Add random command

This command simply prints a random URL. A tag may be specified to limit
the search to that tag. In the Conkeror module this command immediately
loads the random bookmark in the current buffer.

- js/clark.js: If `error' is empty, return the value of `data'. This
  makes it easier for some commands to use the result of the command.
  Add `clark-random' to `clark_keymap'.

3 files changed, 59 insertions, 1 deletions

diff --git a/lisp/clark.asd b/lisp/clark.asd
index fca0f42..48ac718 100644
--- a/lisp/clark.asd
+++ b/lisp/clark.asd
@@ -30,4 +30,5 @@
   :serial t
   :depends-on (:sqlite)
   :components ((:file "package")
-               (:file "clark")))
+               (:file "clark")
+               (:file "queries")))
diff --git a/lisp/clark.lisp b/lisp/clark.lisp
index bfb0868..d9477e8 100644
--- a/lisp/clark.lisp
+++ b/lisp/clark.lisp
@@ -330,6 +330,17 @@ list of tags."
   (clear-tags url)
   (add-tags url tags))
 
+(defun random-item (lst)
+  (nth (random (length lst) (make-random-state t)) lst))
+
+(defcommand random (&optional tag)
+  "Pick a random bookmark, possibly from TAG."
+  "Usage: clark random [<tag>]
+
+Get a random bookmark. If TAG is given limit the result to a bookmark
+having the tag TAG."
+  (format t "~a~%" (random-item (url-list tag))))
+
 (defcommand version ()
     "Show version."
     "Usage: clark version
diff --git a/lisp/queries.lisp b/lisp/queries.lisp
new file mode 100644
index 0000000..1df24c5
--- /dev/null
+++ b/lisp/queries.lisp
@@ -0,0 +1,46 @@
+;; Copyright (C) 2013  Tom Willemsen <tom at ryuslash dot org>
+
+;; This file is part of CLark
+
+;; CLark is free software: you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; CLark is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;; General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with CLark. If not, see <http://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(in-package :org.ryuslash.clark)
+
+(defun url-list-no-tag ()
+  "Get a list of all URLs stored."
+  (mapcar #'car
+          (execute-to-list
+           *db* (sql select "url"
+                     from "bookmark"))))
+
+(defun url-list-for-tag (tag)
+  "Get a list of all the stored URLs with tag TAG."
+  (mapcar
+   #'car
+   (execute-to-list
+    *db* (sql select "url"
+              from "bookmark"
+              where ? in (select "name"
+                          from "tag"
+                          join "bookmark_tag" on ("tag_id = tag.rowid")
+                          where "bookmark_id" = "bookmark.rowid"))
+    tag)))
+
+(defun url-list (&optional tag)
+  "Get a list of URLs, possibly with tag TAG."
+  (if tag
+      (url-list-for-tag tag)
+      (url-list-no-tag)))