package CGI::Armature::Database;

use strict;

use Fcntl;
use DB_File::Lock;
use CGI::Armature::PathInfo;

my %path_info = CGI::Armature::PathInfo::get_paths();

sub new {
    my $class = shift;
    my ($dbfile) = @_;
    die "need dbfile" unless $dbfile;
    my $self = {
        dbfile=>$dbfile,
    };
    return bless($self, $class);
}

sub create {
    my $self = shift;
    my %db_file;
    my $locking = {
        mode=>'write',
        lockfile_name=>"$path_info{sessionpath}/exclusive.lock",
    };
    tie(
        %db_file, 
        'DB_File::Lock', 
        "$path_info{sessionpath}/$self->{dbfile}", 
        O_RDWR|O_CREAT, 
        0600,
        $DB_HASH,
        $locking,
    ) or die "Couldn't tie DB_File $path_info{sessionpath}/$self->{dbfile} $!; aborting";
    untie %db_file;
}

sub delete {
    my $self = shift;
    my $key = shift;
    my %db_file;
    my $locking = {
        mode=>'write',
        lockfile_name=>"$path_info{sessionpath}/exclusive.lock",
    };
    tie(
        %db_file, 
        'DB_File::Lock', 
        "$path_info{sessionpath}/$self->{dbfile}", 
        O_RDWR, 
        0600,
        $DB_HASH,
        $locking,
    ) or die "Couldn't tie DB_File $path_info{sessionpath}/$self->{dbfile} $!; aborting";
    delete $db_file{$key};
    untie %db_file;
}

sub set_value {
    my $self = shift;
    die "not enough values for set_value" unless @_ == 2;
    my ($key, $value) = @_;
    my %db_file;
    my $locking = {
        mode=>'write',
        lockfile_name=>"$path_info{sessionpath}/exclusive.lock",
    };
    tie(
        %db_file, 
        'DB_File::Lock', 
        "$path_info{sessionpath}/$self->{dbfile}", 
        O_RDWR, 
        0600,
        $DB_HASH,
        $locking,
    ) or die "Couldn't tie DB_File $path_info{sessionpath}/$self->{dbfile} $!; aborting";
    $db_file{$key} = $value;
    untie %db_file;
}

sub get_value {
    my $self = shift;
    my $key = shift;
    my %db_file;
    my $locking = {
        mode=>'read',
        lockfile_name=>"$path_info{sessionpath}/exclusive.lock",
    };
    tie(
        %db_file, 
        'DB_File::Lock', 
        "$path_info{sessionpath}/$self->{dbfile}", 
        O_RDONLY, 
        0600,
        $DB_HASH,
        $locking,
    ) or die "Couldn't tie DB_File $path_info{sessionpath}/$self->{dbfile} $!; aborting";
    my $value = $db_file{$key};
    untie %db_file;
    return $value;
}

sub get_keys {
    my $self = shift;
    my %db_file;
    my $locking = {
        mode=>'read',
        lockfile_name=>"$path_info{sessionpath}/exclusive.lock",
    };
    tie(
        %db_file, 
        'DB_File::Lock', 
        "$path_info{sessionpath}/$self->{dbfile}", 
        O_RDONLY, 
        0600,
        $DB_HASH,
        $locking,
    ) or die "Couldn't tie DB_File $path_info{sessionpath}/$self->{dbfile} $!; aborting";
    my @keys =  keys %db_file;
    untie %db_file;
    return \@keys;
}

1;