#!/usr/bin/env perl

use 5.24.0;

package Bot::BB3::Plugin::Factoids;
use DBI;
use DBD::SQLite;
use strict;

use Data::Dumper;
use Text::Handlebars;

#############################
# BIG WARNING ABOUT THE DATABASE IN HERE.
#############################
#
# Despite the name 'original_subject' and 'subject' are logically reversed, e.g. 'original_subject' contains the cleaned up and filtered subject rather than the other way around.
# This should be kept in mind when working on any and all of the code below
#   --simcop2387 (previously also discovered by buu, but not documented or fixed).
#
# This might be fixed later but for now its easier to just "document" it. (boy doesn't this feel enterprisy!)
#
#############################

my $fsep = "\034"; # ASCII file seperator

{my $dbh;
    sub dbh { 
        if( $dbh and $dbh->ping ) {
            return $dbh;
        }

        $dbh = DBI->connect(
            "dbi:SQLite:dbname=var/factoids.db",
            "",
            "",
            { RaiseError => 1, PrintError => 0 }
        );

        return $dbh;
    }
}

sub get_fact_iter {
    my $sth = dbh->prepare("SELECT f.* FROM factoid f JOIN (SELECT max(factoid_id) as factoid_id FROM factoid GROUP BY original_subject) fmax USING (factoid_id) WHERE predicate IS NOT NULL and predicate <> ''");

    $sth->execute();

    return sub {$sth->fetchrow_hashref()};
}

my $fact_iter = get_fact_iter();

my $handlebars = Text::Handlebars->new(
    helpers =>  {
        each_obj => sub {
            my ($context, $object, $options) = @_;
            return join '', map { $options->{fn}->({'@key' => $_, $object->{$_}->%*}) } keys $object->%*;
        },
    }
);

my $vars = {
};

while(my $factoid = $fact_iter->()) {
    if ($factoid->{subject} =~ /^$fsep(.*?)$fsep(.*?)$fsep(.*)$/) { # namespaced
        my ($server, $channel) = ($1, $2);
        $factoid->{subject} = $3;
        push $vars->{servers}{$server}{channels}{$channel}{factoids}->@*, $factoid;
    } else { # default freenode/#perl
        push $vars->{servers}{default}{channels}{everywhere}{factoids}->@*, $factoid;
    }
};

my $doc_template=<<'EOF';
# List of factoids

{{#each_obj servers}}
## {{@key}}

{{#each_obj channels}}
### {{@key}}

{{#each factoids}}
* {{#if protected}}-protected- {{/if}}{{#if compose_macro}}macro {{/if}}{{subject}} [{{copula}}] := {{predicate}}
{{/each}}

{{/each_obj}}
{{/each_obj}}
EOF

say $handlebars->render_string($doc_template, $vars);