1 files changed, 95 insertions, 0 deletions
diff --git a/module/vcomponent/ical/types.scm b/module/vcomponent/ical/types.scm
new file mode 100644
index 00000000..f2787693
--- /dev/null
+++ b/module/vcomponent/ical/types.scm
@@ -0,0 +1,95 @@
+;; see (vcomponent parse types)
+(define-module (vcomponent ical types)
+  :use-module (util)
+  :use-module (util exceptions)
+  :use-module (util base64)
+  :use-module (datetime))
+
+
+(define (write-binary _ value)
+  (bytevector->base64-string value))
+
+(define (write-boolean _ value)
+  (if value "TRUE" "FALSE"))
+
+(define (write-date _ value)
+  (date->string value "~Y~m~d"))
+
+(define (write-datetime param value)
+  ;; NOTE We really should output TZID from param here, but
+  ;; we first need to change so these writers can output
+  ;; parameters.
+  (datetime->string (hashq-ref param '-X-HNH-ORIGINAL value)
+                    "~Y~m~dT~H~M~S~Z"))
+
+(define (write-duration _ value)
+  ((@ (vcomponent duration) format-duration) value))
+
+(define (write-float _ value)
+  (number->string value))
+
+(define (write-integer _ value)
+  (number->string value))
+
+;; TODO
+(define (write-period _ value)
+  (warning "PERIOD writer not yet implemented")
+  (with-output-to-string
+    (lambda () (write value))))
+
+(define (write-recur _ value)
+  ((@ (vcomponent recurrence internal)
+      recur-rule->rrule-string) value))
+
+(define-public (escape-chars str)
+  (define (escape char)
+    (string #\\ char))
+  (string-concatenate
+   (map (lambda (c)
+          (case c
+            ((#\newline) "\\n")
+            ((#\, #\; #\\) => escape)
+            (else => string)))
+        (string->list str))))
+
+(define (write-text _ value)
+  (escape-chars value))
+
+(define (write-time _ value)
+  (time->string value "~H~M~S"))
+
+(define (write-uri _ value)
+  value)
+
+
+(use-modules (datetime timespec))
+
+(define (write-utc-offset _ value)
+  (with-output-to-string
+    (lambda ()
+      (display (if (time-zero? (timespec-time value))
+                   '+ (timespec-sign value)))
+      (display (time->string (timespec-time value) "~H~M"))
+      (when (not (zero? (second (timespec-time value))))
+        (display (time->string (timespec-time value) "~S"))))))
+
+
+(define type-writers (make-hash-table))
+(hashq-set! type-writers 'BINARY write-binary)
+(hashq-set! type-writers 'BOOLEAN write-boolean)
+(hashq-set! type-writers 'CAL-ADDRESS write-uri)
+(hashq-set! type-writers 'DATE write-date)
+(hashq-set! type-writers 'DATE-TIME write-datetime)
+(hashq-set! type-writers 'DURATION write-duration)
+(hashq-set! type-writers 'FLOAT write-float)
+(hashq-set! type-writers 'INTEGER write-integer)
+(hashq-set! type-writers 'PERIOD write-period)
+(hashq-set! type-writers 'RECUR write-recur)
+(hashq-set! type-writers 'TEXT write-text)
+(hashq-set! type-writers 'TIME write-time)
+(hashq-set! type-writers 'URI write-uri)
+(hashq-set! type-writers 'UTC-OFFSET write-utc-offset)
+
+(define-public (get-writer type)
+  (or (hashq-ref type-writers type #f)
+      (error "No writer for type" type)))