sx-question-read-p and mark-read actually work

1 files changed, 26 insertions, 3 deletions

diff --git a/sx-question.el b/sx-question.el
index 607b3f6..76f9a67 100644
--- a/sx-question.el
+++ b/sx-question.el
@@ -67,10 +67,18 @@
 
 
 ;;; Question Properties
+(defvar sx-question--user-read-list nil 
+  "Alist of questions read by the user.
+Each element has the form (SITE . QUESTION-LIST).
+And each element in QUESTION-LIST has the form (QUESTION_ID . LAST-VIEWED-DATE).")
+
 (defun sx-question--read-p (question)
   "Non-nil if QUESTION has been read since last updated."
-  ;; @TODO:
-  (cl-evenp (random)))
+  (sx-assoc-let question
+    (let ((ql (cdr (assoc .site sx-question--user-read-list))))
+      (and ql
+           (>= (or (cdr (assoc .question_id ql)) 0)
+               .last_activity_date)))))
 
 (defun sx-question--accepted-answer-id (question)
   "Return accepted answer in QUESTION, or nil if none."
@@ -80,7 +88,22 @@
 
 (defun sx-question--mark-read (question)
   "Mark QUESTION as being read, until it is updated again."
-  nil)
+  (sx-assoc-let question
+    (let ((site-cell (assoc .site sx-question--user-read-list))
+          (q-cell (cons .question_id .last_activity_date))
+          cell)
+      (cond
+       ;; First question from this site.
+       ((null site-cell)
+        (push (list .site q-cell) sx-question--user-read-list))
+       ;; Question already has an older time.
+       ((setq cell (assoc .question_id site-cell))
+        (setcdr cell .last_activity_date))
+       ;; Question wasn't present.
+       (t 
+        (setcdr site-cell (cons q-cell (cdr site-cell)))))))
+  ;; Save the results.
+  (sx-cache-set 'read-questions sx-question--user-read-list))
 
 (defun sx-question--< (property x y &optional pred)
   "Non-nil if PROPERTY attribute of question X is less than that of Y.