;;; calc-stuff.el --- miscellaneous functions for Calc  -*- lexical-binding:t -*-

;; Copyright (C) 1990-1993, 2001-2022 Free Software Foundation, Inc.

;; Author: David Gillespie <daveg@synaptics.com>

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;;; Code:

;; This file is autoloaded from calc-ext.el.

(require 'calc-ext)
(require 'calc-macs)

(defun calc-num-prefix (n)
  "Use the number at the top of stack as the numeric prefix for the next command.
With a prefix, push that prefix as a number onto the stack."
  (interactive "P")
  (calc-wrapper
   (if n
       (calc-enter-result 0 "" (prefix-numeric-value n))
     (let ((num (calc-top 1)))
       (if (math-messy-integerp num)
	   (setq num (math-trunc num)))
       (or (integerp num)
	   (error "Argument must be a small integer"))
       (calc-pop-stack 1)
       (setq prefix-arg num)
       (message "%d-" num)))))    ; a (lame) simulation of the real thing...


(defun calc-more-recursion-depth (n)
  (interactive "P")
  (calc-wrapper
   (if (calc-is-inverse)
       (calc-less-recursion-depth n)
     (let ((n (if n (prefix-numeric-value n) 2)))
       (if (> n 1)
	   (setq max-lisp-eval-depth (* max-lisp-eval-depth n))))
     (message "max-lisp-eval-depth is now %d" max-lisp-eval-depth))))

(defun calc-less-recursion-depth (n)
  (interactive "P")
  (let ((n (if n (prefix-numeric-value n) 2)))
    (if (> n 1)
	(setq max-lisp-eval-depth (max (/ max-lisp-eval-depth n) 200))))
  (message "max-lisp-eval-depth is now %d" max-lisp-eval-depth))


(defvar calc-which-why nil)
(defvar calc-last-why-command nil)
(defun calc-explain-why (why &optional more)
  (if (eq (car why) '*)
      (setq why (cdr why)))
  (let* ((pred (car why))
	 (arg (nth 1 why))
	 (msg (cond ((not pred) "Wrong type of argument")
		    ((stringp pred) pred)
		    ((eq pred 'integerp) "Integer expected")
		    ((eq pred 'natnump)
		     (if (and arg (Math-objvecp arg) (not (Math-integerp arg)))
			 "Integer expected"
		       "Nonnegative integer expected"))
		    ((eq pred 'posintp)
		     (if (and arg (Math-objvecp arg) (not (Math-integerp arg)))
			 "Integer expected"
		       "Positive integer expected"))
		    ((eq pred 'fixnump)
		     (if (and arg (Math-integerp arg))
			 "Small integer expected"
		       "Integer expected"))
		    ((eq pred 'fixnatnump)
		     (if (and arg (Math-natnump arg))
			 "Small integer expected"
		       (if (and arg (Math-objvecp arg)
				(not (Math-integerp arg)))
			   "Integer expected"
			 "Nonnegative integer expected")))
		    ((eq pred 'fixposintp)
		     (if (and arg (Math-integerp arg) (Math-posp arg))
			 "Small integer expected"
		       (if (and arg (Math-objvecp arg)
				(not (Math-integerp arg)))
			   "Integer expected"
			 "Positive integer expected")))
		    ((eq pred 'posp) "Positive number expected")
		    ((eq pred 'negp) "Negative number expected")
		    ((eq pred 'nonzerop) "Nonzero number expected")
		    ((eq pred 'realp) "Real number expected")
		    ((eq pred 'anglep) "Real number expected")
		    ((eq pred 'hmsp) "HMS form expected")
		    ((eq pred 'datep)
		     (if (and arg (Math-objectp arg)
			      (not (Math-realp arg)))
			 "Real number or date form expected"
		       "Date form expected"))
		    ((eq pred 'numberp) "Number expected")
		    ((eq pred 'scalarp) "Number expected")
		    ((eq pred 'vectorp) "Vector or matrix expected")
		    ((eq pred 'numvecp) "Number or vector expected")
		    ((eq pred 'matrixp) "Matrix expected")
		    ((eq pred 'square-matrixp)
		     (if (and arg (math-matrixp arg))
			 "Square matrix expected"
		       "Matrix expected"))
		    ((eq pred 'objectp) "Number expected")
		    ((eq pred 'constp) "Constant expected")
		    ((eq pred 'range) "Argument out of range")
		    (t (format "%s expected" pred))))
	 (punc ": ")
	 (calc-can-abbrev-vectors t))
    (while (setq why (cdr why))
      (and (car why)
	   (setq msg (concat msg punc (if (stringp (car why))
					  (car why)
					(math-format-flat-expr (car why) 0)))
		 punc ", ")))
    (message "%s%s" msg (if more "  [w=more]" ""))))

(defun calc-why ()
  (interactive)
  (if (not (eq this-command last-command))
      (if (eq last-command calc-last-why-command)
	  (setq calc-which-why (cdr calc-why))
	(setq calc-which-why calc-why)))
  (if calc-which-why
      (progn
	(calc-explain-why (car calc-which-why) (cdr calc-which-why))
	(setq calc-which-why (cdr calc-which-why)))
    (if calc-why
	(progn
	  (message "(No further explanations available)")
	  (setq calc-which-why calc-why))
      (message "No explanations available"))))

;; The following caches are declared in other files, but are
;; reset here.
(defvar math-lud-cache) ; calc-mtx.el
(defvar math-log2-cache) ; calc-bin.el
(defvar math-radix-digits-cache) ; calc-bin.el
(defvar math-radix-float-cache-tag) ; calc-bin.el
(defvar math-random-cache) ; calc-comb.el
(defvar math-max-digits-cache) ; calc-bin.el
(defvar math-integral-cache) ; calcalg2.el
(defvar math-units-table) ; calc-units.el
(defvar math-decls-cache-tag) ; calc-arith.el
(defvar math-format-date-cache) ; calc-forms.el
(defvar math-holidays-cache-tag) ; calc-forms.el

(defun calc-flush-caches (&optional inhibit-msg)
  (interactive "P")
  (calc-wrapper
   (setq math-lud-cache nil
	 math-log2-cache nil
	 math-radix-digits-cache nil
	 math-radix-float-cache-tag nil
	 math-random-cache nil
	 math-max-digits-cache nil
	 math-integral-cache nil
	 math-units-table nil
	 math-decls-cache-tag nil
	 math-eval-rules-cache-tag t
	 math-format-date-cache nil
	 math-holidays-cache-tag t)
   (mapc (lambda (x) (set x -100)) math-cache-list)
   (unless inhibit-msg
     (message "All internal calculator caches have been reset"))))


;;; Conversions.

(defun calc-clean (n)
  (interactive "P")
  (calc-slow-wrapper
   (calc-with-default-simplification
    (let ((func (if (calc-is-hyperbolic) 'calcFunc-clean 'calcFunc-pclean)))
      (calc-enter-result 1 "cln"
			 (if n
			     (let ((n (prefix-numeric-value n)))
			       (list func
				     (calc-top-n 1)
				     (if (<= n 0)
					 (+ n calc-internal-prec)
				       n)))
			   (list func (calc-top-n 1))))))))

(defun calc-clean-num (num)
  (interactive "P")
  (calc-clean (- (if num
		     (prefix-numeric-value num)
		   (if (and (>= last-command-event ?0)
			    (<= last-command-event ?9))
		       (- last-command-event ?0)
		     (error "Number required"))))))


(defvar math-chopping-small nil)
(defun calcFunc-clean (a &optional prec)   ; [X X S] [Public]
  (if prec
      (cond ((Math-messy-integerp prec)
	     (calcFunc-clean a (math-trunc prec)))
	    ((or (not (integerp prec))
		 (< prec 3))
	     (calc-record-why "*Precision must be an integer 3 or above")
	     (list 'calcFunc-clean a prec))
	    ((not (Math-objvecp a))
	     (list 'calcFunc-clean a prec))
	    (t (let ((calc-internal-prec prec)
		     (math-chopping-small t))
		 (calcFunc-clean (math-normalize a)))))
    (cond ((eq (car-safe a) 'polar)
	   (let ((theta (math-mod (nth 2 a)
				  (if (eq calc-angle-mode 'rad)
				      (math-two-pi)
				    360))))
	     (math-neg
	      (math-neg
	       (math-normalize
		(list 'polar
		      (calcFunc-clean (nth 1 a))
		      (calcFunc-clean theta)))))))
	  ((memq (car-safe a) '(vec date hms))
	   (cons (car a) (mapcar 'calcFunc-clean (cdr a))))
	  ((memq (car-safe a) '(cplx mod sdev intv))
	   (math-normalize (cons (car a) (mapcar 'calcFunc-clean (cdr a)))))
	  ((eq (car-safe a) 'float)
	   (if math-chopping-small
	       (if (or (> (nth 2 a) (- calc-internal-prec))
		       (Math-lessp (- calc-internal-prec) (calcFunc-xpon a)))
		   (if (and (math-num-integerp a)
			    (math-lessp (calcFunc-xpon a) calc-internal-prec))
		       (math-trunc a)
		     a)
		 0)
	     a))
	  ((Math-objectp a) a)
	  ((math-infinitep a) a)
	  (t (list 'calcFunc-clean a)))))

(defun calcFunc-pclean (a &optional prec)
  (math-map-over-constants (lambda (x) (calcFunc-clean x prec))
			   a))

(defun calcFunc-pfloat (a)
  (math-map-over-constants 'math-float a))

(defun calcFunc-pfrac (a &optional tol)
  (math-map-over-constants (lambda (x) (calcFunc-frac x tol))
			   a))

;; The variable math-moc-func is local to math-map-over-constants,
;; but is used by math-map-over-constants-rec, which is called by
;; math-map-over-constants.
(defvar math-moc-func)

(defun math-map-over-constants (moc-func expr)
  (let ((math-moc-func moc-func))
    (math-map-over-constants-rec expr)))

(defun math-map-over-constants-rec (expr)
  (cond ((or (Math-primp expr)
	     (memq (car expr) '(intv sdev)))
	 (or (and (Math-objectp expr)
		  (funcall math-moc-func expr))
	     expr))
	((and (memq (car expr) '(^ calcFunc-subscr))
	      (eq math-moc-func 'math-float)
	      (= (length expr) 3)
	      (Math-integerp (nth 2 expr)))
	 (list (car expr)
	       (math-map-over-constants-rec (nth 1 expr))
	       (nth 2 expr)))
	(t (cons (car expr) (mapcar 'math-map-over-constants-rec (cdr expr))))))

(provide 'calc-stuff)

;;; calc-stuff.el ends here