Cleanup modules.

Primarly this moves all vcompenent input and output code to clearly
labeled modules, instead of being spread out. At the same time it also
removes a handfull of unused procedures.

3 files changed, 665 insertions, 0 deletions

diff --git a/module/vcomponent/formats/ical/output.scm b/module/vcomponent/formats/ical/output.scm
new file mode 100644
index 00000000..9efac3c4
--- /dev/null
+++ b/module/vcomponent/formats/ical/output.scm
@@ -0,0 +1,234 @@
+(define-module (vcomponent formats ical output)
+  :use-module (calp util exceptions)
+  :use-module (calp util)
+  :use-module (datetime)
+  :use-module (datetime zic)
+  :use-module ((datetime instance) :select (zoneinfo))
+  :use-module (glob)
+  :use-module (ice-9 format)
+  :use-module (ice-9 match)
+  :use-module (srfi srfi-1)
+  :use-module (srfi srfi-41)
+  :use-module (srfi srfi-41 util)
+  :use-module (vcomponent)
+  :use-module (vcomponent datetime)
+  :use-module (vcomponent geo)
+  :use-module (vcomponent formats ical types)
+  :use-module (vcomponent recurrence)
+  :autoload (vcomponent util instance) (global-event-object)
+  )
+
+(define (prodid)
+  (format #f "-//hugo//calp ~a//EN"
+          (@ (calp) version)))
+
+
+;; Format value depending on key type.
+;; Should NOT emit the key.
+(define (value-format key vline)
+
+  (define writer
+    ;; fields which can hold lists need not be considered here,
+    ;; since they are split into multiple vlines when we parse them.
+    (cond
+     ;; TODO parameters return? One or many‽
+     [(and=> (param vline 'VALUE) (compose string->symbol car)) => 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 '(CATEGORIES RESOURCES))
+      (lambda (p v)
+        (string-join (map (lambda (v) ((get-writer 'TEXT) p v))
+                          v)
+                     ","))]
+
+     [(memv key '(CALSCALE METHOD PRODID COMMENT DESCRIPTION
+                        LOCATION SUMMARY TZID TZNAME
+                        CONTACT RELATED-TO UID
+
+                        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)
+        (define fl (get-writer 'FLOAT))
+        (format #f "~a:~a"
+                (fl (geo-latitude v))
+                (fl (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)]))
+
+  (catch #t #; 'wrong-type-arg
+    (lambda ()
+      (writer ((@@ (vcomponent base) get-vline-parameters) vline)
+              (value vline)))
+    (lambda (err caller fmt args call-args)
+      (define fallback-string
+        (with-output-to-string (lambda () (display value))))
+      (warning "key = ~a, caller = ~s, call-args = ~s~%~k~%Falling back to ~s"
+               key caller call-args fmt args
+               fallback-string)
+      fallback-string)))
+
+
+;; Fold long lines to limit width.
+;; Since this works in characters, but ics works in bytes
+;; this will overshoot when faced with multi-byte characters.
+;; But since the line wrapping is mearly a recomendation it's
+;; not a problem.
+;; Setting the wrap-len to slightly lower than allowed also help
+;; us not overshoot.
+(define* (ical-line-fold string #:key (wrap-len 70))
+  (cond [(< wrap-len (string-length string))
+         (format #f "~a\r\n ~a"
+                 (string-take string wrap-len)
+                 (ical-line-fold (string-drop string wrap-len)))]
+        [else string]))
+
+
+
+(define (vline->string vline)
+  (define key (vline-key vline))
+  (ical-line-fold
+   ;; Expected output: key;p1=v;p3=10:value
+   (string-append
+    (symbol->string key)
+    (string-concatenate
+     (map (match-lambda
+            [(? (compose internal-field? car)) ""]
+            [(key values ...)
+             (string-append
+              ";" (symbol->string key) "="
+              (string-join (map (compose escape-chars ->string) values)
+                           "," 'infix))])
+          (parameters vline)))
+    ":" (value-format key vline))))
+
+(define-public (component->ical-string component)
+  (format #t "BEGIN:~a\r\n" (type component))
+  (for-each
+   ;; Special cases depending on key.
+   ;; Value formatting is handled in @code{value-format}.
+   (match-lambda
+
+     [(? (compose internal-field? car)) 'noop]
+
+     [(key vlines ...)
+      (for vline in vlines
+           (display (vline->string vline))
+           (display "\r\n"))]
+
+     [(key . vline)
+      (display (vline->string vline))
+      (display "\r\n")])
+   (properties component))
+  (for-each component->ical-string (children component))
+  (format #t "END:~a\r\n" (type component))
+
+  ;; If we have alternatives, splice them in here.
+  (cond [(prop component '-X-HNH-ALTERNATIVES)
+         => (lambda (alts) (hash-map->list (lambda (_ comp) (component->ical-string comp))
+                                      alts))]))
+
+
+
+(define (print-header)
+  (format #t
+"BEGIN:VCALENDAR\r
+PRODID:~a\r
+VERSION:2.0\r
+CALSCALE:GREGORIAN\r
+" (prodid)
+))
+
+
+(define (print-footer)
+  (format #t "END:VCALENDAR\r\n"))
+
+(define (get-tz-names events)
+  (lset-difference
+   equal? (lset-union
+           equal? '("dummy")
+           (filter-map
+            (lambda (vline) (and=> (param vline 'TZID) car))
+            (filter-map (extract* 'DTSTART)
+                        events)))
+   '("dummy" "local")))
+
+
+(define-public (print-components-with-fake-parent events)
+
+  ;; The events are probably sorted before, but until I can guarantee
+  ;; that we sort them again here. We need them sorted from earliest
+  ;; and up to send the earliest to zoneinfo->vtimezone
+  (set! events (sort* events date/-time<=? (extract 'DTSTART)))
+
+  (print-header)
+
+  (when (provided? 'zoneinfo)
+    (let ((tz-names (get-tz-names events)))
+      (for-each component->ical-string
+                ;; TODO we realy should send the earliest event from each timezone here,
+                ;; instead of just the first.
+                (map (lambda (name) (zoneinfo->vtimezone
+                                      (zoneinfo)
+                                      name (car events)))
+                     tz-names))))
+
+  (for-each component->ical-string events)
+
+  (print-footer))
+
+
+(define-public (print-all-events)
+  (print-components-with-fake-parent
+   (append (get-fixed-events global-event-object)
+           ;; TODO RECCURENCE-ID exceptions
+           ;; We just dump all repeating objects, since it's much cheaper to do
+           ;; it this way than to actually figure out which are applicable for
+           ;; the given date range.
+           (get-repeating-events global-event-object))))
+
+(define-public (print-events-in-interval start end)
+  (print-components-with-fake-parent
+   (append (fixed-events-in-range start end)
+           ;; TODO RECCURENCE-ID exceptions
+           ;; We just dump all repeating objects, since it's much cheaper to do
+           ;; it this way than to actually figure out which are applicable for
+           ;; the given date range.
+           (get-repeating-events global-event-object))))
diff --git a/module/vcomponent/formats/ical/parse.scm b/module/vcomponent/formats/ical/parse.scm
new file mode 100644
index 00000000..d76044a3
--- /dev/null
+++ b/module/vcomponent/formats/ical/parse.scm
@@ -0,0 +1,336 @@
+(define-module (vcomponent formats ical parse)
+  :use-module ((ice-9 rdelim) :select (read-line))
+  :use-module (calp util exceptions)
+  :use-module (calp util)
+  :use-module (datetime)
+  :use-module (srfi srfi-1)
+  :use-module (srfi srfi-26)
+  :use-module (srfi srfi-9 gnu)
+  :use-module (vcomponent base)
+  :use-module (vcomponent geo)
+  :use-module (vcomponent formats common types)
+ )
+
+(define string->symbol
+  (let ((ht (make-hash-table 1000)))
+    (lambda (str)
+      (or (hash-ref ht str)
+          (let ((symb ((@ (guile) string->symbol) str)))
+            (hash-set! ht str symb)
+            symb)))))
+
+;; TODO rename to parse-vcomponent, or parse-ical (?).
+(define-public (parse-calendar port)
+  (parse (map tokenize (read-file port))))
+
+(define-immutable-record-type <line>
+  (make-line string file line)
+  line?
+  (string get-string)
+  (file get-file)
+  (line get-line))
+
+
+;; port → (list <line>)
+(define (read-file port)
+  (define fname (port-filename port))
+  (let loop ((line-number 1) (done '()))
+    (let ((ostr (open-output-string)))
+      (define ret
+        (let loop ((line (read-line port)))
+          (if (eof-object? line)
+              'eof
+              (let ((line (string-trim-right line #\return)))
+               (let ((next (peek-char port)))
+                 (display line ostr)
+                 (cond ((eof-object? next)
+                        'final-line)
+                       ;; Line Wrapping
+                       ;; If the first character on a line is space (whitespace?)
+                       ;; then it's a continuation line, and should be merged
+                       ;; with the one preceeding it.
+                       ;; TODO if the line is split inside a unicode character
+                       ;; then this produces multiple broken unicode characters.
+                       ;; It could be solved by checking the start of the new line,
+                       ;; and the tail of the old line for broken char
+                       ;; TODO what about other leading whitespace?
+                       ((char=? next #\space)
+                        (read-char port) ; discard leading whitespace
+                        (loop (read-line port)))
+                       (else
+                        ;; (unread-char next)
+                        'line)))))))
+      (case ret
+        ((line)
+         (let ((str (get-output-string ostr)))
+           (close-port ostr)
+           (loop (1+ line-number)
+                 (cons (make-line str fname line-number)
+                       done))))
+        ((eof)
+         (close-port ostr)
+         (reverse! done))
+        ((final-line)
+         (let ((str (get-output-string ostr)))
+           (close-port ostr)
+           (reverse! (cons (make-line str fname line-number)
+                           done))))))))
+
+(define-immutable-record-type <tokens>
+  (make-tokens metadata data)
+  tokens?
+  (metadata get-metadata) ; <line>
+  (data get-data) ; (key kv ... value)
+  )
+
+;; <line> → <tokens>
+(define (tokenize line-obj)
+  (define line (get-string line-obj))
+  (define colon-idx (string-index line #\:))
+  (define semi-idxs
+    (let loop ((idx 0))
+      (aif (string-index line #\; idx colon-idx)
+           (cons it (loop (1+ it)))
+           (list colon-idx (string-length line)))))
+  (make-tokens
+   line-obj
+   (map (lambda (start end)
+          (substring line (1+ start) end))
+        (cons -1 semi-idxs)
+        semi-idxs)))
+
+
+#;
+'(ATTACH ATTENDEE CATEGORIES
+         COMMENT CONTACT EXDATE
+         REQUEST-STATUS RELATED-TO
+         RESOURCES RDATE
+         ;; x-prop
+         ;; iana-prop
+         )
+
+(define (list-parser symbol)
+  (let ((parser (get-parser symbol)))
+    (lambda (params value)
+      (map (lambda (v) (parser params v))
+           (string-split value #\,)))))
+
+(define* (enum-parser enum optional: (allow-other #t))
+  (let ((parser (compose car (get-parser 'TEXT))))
+    (lambda (params value)
+      (let ((vv (parser params value)))
+        (when (list? vv)
+          (throw 'parse-error "List in enum field"))
+        (let ((v (string->symbol vv)))
+          (unless (memv v enum)
+            (warning "~a ∉ { ~{~a~^, ~} }"
+                     v enum))
+          v)))))
+
+;; params could be made optional, with an empty hashtable as default
+(define (build-vline key value params)
+  (let ((parser
+         (cond
+          [(and=> (hashq-ref params 'VALUE) string->symbol) => get-parser]
+
+          [(memv key '(COMPLETED DTEND DUE DTSTART RECURRENCE-ID RDATE
+                              CREATED DTSTAMP LAST-MODIFIED
+                              ;; only on VALARM
+                              ACKNOWLEDGED
+                              ))
+           (get-parser 'DATE-TIME)]
+
+          [(memv key '(EXDATE))
+           (list-parser 'DATE-TIME)]
+
+          [(memv key '(TRIGGER DURATION))
+           (get-parser 'DURATION)]
+
+          [(memv key '(FREEBUSY))
+           (list-parser 'PERIOD)]
+
+          [(memv key '(CALSCALE METHOD PRODID  COMMENT DESCRIPTION
+                             LOCATION SUMMARY TZID TZNAME
+                             CONTACT RELATED-TO UID))
+           (lambda (params value)
+             (let ((v ((get-parser 'TEXT) params value)))
+               (unless (= 1 (length v))
+                 (warning "List in non-list field: ~s" v))
+               (string-join v ",")))]
+
+          ;; TEXT, but allow a list
+          [(memv key '(CATEGORIES RESOURCES))
+           ;; TODO An empty value should lead to an empty set
+           ;; currently it seems to lead to '("")
+           (get-parser 'TEXT)]
+
+          [(memv key '(VERSION))
+           (lambda (params value)
+             (let ((v (car ((get-parser 'TEXT) params value))))
+               (unless (and (string? v) (string=? "2.0" v))
+                 #f
+                 ;; (warning "File of unsuported version. Proceed with caution")
+                 )
+               v))]
+
+          [(memv key '(TRANSP))
+           (enum-parser '(OPAQUE TRANSPARENT) #f)]
+
+          [(memv key '(CLASS))
+           (enum-parser '(PUBLIC PRIVATE CONFIDENTIAL))]
+
+          [(memv key '(PARTSTAT))
+           (enum-parser '(NEEDS-ACTION
+                          ACCEPTED DECLINED
+                          TENTATIVE DELEGATED
+                          IN-PROCESS))]
+
+          [(memv key '(STATUS))
+           (enum-parser '(TENTATIVE
+                          CONFIRMED CANCELLED
+                          NEEDS-ACTION COMPLETED IN-PROCESS
+                          DRAFT FINAL CANCELED))]
+
+          [(memv key '(REQUEST-STATUS))
+           (throw 'parse-error "TODO Implement REQUEST-STATUS")]
+
+          [(memv key '(ACTION))
+           (enum-parser '(AUDIO DISPLAY EMAIL
+                                NONE    ; I don't know where NONE is from
+                                        ; but it appears to be prevelant.
+                                ))]
+
+          [(memv key '(TZOFFSETFROM TZOFFSETTO))
+           (get-parser 'UTC-OFFSET)]
+
+          [(memv key '(ATTACH TZURL URL))
+           (get-parser 'URI)]
+
+          [(memv key '(PERCENT-COMPLETE PRIORITY REPEAT SEQUENCE))
+           (get-parser 'INTEGER)]
+
+          [(memv key '(GEO))
+           ;; two semicolon sepparated floats
+           (lambda (params value)
+             (let* (((left right) (string-split value #\;)))
+               (make-geo ((get-parser 'FLOAT) params left)
+                         ((get-parser 'FLOAT) params right))))]
+
+          [(memv key '(RRULE))
+           (get-parser 'RECUR)]
+
+          [(memv key '(ORGANIZER ATTENDEE))
+           (get-parser 'CAL-ADDRESS)]
+
+          [(x-property? key)
+           (compose car (get-parser 'TEXT))]
+
+          [else
+           (warning "Unknown key ~a" key)
+           (compose car (get-parser 'TEXT))])))
+
+    ;; If we produced a list create multiple VLINES from it.
+    ;; NOTE that the created vlines share parameter tables.
+    ;; TODO possibly allow vlines to reference each other, to
+    ;; indicate that all these vlines are the same.
+    (let ((parsed (parser params value)))
+      (if (list? parsed)
+          (apply values
+                 (map (lambda (p) (make-vline key p params))
+                      parsed))
+       (make-vline key parsed params)))))
+
+;; (parse-itemline '("DTEND"  "20200407T130000"))
+;; => DTEND
+;; => "20200407T130000"
+;; => #<hash-table 7f76b5f82a60 0/31>
+(define (parse-itemline itemline)
+  (define key (string->symbol (car itemline)))
+  (define parameters (make-hash-table))
+  (let loop ((rem (cdr itemline)))
+    (if (null? (cdr rem))
+        (values key (car rem) parameters )
+        (let* ((kv (car rem))
+               (idx (string-index kv #\=)))
+          ;; TODO lists in parameters
+          (hashq-set! parameters (string->symbol (substring kv 0 idx))
+                      (substring kv (1+ idx)))
+          (loop (cdr rem))))))
+
+
+;; (list <tokens>) → <vcomponent>
+(define (parse lst)
+  (let loop ((lst lst)
+             (stack '()))
+    (if (null? lst)
+        stack
+        (let* ((head* (car lst))
+               (head (get-data head*)))
+          (catch 'parse-error
+            (lambda ()
+             (parameterize
+                 ((warning-handler
+                   (lambda (fmt . args)
+                     (let ((linedata (get-metadata head*)))
+                       (format
+                        #f "WARNING parse error around ~a
+  ~?
+  line ~a ~a~%"
+                        (get-string linedata)
+                        fmt args
+                        (get-line linedata)
+                        (get-file linedata)
+                        )))))
+               (cond [(string=? "BEGIN" (car head))
+                      (loop (cdr lst)
+                            (cons (make-vcomponent (string->symbol (cadr head)))
+                                  stack))]
+                     [(string=? "END" (car head))
+                      (loop (cdr lst)
+                            (if (null? (cdr stack))
+                                ;; return
+                                (car stack)
+                                (begin (add-child! (cadr stack) (car stack))
+                                       (cdr stack))))]
+                     [else
+                      (let* ((key value params (parse-itemline head)))
+                        (call-with-values (lambda () (build-vline key value params))
+                          (lambda vlines
+                            (for vline in vlines
+                                 (define key (vline-key vline))
+
+                                 (set! (vline-source vline)
+                                   (get-metadata head*))
+
+                                 ;; See RFC 5545 p.53 for list of all repeating types
+                                 ;; (for vcomponent)
+                                 (if (memv key '(ATTACH ATTENDEE CATEGORIES
+                                                     COMMENT CONTACT EXDATE
+                                                     REQUEST-STATUS RELATED-TO
+                                                     RESOURCES RDATE
+                                                     ;; x-prop
+                                                     ;; iana-prop
+                                                     ))
+                                     (aif (prop* (car stack) key)
+                                          (set! (prop* (car stack) key) (cons vline it))
+                                          (set! (prop* (car stack) key) (list vline)))
+                                     ;; else
+                                     (set! (prop* (car stack) key) vline))))))
+
+                      (loop (cdr lst) stack)])))
+            (lambda (err fmt . args)
+              (let ((linedata (get-metadata head*)))
+                (display (format
+                          #f "ERROR parse error around ~a
+  ~?
+  line ~a ~a
+  Defaulting to string~%"
+                          (get-string linedata)
+                          fmt args
+                          (get-line linedata)
+                          (get-file linedata))
+                         (current-error-port))
+                (let* ((key value params (parse-itemline head)))
+                  (set! (prop* (car stack) key)
+                    (make-vline key value params))
+                  (loop (cdr lst) stack)))))))))
diff --git a/module/vcomponent/formats/ical/types.scm b/module/vcomponent/formats/ical/types.scm
new file mode 100644
index 00000000..d063ca8f
--- /dev/null
+++ b/module/vcomponent/formats/ical/types.scm
@@ -0,0 +1,95 @@
+;; see (vcomponent parse types)
+(define-module (vcomponent formats ical types)
+  :use-module (calp util)
+  :use-module (calp util exceptions)
+  :use-module (base64)
+  :use-module (datetime)
+  :use-module (datetime timespec))
+
+;; TODO shouldn't these really take vline:s?
+
+(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)
+
+
+(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)))