File Coverage

blib/lib/Web/Machine/FSM/States.pm

Criterion	Covered	Total	%
statement	323	328	98.4
branch	188	202	93.0
condition	28	35	80.0
subroutine	79	80	98.7
pod	0	61	0.0
total	618	706	87.5

package Web::Machine::FSM::States;
# ABSTRACT: The States for Web Machine

use strict;
use warnings;

our $VERSION = '0.16';

use B ();
use Hash::MultiValue;

use Carp qw[ confess ];

use Web::Machine::Util qw[
    first
    pair_key
    pair_value
    create_header
];
use Web::Machine::Util::BodyEncoding qw[
    encode_body_if_set
    encode_body
];
use Web::Machine::Util::ContentNegotiation qw[
    choose_media_type
    match_acceptable_media_type
    choose_language
    choose_charset
    choose_encoding
];

use Sub::Exporter -setup => {
    exports => [qw[
        start_state
        is_status_code
        is_new_state
        get_state_name
        get_state_desc
    ]]
};

my %STATE_DESC;

# my exports ...

sub start_state    { \&b13 }
sub is_status_code { ref $_[0] eq 'SCALAR' }
sub is_new_state   { ref $_[0] eq 'CODE'   }
sub get_state_name { B::svref_2object( shift )->GV->NAME }
sub get_state_desc { $STATE_DESC{ ref $_[0] ? get_state_name( shift ) : shift } }

# some utilities ...

sub _unquote_header {
    my $value = shift;
    if ( $value =~ /^"(.*)"$/ ) {
        return $1;
    }
    return $value;
}

sub _ensure_quoted_header {
    my $value = shift;
    return $value if $value =~ /^"(.*)"$/;
    return '"' . $value . '"';
}

sub _get_acceptable_content_type_handler {
    my ($resource, $request) = @_;
    my $acceptable = match_acceptable_media_type(
        ($request->header('Content-Type') || 'application/octet-stream'),
        $resource->content_types_accepted
    );
    return \415 unless $acceptable;
    return pair_value( $acceptable );
}

sub _add_caching_headers {
    my ($resource, $response) = @_;
    if ( my $etag = $resource->generate_etag ) {
        $response->header( 'Etag' => _ensure_quoted_header( $etag ) );
    }
    if ( my $expires = $resource->expires ) {
        $response->header( 'Expires' => $expires );
    }
    if ( my $modified = $resource->last_modified ) {
        $response->header( 'Last-Modified' => $modified );
    }
}

sub _handle_304 {
    my ($resource, $response) = @_;
    $response->headers->remove_header('Content-Type');
    $response->headers->remove_header('Content-Encoding');
    $response->headers->remove_header('Content-Language');
    _add_caching_headers($resource, $response);
    return \304;
}

sub _is_redirect {
    my ($response) = @_;
    # NOTE:
    # this makes a guess that the user has
    # told the Plack::Response that they
    # want to redirect. We do this based
    # on the fact that the ->redirect method
    # will set the status, while in almost all
    # other cases the status of the response
    # will not be set yet.
    # - SL
    return 1 if $response->status;
    return;
}

sub _metadata {
    my ($request) = @_;
    return $request->env->{'web.machine.context'};
}

## States

$STATE_DESC{'b13'} = 'service_available';
sub b13 {
    my ($resource, $request, $response) = @_;
    $resource->service_available ? \&b12 : \503;
}

$STATE_DESC{'b12'} = 'known_method';
sub b12 {
    my ($resource, $request, $response) = @_;
    my $method = $request->method;
    (grep { $method eq $_ } @{ $resource->known_methods }) ? \&b11 : \501;
}

$STATE_DESC{'b11'} = 'uri_too_long';
sub b11 {
    my ($resource, $request, $response) = @_;
    $resource->uri_too_long( $request->uri ) ? \414 : \&b10;
}

$STATE_DESC{'b10'} = 'method_allowed';
sub b10 {
    my ($resource, $request, $response) = @_;
    my $method = $request->method;
    my @allowed_methods = @{ $resource->allowed_methods };
    return \&b9 if grep { $method eq $_ } @allowed_methods;
    $response->header('Allow' => join ", " => @allowed_methods );
    return \405;
}

$STATE_DESC{'b9'} = 'malformed_request';
sub b9 {
    my ($resource, $request, $response) = @_;
    $resource->malformed_request ? \400 : \&b8;
}

$STATE_DESC{'b8'} = 'is_authorized';
sub b8 {
    my ($resource, $request, $response) = @_;
    my $result = $resource->is_authorized( $request->header('Authorization') );
    # if we get back a status, then use it
    if ( is_status_code( $result ) ) {
        return $result;
    }
    # if we just get back true, then
    # move onto the next state
    elsif ( defined $result && "$result" eq "1" ) {
        return \&b7
    }
    # anything else will either be
    # a WWW-Authenticate header or
    # a simple false value
    else {
        if ( $result ) {
            $response->header( 'WWW-Authenticate' => $result );
        }
        return \401;
    }
}

$STATE_DESC{'b7'} = 'forbidden';
sub b7 {
    my ($resource, $request, $response) = @_;
    $resource->forbidden ? \403 : \&b6;
}

$STATE_DESC{'b6'} = 'content_headers_okay';
sub b6 {
    my ($resource, $request, $response) = @_;

    # FIX-ME
    # there is a better way to do this,
    # also, HTTP::Headers will usually
    # group things into arrays, so we
    # can either avoid or better take
    # advantage of Hash::MultiValue.
    # But we are almost certainly not
    # handling that case properly maybe.
    my $content_headers = Hash::MultiValue->new;
    $request->headers->scan(sub {
        my ($name, $value) = @_;
        $content_headers->add( $name, $value ) if (lc $name) =~ /^content-/;
    });

    $resource->valid_content_headers( $content_headers ) ? \&b5 : \501;
}

$STATE_DESC{'b5'} = 'known_content_type';
sub b5 {
    my ($resource, $request, $response) = @_;
    $resource->known_content_type( $request->header('Content-Type') ) ? \&b4 : \415;
}

$STATE_DESC{'b4'} = 'request_entity_too_large';
sub b4 {
    my ($resource, $request, $response) = @_;
    $resource->valid_entity_length( $request->content_length ) ? \&b3 : \413;
}

$STATE_DESC{'b3'} = 'method_is_options';
sub b3 {
    my ($resource, $request, $response) = @_;
    if ( $request->method eq 'OPTIONS' ) {
        $response->headers( $resource->options );
        return \200;
    }
    return \&c3
}

$STATE_DESC{'c3'} = 'accept_header_exists';
sub c3 {
    my ($resource, $request, $response) = @_;
    my $metadata = _metadata($request);
    if ( !$request->header('Accept') ) {
        $metadata->{'Content-Type'} = create_header( MediaType => (
            pair_key( $resource->content_types_provided->[0] )
        ));
        return \&d4
    }
    return \&c4;
}

$STATE_DESC{'c4'} = 'acceptable_media_type_available';
sub c4 {
    my ($resource, $request, $response) = @_;
    my $metadata = _metadata($request);

    my @types = map { pair_key( $_ ) } @{ $resource->content_types_provided };

    if ( my $chosen_type = choose_media_type( \@types, $request->header('Accept') ) ) {
        $metadata->{'Content-Type'} = $chosen_type;
        return \&d4;
    }

    return \406;
}

$STATE_DESC{'d4'} = 'accept_language_header_exists';
sub d4 {
    my ($resource, $request, $response) = @_;
    (not $request->header('Accept-Language')) ? \&e5 : \&d5;
}


$STATE_DESC{'d5'} = 'accept_language_choice_available';
sub d5 {
    my ($resource, $request, $response) = @_;
    my $metadata = _metadata($request);

    if ( my $language = choose_language( $resource->languages_provided, $request->header('Accept-Language') ) ) {
        $metadata->{'Language'} = $language;
        # handle the short circuit here ...
        $response->header( 'Content-Language' => $language ) if "$language" ne "1";
        return \&e5;
    }

    return \406;
}

$STATE_DESC{'e5'} = 'accept_charset_exists';
sub e5 {
    my ($resource, $request, $response) = @_;
    (not $request->header('Accept-Charset')) ? \&f6 : \&e6;
}

$STATE_DESC{'e6'} = 'accept_charset_choice_available';
sub e6 {
    my ($resource, $request, $response) = @_;
    my $metadata = _metadata($request);

    if ( my $charset = choose_charset( $resource->charsets_provided, $request->header('Accept-Charset') ) ) {
        # handle the short circuit here ...
        $metadata->{'Charset'} = $charset if "$charset" ne "1";
        return \&f6;
    }

    return \406;
}

$STATE_DESC{'f6'} = 'accept_encoding_exists';
# (also, set content-type header here, now that charset is chosen)
sub f6 {
    my ($resource, $request, $response) = @_;
    my $metadata = _metadata($request);

    # If the client doesn't provide an Accept-Charset header we should just
    # encode with the default.
    if ( $resource->default_charset && !$request->header('Accept-Charset') ) {
        my $default = $resource->default_charset;
        $metadata->{'Charset'} = ref $default ? pair_key($default) : $default;
    }

    if ( my $charset = $metadata->{'Charset'} ) {
        # Add the charset to the content type now ...
        $metadata->{'Content-Type'}->add_param( 'charset' => $charset );
    }
    # put the content type in the header now ...
    $response->header( 'Content-Type' => $metadata->{'Content-Type'}->as_string );

    if ( $request->header('Accept-Encoding') ) {
        return \&f7
    }
    else {
        if ( my $encoding = choose_encoding( $resource->encodings_provided, "identity;q=1.0,*;q=0.5" ) ) {
            $response->header( 'Content-Encoding' => $encoding ) unless $encoding eq 'identity';
            $metadata->{'Content-Encoding'} = $encoding;
            return \&g7;
        }
        else {
            return \406;
        }
    }
}

$STATE_DESC{'f7'} = 'accept_encoding_choice_available';
sub f7 {
    my ($resource, $request, $response) = @_;
    my $metadata = _metadata($request);

    if ( my $encoding = choose_encoding( $resource->encodings_provided, $request->header('Accept-Encoding') ) ) {
        $response->header( 'Content-Encoding' => $encoding ) unless $encoding eq 'identity';
        $metadata->{'Content-Encoding'} = $encoding;
        return \&g7;
    }

    return \406;
}

$STATE_DESC{'g7'} = 'resource_exists';
sub g7 {
    my ($resource, $request, $response) = @_;

    # NOTE:
    # set Vary header here since we are
    # done with content negotiation
    # - SL
    my @variances = @{ $resource->variances };

    push @variances => 'Accept'          if scalar @{ $resource->content_types_provided } > 1;
    push @variances => 'Accept-Encoding' if scalar keys %{ $resource->encodings_provided } > 1;
    push @variances => 'Accept-Charset'  if defined $resource->charsets_provided && scalar @{ $resource->charsets_provided } > 1;
    push @variances => 'Accept-Language' if scalar @{ $resource->languages_provided } > 1;

    $response->header( 'Vary' => join ', ' => @variances ) if @variances;

    $resource->resource_exists ? \&g8 : \&h7;
}

$STATE_DESC{'g8'} = 'if_match_exists';
sub g8 {
    my ($resource, $request, $response) = @_;
    $request->header('If-Match') ? \&g9 : \&h10;
}

$STATE_DESC{'g9'} = 'if_match_is_wildcard';
sub g9 {
    my ($resource, $request, $response) = @_;
    _unquote_header( $request->header('If-Match') ) eq "*" ? \&h10 : \&g11;
}

$STATE_DESC{'g11'} = 'etag_in_if_match_list';
sub g11 {
    my ($resource, $request, $response) = @_;
    my @etags = map { _unquote_header( $_ ) } split /\s*\,\s*/ => $request->header('If-Match');
    my $etag  = $resource->generate_etag;
    (grep { $etag eq $_ } @etags) ? \&h10 : \412;
}

$STATE_DESC{'h7'} = 'if_match_exists_and_if_match_is_wildcard';
sub h7 {
    my ($resource, $request, $response) = @_;
    ($request->header('If-Match') && _unquote_header( $request->header('If-Match') ) eq "*") ? \412 : \&i7;
}

$STATE_DESC{'h10'} = 'if_unmodified_since_exists';
sub h10 {
    my ($resource, $request, $response) = @_;
    $request->header('If-Unmodified-Since') ? \&h11 : \&i12;
}

$STATE_DESC{'h11'} = 'if_unmodified_since_is_valid_date';
sub h11 {
    my ($resource, $request, $response) = @_;
    my $metadata = _metadata($request);
    if ( my $date = $request->header('If-Unmodified-Since') ) {
        $metadata->{'If-Unmodified-Since'} = $date;
        return \&h12;
    }
    return \&i12;
}

$STATE_DESC{'h12'} = 'last_modified_is_greater_than_if_unmodified_since';
sub h12 {
    my ($resource, $request, $response) = @_;
    my $metadata = _metadata($request);
    defined $resource->last_modified
        &&
    ($resource->last_modified->epoch > $metadata->{'If-Unmodified-Since'}->epoch)
        ? \412 : \&i12;
}

$STATE_DESC{'i4'} = 'moved_permanently';
sub i4 {
    my ($resource, $request, $response) = @_;
    if ( my $uri = $resource->moved_permanently ) {
        if ( is_status_code( $uri ) ) {
            return $uri;
        }
        $response->header('Location' => $uri );
        return \301;
    }
    return \&p3;
}

$STATE_DESC{'i7'} = 'method_is_put';
sub i7 {
    my ($resource, $request, $response) = @_;
    $request->method eq 'PUT' ? \&i4 : \&k7
}

$STATE_DESC{'i12'} = 'if_none_match_exists';
sub i12 {
    my ($resource, $request, $response) = @_;
    $request->header('If-None-Match') ? \&i13 : \&l13
}

$STATE_DESC{'i13'} = 'if_none_match_is_wildcard';
sub i13 {
    my ($resource, $request, $response) = @_;
    $request->header('If-None-Match') eq "*" ? \&j18 : \&k13
}

$STATE_DESC{'j18'} = 'method_is_get_or_head';
sub j18 {
    my ($resource, $request, $response) = @_;
    $request->method eq 'GET' || $request->method eq 'HEAD'
        ? _handle_304( $resource, $response )
        : \412
}

$STATE_DESC{'k5'} = 'moved_permanently';
sub k5 {
    my ($resource, $request, $response) = @_;
    if ( my $uri = $resource->moved_permanently ) {
        if ( is_status_code( $uri ) ) {
            return $uri;
        }
        $response->header('Location' => $uri );
        return \301;
    }
    return \&l5;
}

$STATE_DESC{'k7'} = 'previously_existed';
sub k7 {
    my ($resource, $request, $response) = @_;
    $resource->previously_existed ? \&k5 : \&l7;
}

$STATE_DESC{'k13'} = 'etag_in_if_none_match';
sub k13 {
    my ($resource, $request, $response) = @_;
    my @etags = map { _unquote_header( $_ ) } split /\s*\,\s*/ => $request->header('If-None-Match');
    my $etag  = $resource->generate_etag;
    $etag && (grep { $etag eq $_ } @etags) ? \&j18 : \&l13;
}

$STATE_DESC{'l5'} = 'moved_temporarily';
sub l5 {
    my ($resource, $request, $response) = @_;
    if ( my $uri = $resource->moved_temporarily ) {
        if ( is_status_code( $uri ) ) {
            return $uri;
        }
        $response->header('Location' => $uri );
        return \307;
    }
    return \&m5;
}

$STATE_DESC{'l7'} = 'method_is_post';
sub l7 {
    my ($resource, $request, $response) = @_;
    $request->method eq 'POST' ? \&m7 : \404
}

$STATE_DESC{'l13'} = 'if_modified_since_exists';
sub l13 {
    my ($resource, $request, $response) = @_;
    $request->header('If-Modified-Since') ? \&l14 : \&m16
}

$STATE_DESC{'l14'} = 'if_modified_since_is_valid_date';
sub l14 {
    my ($resource, $request, $response) = @_;
    my $metadata = _metadata($request);
    if ( my $date = $request->header('If-Modified-Since') ) {
        $metadata->{'If-Modified-Since'} = $date;
        return \&l15;
    }
    return \&m16;
}

$STATE_DESC{'l15'} = 'if_modified_since_greater_than_now';
sub l15 {
    my ($resource, $request, $response) = @_;
    my $metadata = _metadata($request);
    ($metadata->{'If-Modified-Since'}->epoch > (scalar time)) ? \&m16 : \&l17;
}

$STATE_DESC{'l17'} = 'last_modified_is_greater_than_if_modified_since';
sub l17 {
    my ($resource, $request, $response) = @_;
    my $metadata = _metadata($request);
    defined $resource->last_modified
        &&
    ($resource->last_modified->epoch > $metadata->{'If-Modified-Since'}->epoch)
        ? \&m16 : _handle_304( $resource, $response );
}

$STATE_DESC{'m5'} = 'method_is_post';
sub m5 {
    my ($resource, $request, $response) = @_;
    $request->method eq 'POST' ? \&n5 : \410
}

$STATE_DESC{'m7'} = 'allow_post_to_missing_resource';
sub m7 {
    my ($resource, $request, $response) = @_;
    $resource->allow_missing_post ? \&n11 : \404
}

$STATE_DESC{'m16'} = 'method_is_delete';
sub m16 {
    my ($resource, $request, $response) = @_;
    $request->method eq 'DELETE' ? \&m20 : \&n16
}

$STATE_DESC{'m20'} = 'delete_enacted_immediately';
sub m20 {
    my ($resource, $request, $response) = @_;
    $resource->delete_resource ? \&m20b : \500
}

$STATE_DESC{'m20b'} = 'did_delete_complete';
sub m20b {
    my ($resource, $request, $response) = @_;
    $resource->delete_completed ? \&o20 : \202
}

$STATE_DESC{'n5'} = 'allow_post_to_missing_resource';
sub n5 {
    my ($resource, $request, $response) = @_;
    $resource->allow_missing_post ? \&n11 : \410
}

sub _n11_create_path {
    my ($resource, $request, $response) = @_;

    my $uri = $resource->create_path;
    confess "Create Path Nil" unless $uri;
    my $base_uri = $resource->base_uri || $request->base;

    # do a little cleanup
    $base_uri =~ s!/$!! if $uri =~ m!^/!;
    $base_uri .= '/'    if $uri !~ m!^/! && $base_uri !~ m!/$!;
    my $new_uri = URI->new( $base_uri . $uri )->canonical;
    # NOTE:
    # the ruby and JS versions will set the path_info
    # for the request object here, but since our requests
    # are immutable, we don't allow that. I don't see
    # where this ends up being useful so I am going to
    # skip it and not bother.
    # - SL
    $response->header( 'Location' => $new_uri->path_query );
}

$STATE_DESC{'n11'} = 'redirect';
sub n11 {
    my ($resource, $request, $response) = @_;
    if ( $resource->post_is_create ) {

        # the default behavior as specified by
        # the Erlang/Ruby versions, however this
        # is a very unpopular "feature" so we are
        # allowing it to be bypassed here.
        _n11_create_path( $resource, $request, $response )
            if not $resource->create_path_after_handler;

        my $handler = _get_acceptable_content_type_handler( $resource, $request );
        return $handler if is_status_code( $handler );

        my $result = $resource->$handler();
        return $result if is_status_code( $result );

        _n11_create_path( $resource, $request, $response )
            if $resource->create_path_after_handler;
    }
    else {
        my $result = $resource->process_post;
        if ( $result ) {
            return $result if is_status_code( $result );
            encode_body_if_set( $resource, $response );
        }
        else {
            confess "Process Post Invalid";
        }
    }

    if ( _is_redirect( $response ) ) {
        if ( $response->location ) {
            return \303;
        }
        else {
            confess "Bad Redirect"
        }
    }

    return \&p11;
}

$STATE_DESC{'n16'} = 'method_is_post';
sub n16 {
    my ($resource, $request, $response) = @_;
    $request->method eq 'POST' ? \&n11 : \&o16
}

$STATE_DESC{'o14'} = 'in_conflict';
sub o14 {
    my ($resource, $request, $response) = @_;
    return \409 if $resource->is_conflict;

    my $handler = _get_acceptable_content_type_handler( $resource, $request );
    return $handler if is_status_code( $handler );

    my $result  = $resource->$handler();

    return $result if is_status_code( $result );
    return \&p11;
}

$STATE_DESC{'o16'} = 'method_is_put';
sub o16 {
    my ($resource, $request, $response) = @_;
    $request->method eq 'PUT' ? \&o14 : \&o18;
}

$STATE_DESC{'o18'} = 'multiple_representations';
sub o18 {
    my ($resource, $request, $response) = @_;
    my $metadata = _metadata($request);
    if ( $request->method eq 'GET' || $request->method eq 'HEAD' ) {
        _add_caching_headers( $resource, $response );

        my $content_type = $metadata->{'Content-Type'};
        my $match        = first {
            my $ct = create_header( MediaType => pair_key( $_ ) );
            $content_type->match( $ct )
        } @{ $resource->content_types_provided };

        my $handler = pair_value( $match );
        my $result  = $resource->$handler();

        return $result if is_status_code( $result );

        unless($request->method eq 'HEAD') {
            if (ref($result) eq 'CODE') {
                $request->env->{'web.machine.streaming_push'} = $result;
            }
            else {
                $response->body( $result );
            }
            encode_body( $resource, $response );
        }
        return \&o18b;
    }
    else {
        return \&o18b;
    }

}

$STATE_DESC{'o18b'} = 'multiple_choices';
sub o18b {
    my ($resource, $request, $response) = @_;
    $resource->multiple_choices ? \300 : \200;
}

$STATE_DESC{'o20'} = 'response_body_includes_entity';
sub o20 {
    my ($resource, $request, $response) = @_;
    $response->body ? \&o18 : \204;
}

$STATE_DESC{'p3'} = 'in_conflict';
sub p3 {
    my ($resource, $request, $response) = @_;
    return \409 if $resource->is_conflict;

    my $handler = _get_acceptable_content_type_handler( $resource, $request );
    return $handler if is_status_code( $handler );

    my $result  = $resource->$handler();

    return $result if is_status_code( $result );
    return \&p11;
}

$STATE_DESC{'p11'} = 'new_resource';
sub p11 {
    my ($resource, $request, $response) = @_;
    (not $response->header('Location')) ? \&o20 : \201
}

1;

__END__