "examining part $part_min -> $part_max" if $DEBUG;
 
            #chunk too early
            next if ( $part_max < $offset );
            #chunk too late;
            next if ( $part_min > $maxoff );
 
warn "using part $part_min -> $part_max" if $DEBUG;
 
            my @_paths = split ', ', $_paths;
            foreach my $_path ( @_paths ) {
warn "offset=$offset part_min=$part_min maxoff=$maxoff part_max=$part_max" if $DEBUG;
                my $range = ($offset-$part_min) . "-" . ($maxoff-$part_min);
warn "getting Range: bytes=$range" if $DEBUG;
                my $response = $ua->get( $_path, "Range" => "bytes=$range" );
                if ( $response->is_success() ) {
                    $buf .= $response->content();
warn "data length=".length($buf) if $DEBUG;
                    if ( length( $buf ) == $length ) {
warn "got all the data (1)!" if $DEBUG;
                        return $buf;
                    }
                    elsif ( $offset + length( $buf ) == $maxoff ) {
warn "got all the data (2)!" if $DEBUG;
                        return $buf;
                    }
                    $offset += length( $buf );
                    last;
                }
            }
        }
        if ( length( $buf ) != $length ) {
            return -ENOENT();
        }
        else {
            return $buf;
        }
    }
}
 
sub e_rename {
    my ( $old, $new ) = @_;
    $old =~ s#.*/##;
    $new =~ s#.*/##;
 
    warn "main::e_rename: $old -> $new" if $DEBUG;
 
    # Rename this file
    $mogilefs->rename($old, $new);
 
    return 0;
}
 
sub e_statfs { return 255, 1, 1, 1, 1, 2 }
 
sub e_unlink {
    my $filename = shift;
    $filename =~ s#.*/##;
 
    warn "main::e_unlink: $filename" if $DEBUG;
 
    $mogilefs->delete($filename);
 
    return 0;
}
 
sub e_write {
    my ( $filename, $buf, $offset ) = @_;
    $filename =~ s#.*/##;
 
    warn("main::e_write: $filename pos=$offset len=".length($buf)) if $DEBUG;
 
    my $finfo = get_file_info($filename);
 
    return -ENOENT() unless $finfo;
 
    my $cont = get_file_data($filename);
 
    substr($$cont, $offset, length($buf), $buf);
 
    $mogilefs->store_content($filename, undef, $cont);
    rm_file_cache($filename);
 
    return length($buf);
}
 
#################################################
sub logmsg { warn(join "\t",@_) if $DEBUG }
 
sub get_file_data {
    my ($file) = @_;
    my $entry = $FILE_CACHE{$file};
    my $meta  = $FILE_CACHE{'/'};
 
    if ($entry) {
        # See if this data is too old
        if ((time - $entry->{created}) < $CACHE_AGE) {
            logmsg(1, "-- get_file_data: hit");
 
            # If its still valid, return it
            return $entry->{data};
        } else {
            logmsg(1, "-- get_file_data: miss - expired");
 
            rm_file_cache($file);
        }
    }
 
    my $cont = $mogilefs->get_file_data($file);
    my $size = length($$cont);
 
    if ($meta->{size} + $size > $CACHE_SIZE) {
        # If adding this would go beyond our max cache size, delete things until
        # we can fit it
        foreach my $f (sort {$a->{age} <=> $b->{age}} keys %FILE_CACHE) {
            next if $f eq '/';
 
            my $rm_size = rm_file_cache($f);
 
            logmsg(1, "-- get_file_data: purging - $rm_size bytes");
 
            last if $meta->{size} + $size < $CACHE_SIZE;
        }
    }
 
    logmsg(1, "-- get_file_data: added - $size bytes");
 
    # Create a new entry
    $FILE_CACHE{$file} = {created => time,
                          size    => $size,
                          data    => $cont};
    $meta->{size} += $size;
 
    return $cont;
}
 
sub get_file_info {
    my ($path) = @_;
 
    if ($path eq '/') {
        return {name         => '/',
                is_directory => 1};
    }
    else {
      foreach my $f ( $mogilefs->list_keys( $path ) ) {
        return $f if $f eq $path;
      }
    }
    return undef;
}
 
sub rm_file_cache {
    my ($file) = @_;
    my $entry = delete $FILE_CACHE{$file};
    return unless $entry;
 
    # Decrement how large our cache size is
    my $size = $entry->{size};
    $FILE_CACHE{'/'}->{size} -= $size;
 
    return $size;
}
 
__DATA__
#des no description
#type file
#compressed 0
#filename somefile.mpeg
#chunks 2
#size 90189828
#
#part 1 bytes=67108864 md5=8066369552b71fd49cfbe9ccdce74051 paths: http://10.10.0.100:7500/dev6/0/000/119/0000119968.fid, http://10.10.0.101:7500/dev2/0/000/119/0000119968.fid
#part 2 bytes=23080964 md5=af45f7ac80ca34328db3c90de1db1ab0 paths: http://10.10.0.100:7500/dev8/0/000/119/0000119969.fid, http://10.10.0.101:7500/dev2/0/000/119/0000119969.fid