;;; -*- Mode: LISP; Syntax: Common-Lisp; Package: LKB -*-


;;; Copyright (c) 2003--2020
;;;   John Carroll, Ann Copestake, Robert Malouf, Stephan Oepen;
;;;   see `LICENSE' for conditions.


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;        file: sppp.lsp
;;;      module: simple preprocessor protocol
;;;     version: 0.0 (27-feb-03)
;;;  written by: oe, celi torino
;;; last update: 
;;;  updated by: 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; author            | date        | modification
;;; ------------------|-------------|------------------------------------------
;;;                   |             |
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;;
;;; ToDo
;;;
;;; - respect `encoding' header in incoming message: read in 8-bit mode and use
;;;   XML header to explicitly convert strings; arguably the XML parser might
;;;   be expected to do this for us, but it seems to not respect the encoding
;;;   declaration and just return what was read.
;;; - experiment with generic lexical entries that are activaed on the basis of
;;;   POS assignments.
;;; - write DTD and experiment with validating parser; the way we dissect the
;;;   parsed XML feels overly clumsy for the time being.
;;; - add more tracing and debugging support; currently grammarians need to
;;;   know to inspect *tchart* and run the preprocessor stand-alone to debug
;;;   the integration.
;;; - investigate ways of allowing tokenization ambiguity; presumably, this 
;;;   would have to be part of a full refactoring of the LKB preprocessing and
;;;   lexical look-up machinery, and ann would want to take part in that.
;;;

(in-package :lkb)

(defvar *sppp-pid* nil)

(defvar *sppp-stream* nil)

(defparameter *sppp-application* nil)

(defparameter *sppp-coding-system* :utf-8)

(defparameter *sppp-position-based-characterization-p* nil)

(defparameter *sppp-input-buffer* 
  (make-array 2048 :element-type 'character :adjustable nil :fill-pointer 0))

(defvar *sppp-debug-p* nil)

(defun initialize-sppp ()

  (when *sppp-application*
    (shutdown-sppp)
    (let (foo)
      (multiple-value-setq (*sppp-stream* foo *sppp-pid*)
        (run-process *sppp-application*
                     :wait nil
                     :output :stream :input :stream :error-output nil))
      ;;
      ;; this may seem silly: suppress compiler warning about unused .foo.
      ;;
      (when foo (setf foo foo)))))

(defun shutdown-sppp ()

  (when *sppp-stream*
    (close *sppp-stream*)
    (setf *sppp-stream* nil))
  (when *sppp-pid*
    (ignore-errors
     (run-process (format nil "kill -HUP ~d" *sppp-pid*)
                  :wait t :output "/dev/null" :error-output "/dev/null")
     (run-process (format nil "kill -TERM ~d" *sppp-pid*)
                  :wait t :output "/dev/null" :error-output "/dev/null")
     (run-process (format nil "kill -QUIT ~d" *sppp-pid*)
                  :wait t :output "/dev/null" :error-output "/dev/null"))
    #+:allegro
    (sys:os-wait nil *sppp-pid*)
    (setf *sppp-pid* nil)
    (setf *morph-option* :default)))

(defun sppp-setup-morphs (tokens)
  ;; JAC 17-Aug-2022 - removed undocumented and apparently unused field :inflection
  (loop
      for i from 0
      for token in tokens
      for form = (rest (assoc :form token))
      for start = (or (rest (assoc :start token)) -1)
      for end = (or (rest (assoc :end token)) -1)
      for from = (or (rest (assoc :from token)) -1)
      for to = (or (rest (assoc :to token)) -1)
      for edge
      = (add-token-edge form (string-upcase form) start end from to)
      for leaves = (token-edge-leaves edge)
      do
        (loop
            for analysis in (rest (assoc :analyses token))
            for stem = (string-upcase (rest (assoc :stem analysis)))
            for rules = (rest (assoc :rules analysis))
            do
              (add-morpho-stem-edge
                stem
                (loop
                    for rule in rules
                    collect (list (rest (assoc :id rule))
                                  (rest (assoc :form rule))))
                start end (string-upcase form) form from to leaves edge))))

(defun sppp (text &key (stream *sppp-stream*))
  (when (streamp stream)
    #+:allegro
    (setf (stream-external-format stream)
      (excl:find-external-format *sppp-coding-system*))
    (when (output-stream-p stream)
      (format
       stream
       "<?xml version='1.0' encoding='~(~a~)'?><text>~a</text>~%~a~%"
       *sppp-coding-system*
       (xml-escape-string text) #\page)
      (force-output stream))
    (let ((*package* (find-package :lkb))
          (n (loop
                 with size = (array-dimension *sppp-input-buffer* 0)
                 initially (setf (fill-pointer *sppp-input-buffer*) 0)
                 for n from 1
                 for c = (read-char stream nil nil)
                 when (null c) do 
                   (format
                    t
                    "sppp(): premature end of file (after ~a characters)~%" 
                    n)
                   (return)
                 when (= n size) do
                   (incf size size)
                   (setf *sppp-input-buffer* 
                     (adjust-array *sppp-input-buffer* size))
                 when (char= c #\page) do
                   (return n)
                 while c do (vector-push c *sppp-input-buffer*))))
      (when (and (numberp n) (> n 1))
        (multiple-value-bind (xml condition) 
            (ignore-errors
             #+:pxml
	     (net.xml.parser:parse-xml
              (string-trim '(#\newline) *sppp-input-buffer*))
	     #-:pxml
	     (list
              :dummy
              (lxml::shift-package
               (s-xml:parse-xml-string
                (string-trim '(#\newline) *sppp-input-buffer*))
               *package*)))
          (if condition
            (format
             t
             "sppp(): error parsing XML (~a characters)~%"
             n)
            (when (eq (first (second xml)) '|segment|)
              (sppp-process-segment (rest (second xml))))))))))

(defun sppp-process-segment (segment)
  (let (tokens)
    (loop
        for element in segment
        for token = (when (consp element) (sppp-process-token element))
        for form = (rest (assoc :form token))
        for from = (rest (assoc :from token))
        for to = (rest (assoc :to token))
        when (and from to (not (punctuationp form)))
        do (push token tokens))
    (sppp-serialize-tokens (nreverse tokens))))

(defun sppp-process-token (token)
  (loop
      with analyses = nil
      with base = (first token)
      with from = (sppp-xml-get base '|from| :type :number)
      with to = (sppp-xml-get base '|to| :type :number)
      with form = (sppp-xml-get base '|form|)
      for element in (rest token)
      when (consp element) do
        (push (sppp-process-analysis element) analyses)
      finally (return (pairlis '(:form :from :to :analyses)
                               (list form from to (nreverse analyses))))))

(defun sppp-process-analysis (analysis)
  ;; JAC 17-Aug-2022 - removed undocumented and apparently unused field :inflection
  (let* ((base (first analysis))
         (stem (sppp-xml-get base '|stem|))
         (tag (sppp-xml-get base '|tag|))
         (probability (sppp-xml-get base '|probability|))
         rules)
    (loop
        for element in (rest analysis)
        when (consp element) do
          (let* ((base (first element))
                 (id (let ((foo (sppp-xml-get base '|id|)))
                       (when (stringp foo)
                         (intern (string-upcase foo) :lkb)))) 
                 (form (sppp-xml-get base '|form|)))
            (push (pairlis '(:id :form) (list id form)) rules)))
    (pairlis '(:stem :rules :tag :probability)
             (list stem (nreverse rules) tag probability))))

(defun sppp-serialize-tokens (tokens)
  #+:debug
  (setf %tokens tokens)
  ;;
  ;; _fix_me_
  ;; this code assumed the original SPPP approach to characterization, counting
  ;; character positions rather than character ranges.  thus, in |kim sleeps.|,
  ;; |kim| is anchored at positions 0 -- 2, and the final period at 10 -- 10.
  ;; in this setup (as currently documented on the DELPH-IN wiki at LkbSppp), a
  ;; single character can correspond to distinct chart vertices, which is why
  ;; the code below is so complex.  in REPP we have long moved to using ranges
  ;; instead, and that is what FreeLing appears to be using just now.  i will
  ;; make range-based characterization the default as of today, but preserve 
  ;; the old code for backwards compatibility for a little while.
  ;;                                                            (10-jul-10; oe)
  (let* ((n (loop
                for token in tokens
                maximize (rest (assoc :to token))))
         (map (make-array (+ n 1)))
         (end 0))
    (loop
        for i from 0 to n
        do (setf (aref map i) (cons nil nil)))
    (cond
     (*sppp-position-based-characterization-p*
      (loop
          for token in tokens
          for from = (rest (assoc :from token))
          for to = (rest (assoc :to token))
          do
            (setf (first (aref map from)) t)
            (setf (rest (aref map to)) t))
      (loop
          with last = 0 with endp = t
          for i from 0 to n
          when (first (aref map i)) do
            (unless endp (incf last))
            (setf (first (aref map i)) last)
            (setf endp nil)
          when (rest (aref map i)) do
            (unless (eql (first (aref map i)) last) (incf last))
            (setf (rest (aref map i)) last)
            (setf endp t))
      (loop
          for token in tokens
          for from = (rest (assoc :from token))
          for to = (rest (assoc :to token))
          for start = (first (aref map from))
          for end = (rest (aref map to))
          do (nconc token (pairlis '(:start :end) (list start end)))))
     (t
      (loop
          for token in tokens
          for from = (rest (assoc :from token))
          for to = (rest (assoc :to token))
          do
            (push token (first (aref map from)))
            (push token (rest (aref map to)))
            (setf end (max end to)))
      (loop
          with vertex = 0
          for i from 0 to n
          for tokens = (aref map i)
          when (or (first tokens) (rest tokens)) do
            (setf (aref map i) vertex)
            (when (first tokens) (incf vertex)))
      (loop
          for token in tokens
          for from = (rest (assoc :from token))
          for to = (rest (assoc :to token))
          for start = (aref map from)
          for end = (aref map to)
          do (nconc token (pairlis '(:start :end) (list start end))))))
    tokens))

(defun sppp-xml-get (element attribute &key type)
  (loop
      for attributes = (rest element) then (rest (rest attributes))
      while attributes
      when (eq (first attributes) attribute) do
        (return
          (case type
            (:number
             (read-from-string (second attributes) nil nil))
            (t
             (second attributes))))))

(defun xml-escape-string (string)
  (declare (optimize (speed 3) (safety 1) (space 0) (debug 0)))
  (if (and string (stringp string))
    (loop
        with padding
        = (loop
              for c across string
              when (char= c #\&) sum 4
              else when (or (char= c #\<) (char= c #\>)) sum 3
              else when (or (char= c #\') (char= c #\")) sum 5)
        with result = (make-string (+ (length string) padding))
        with i = -1
        for c of-type character across (the string string)
        when (char= c #\&) do
          (setf (schar result (incf i)) #\&)
          (setf (schar result (incf i)) #\a)
          (setf (schar result (incf i)) #\m)
          (setf (schar result (incf i)) #\p)
          (setf (schar result (incf i)) #\;)
        else when (char= c #\<) do
          (setf (schar result (incf i)) #\&)
          (setf (schar result (incf i)) #\l)
          (setf (schar result (incf i)) #\t)
          (setf (schar result (incf i)) #\;)
        else when (char= c #\>) do
          (setf (schar result (incf i)) #\&)
          (setf (schar result (incf i)) #\g)
          (setf (schar result (incf i)) #\t)
          (setf (schar result (incf i)) #\;)
        else when (char= c #\') do
          (setf (schar result (incf i)) #\&)
          (setf (schar result (incf i)) #\a)
          (setf (schar result (incf i)) #\p)
          (setf (schar result (incf i)) #\o)
          (setf (schar result (incf i)) #\s)
          (setf (schar result (incf i)) #\;)
        else when (char= c #\") do
          (setf (schar result (incf i)) #\&)
          (setf (schar result (incf i)) #\q)
          (setf (schar result (incf i)) #\u)
          (setf (schar result (incf i)) #\o)
          (setf (schar result (incf i)) #\t)
          (setf (schar result (incf i)) #\;)
        else do
          (setf (schar result (incf i)) c)
        finally
          (return result))
    string))

(defun sppp-for-pet (string &optional tagger &key stream)
  (declare (ignore tagger))
  (let ((result
         (with-output-to-string (stream)
           (loop
               with *package* = (find-package :lkb)
               with id = -1
               for token in (sppp string)
               for form = (rest (assoc :form token))
               for start = (rest (assoc :start token))
               for end = (rest (assoc :end token))
               do
                 (loop
                     for analysis in (rest (assoc :analyses token))
                     for stem = (rest (assoc :stem analysis))
                     for tag = (rest (assoc :tag analysis))
                     for probability
                     = (when tag (or (rest (assoc :probability analysis)) 0.0))
                     for rules = (loop
                                     for rule in (rest (assoc :rules analysis))
                                     collect (rest (assoc :id rule)))
                     do
                       (format
                        stream
                        "(~a, ~a, ~a, 0, ~s ~s, 0, ~{\"$~(~s~)\"~^ ~}~
                         ~:[~;, ~s ~a~]) "
                        (incf id) start end stem form rules
                        tag tag probability))))))
    (cond
     ((or (streamp stream) (eq stream t))
      (format stream "~a~%" result))
     ((stringp stream)
      (with-open-file (stream stream
                       :direction :output :if-exists :supersede)
        (format stream "~a~%" result)))
     (t                 
      result))))