# Copyright (C) 2004 by Dominic Mitchell. All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 
# THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.

=pod

=head1 NAME

Config::Setting::FileProvider - return the contents of files.

=head1 SYNOPSIS

  use Config::Setting::FileProvider;
  my $p = Config::Setting::FileProvider->new(Env => "MYRCFILES",
                                             Paths => ["/etc/myrc",
                                                       "~/.myrc"]);
  my @contents = $p->provide();

=head1 DESCRIPTION

This class presents an interface to file contents.  It returns the
contents of various files, in order to the application that requests it.

It is not intended that this class be used standalone, rather that it
be used as part of the L<Config::Setting> module.

=head1 METHODS

=over 4

=item new ( ARGS )

Create a new object.  ARGS is a set of keyword / value pairs.
Recognised options are:

=over 4

=item Env

The name of an environment variable to look at.  If it exists, it will
contain a colon separated list of paths to settings files.

=item Paths

A list of file paths to be used, in order, for settings files.

=back

In both Env and Paths, you may use the tilde-notation ("~") to specify
home directories.

Any files specified in Paths will also have an identical file searched
for but with the hostname specified.  This should make per-host
customization simpler.

Any Env settings files will be looked at I<after> any Paths settings
files.

It is reccomended that you specify both parameters in the constructor.

=item provide ( )

Return a list of file contents, one per file read.

=back

=head1 AUTHOR

Dominic Mitchell, E<lt>cpan (at) happygiraffe.netE<gt>

=head1 SEE ALSO

L<Config::Setting>.

=cut

package Config::Setting::FileProvider;

use strict;
use vars qw($rcsid $VERSION $default);

use Carp;
use Sys::Hostname;

$rcsid = '@(#) $Id: FileProvider.pm 765 2005-08-31 20:05:59Z dom $ ';
$VERSION = (qw( $Revision: 765 $ ))[1];
$default = "~/.settingsrc";

sub new {
        my $class = shift;
        my (%args) = @_;

        my $self = {
                Env => "SETTINGS_FILES",
                Paths => [ $default ],
                %args,
                Files => [ ],   # Must not be overridden!
        };
        bless $self, $class;
        return $self->_init();
}

sub _init() {
        my $self  = shift;
        my @files = @{ $self->{ Paths } };

        # Allow listed files to be overridden by a hostname-specific
        # one.
        my $hn = hostname;
        @files = map { $_, "$_.$hn" } @files;

        # Always allow the environment to override previous choices.
        my $envvar = $self->{ Env };
        if ( $envvar && $ENV{ $envvar } ) {
                push @files, split /:/, $ENV{ $envvar };
        }
        push @{ $self->{ Files } }, @files;
        return $self;
}

sub provide {
        my $self = shift;
        # Allow tilde notation for home directory.
        my @files = map(glob, @{ $self->{Files} });
        my @texts;
        foreach my $f (@files) {
                next unless -f $f;
                open my $fh, $f
                        or croak "open($f): $!";
                push @texts, do { local $/; <$fh> };
                close $fh;
        }
        return @texts;
}

1;
__END__

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