(define-module (starlet base)
  #:use-module (oop goops)
  #:use-module (ice-9 threads)
  #:use-module (ice-9 atomic)
  #:use-module (web client)
  #:use-module (web http)
  #:use-module (web uri)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-9)
  #:export (<fixture>
            <fixture-attribute>
            <starlet-state>
            start-ola-output
            patch-fixture!
            scanout-freq
            make-empty-state
            register-state!
            percent->dmxval
            hirestime
            state-for-each
            set-in-state!
            get-attr-name
            value->number
            merge-states-htp
            get-state-hash-table
            scanout-fixture
            attr-continuous
            attr-boolean
            attr-list
            current-state
            lighting-state
            apply-state
            at
            home-state
            blackout-state
            intensity?))

(define-class <fixture-attribute> (<object>)
  (name
    #:init-value 'unnamed-attribute
    #:init-keyword #:name
    #:getter get-attr-name)

  (range
    #:init-value '()
    #:init-keyword #:range
    #:getter get-attr-range)

  (translator
    #:init-value (lambda (universe start-addr value set-dmx) #f)
    #:init-keyword #:translator
    #:getter get-attr-translator)

  (type
    #:init-value 'continuous
    #:init-keyword #:type
    #:getter get-attr-type)

  (home-value
    #:init-value 0
    #:init-keyword #:home-value
    #:getter get-attr-home-value
    #:setter set-attr-home-value!))


(define-class <fixture> (<object>)
  (universe
    #:init-value #f
    #:init-keyword #:uni
    #:getter get-fixture-universe
    #:setter set-fixture-universe!)

  (start-addr
    #:init-value #f
    #:init-keyword #:sa
    #:getter get-fixture-addr
    #:setter set-fixture-addr!)

  (friendly-name
    #:init-value "Fixture"
    #:init-keyword #:friendly-name
    #:getter get-fixture-friendly-name
    #:setter set-fixture-friendly-name!)

  (scanout-func
    #:init-value (lambda (universe start-addr value set-dmx) #f)
    #:init-keyword #:scanout-func
    #:getter get-scanout-func))


;; A "state" is just a thin wrapper around a hash table
;; of (fixture . attribute)  -->  value
(define-class <starlet-state> (<object>)
  (hash-table
   #:init-form (make-hash-table)
   #:getter get-state-hash-table
   #:setter set-state-hash-table!))


(define-method (set-in-state! (state <starlet-state>)
                              (fix <fixture>)
                              (attr <fixture-attribute>)
                              value)
  (hash-set! (get-state-hash-table state)
             (cons fix attr)
             value))



;; List of fixtures
(define patched-fixture-list (make-atomic-box '()))

;; Basic state which holds everything at "home" unless
;; commanded otherwise
(define home-state (make <starlet-state>))

;; Basic state which sets all intensities to zero
(define blackout-state (make <starlet-state>))

(define (make-empty-state)
  (make <starlet-state>))

;; List of states being scanned out
(define state-list (make-atomic-box (list home-state)))


;; Set a single attribute to home position
(define (home-attr! state fix attr)
  (set-in-state! state
                 fix
                 attr
                 (get-attr-home-value attr)))


;; Set all attributes of a fixture to home position
(define (home-all! state fix)
  (for-each (lambda (attr)
              (home-attr! state fix attr))
            (slot-ref fix 'attributes)))


(define (intensity? a)
  (eq? 'intensity (get-attr-name a)))


(define (find-attr fix attr-name)
  (find (lambda (a)
          (eq? (get-attr-name a)
               attr-name))
        (slot-ref fix 'attributes)))

(define (register-state! new-state)
  (atomic-box-set! state-list
                   (cons new-state
                         (atomic-box-ref state-list))))

;; Set an attribute by name
(define (set-attr! state fix attr-name value)
  (let ((attr (find-attr fix attr-name)))
    (when attr (set-in-state! state fix attr value))))


(define (fade-frac fade-time start-time time-now)
  (min (/ (- time-now start-time)
          fade-time)
       1.0))


;; Patch a new fixture
(define* (patch-fixture! class
                         start-addr
                         #:key (universe 1) (friendly-name "Fixture"))
  (let ((new-fixture (make class
                       #:sa start-addr
                       #:uni universe
                       #:friendly-name friendly-name)))
    (home-all! home-state new-fixture)
    (set-in-state! blackout-state
                   new-fixture
                   (find-attr new-fixture 'intensity)
                   0.0)
    (atomic-box-set! patched-fixture-list
                     (cons new-fixture
                           (atomic-box-ref patched-fixture-list)))
    new-fixture))



;; Helper functions for attribute translators
(define (round-dmx a)
  (inexact->exact
   (min 255 (max 0 (round a)))))

(define (percent->dmxval val)
  (round-dmx (/ (* 256 val) 100)))

(define (msb val)
  (round-dmx (/ val 256)))

(define (lsb val)
  (round-dmx (logand (inexact->exact (round val))
                     #b11111111)))


(define (state-for-each func state)
  (hash-for-each (lambda (key value)
                   (func (car key)
                         (cdr key)
                         value))
                 (get-state-hash-table state)))

(define (state-find fix attr state)
  (hash-ref (get-state-hash-table state)
            (cons fix attr)))


;; Add the contents of state "new" to "combined-state"
(define (add-state-to-state! merge-rule new combined-state)
  (state-for-each (lambda (fix attr value)
                    (let ((current-value (state-find fix
                                                     attr
                                                     combined-state)))
                      (if current-value
                          (set-in-state! combined-state
                                         fix
                                         attr
                                         (merge-rule attr current-value value))
                          (set-in-state! combined-state
                                         fix
                                         attr
                                         value))))
                 new))


(define (apply-state state)
  (add-state-to-state! merge-rule-ltp state (current-state)))


(define (value->number val time)
  (if (procedure? val)
      (val time)
      val))


(define (merge-rule-ltp attr a b)
  (lambda (time)
    (value->number b time)))

(define (merge-rule-htp attr a b)
  (if (intensity? attr)

      ;; HTP only for intensity attributes
      (lambda (time)
        (max (value->number a time)
             (value->number b time)))

      ;; LTP for all non-intensity attributes
      (lambda (time)
        (value->number b time))))

(define (merge-states-htp list-of-states)
  (merge-states merge-rule-htp
                list-of-states))

;; Combine states
(define (merge-states merge-rule list-of-states)
  (let ((combined-state (make <starlet-state>)))
    (for-each (lambda (state)
                (add-state-to-state! merge-rule
                                     state
                                     combined-state))
              list-of-states)
    combined-state))


;; Scanout
(define (bytevec->string bv)
  (string-join
    (map
      number->string
      (u8vector->list bv))
    ","))


(define (send-to-ola ola-uri ola-socket universe)
  (http-post
    ola-uri
    #:port ola-socket
    #:keep-alive? #t
    #:headers (acons 'content-type
                     (parse-header 'content-type
                                   "application/x-www-form-urlencoded")
                     '())
    #:body (string-append "u="
                          (number->string (car universe))
                          "&d="
                          (bytevec->string (cdr universe)))))


(define (hirestime)
  (let ((a (gettimeofday)))
    (+ (car a)
       (/ (cdr a)
          1000000))))

(define scanout-freq 0)

(define-generic scanout-fixture)

(define (start-ola-output)
  (let* ((ola-uri (build-uri 'http
                             #:host "127.0.0.1"
                             #:port 9090
                             #:path "/set_dmx"))
         (ola-socket (open-socket-for-uri ola-uri))
         (start-time (hirestime)))

    (begin-thread
     (let scanout-loop ((count 0))

        (let ((universes '()))


          ;; Helper function for scanout functions to set individual DMX values
          (define (set-dmx universe addr value)

            ;; Create DMX array for universe if it doesn't exist already
            (unless (assq universe universes)
              (set! universes (acons universe
                                     (make-u8vector 512 0)
                                     universes)))

            ;; Set the value in the DMX array
            (u8vector-set! (assq-ref universes universe)
                           (- addr 1)                   ; u8vector-set indexing starts from zero
                           (round-dmx value)))

          ;; Make a combined state
          (let* ((combined-state (merge-states-htp
                                   (reverse   ;; Put "home" state last
                                    (atomic-box-ref state-list)))))

            ;; Request all fixtures to output their DMX values
            (for-each (lambda (fix)

                        ;; Helper function to get a value for this
                        ;; fixture in the current state
                        (define (get-attr attr-name)
                          (value->number (state-find fix
                                                     (find-attr fix attr-name)
                                                     combined-state)
                                         (hirestime)))

                        ;; Helper function to set 8-bit DMX value
                        (define (set-chan relative-channel-number value)
                          (set-dmx (get-fixture-universe fix)
                                   (+ (get-fixture-addr fix)
                                      (- relative-channel-number 1))
                                   value))

                        ;; Helper function to set 16-bit DMX value
                        (define (set-chan-16bit relative-channel-number value max-value)
                          (let ((val16 (* value (/ 65535 max-value))))
                            (set-chan relative-channel-number (msb val16))
                            (set-chan (+ relative-channel-number 1) (lsb val16))))

                        (scanout-fixture fix get-attr set-chan set-chan-16bit))

                      (atomic-box-ref patched-fixture-list)))


          ;; Send everything to OLA
          (for-each (lambda (a)
                      (send-to-ola ola-uri ola-socket a))
                    universes))

        (usleep 10000)
        (if (eq? count 100)
            (begin
              (set! scanout-freq
                (exact->inexact (/ 100
                                   (- (hirestime) start-time))))
              (set! start-time (hirestime))
              (scanout-loop 0))
            (scanout-loop (+ count 1)))))))


(define-syntax attr-continuous
  (syntax-rules ()
    ((_ attr-name attr-range attr-home-value)
     (make <fixture-attribute>
       #:name attr-name
       #:range attr-range
       #:type 'continuous
       #:home-value attr-home-value))))


(define-syntax attr-boolean
  (syntax-rules ()
    ((_ attr-name attr-home-value)
     (make <fixture-attribute>
       #:name attr-name
       #:type 'boolean
       #:home-value attr-home-value))))


(define-syntax attr-list
  (syntax-rules ()
    ((_ attr-name attr-allowed-values attr-home-value)
     (make <fixture-attribute>
       #:name attr-name
       #:range attr-allowed-values
       #:type 'list
       #:home-value attr-home-value))))


(define current-state (make-parameter (make-empty-state)))
(register-state! (current-state))


(define-syntax lighting-state
  (syntax-rules ()
    ((_ body ...)
     (parameterize ((current-state (make-empty-state)))
       body ...
       (current-state)))))


(define-syntax at
  (syntax-rules ()

    ;; No attribute named -> set intensity
    ((_ fixture value)
     (set-attr! (current-state) fixture 'intensity value))

    ;; Set specified attribute
    ((_ fixture attr-name value)
     (set-attr! (current-state) fixture attr-name value))))