package JWebmail::Plugin::RenderMail;

use Mojo::Base 'Mojolicious::Plugin';

use Mojo::ByteStream;
use Mojo::Util 'xml_escape';


sub render_text_plain {
    my ($_c, $_subtype, $content, $_path) = @_;

    $content = xml_escape($content);
    $content =~ s/\n/<br>/g;

    return qq'<div class="jwm-mail-body jwm-mail-body-text-plain">\n $content </div>\n';
}

sub render_text_html {
    my ($c, $_subtype, $_content, $path) = @_;

    my $url = $c->url_for('raw', id => $c->stash('id'));
    $url = $url->query(path => join('.', @$path)) if @$path;

    return qq'<iframe src="$url" class="jwm-mail-body-text-html" ></iframe>\n';
}

sub render_multipart_alternative {
    my ($c, $_subtype, $content, $path) = @_;

    my $parts = $content->{parts};
    my $R = qq'<div class="jwm-mail-body jwm-mail-body-multipart-alternative"\n>';
    my $i = 0;
    my $end;

    for (reverse @$parts) {
        if (!$end) {
            my $x = mime_render($c, to_mime_types($_->{head}), $_->{body}, [@$path, $#$parts-$i]);
            if ($x) {
                $R .= $x;
                $end = 1;
            }
        }
        else {
            $R .= '<details class="jwm-mail-body-multipart-alternative-extra" >';
            $R .= '<summary>';
            $R .= to_mime_type($_->{head});
            $R .= "</summary>\n";
            $R .= mime_render($c, to_mime_types($_->{head}), $_->{body}, [@$path, $#$parts-$i]);
            $R .= "</details>\n";
        }
        ++$i;
    }
    return $R . "</div>\n";
}

sub render_multipart {
    my ($c, $_subtype, $content, $path) = @_;

    my $parts = $content->{parts};
    my $R = qq'<div class="jwm-mail-body jwm-mail-body-multipart"\n>';
    my $i = 0;

    for (@$parts) {
        if (     !$_->{head}{content_disposition}
            || lc $_->{head}{content_disposition} eq 'none'
            || lc $_->{head}{content_disposition} eq 'inline') {

            $R .= mime_render($c, to_mime_types($_->{head}), $_->{body}, [@$path, $i]);
        }
        elsif (lc $_->{head}{content_disposition} eq 'attachment') {
            $R .= '<p>';
            $R .= $c->link_to($c->url_for(raw => id => $c->stash('id'))->query(path => join('.', @$path, $i))->to_abs, (download => $_->{head}{filename}) => sub {
                'Attachment ' . xml_escape($_->{head}{filename}) . ' of type ' . to_mime_type($c, $_->{head});
            });
            $R .= "</p>\n";
        }
        else {
            warn "unknown Content-Disposition '$_->{head}{content_disposition}'";
            $R .= "<p>unknown Content-Disposition '$_->{head}{content_disposition}'</p>\n";
        }
        ++$i;
    }
    return $R . "</div>\n";
}

sub _format_header {
    my ($c, $category, $value) = @_;

    my $R = '';

    if (ref $value eq 'ARRAY' && $value->@*) {
        $R .= '<dt>' . xml_escape(uc $c->l($category)) . "</dt>\n";
        for ($value->@*) {
            $R .= '<dd>';
            $R .= xml_escape($_->{display_name} ? qq("$_->{display_name}" <$_->{address}>) : "$_->{address}");
            $R .= "<dd>\n";
        }
    }
    return $R;
}

sub render_message {
    my ($c, $subtype, $msg, $path) = @_;

    warn "unkown mime-subtype $subtype" unless $subtype eq 'rfc822';

    my $R .= '<div clas="jwm-mail">';

    $R .= '<dl class="jwm-mail-header">';
    $R .= '<dt>' . xml_escape(uc $c->l('subject')) . '</dt>';
    $R .= '<dd>' . xml_escape($msg->{head}{subject}) . "</dd>\n";
    $R .= _format_header($c, from => $msg->{head}{from});
    $R .= _format_header($c, to   => $msg->{head}{to});
    $R .= _format_header($c, cc   => $msg->{head}{cc});
    $R .= _format_header($c, bcc  => $msg->{head}{bcc});
    $R .= '<dt>' . xml_escape(uc $c->l('date')) . '</dt>';
    $R .= '<dd>' . xml_escape($msg->{head}{date}) . "</dd>\n";
    $R .= '<dt>' . xml_escape(uc $c->l('content-type')) . '</dt>';
    $R .= '<dd>' . to_mime_type($msg->{head}{mime}) . "</dd>\n";
    $R .= "</dl>\n";

    #my $content = ref $msg->{body} && exists $msg->{body}{parts} ? $msg->{body}{parts} : $msg->{body};

    $R .= mime_render($c, to_mime_types($msg->{head}{mime}), $msg->{body}, [@$path, 0]);

    return $R . "</div>\n";
}

our %MIME_Render_Subs = (
    'text/plain'            => \&render_text_plain,
    'text/html'             => \&render_text_html,
    'multipart/alternative' => \&render_multipart_alternative,
    'multipart'             => \&render_multipart,
    'message'               => \&render_message,
);

sub mime_render {
    my ($c, $maintype, $subtype, $content, $path) = @_;

    my $renderer = $MIME_Render_Subs{"$maintype/$subtype"} || $MIME_Render_Subs{$maintype};

    unless ($renderer) {
        return "<p>Unsupported MIME type of <code>$maintype/$subtype</code>.</p>\n";
    }

    return $renderer->($c, $subtype, $content, $path);
}


sub to_mime_type  { lc xml_escape("$_[0]->{content_maintype}/$_[0]->{content_subtype}") }
sub to_mime_types { return xml_escape($_[0]->{content_maintype}), xml_escape($_[0]->{content_subtype}) }


sub register {
    my ($self, $app, $conf) = @_;
    $conf //= {};

    $app->helper('render_mail.format_mail' => sub { Mojo::ByteStream->new(mime_render($_[0], 'message', 'rfc822', $_[1], [])) });
    $app->helper(to_mime_type => sub { shift; to_mime_type(@_) });
}

1

__END__

=encoding utf-8

=head1 NAME

JWebmail::Plugin::RenderMail - Does the heavy lifting of converting an E-Mail to HTML

=head1 HELPERS

=head2 render_mail.format_mail

Renders a mail to html recursively.

=head2 to_mime_type

Combines the content_maintype and content_subtype attributes into the regular MIME description.
These attributes are found in a mail head mime section or as head for multipart messages.