package BookmarkApp;
use strict;
use warnings;
use base qw{CGI::Application};

use CGI::Application::Plugin::TT;

use Encode;
use HTTP::Date qw{time2isoz};
use JSON;
use Bookmarks;
use URI;

my $dbname = 'fk.db';

sub setup {
    my $self = shift;
    $self->mode_param(path_info => 1);
    $self->run_modes([qw{
        list
        feed
        view
        view_field
        edit
    }]);
    my $base_uri = URI->new;
    $base_uri->scheme('http');
    $base_uri->host($ENV{HTTP_X_FORWARDED_HOST} || $ENV{SERVER_NAME});
    $base_uri->port($ENV{SERVER_PORT});
    $base_uri->path($ENV{SCRIPT_NAME} . '/');

    my $bookmarks = Bookmarks->new({
        dbname   => $dbname,
        base_uri => $base_uri,
    });

    $self->param(
        base_uri  => $base_uri,
        bookmarks => $bookmarks,
    );
}

sub _bookmarks { $_[0]->param('bookmarks') }

sub _get_list_links {
    my $self = shift;
    my ($self_type, $tags) = @_;
    my @links = (
        {
            text => 'HTML',
            type => 'text/html',
            query => {
                tag => $tags,
            },
        },
        {
            text => 'JSON',
            type => 'application/json',
            query => {
                tag => $tags,
                format => 'json',
            },
        },
        {
            text => 'XBEL',
            type => 'application/xml',
            query => {
                tag => $tags,
                format => 'xbel',
            },
        },
        {
            text => 'Atom',
            type => 'application/atom+xml',
            path => 'feed',
            query => {
                tag => $tags,
            },
        },
        {
            text => 'URI List',
            type => 'text/uri-list',
            query => {
                tag => $tags,
            },
        }
    );

    for my $link (@links) {
        $link->{rel}  = $link->{type} eq $self_type ? 'self' : 'alternate';
        $link->{href} = URI->new_abs($link->{path} || '', $self->param('base_uri'));
        $link->{href}->query_form($link->{query});
    }

    return @links;
}

sub list {
    my $self = shift;
    my $q = $self->query;

    # check for a uri param, and if there is one present,
    # see if a bookmark for that URI already exists
    if (defined(my $uri = $q->param('uri'))) {
        my $bookmark = $self->_bookmarks->get_bookmark({ uri => $uri });
        if ($bookmark) {
            # redirect to the view of the existing bookmark
            $self->header_type('redirect');
            $self->header_props(
                -uri => $q->url . '/' . $bookmark->{id},
            );
            return;
        } else {
            # bookmark was not found; show the form to create a new bookmark
            $bookmark->{uri} = $uri;
            $bookmark->{title} = $q->param('title');
            $self->header_props(
                -type    => 'text/html',
                -charset => 'UTF-8',
                -status  => 404,
            );
            return $self->tt_process(
                'bookmark.tt',
                $bookmark,
            );
        }
    }

    # list all the bookmarks 
    my $format = $q->param('format') || 'html';

    my @tags = grep { $_ ne '' } $q->param('tag');
    my $limit = $q->param('limit');
    my $offset = $q->param('offset');
    my @resources = $self->_bookmarks->get_bookmarks({
        tag    => \@tags,
        limit  => $limit,
        offset => $offset,
    });
    my @all_tags = $self->_bookmarks->get_tags({ selected => $tags[0] });
    my @cotags = $self->_bookmarks->get_cotags({ tag => \@tags });
    
    my $title = 'Bookmarks' . (@tags ? " tagged as " . join(' & ', @tags) : '');

    if ($format eq 'json') {
        $self->header_props(
            -type    => 'application/json',
            -charset => 'UTF-8',
        );
        return decode_utf8(
            JSON->new->utf8->convert_blessed->encode({
                bookmarks => \@resources,
            })
        );
    } elsif ($format eq 'xbel') {
        require XML::XBEL;
        #TODO: conditional support; if XML::XBEL is not present, return a 5xx response

        my $xbel = XML::XBEL->new;

        $xbel->new_document({
            title => $title,
        });

        for my $bookmark (@resources) {
            my $cdatetime = time2isoz $bookmark->ctime;
            my $mdatetime = time2isoz $bookmark->mtime;
            # make the timestamps W3C-correct
            s/ /T/ foreach ($cdatetime, $mdatetime);

            $xbel->add_bookmark({
                href     => $bookmark->uri,
                title    => $bookmark->title,
                desc     => 'Tags: ' . join(', ', @{ $bookmark->tags }),
                added    => $cdatetime,
                #XXX: are we sure that modified is the mtime of the bookmark or the resource?
                modified => $mdatetime,
            });
        }

        $self->header_props(
            -type    => 'application/xml',
            -charset => 'UTF-8',
        );

        return $xbel->toString;
    } elsif ($format eq 'text') {
        $self->header_props(
            -type    => 'text/uri-list',
            -charset => 'UTF-8',
        );
        return join '', 
            map {
                sprintf "# %s\n# Tags: %s\n%s\n",
                $_->title,
                join(', ', @{ $_->tags }), 
                $_->uri
            } @resources;
    } else {
        $self->header_props(
            -type    => 'text/html',
            -charset => 'UTF-8',
        );

        # set the base URL, adding a trailing slash if needed
        my $base_url = $q->url;
        $base_url .= '/' if $base_url =~ m{/bookmarks$};

        return $self->tt_process(
            'list.tt',
            {
                base_url     => $base_url,
                title        => $title,
                selected_tag => $tags[0],
                search_tags  => \@tags,
                links        => [ $self->_get_list_links('text/html', \@tags) ],
                all_tags     => \@all_tags,
                cotags       => \@cotags,
                resources    => \@resources,
            },
        );
    }
}

sub feed {
    my $self = shift;
    my $q = $self->query;

    my @tags = grep { $_ ne '' } $q->param('tag');
    my $title = 'Bookmarks' . (@tags ? " tagged as " . join(' & ', @tags) : '');

    require XML::Atom;
    $XML::Atom::DefaultVersion = "1.0";

    require XML::Atom::Feed;
    require XML::Atom::Entry;
    require XML::Atom::Link;

    my $feed = XML::Atom::Feed->new;
    $feed->title($title);

    my $feed_uri = URI->new_abs('feed', $self->param('base_uri'));
    $feed_uri->query_form(tag => \@tags);
    $feed->id($feed_uri->canonical);

    for my $link ($self->_get_list_links('application/atom+xml', \@tags)) {
        my $atom_link = XML::Atom::Link->new;
        $atom_link->type($link->{type});
        $atom_link->rel($link->{rel});
        $atom_link->href($link->{href}->canonical);
        $feed->add_link($atom_link);
    }

    # construct a feed from the most recent 12 bookmarks
    for my $bookmark ($self->_bookmarks->get_bookmarks({ tag => \@tags, limit => 12 })) {
        my $entry = XML::Atom::Entry->new;
        $entry->id($bookmark->bookmark_uri->canonical);
        $entry->title($bookmark->title);
        my $link = XML::Atom::Link->new;
        $link->href($bookmark->uri);
        $entry->add_link($link);
        $entry->summary('Tags: ' . join(', ', @{ $bookmark->tags }));
        my $mdatetime = time2isoz $bookmark->mtime;
        # make the timestamp W3C-correct
        $mdatetime =~ s/ /T/;
        $entry->updated($mdatetime);
        $feed->add_entry($entry);
    }

    $self->header_props(
        -type => 'application/atom+xml',
        -charset => 'UTF-8',
    );
    return $feed->as_xml;
}

sub view {
    my $self = shift;
    my $id = $self->param('id');
    my $format = $self->query->param('format') || 'html';

    my $bookmark = $self->_bookmarks->get_bookmark({ id => $id });
    if ($bookmark) {
        if ($format eq 'json') {
            $self->header_props(
                -type    => 'application/json',
                -charset => 'UTF-8',
            );
            return decode_utf8(JSON->new->utf8->convert_blessed->encode($bookmark));
        } else {
            # display the bookmark form for this bookmark
            $bookmark->{exists} = 1;
            $bookmark->{created} = "Created " . localtime($bookmark->ctime);
            $bookmark->{created} .= '; Updated ' . localtime($bookmark->mtime) unless $bookmark->ctime == $bookmark->mtime;
            $self->header_props(
                -type    => 'text/html',
                -charset => 'UTF-8',
            );
            return $self->tt_process(
                'bookmark.tt',
                $bookmark,
            );
        }
    } else {
        $self->header_props(
            -type    => 'text/html',
            -charset => 'UTF-8',
            -status  => 404,
        );
        return "Bookmark $id Not Found";
    }
}

sub view_field {
    my $self = shift;
    my $id = $self->param('id');
    my $field = $self->param('field');

    my $bookmark = $self->_bookmarks->get_bookmark({ id => $id });
    if ($bookmark) {
        # respond with just the requested field as plain text
        my $value = eval { $bookmark->$field };
        if ($@) {
            if ($@ =~ /Can't locate object method/) {
                $self->header_props(
                    -type    => 'text/plain',
                    -charset => 'UTF-8',
                    -status  => 404,
                );
                return qq{"$field" is not a valid bookmark data field};
            } else {
                die $@;
            }
        }
        $self->header_props(
            -type    => 'text/plain',
            -charset => 'UTF-8',
        );
        return ref $value eq 'ARRAY' ? join(',', @{ $value }) : $value;
    } else {
        $self->header_props(
            -type    => 'text/html',
            -charset => 'UTF-8',
            -status  => 404,
        );
        return "Bookmark $id Not Found";
    }
}

#TODO: split this into edit and create methods
sub edit {
    my $self = shift;
    my $q = $self->query;
    #TODO: get the bookmark based on the id and edit it directly?
    #TODO: deal with changing URIs
    my $uri = $q->param('uri');
    my $title = $q->param('title');
    my @tags = split ' ', $q->param('tags');
    $self->_bookmarks->add({
        uri   => $uri,
        title => $title,
        tags  => \@tags,
    });

=begin

    my $location = URI->new($q->url);
    $location->query_form(uri => $uri) if defined $q->url_param('uri');
    $location->fragment('updated');

=cut

    # return to the form
    $self->header_type('redirect');
    $self->header_props(
        -uri => $ENV{REQUEST_URI},
        -status => 303,
    );
}

1;