JSAN::Librarian - JavaScript::Librarian adapter for a JSAN installation

package JSAN::Librarian;

use 5.006;
use strict;
use Carp                     ();
use File::Spec               ();
use File::Path               ();
use Config::Tiny             ();
use Params::Util             qw{ _STRING };
use File::Basename           ();
use File::Find::Rule         ();
use JSAN::Parse::FileDeps    ();
use JSAN::Librarian::Book    ();
use JSAN::Librarian::Library ();

use vars qw{$VERSION $VERBOSE @DEFAULT};
BEGIN {
	$VERSION = '0.03';

	# Silent by default
	$VERBOSE ||= 0;

	# Look for the index at existing places.
	# If none found, assume the first.
	@DEFAULT = qw{
		openjsan.deps
		.openjsan.deps
	};
}





#####################################################################
# Constructor

sub new {
	my $class      = shift;
	my $root       = (defined _STRING($_[0]) and -d $_[0]) ? shift : return undef;

	# Create the object
	my $self = bless {
		root => $root,
	}, $class;

	# Check passed index file or use a default
	$self->{index_file} = @_
		? $self->_new_param(shift)
		: $self->_new_default
		or return undef;

	return $self;
}

# Check index file param
sub _new_param {
	my $self  = shift;
	my $param = shift or return undef;
	return "$param";
}

# Determine default
sub _new_default {
	my $self = shift;
	my $root = $self->root;

	# Does it have an existing index
	foreach my $file ( @DEFAULT ) {
		my $path = File::Spec->catfile( $root, $file );
		next unless -f $path;
		$self->_print("Found index at $path");
		return $file;
	}

	# It doesn't exist, but use the primary default
	my $path = File::Spec->catfile( $root, $DEFAULT[0] );
	$self->_print("Using default path $DEFAULT[0]");
	return $DEFAULT[0];
}

sub root {
	$_[0]->{root};
}

sub index_file {
	$_[0]->{index_file};
}





#####################################################################
# JSAN::Librarian Methods

sub index_path {
	my $self = shift;
	my $file = $self->index_file;
	return File::Spec->file_name_is_absolute($file)
		? $file
		: File::Spec->catfile( $self->root, $file );
}

sub index_exists {
	return -f $_[0]->index_path;
}

sub build_index {
	my $self   = shift;
	my $config = Config::Tiny->new;
	my $root   = $self->root;

	# Find all the files
	$self->_print("Searching $root for .js files...");
	my @files = File::Find::Rule->name('*.js')
	                            ->not_name(qr/_deps\.js$/)
	                            ->file
                                    ->relative
	                            ->in( $root );
	foreach my $js ( @files ) {
		$config->{$js} = {};
		my $path = File::Spec->catfile( $root, $js );
		$self->_print("Scanning $js");
		my @deps = JSAN::Parse::FileDeps->file_deps( $path );
		foreach ( @deps ) {
			$config->{$js}->{$_} = 1;
		}
	}

	return $config;
}

sub make_index {
	my $self = shift;
	my $path = $self->index_path;

	# Make sure the output path exists
	if ( -e $path ) {
		-w $path or Carp::croak(
			"Insufficient permissions to change index file '$path'"
			);
	} else {
		my $dir = File::Basename::dirname( $path );
		unless ( -d $dir ) {
			eval { File::Path::mkpath( $dir, $VERBOSE ); };
			Carp::croak("$!: Failed to mkdir '$dir' for JSAN::Librarian index file") if $@;
		}
	}

	# Generate the Config::Tiny object
	my $config = $self->build_index( $self->root );

	# Save the index file
	$self->_print("Saving $path");
	$config->write( $path ) or Carp::croak(
		"Failed to write JSAN::Librarian index file '$path'"
	);
}

sub library {
	my $self = shift;
	my $from = $self->index_exists
		? $self->index_path
		: $self->build_index;
	return JSAN::Librarian::Library->new( $from );
}





#####################################################################
# Coercion Support

sub __as_JSAN_Librarian_Library       { shift->library }
sub __as_JavaScript_Librarian_Library { shift->library }
sub __as_Algorithm_Dependency_Source  { shift->library }





#####################################################################
# Support Methods

sub _print {
	my $msg = shift;
	$msg =~ s/\n*/\n/g;
	print $msg if $VERBOSE;
	return 1;
}

1;