1 ;;;; feedbot-utils.lisp
 2 
 3 (in-package :feedbot)
 4 
 5 (defmacro with-gensyms (syms &body body)
 6   `(let ,(loop for s in syms collect `(,s (gensym)))
 7     ,@body))
 8 
 9 (defun sanitize-string (str)
10   "Remove non-printable characters from string, including vertical
11 whitespace and non-ASCII strings."
12   (let ((asciied-str (remove-if #'(lambda (c)
13                                     (or (< (char-code c) #x20)
14                                         (> (char-code c) #x7f)))
15                                 str)))
16     (string-trim '(#\Space #\Tab #\Newline) asciied-str)))
17 
18 (defun try-parse-feed (url)
19   "Call `feedparse:parse-feed' and, if it returns without an error,
20 return the feed item. Otherwise, return NIL and its exception object as
21 multiple values."
22   (handler-case
23       (parse-feed url)
24     (t (c)
25       (format *error-output*
26               "Error fetching/parsing feed ~a: ~s.~%"
27               url (class-name (class-of c)))
28       (return-from try-parse-feed (values nil c)))))
29 
30 (defun send-ison (bot nicks)
31   "Send ISON message from `bot' to set of `nicks'."
32   (labels ((add-nick (params nick)
33              (format nil "~a ~a" params nick))
34            (make-ison-params (nicklist)
35              (let ((ison-params (list ""))
36                    (nicks (copy-list nicklist)))
37                ;; If we don't have any nicks to check, then return.
38                (when (null nicks)
39                  (return-from make-ison-params))
40                ;; Make ISON parameters and push them in ison-params
41                (loop until (null nicks) do
42                     (let* ((nick (pop nicks))
43                            (newcar-ison-params (add-nick (car ison-params) nick)))
44                       ;; When we either have nothing in ison-params or the
45                       ;; list is too long, push a fresh list of
46                       ;; parametes. 512 is a magic number given in RFC
47                       ;; 1459.
48                       (if (> (length newcar-ison-params) 512)
49                           (push nick ison-params)
50                           (setf (car ison-params) newcar-ison-params))))
51                ison-params)))
52     (loop for ison-param in (make-ison-params nicks) do
53          (ison (ircbot-connection bot) ison-param))))
54 
55 (defun split-string-by (sep str)
56   "Split string `str' by character `sep', returning the result in a
57 list."
58   ;; Special case, empty string.
59   (when (string= "" str)
60     (return-from split-string-by))
61   ;; Otherwise, we "take" from `str' until we come to string without
62   ;; spaces.
63   (loop with source = str
64        with sink = nil
65      for pos = (position sep source)
66      until (null pos) do
67        (push (subseq source 0 pos) sink)
68        (setq source (subseq source (1+ pos)))
69      finally (return (nreverse (push source sink)))))
70 
71 (defun parse-ison (ison-param)
72   "Parse ISON parameter, returning a list of nicks."
73   (remove "" (split-string-by #\Space ison-param)
74           :test #'string=))
75 
76 (defun parse-arguments (arguments)
77   "Feedbot-specific code to parse Trilemabot `arguments'.
78 
79 This returns the first argument passed to the bot and ignores
80 everything else."
81   (assert (stringp arguments))
82   (let* ((sanitized-args (string-trim '(#\Space #\Newline #\Tab) arguments))
83 	 (pos (position #\Space sanitized-args)))
84     (if (null pos)
85 	sanitized-args
86 	(subseq arguments 0 pos))))
87 
88 (defun response-rcpt (bot src-message channel)
89   "Get the response-message recipient of `src-message'.
90 
91 If the message was sent in a channel, then the recipient is that
92 channel. Otherwise, the sender's nickname is returned."
93   (let ((src (source src-message)))
94     (if (string= channel (ircbot-nick bot))
95 	src
96 	channel)))