Duolingo API Script

Duolingo.pl

#!/usr/bin/perl

use strict;
use warnings;

use WWW::Mechanize;
use JSON::Any;
use HTTP::CookieJar::LWP;

my $user = 'username';
my $pass = 'password';

sub new {
    my %params = @_;
    if (!defined $params{user} || !defined $params{pass}) {
        die "'new' requires your 'user' and 'pass' key values\n";
    }
    my $cookie_jar = HTTP::CookieJar::LWP->new();
    if (!defined $params{mech}) {
        $params{mech} = WWW::Mechanize->new(autocheck => 1, cookie_jar => $cookie_jar, agent => 'Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; MDDRJS; rv:11.0) like Gecko');
    }
    my $self = { username => $params{user}, password => $params{password}, mechanize => $params{mech}, base_url => 'https://www.duolingo.com' };
    bless $self;
    
    $self->authenticate();
    return $self;
}

sub authenticate {
    my $self = shift;
    my $response =  $self->{mechanize}->post($self->{base_url} . '/login', [ 'login' => $user, 'password' => $pass ]);
    my $json = $response->decoded_content();
    my $content =JSON::XS::decode_json($json);
    unless ( $content->{response} eq 'OK' ) {
        die "Authentication Failed\n";
    }
    $self->{user_id} = $content->{user_id};
    my $headers = $response->headers();
    $self->{jwt} = $headers->{jwt};
}

sub response {
    my $self = shift;
    my %params = @_;
    if (!defined $self->{jwt}) {
        die "Session has not yet been authenticated. Must initialize with 'new'.\n";
    }
    my $response = $self->{mechanize}->get($self->{base_url} . $params{resource} );
    my $json = $response->decoded_content();
    my $content = JSON::XS::decode_json($json);
    return $content;
}

my $duo = new( user => $user, pass => $pass );

# The regular API requires the tedious work of finding all activity
# timestamped for today, then adding up the xp to provide a total.
# I only want the streak length, goal, and today's xp, so I'm going
# to be lazy and use an older API that does the tally for me.
$duo->{base_url} = 'https://www.duolingo.com/2017-06-30';

# The fetch line is the slightly different because the current API
# uses the 'username', while the old one uses the 'user_id'. Luckily,
# I stored the 'user_id' during authentication!
# my $data = $duo->response(resource => "/users/" . $self->{username});
my $data = $duo->response(resource => "/users/" . $duo->{user_id});

# Note: The data collected is structured different for each API
# version, so the following won't work for the current one. I also only
# print the values I care about. Dump the data structure to find which
# values you need:
# use Data::Dump 'dump';
# print Data::Dump::dump($data);

# The current day's xp isn't entirely simple to fetch in the old API
# either. The only place that it is pre-calculated is in an array of
# global achievements:
my $xp;
my @achievements = @{$data->{_achievements}};
foreach (@achievements) {
    if ($_->{name} eq 'xp') {
        $xp = $_->{count};
        last;
    }
}
    
print JSON::XS::encode_json { goal_met => $data->{xpGoalMetToday}, streak => $data->{streakData}->{length}, xp => $xp . '/' . $data->{streakData}->{xpGoal} } ;