use strict;
use warnings;

no warnings 'experimental';
use feature qw{signatures};

use Date::Format qw{strftime};

use URL::Encode  ();
use Text::Xslate ();
use Plack::MIME  ();
use Mojo::File   ();
use DateTime::Format::HTTP();
use Encode qw{encode_utf8};

#Grab our custom routes
use lib 'lib';
use Trog::Routes::HTML;
use Trog::Routes::JSON;

# Troglodyne philosophy - simple as possible

# Import the routes
my %routes = %Trog::Routes::HTML::routes;
@routes{keys(%Trog::Routes::JSON::routes)} = values(%Trog::Routes::JSON::routes);

# Things we will actually produce from routes rather than just serving up files
my $ct = 'Content-type';
my %content_types = (
    plain => "$ct:text/plain;",
    html  => "$ct:text/html; charset=UTF-8",
    json  => "$ct:application/json;",
    blob  => "$ct:application/octet-stream;",
);

my $cd = 'Content-disposition';
my %content_dispositions = (
    attachment => 'attachment; filename=',
    inline     => 'inline; filename=',
);

my $cc = 'Cache-control';
my %cache_control = (
    revalidate => "$cc: no-cache, max-age=0;",
    nocache    => "$cc: no-store;",
    static     => "$cc: public, max-age=604800, immutable",
);

my $app = sub {
    my $env = shift;

    my $last_fetch = 0;
    if ($env->{HTTP_IF_MODIFIED_SINCE}) {
        $last_fetch = DateTime::Format::HTTP->parse_datetime($env->{HTTP_IF_MODIFIED_SINCE})->epoch();
    }

    my $query = {};
    $query = URL::Encode::url_params_mixed($env->{QUERY_STRING}) if $env->{QUERY_STRING};
    my $path = $env->{PATH_INFO};

    #Disallow any paths that are naughty ( starman auto-removes .. up-traversal)
    if (index($path,'/templates') == 0 || $path =~ m/.*\.psgi$/i ) {
        return [ 403, [$content_types{plain}], ["STAY OUT YOU RED MENACE"]];
    }

    # If it's just a file, serve it up
    return _serve("www/$path", $last_fetch) if -f "www/$path";

    #TODO reject inappropriate content-lengths
    return [ 404, [$content_types{plain}], ["RETURN TO SENDER"]] unless exists $routes{$path};
    return [ 400, [$content_types{plain}], ["BAD REQUEST"]] unless $routes{$path}{method} eq $env->{REQUEST_METHOD};

    #TODO fish out what user is in cookie
    $query->{user} = 'Nobody';

    my $output =  $routes{$path}{callback}->($query,$env->{input}, \&_render);
    return $output;
};

sub _serve ($path, $last_fetch=0) {
    my $mf = Mojo::File->new($path);
    my $ext = '.'.$mf->extname();
    my $ft;
    $ft = Plack::MIME->mime_type($ext) if $ext;
    $ft = "$ct:$ft;" if $ft;
    $ft ||= $content_types{plain};

    my @headers = ($ft);

    #TODO figure out content-disposition

    #TODO use static Cache-Control for everything but JS/CSS?
    push(@headers,$cache_control{revalidate});


    #TODO Return 304 unchanged for files that haven't changed since the requestor reports they last fetched
    my $mt = (stat($path))[9];
    my @gm = gmtime($mt);
    my $now_string = strftime( "%a, %d %b %Y %H:%M:%S GMT", @gm );
    my $code = $mt > $last_fetch ? 200 : 304;

    push(@headers, "Last-Modified: $now_string\n");

    my $h = join("\n",@headers);
    if (open(my $fh, '<', $path)) {
        return [ $code, [$h], $fh];
    }
    return [ 403, [$content_types{plain}], ["STAY OUT YOU RED MENACE"]];
}

sub _render ($template, $vars) {

    my $processor = Text::Xslate->new(
        path   => 'www/templates',
        header => ['header.tx'],
        footer => ['footer.tx'],
    );

    #XXX default vars that need to be pulled from config
    $vars->{dir}       //= 'ltr';
    $vars->{lang}      //= 'en-US';
    $vars->{title}     //= 'tCMS';
    #XXX Need to have minification detection and so forth, use LESS
    $vars->{stylesheets}  //= [];
    #XXX Need to have minification detection, use Typescript
    $vars->{scripts} //= [];

    $vars->{contenttype} //= $content_types{html};
    $vars->{cachecontrol} //= $cache_control{revalidate};

    my @headers = ($vars->{contenttype});
    push(@headers,$vars->{contentdisposition}) if $vars->{contentdisposition};
    push(@headers, $vars->{cachecontrol}) if $vars->{cachecontrol};
    my $h = join("\n",@headers);

    my $body = $processor->render($template,$vars);
    return [200, [$h], [encode_utf8($body)]];
}