1 files changed, 108 insertions, 0 deletions
diff --git a/module/output/xcal.scm b/module/output/xcal.scm
new file mode 100644
index 00000000..554955c5
--- /dev/null
+++ b/module/output/xcal.scm
@@ -0,0 +1,108 @@
+(define-module (output xcal)
+  :use-module (util)
+  :use-module (util exceptions)
+  :use-module (vcomponent)
+  :use-module (vcomponent geo)
+  :use-module (output sxml-types)
+  :use-module (ice-9 match)
+  :use-module (output common)
+  :use-module (datetime)
+  :use-module (datetime util)
+  )
+
+
+(define (vline->value-tag vline)
+  (define key (vline-key vline))
+
+  (define writer
+   (cond
+    [(and=> (prop vline 'VALUE) string->symbol) => get-writer]
+    [(memv key '(COMPLETED DTEND DUE DTSTART RECURRENCE-ID
+                        CREATED DTSTAMP LAST-MODIFIED
+                        ACKNOWLEDGED EXDATE))
+     (get-writer 'DATE-TIME)]
+
+    [(memv key '(TRIGGER DURATION))
+     (get-writer 'DURATION)]
+
+    [(memv key '(FREEBUSY))
+     (get-writer 'PERIOD)]
+
+    [(memv key '(CALSCALE METHOD PRODID COMMENT DESCRIPTION
+                       LOCATION SUMMARY TZID TZNAME
+                       CONTACT RELATED-TO UID
+
+                       CATEGORIES RESOURCES
+
+                       VERSION))
+     (get-writer 'TEXT)]
+
+    [(memv key '(TRANSP
+              CLASS
+              PARTSTAT
+              STATUS
+              ACTION))
+     (lambda (p v) ((get-writer 'TEXT) p (symbol->string v)))]
+
+    [(memv key '(TZOFFSETFROM TZOFFSETTO))
+     (get-writer 'UTC-OFFSET)]
+
+    [(memv key '(ATTACH TZURL URL))
+     (get-writer 'URI)]
+
+    [(memv key '(PERCENT-COMPLETE PRIORITY REPEAT SEQUENCE))
+     (get-writer 'INTEGER)]
+
+    [(memv key '(GEO))
+     (lambda (_ v)
+       `(geo
+         (latitude ,(geo-latitude v))
+         (longitude ,(geo-longitude v))))]
+
+    [(memv key '(RRULE))
+     (get-writer 'RECUR)]
+
+    [(memv key '(ORGANIZER ATTENDEE))
+     (get-writer 'CAL-ADDRESS)]
+
+    [(x-property? key)
+     (get-writer 'TEXT)]
+
+    [else
+     (warning "Unknown key ~a" key)
+     (get-writer 'TEXT)]))
+
+  (writer ((@@ (vcomponent base) get-vline-parameters) vline) (value vline)))
+
+(define-public (vcomponent->sxml component)
+  `(,(downcase-symbol (type component))
+    (properties
+     ,@(hash-map->list
+        (match-lambda*
+          [(? (compose internal-field? car)) '()]
+
+          ;; TODO parameters
+
+          [(key (vlines ...))
+           `(,(downcase-symbol key)
+             #;
+             ,(unless (null? (properties vline))
+                `(parameters
+                  ,@(map vline->value-tag (properties vline))))
+             ,@(for vline in vlines
+                    (vline->value-tag vline)))]
+
+          [(key vline)
+           `(,(downcase-symbol key)
+             #;
+             ,(unless (null? (properties vline))
+                `(parameters
+                  ,@(map vline->value-tag (properties vline))))
+             ,(vline->value-tag vline))])
+        (attributes component)))
+    (components ,@(map vcomponent->sxml (children component)))))
+
+(define-public (main calendar)
+  `(*TOP* (*PI* xml "version=\"1.0\" encoding=\"utf-8\"")
+          (icalendar (@ (xmlns "urn:ietf:params:xml:ns:icalendar-2.0"))
+                     ,(vcomponent->sxml calendar))))