#!/usr/bin/perl

use Mojolicious::Lite;
use String::Random;
use Mojo::Pg;
use Arthas::Defaults::520;

my $version = '1.0.0';

my $config = {
    db      => {
        host    => 'localhost',
        name    => 'cgshorten',
        user    => 'dbuser',
        pwd     => 'dbpass',
    },
    auth    => 'writepass',
};

get '/' => sub($self) {
    return $self->render(text => '_');
};

get '/:shortcode' => [shortcode => qr/[A-Za-z0-9]{8}/] => sub($self) {
    my $link = $self->pg->db->query('select targeturl from links where shortcode = ?', $self->stash->{shortcode})->hash;
    if (defined $link) {
        $self->res->code(303);
        return $self->redirect_to( $link->{targeturl} );
    }
    return $self->render(text => 'Notfound-shortcode');
};

post '/create' => sub($self) {
    my $args = $self->req->json;
    my $db = $self->pg->db;

    # Handle obvious error cases
    return $self->mkerror('invalid-JSON-content')
        if !defined $args;
    return $self->mkerror('invalid-auth-information')
        if $args->{auth} ne $config->{auth};

    return $self->mkerror('please-provide-URL') if !$args->{targeturl};
    my $targeturl = Mojo::URL->new( $args->{targeturl} );
    return $self->mkerror('invalid-URL') if !defined $targeturl;
    return $self->mkerror('invalid-URL-scheme')
        if $targeturl->scheme ne 'http' && $targeturl->scheme ne 'https';

    my $link = $db->query('select shortcode from links where targeturl = ?', $targeturl)->hash;
    if (defined $link) {
        return $self->render('json', {
          status      => 'ok',
          action      => 'fetched',
          shortcode   => $link->{shortcode},
          shorturl    => $self->url_for("/$link->{shortcode}")->to_abs,
        });
    }

    my $string_gen = String::Random->new;
    my $shortcode = $string_gen->randregex('[A-Za-z0-9]{8}');

    my $saved = 0;
    my $loopcount = 0;
    while ( !$saved ) {
        if ( $loopcount == 10 ) {
            return $self->mkerror('too-much-recursion-in-insert');
        }
        try {
            $db->query('insert into links (shortcode, targeturl) values (?, ?)', $shortcode, $targeturl);
            $saved = 1;
        } catch {
            die $_ if $_ !~ m/duplicate\s+key/;
        };
        $loopcount++;
    }

    return $self->render('json', {
        status      => 'ok',
        action      => 'created',
        shortcode   => $shortcode,
        shorturl    => $self->url_for("/$shortcode")->to_abs,
    });
};

helper mkerror => sub {
    my ($self, $error) = @_;

    return $self->render('json', {
        status  => 'error',
        error   => $error,
    });
};

helper pg => sub {
    state $pg = Mojo::Pg->new("postgresql://$config->{db}->{user}:$config->{db}->{pwd}\@$config->{db}->{host}/$config->{db}->{name}?PrintError=0&RaiseError=1");
};

app->start;