package Catalyst::View::Mason;

use strict;
use warnings;
use base qw/Catalyst::View/;
use Scalar::Util qw/blessed/;
use File::Spec;
use HTML::Mason;
use MRO::Compat;

our $VERSION = '0.18';

__PACKAGE__->mk_accessors('template');

=head1 NAME

Catalyst::View::Mason - Mason View Class

=head1 SYNOPSIS

    # use the helper
    script/create.pl view Mason Mason

    # lib/MyApp/View/Mason.pm
    package MyApp::View::Mason;

    use base 'Catalyst::View::Mason';

    __PACKAGE__->config(use_match => 0);

    1;

    $c->forward('MyApp::View::Mason');

=head1 DESCRIPTION

Want to use a Mason component in your views? No problem!
Catalyst::View::Mason comes to the rescue.

=head1 EXAMPLE

From the Catalyst controller:

    $c->stash->{name} = 'Homer'; # Pass a scalar
    $c->stash->{extra_info} = {
               last_name => 'Simpson',
               children => [qw(Bart Lisa Maggie)]
    }; # A ref works too

From the Mason template:

    <%args>
    $name
    $extra_info
    </%args>
    <p>Your name is <strong><% $name %> <% $extra_info->{last_name} %></strong>
    <p>Your children are:
    <ul>
    % foreach my $child (@{$extra_info->{children}}) {
    <li><% $child %></li>
    % }
    </ul>

=head1 METHODS

=cut

=head2 new($app, \%config)

=cut

sub new {
    my ($self, $app, $arguments) = @_;

    my %config = (
        comp_root                        => $app->config->{root},
        data_dir                         => File::Spec->catdir(
            File::Spec->tmpdir,
            sprintf('%s_%d_mason_data_dir', $app, $<),
        ),
        use_match                        => 0,
        allow_globals                    => [],
        template_extension               => q//,
        always_append_template_extension => 0,
        %{ $self->config },
        %{ $arguments },
    );

    # stringify data_dir
    $config{data_dir}  .= q//;

    # stringify comp_root if it isn't an unblessed array reference already
    $config{comp_root} .= q//
        if blessed($config{comp_root}) || ref $config{comp_root} ne 'ARRAY';

    unshift @{ $config{allow_globals} }, qw/$c $base $name/;
    $self = $self->next::method($app, \%config);
    $self->{output} = q//;

    $self->config({ %config });

    # those are config options for the view, not mason itself.
    delete @config{qw/
        use_match
        template_extension
        always_append_template_extension
        catalyst_component_name
    /};

    if ($self->config->{use_match}) {
        $app->log->warn(sprintf(<<'EOW', ref $self));
DEPRECATION WARNING: %s sets the use_match config variable to a true value.
This has been deprecated. Please see the Catalyst::View::Mason
documentation for details on use_match.
EOW
    }

    $self->template(
        HTML::Mason::Interp->new(
            %config,
            out_method => \$self->{output},
        )
    );

    return $self;
}

=head2 get_component_path

Returns the component path from $c->stash->{template} or
$c->request->match or $c->action (depending on the use_match setting).

=cut

sub get_component_path {
    my ($self, $c) = @_;

    my $component_path = $c->stash->{template};
    my $extension      = $self->config->{template_extension};

    if (defined $component_path) {
        $component_path .= $extension
            if $self->config->{always_append_template_extension};
    }
    else {
        $component_path = $self->config->{use_match}
            ? $c->request->match
            : $c->action;

        $component_path .= $extension;
    }

    return $component_path;
}

=head2 process

Renders the component specified in $c->stash->{template} or $c->request->match
or $c->action (depending on the use_match setting) to $c->response->body.

Note that the component name must be absolute, or is converted to absolute
(i.e., a / is added to the beginning if it doesn't start with one).

Mason global variables C<$base>, C<$c>, and C<$name> are automatically
set to the base, context, and name of the app, respectively.

=cut

sub process {
    my ($self, $c) = @_;

    my $component_path = $self->get_component_path($c);
    my $output         = $self->render($c, $component_path);

    if (blessed($output) && $output->isa('HTML::Mason::Exception')) {
        chomp $output;
        my $error = qq/Couldn't render component "$component_path" - error was "$output"/;
        $c->log->error($error);
        $c->error($error);
        return 0;
    }

    unless ($c->response->content_type) {
        $c->response->content_type('text/html; charset=utf-8');
    }

    $c->response->body($output);

    return 1;
}

=head2 render($c, $component_path, \%args)

Renders the given template and returns output, or a HTML::Mason::Exception
object upon error.

The template variables are set to %$args if $args is a hashref, or
$c-E<gt>stash otherwise.

=cut

sub _default_globals {
    my ($self, $c) = @_;

    my %default_globals = (
        '$c'    => $c,
        '$base' => $c->request->base,
        '$name' => $c->config->{name},
    );

    return %default_globals;
}

sub render {
    my ($self, $c, $component_path, $args) = @_;

    if ($component_path !~ m{^/}) {
        $component_path = '/' . $component_path;
    }

    $c->log->debug(qq/Rendering component "$component_path"/) if $c->debug;

    # Set the URL base, context and name of the app as global Mason vars
    # $base, $c and $name
    my %default_globals = $self->_default_globals($c);
    while (my ($key, $val) = each %default_globals) {
        $self->template->set_global($key => $val);
    }

    $self->{output} = q//;

    eval {
        $self->template->exec(
            $component_path,
            ref $args eq 'HASH' ? %{ $args } : %{ $c->stash },
        );
    };

    if (my $error = $@) {
        return $error;
    }

    return $self->{output};
}

=head3 config

This allows you to to pass additional settings to the HTML::Mason::Interp
constructor or to set the options as below:

=over

=item C<template_extension>

This string is appended (if present) to C<< $c->action >> when generating a
template path.

Defaults to an empty string.

Example: C<< template_extension => '.html' >>

=item C<always_append_template_extension>

Set this to a true value if you want C<template_extension> to be appended to
the component path even if it was explicitly set.

Defaults to 0.

Example: C<< always_append_template_extension => 1 >>

=item C<use_match>

Use C<$c-E<gt>request-E<gt>match> instead of C<$c-E<gt>action> to determine
which template to use if C<$c-E<gt>stash-E<gt>{template}> isn't set. This option
is deprecated and exists for backward compatibility only.

Currently defaults to 0. Old code should set this to 1 to avoid breakage.

Example: C<< use_match => 0 >>

=back

The default HTML::Mason::Interp config options are as follows:

=over

=item C<comp_root>

C<$app-E<gt>config-E<gt>root>

=item C<data_dir>

C<File::Spec-E<gt>catdir( File::Spec-E<gt>tmpdir, sprintf('%s_%d_mason_data_dir', $app, $E<lt>) )>

=item C<allow_globals>

C<qw/$c $name $base/>

If you add additional allowed globals those will be appended to the list of
default globals.

=back

=cut

=head1 SEE ALSO

L<Catalyst>, L<HTML::Mason>, "Using Mason from a Standalone Script" in L<HTML::Mason::Admin>

=head1 AUTHORS

=over 4

=item Andres Kievsky C<ank@cpan.org>

=item Sebastian Riedel C<sri@cpan.org>

=item Marcus Ramberg

=item Florian Ragwitz C<rafl@debian.org>

=item Justin Hunter C<justin.d.hunter@gmail.com>

=back

=head1 COPYRIGHT

This program is free software, you can redistribute it and/or modify it under
the same terms as Perl itself.

=cut

1;