package DBIx::Class::Schema::Config;
use 5.005;
use warnings;
use strict;
use base 'DBIx::Class::Schema';
use File::HomeDir;
use Storable qw( dclone );
use Hash::Merge qw( merge );
use namespace::clean;

our $VERSION = '0.001012'; # 0.1.12
$VERSION = eval $VERSION;

sub connection {
    my ( $class, @info ) = @_;

    if ( ref($info[0]) eq 'CODE' ) {
        return $class->next::method( @info );
    }

    my $attrs = $class->_make_connect_attrs(@info);

    # We will not load credentials for someone who uses dbh_maker,
    # however we will pass their request through.
    return $class->next::method( $attrs )
        if defined $attrs->{dbh_maker};

    # Take responsibility for passing through normal-looking
    # credentials.
    $attrs = $class->load_credentials($attrs)
        unless $attrs->{dsn} =~ /dbi:/i;

    return $class->next::method( $attrs );
}

# Normalize arguments into a single hash.  If we get a single hashref,
# return it.
# Check if $user and $pass are hashes to support things like
# ->connect( 'CONFIG_FILE', { hostname => 'db.foo.com' } );

sub _make_connect_attrs {
    my ( $class, $dsn, $user, $pass, $dbi_attr, $extra_attr ) = @_;
    return $dsn if ref $dsn eq 'HASH';

    return {
        dsn => $dsn,
        %{ref $user eq 'HASH' ? $user : { user => $user }},
        %{ref $pass eq 'HASH' ? $pass : { password => $pass }},
        %{$dbi_attr || {} },
        %{ $extra_attr || {} }
    };
}

# Cache the loaded configuration.
sub config {
    my ( $class ) = @_;

    if ( ! $class->_config ) {
        $class->_config( $class->_load_config );
    } 
    return dclone( $class->_config );
}


sub _load_config {
    my ( $class ) = @_;
    require Config::Any; # Only loaded if we need to load credentials.

    # If we have ->config_files, we'll use those and load_files
    # instead of the default load_stems.
    my %cf_opts = ( use_ext => 1 );
    return @{$class->config_files}
        ? Config::Any->load_files({ files => $class->config_files, %cf_opts })
        : Config::Any->load_stems({ stems => $class->config_paths, %cf_opts });
}


sub load_credentials {
    my ( $class, $connect_args ) = @_;

    # While ->connect is responsible for returning normal-looking
    # credential information, we do it here as well so that it can be
    # independently unit tested.
    return $connect_args if $connect_args->{dsn} =~ /^dbi:/i;

    return $class->filter_loaded_credentials(
        $class->_find_credentials( $connect_args, $class->config ),
        $connect_args
    );

}

# This will look through the data structure returned by Config::Any
# and return the first instance of the database credentials it can
# find.
sub _find_credentials {
    my ( $class, $connect_args, $ConfigAny ) = @_;

    for my $cfile ( @$ConfigAny ) {
        for my $filename ( keys %$cfile ) {
            for my $database ( keys %{$cfile->{$filename}} ) {
                if ( $database eq $connect_args->{dsn} ) {
                    return $cfile->{$filename}->{$database};
                }
            }
        }
    }
}

sub get_env_vars {
    return $ENV{DBIX_CONFIG_DIR} . "/dbic" if exists $ENV{DBIX_CONFIG_DIR};
    return ();
}

# Intended to be sub-classed, the default behavior is to
# overwrite the loaded configuration with any specified
# configuration from the connect() call, with the exception
# of the DSN itself.

sub filter_loaded_credentials {
    my ( $class, $new, $old ) = @_;

    local $old->{password}, delete $old->{password} unless $old->{password};
    local $old->{user},     delete $old->{user}     unless $old->{user};
    local $old->{dsn},      delete $old->{dsn};

    return merge( $old, $new );
};

__PACKAGE__->mk_classaccessor('config_paths');
__PACKAGE__->mk_classaccessor('config_files');
__PACKAGE__->mk_classaccessor('_config');
__PACKAGE__->config_paths([( get_env_vars(), './dbic', File::HomeDir->my_home . '/.dbic', '/etc/dbic')]);
__PACKAGE__->config_files([  ] );

1;

=encoding UTF-8

=head1 NAME

DBIx::Class::Schema::Config - Credential Management for DBIx::Class

=head1 DESCRIPTION

DBIx::Class::Schema::Config is a subclass of DBIx::Class::Schema that allows
the loading of credentials & configuration from a file.  The actual code itself
would only need to know about the name used in the configuration file. This
aims to make it simpler for operations teams to manage database credentials.

A simple tutorial that compliments this documentation and explains converting 
an existing DBIx::Class Schema to use this software to manage credentials can 
be found at L<http://www.symkat.com/credential-management-in-dbix-class>

=head1 SYNOPSIS

    /etc/dbic.yaml
    MY_DATABASE:
        dsn: "dbi:Pg:host=localhost;database=blog"
        user: "TheDoctor"
        password: "dnoPydoleM"
        TraceLevel: 1

    package My::Schema
    use warnings;
    use strict;

    use base 'DBIx::Class::Schema::Config';
    __PACKAGE__->load_namespaces;

    package My::Code;
    use warnings;
    use strict;
    use My::Schema;

    my $schema = My::Schema->connect('MY_DATABASE');

    # arbitrary config access from anywhere in your $app
    my $level = My::Schema->config->{TraceLevel};

=head1 CONFIG FILES

This module will load the files in the following order if they exist:

=over 4

=item * C<$ENV{DBIX_CONFIG_DIR}> . '/dbic',

C<$ENV{DBIX_CONFIG_DIR}> can be configured at run-time, for instance:

    DBIX_CONFIG_DIR="/var/local/" ./my_program.pl

=item * ./dbic.*

=item * ~/.dbic.*

=item * /etc/dbic.*

=back

The files should have an extension that L<Config::Any> recognizes,
for example /etc/dbic.B<yaml>.

NOTE:  The first available credential will be used.  Therefore I<DATABASE>
in ~/.dbic.yaml will only be looked at if it was not found in ./dbic.yaml.
If there are duplicates in one file (such that DATABASE is listed twice in
~/.dbic.yaml,) the first configuration will be used.

=head1 CHANGE CONFIG PATH

Use C<__PACKAGE__-E<gt>config_paths([( '/file/stub', '/var/www/etc/dbic')]);>
to change the paths that are searched.  For example:

    package My::Schema
    use warnings;
    use strict;

    use base 'DBIx::Class::Schema::Config';
    __PACKAGE__->config_paths([( '/var/www/secret/dbic', '/opt/database' )]);

The above code would have I</var/www/secret/dbic.*> and I</opt/database.*> 
searched, in that order.  As above, the first credentials found would be used.  
This will replace the files originally searched for, not add to them.

=head1 USE SPECIFIC CONFIG FILES

If you would rather explicitly state the configuration files you
want loaded, you can use the class accessor C<config_files>
instead.

    package My::Schema
    use warnings;
    use strict;

    use base 'DBIx::Class::Schema::Config';
    __PACKAGE__->config_files([( '/var/www/secret/dbic.yaml', '/opt/database.yaml' )]);

This will check the files, C</var/www/secret/dbic.yaml>,
and C</opt/database.yaml> in the same way as C<config_paths>,
however it will only check the specific files, instead of checking
for each extension that L<Config::Any> supports.  You MUST use the
extension that corresponds to the file type you are loading.
See L<Config::Any> for information on supported file types and
extension mapping.

=head1 ACCESSING THE CONFIG FILE

The config file is stored via the  C<__PACKAGE__-E<gt>config> accessor, which can be
called as both a class and instance method.

=head1 OVERRIDING

The API has been designed to be simple to override if you have additional
needs in loading DBIC configurations.

=head2 Overriding Connection Configuration

Simple cases where one wants to replace specific configuration tokens can be
given as extra parameters in the ->connect call.

For example, suppose we have the database MY_DATABASE from above:

    MY_DATABASE:
        dsn: "dbi:Pg:host=localhost;database=blog"
        user: "TheDoctor"
        password: "dnoPydoleM"
        TraceLevel: 1

If you’d like to replace the username with “Eccleston” and we’d like to turn 
PrintError off.

The following connect line would achieve this:

    $Schema->connect(“MY_DATABASE”, “Eccleston”, undef, { PrintError => 0 } );

The name of the connection to load from the configuration file is still given 
as the first argument, while other arguments may be given exactly as you would
for any other call to C<connect>.

Historical Note: This class accepts numerous ways to connect to DBIC that would
otherwise not be valid.  These connection methods are discouraged but tested for
and kept for compatibility with earlier versions.  For valid ways of connecting to DBIC
please see L<https://metacpan.org/pod/DBIx::Class::Storage::DBI#connect_info>

=head2 filter_loaded_credentials

Override this function if you want to change the loaded credentials before
they are passed to DBIC.  This is useful for use-cases that include decrypting
encrypted passwords or making programmatic changes to the configuration before
using it.

    sub filter_loaded_credentials {
        my ( $class, $loaded_credentials, $connect_args ) = @_;
        ...
        return $loaded_credentials;
    }

C<$loaded_credentials> is the structure after it has been loaded from the
configuration file.  In this case, C<$loaded_credentials-E<gt>{user}> eq
B<WalterWhite> and C<$loaded_credentials-E<gt>{dsn}> eq
B<DBI:mysql:database=students;host=%s;port=3306>.

C<$connect_args> is the structure originally passed on C<-E<gt>connect()>
after it has been turned into a hash.  For instance,
C<-E<gt>connect('DATABASE', 'USERNAME')> will result in
C<$connect_args-E<gt>{dsn}> eq B<DATABASE> and C<$connect_args-E<gt>{user}>
eq B<USERNAME>.

Additional parameters can be added by appending a hashref,
to the connection call, as an example, C<-E<gt>connect( 'CONFIG',
{ hostname =E<gt> "db.foo.com" } );> will give C<$connect_args> a
structure like C<{ dsn =E<gt> 'CONFIG', hostname =E<gt> "db.foo.com" }>.

For instance, if you want to use hostnames when you make the
initial connection to DBIC and are using the configuration primarily
for usernames, passwords and other configuration data, you can create
a config like the following:

    DATABASE:
        dsn: "DBI:mysql:database=students;host=%s;port=3306"
        user: "WalterWhite"
        password: "relykS"

In your Schema class, you could include the following:

    package My::Schema
    use warnings;
    use strict;
    use base 'DBIx::Class::Schema::Config';

    sub filter_loaded_credentials {
        my ( $class, $loaded_credentials, $connect_args ) = @_;
        if ( $loaded_credentials->{dsn} =~ /\%s/ ) {
            $loaded_credentials->{dsn} = sprintf( $loaded_credentials->{dsn},
                $connect_args->{hostname});
        }
    }

    __PACKAGE__->load_classes;
    1;

Then the connection could be done with
C<$Schema-E<gt>connect('DATABASE', { hostname => 'my.hostname.com' });>

See L</load_credentials> for more complex changes that require changing
how the configuration itself is loaded.

=head2 load_credentials

Override this function to change the way that L<DBIx::Class::Schema::Config>
loads credentials.  The function takes the class name, as well as a hashref.

If you take the route of having C<-E<gt>connect('DATABASE')> used as a key for
whatever configuration you are loading, I<DATABASE> would be
C<$config-E<gt>{dsn}>

    Some::Schema->connect(
        "SomeTarget",
        "Yuri",
        "Yawny",
        {
            TraceLevel => 1
        }
    );

Would result in the following data structure as $config in
C<load_credentials($class, $config)>:

    {
        dsn             => "SomeTarget",
        user            => "Yuri",
        password        => "Yawny",
        TraceLevel      => 1,
    }

Currently, load_credentials will NOT be called if the first argument to
C<-E<gt>connect()> looks like a valid DSN.  This is determined by match
the DSN with C</^dbi:/i>.

The function should return the same structure.  For instance:

    package My::Schema
    use warnings;
    use strict;
    use base 'DBIx::Class::Schema::Config';
    use LWP::Simple;
    use JSON

    # Load credentials from internal web server.
    sub load_credentials {
        my ( $class, $config ) = @_;

        return decode_json(
            get( "http://someserver.com/v1.0/database?key=somesecret&db=" .
                $config->{dsn}  ));
    }

    __PACKAGE__->load_classes;

=head1 AUTHOR

Kaitlyn Parkhurst (SymKat) I<E<lt>symkat@symkat.comE<gt>> ( Blog: L<http://symkat.com/> )

=head1 CONTRIBUTORS

=over 4

=item * Matt S. Trout (mst) I<E<lt>mst@shadowcat.co.ukE<gt>>

=item * Peter Rabbitson (ribasushi) I<E<lt>ribasushi@cpan.orgE<gt>>

=item * Christian Walde (Mihtaldu) I<E<lt>walde.christian@googlemail.comE<gt>>

=item * Dagfinn Ilmari Mannsåker (ilmari) I<E<lt>ilmari@ilmari.orgE<gt>>

=item * Matthew Phillips (mattp)  I<E<lt>mattp@cpan.orgE<gt>>

=back

=head1 COPYRIGHT AND LICENSE

This library is free software and may be distributed under the same terms
as perl itself.

=head1 AVAILABILITY

The latest version of this software is available at
L<https://github.com/symkat/DBIx-Class-Schema-Config>

=cut
