1 files changed, 72 insertions, 0 deletions
diff --git a/module/vcomponent/datetime/output.scm b/module/vcomponent/datetime/output.scm
new file mode 100644
index 00000000..eb127ceb
--- /dev/null
+++ b/module/vcomponent/datetime/output.scm
@@ -0,0 +1,72 @@
+(define-module (vcomponent datetime output)
+  :use-module (util)
+  :use-module (util config)
+  :use-module (util exceptions)
+  :use-module (datetime)
+  :use-module (vcomponent base)
+  :use-module (text util)
+  )
+
+(define-config summary-filter (lambda (_ a) a)
+  ""
+  pre: (ensure procedure?))
+
+(define-config description-filter (lambda (_ a) a)
+  ""
+  pre: (ensure procedure?))
+
+;; ev → sxml
+(define-public (format-recurrence-rule ev)
+  `("Upprepas "
+    ,((@ (vcomponent recurrence display) format-recurrence-rule)
+      (prop ev 'RRULE))
+    ,@(awhen (prop* ev 'EXDATE)
+             (list
+              ", undantaget "
+              (add-enumeration-punctuation
+               (map (lambda (d)
+                      (if (date? d)
+                          ;; NOTE possibly show year?
+                          (date->string d "~e ~b")
+                          ;; NOTE only show time when it's different than the start time?
+                          ;; or possibly only when FREQ is hourly or lower.
+                          (if (memv ((@ (vcomponent recurrence internal) freq)
+                                     (prop ev 'RRULE))
+                                    '(HOURLY MINUTELY SECONDLY))
+                              (datetime->string d "~e ~b ~k:~M")
+                              (datetime->string d "~e ~b"))))
+                    (map value it)))))
+    "."))
+
+(define-public (format-summary ev str)
+  ((get-config 'summary-filter) ev str))
+
+;; NOTE this should have information about context (html/term/...)
+(define-public (format-description ev str)
+  (catch #t (lambda () ((get-config 'description-filter) ev str))
+    (lambda (err . args)
+      (warning "~a on formatting description, ~s" err args)
+      str)))
+
+;; Takes an event, and returns a pretty string for the time interval
+;; the event occupies.
+(define-public (fmt-time-span ev)
+  (cond [(prop ev 'DTSTART) date?
+         => (lambda (s)
+              (cond [(prop ev 'DTEND)
+                     => (lambda (e)
+                          (if (date= e (date+ s (date day: 1)))
+                              (date->string s)  ; start = end, only return one value
+                              (values (date->string s)
+                                      (date->string e))))]
+                    ;; no end value, just return start
+                    [else (date->string s)]))]
+        [else ; guaranteed datetime
+         (let ((s (prop ev 'DTSTART))
+               (e (prop ev 'DTEND)))
+           (if e
+               (let ((fmt-str (if (date= (get-date s) (get-date e))
+                                  "~H:~M" "~Y-~m-~d ~H:~M")))
+                 (values (datetime->string s fmt-str)
+                         (datetime->string e fmt-str)))
+               (datetime->string s "~Y-~m-~d ~H:~M")))]))