Login SIMPEL

public function login_post()
    {
        $username    = trim($this->post('username'));
        $password    = trim($this->post('password'));
        $tokenDevice = trim($this->post('tokenDevice'));

        if ($username == '') {
            $response = [
                'resp_error' => true,
                'resp_msg'   => 'Username harap diisi.',
            ];
        } elseif ($password == '') {
            $response = [
                'resp_error' => true,
                'resp_msg'   => 'Password harap diisi.',
            ];
        } elseif ($tokenDevice == '') {
            $response = [
                'resp_error' => true,
                'resp_msg'   => 'Token Device kosong.',
            ];
        } else {
            // Check Username
            $this->db->select('*');
            $this->db->from('lemlit_users');
            $this->db->where('user_username', $username);
            $this->db->where('user_active', 'Active');
            $checkuser = $this->db->get()->row();
            if (count($checkuser) == 0) {
                $response = [
                    'resp_error' => true,
                    'resp_msg'   => 'Username Tidak Terdaftar.',
                ];
            } else {
                $this->db->select('u.*, l.lecture_id, l.position_id, l.lecture_review');
                $this->db->from('lemlit_users u');
                $this->db->join('lemlit_lecture l', 'u.user_username=l.user_username', 'left');
                $this->db->where('u.user_username', $username);
                $this->db->where('u.user_password', sha1($password));
                $this->db->where('u.user_active', 'Active');
                $checkaccount = $this->db->get()->row();

                if (count($checkaccount) == 0) {
                    $response = [
                        'resp_error' => true,
                        'resp_msg'   => 'Password Anda Salah.',
                    ];
                } else {
                    // Otomatis Update Device
                    $data = array(
                        'device_id' => $tokenDevice,
                    );

                    $this->db->where('user_username', $username);
                    $this->db->update('lemlit_users', $data);

                    if ($checkaccount->user_avatar != '') {
                        $avatar = base_url('img/icon/' . $checkaccount->user_avatar);
                    } else {
                        $avatar = base_url('img/user.png');
                    }

                    $response = [
                        'resp_error' => false,
                        'resp_msg'   => 'success',
                        'username'   => trim($checkaccount->user_username),
                        'nama'       => trim($checkaccount->user_name),
                        'email'      => trim($checkaccount->user_email),
                        'avatar'     => $avatar,
                        'level'      => trim($checkaccount->user_level),
                        'lecture_id' => trim($checkaccount->lecture_id),
                        'reviewer'   => ($checkaccount->lecture_review == 0 ? 'Tidak' : 'Ya'),
                    ];
                }
            }
        }

        $this->response($response, 200);
    }