#!/usr/bin/guile \
-e main -s
!#

(add-to-load-path (dirname (current-filename)))

(use-modules (srfi srfi-1)
             (srfi srfi-19)
             (srfi srfi-19 util)
             (srfi srfi-26)
             (srfi srfi-41)
             (srfi srfi-41 util)
             (ice-9 format)
             (texinfo string-utils)     ; string->wrapped-lines
             (util)
             (vcalendar)
             (vcalendar recur)
             (vcalendar datetime)
             (vcalendar output)
             (terminal escape)
             (terminal util))

(define (ev-time<? a b)
  (time<? (attr a 'DTSTART)
          (attr b 'DTSTART)))

;;; ------------------------------------------------------------

#; (define pizza-event (search cal "pizza"))

(define (trim-to-width str len)
  (let ((trimmed (string-pad-right str len)))
    (if (< (string-length trimmed)
           (string-length str))
        (string-append (string-drop-right trimmed 1)
                       "…")
        trimmed)))
  ; TODO show truncated string


(define (main-loop regular-events repeating-events)
  (define time (date->time-utc (current-date)))
  (define cur-event 0)
  (let loop ((char #\nul))
    (let ((events
           (merge (filter-sorted
                   (cut event-in? <> time)
                   regular-events)

                  (stream->list
                   (filter-sorted-stream
                    (cut event-in? <> time)
                    repeating-events))

                  ev-time<?)))

      (case char
        ;; TODO The explicit loop call is a hack to rerender the display
        ;; It's REALLY ugly.
        ((#\L #\l) (set! time (add-day time))    (set! cur-event 0) (loop #\nul))
        ((#\h #\H) (set! time (remove-day time)) (set! cur-event 0) (loop #\nul))
        ((#\j #\J) (unless (= cur-event (1- (length events)))
                     (set! cur-event (1+ cur-event))))
        ((#\k #\K) (unless (= cur-event 0)
                     (set! cur-event (1- cur-event)))))

      (cls)
      (display-calendar-header! (time-utc->date time))
      ;; (line)
      (format #t "~a┬~a┬~a~%"
              (make-string 20 #\─)
              (make-string 32 #\─)
              (make-string 10 #\─))


      (for-each
       (lambda (ev i)
         (format #t "~a │ ~a~a~a~a │ ~a~a~%"
                 (time->string (attr ev 'DTSTART) "~1 ~3") ; TODO show truncated string
                 (if (= i cur-event) "\x1b[7m" "")
                 (color-escape (attr (parent ev) 'COLOR))
                 (trim-to-width (attr ev 'SUMMARY) 30)
                 STR-RESET
                 (trim-to-width
                  (or (attr ev 'LOCATION) "\x1b[1;30mINGEN LOKAL") 20)
                 STR-RESET))
       events
       (iota (length events)))

      (format #t "~a┴~a┴~a~%"
              (make-string 20 #\─)
              (make-string 32 #\─)
              (make-string 10 #\─))

      (unless (null? events)
       (let ((ev (list-ref events cur-event)))
         (format #t "~a~%~aStart: ~a	Slut: ~a~%~%~a~%"
                 (attr ev 'SUMMARY)
                 (or (and=> (attr ev 'LOCATION) (cut string-append "Plats: " <> "\n")) "")
                 (time->string (attr ev 'DTSTART) "~1 ~3")
                 (time->string (attr ev 'DTEND) "~1 ~3")
                 (string-join      ; TODO replace this with a better text flower
                  (take-to         ; This one destroys newlines used for layout
                   (string->wrapped-lines (or (attr ev 'DESCRIPTION) "")
                                          #:line-width 60
                                          #:collapse-whitespace? #f)
                   10)
                  (string #\newline))
                 )))

      ;; (format #t "c = ~c (~d)~%" char (char->integer char))

      (unless (or (eof-object? char)
                  ;; TODO this requires that `q' is pressed as many
                  ;; times as other inputs where pressed to actually
                  ;; quit.
                  ;; ^C only works because it force closes the
                  ;; program.
                  (memv char (list #\q (ctrl #\C))))
        (loop (read-char (current-input-port)))))))

(load "config.scm")


(define (main args)

  (define calendars (map make-vcomponent calendar-files))
  (define events (concatenate (map (cut children <> 'VEVENT) calendars)))

  (let* ((repeating regular (partition repeating? events)))
    (sort*! repeating time<? (extract 'DTSTART))
    (sort*! regular   time<? (extract 'DTSTART))

    (let ((repeating (interleave-streams ev-time<?
                      (map generate-recurrence-set repeating))))
      (with-vulgar
       (lambda () (main-loop regular repeating))))))