/*

  Copyright 2006-2018 by

  Laboratoire de l'Informatique du Parallelisme,
  UMR CNRS - ENS Lyon - UCB Lyon 1 - INRIA 5668,

  Laboratoire d'Informatique de Paris 6, equipe PEQUAN,
  UPMC Universite Paris 06 - CNRS - UMR 7606 - LIP6, Paris, France,

  Laboratoire d'Informatique de Paris 6 - Équipe PEQUAN
  Sorbonne Universités
  UPMC Univ Paris 06
  UMR 7606, LIP6
  Boîte Courrier 169
  4, place Jussieu
  F-75252 Paris Cedex 05
  France,

  Sorbonne Université
  CNRS, Laboratoire d'Informatique de Paris 6, LIP6
  F - 75005 Paris
  France,

  LORIA (CNRS, INPL, INRIA, UHP, U-Nancy 2)

  and by

  Centre de recherche INRIA Sophia Antipolis Mediterranee, equipe APICS,
  Sophia Antipolis, France.

  Contributors Ch. Lauter, S. Chevillard

  christoph.lauter@christoph-lauter.org
  sylvain.chevillard@ens-lyon.org

  This software is a computer program whose purpose is to provide an
  environment for safe floating-point code development. It is
  particularly targeted to the automated implementation of
  mathematical floating-point libraries (libm). Amongst other features,
  it offers a certified infinity norm, an automatic polynomial
  implementer and a fast Remez algorithm.

  This software is governed by the CeCILL-C license under French law and
  abiding by the rules of distribution of free software.  You can  use,
  modify and/ or redistribute the software under the terms of the CeCILL-C
  license as circulated by CEA, CNRS and INRIA at the following URL
  "http://www.cecill.info".

  As a counterpart to the access to the source code and  rights to copy,
  modify and redistribute granted by the license, users are provided only
  with a limited warranty  and the software's author,  the holder of the
  economic rights,  and the successive licensors  have only  limited
  liability.

  In this respect, the user's attention is drawn to the risks associated
  with loading,  using,  modifying and/or developing or reproducing the
  software by the user in light of its specific status of free software,
  that may mean  that it is complicated to manipulate,  and  that  also
  therefore means  that it is reserved for developers  and  experienced
  professionals having in-depth computer knowledge. Users are therefore
  encouraged to load and test the software's suitability as regards their
  requirements in conditions enabling the security of their systems and/or
  data to be ensured and,  more generally, to use and operate it in the
  same conditions as regards security.

  The fact that you are presently reading this means that you have had
  knowledge of the CeCILL-C license and that you accept its terms.

  This program is distributed WITHOUT ANY WARRANTY; without even the
  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

*/

#define _BSD_SOURCE
#define _DEFAULT_SOURCE

#include <gmp.h>
#include <mpfr.h>
#include <stdio.h> /* fprintf, fopen, fclose, */
#include <sys/wait.h> /* wait */
#include <unistd.h> /* execve, fork, daemon */
#include <stdlib.h> /* exit, free, mktemp */
#include <errno.h>
#include <string.h>
#include "plot.h"
#include "expression.h"
#include "general.h"
#include "infnorm.h"
#include "chain.h"
#include "printf.h"
#include "signalhandling.h"

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif

extern int fileNumber;

int checkFileDescriptor(FILE *fd, char *s) {
  if (fd == NULL) {
    printMessage(1,SOLLYA_MSG_PLOT_COULD_NOT_OPEN_FILE,"Error: the file %s requested by plot could not be opened for writing: ",s);
    printMessage(1,SOLLYA_MSG_CONTINUATION,"\"%s\".\n",strerror(errno));
    return 0;
  }
  return 1;
}

void plotTree(chain *treeList, mpfr_t a, mpfr_t b, unsigned long int points, mp_prec_t prec, char *name, int type) {
  int test, i, flush;
  chain *list;
  node *tree;
  mpfr_t current_x, x, y, step, perturb, cutoff;
  gmp_randstate_t random_state;
  double xd, yd, ad, bd;
  FILE *file;
  char *gplotname;
  char *dataname;
  char *outputname;
  int tern;
  mp_prec_t p, pp;
  int overflow;
  int plotPossible;
  int n;
  char *gnuplotname;

  gnuplotname = getGnuplotName();

  plotPossible = 0;

  pp = prec;
  if (prec < 64) pp = 64;

  mpfr_init2(x, pp);
  mpfr_init2(step, pp);
  mpfr_init2(y, 64);

  mpfr_sub(step, b, a, GMP_RNDN);
  mpfr_div_ui(step, step, points, GMP_RNDN);

  if (mpfr_sgn(step) == 0) {
    list = treeList;
    mpfr_set_prec(y,prec);
    while(list != NULL) {
      tree = (node *)(list->value);
      evaluateFaithful(y,tree,a,prec);
      if (!mpfr_number_p(y)) {
	printMessage(1,SOLLYA_MSG_CONSTANT_EXPR_CANNOT_BE_EVALUATED_AT_ALL,"Warning: this constant function is not evaluable by this tool.\n");
      }
      outputMode();
      printValue(&y);
      sollyaPrintf("\n");
      list = list->next;
    }
    mpfr_clear(x); mpfr_clear(y); mpfr_clear(step);
    return;
  }

  if (mpfr_sgn(step) < 0) {
    printMessage(1,SOLLYA_MSG_DOMAIN_IS_EMPTY,"Warning: the interval is empty\n");
    mpfr_clear(x); mpfr_clear(y); mpfr_clear(step);
    return;
  }

  test=1;
  list = treeList;
  while(list != NULL && (test==1)) {
    tree = (node *)(list->value);
    if(!isConstant(tree)) test=0;
    list = list->next;
  }

  if (test) {
    mpfr_set_prec(y,prec);
    mpfr_set_d(x,1.0,GMP_RNDN);
    list = treeList;
    while(list != NULL && (test==1)) {
      tree = (node *)(list->value);
      evaluateFaithful(y,tree,x,prec);
      if (!mpfr_number_p(y)) {
	printMessage(1,SOLLYA_MSG_CONSTANT_EXPR_CANNOT_BE_EVALUATED_AT_ALL,"Warning: this constant function is not evaluable by this tool.\n");
      }
      outputMode();
      printValue(&y);
      sollyaPrintf("\n");
      list = list->next;
    }
    mpfr_clear(x); mpfr_clear(y); mpfr_clear(step);
    return;
  }

  if(name==NULL) {
    n = sollya_snprintf(NULL, 0, "%s/%s%s-%04d", getTempDir(), PACKAGE_NAME, getUniqueId(), fileNumber);
    gplotname = (char *)safeCalloc(n+3, sizeof(char));
    sollya_snprintf(gplotname, n+3, "%s/%s%s-%04d.p",getTempDir(), PACKAGE_NAME, getUniqueId(), fileNumber);
    dataname = (char *)safeCalloc(n+5, sizeof(char));
    sollya_snprintf(dataname, n+5, "%s/%s%s-%04d.dat",getTempDir(),PACKAGE_NAME,getUniqueId(), fileNumber);
    outputname = (char *)safeCalloc(1, sizeof(char));
    fileNumber++;
    if (fileNumber >= NUMBEROFFILES) fileNumber=0;
  }
  else {
    gplotname = (char *)safeCalloc(strlen(name)+3,sizeof(char));
    sprintf(gplotname,"%s.p",name);
    dataname = (char *)safeCalloc(strlen(name)+5,sizeof(char));
    sprintf(dataname,"%s.dat",name);
    outputname = (char *)safeCalloc(strlen(name)+5,sizeof(char));
    if ((type==PLOTPOSTSCRIPT) || (type==PLOTPOSTSCRIPTFILE)) sprintf(outputname,"%s.eps",name);
  }

  file = fopen(gplotname, "w");
  if (checkFileDescriptor(file, gplotname)) {
    sollyaFprintf(file, "# Gnuplot script generated by %s\n",PACKAGE_NAME);
    ad = sollya_mpfr_get_d(a, GMP_RNDD);
    bd = sollya_mpfr_get_d(b, GMP_RNDU);
    if ((!(ad-ad == 0.0)) || (!(bd-bd == 0.0)))
      printMessage(1, SOLLYA_MSG_PLOT_OVERFLOW_OCCURRED_ON_CONVERSION_TO_DOUBLE, "Warning: an overflow occurred in a conversion mpfr to double while plotting.\n");
    if (!(ad-ad == 0.0))
      ad = -MAX_VALUE_GNUPLOT;
    if (!(bd-bd == 0.0))
      bd = MAX_VALUE_GNUPLOT;
    if ((type==PLOTPOSTSCRIPT) || (type==PLOTPOSTSCRIPTFILE)) sollyaFprintf(file,"set terminal postscript eps color\nset out \"%s\"\n",outputname);
    sollyaFprintf(file, "set format x \"%%g\"\n");
    sollyaFprintf(file, "set format y \"%%g\"\n");
    sollyaFprintf(file, "set xrange [%1.50e:%1.50e]\n",  ad, bd);

    sollyaFprintf(file, "plot ");
    i=2;
    list = treeList;
    while(list != NULL) {
      sollyaFprintf(file,"\"%s\" using 1:%d with lines t \"\"",dataname,i);
      if(list->next != NULL) sollyaFprintf(file,",");
      i++;
      list = list->next;
    }
    sollyaFprintf(file,"\n");
    if ((name==NULL) || (type==PLOTFILE)) {
      sollyaFprintf(file,"pause mouse close\n");
    }
    fclose(file);

    file = fopen(dataname, "w");
    if (checkFileDescriptor(file, dataname)) {
      plotPossible = 1;

      mpfr_init2(cutoff, pp);
      mpfr_set_d(cutoff,1.0,GMP_RNDN);
      p = prec;
      if (p < 64) p = 64;
      mpfr_div_2ui(cutoff,cutoff,4*p,GMP_RNDN);

      overflow = 0;
      flush = 0;

      mpfr_init2(current_x, pp);
      gmp_randinit_default(random_state);
      gmp_randseed_ui(random_state, 65845285);
      mpfr_init2(perturb, pp);

      mpfr_set(current_x,a,GMP_RNDN);
      mpfr_set(x, current_x, GMP_RNDN);
      while(mpfr_lessequal_p(x,b)) {
	xd =  sollya_mpfr_get_d(x, GMP_RNDN);
	if (xd >= MAX_VALUE_GNUPLOT) xd = MAX_VALUE_GNUPLOT;
	if (xd <= -MAX_VALUE_GNUPLOT) xd = -MAX_VALUE_GNUPLOT;
	sollyaFprintf(file, "%1.50e",xd);

	list = treeList;
	while(list != NULL) {
	  tree = (node *)(list->value);
	  tern = evaluateFaithfulWithCutOff(y, tree, x, cutoff, prec);
	  if (tern == 2) {
	    flush = 1;
	    printMessage(2,SOLLYA_MSG_PLOT_FUNC_PROVEN_LESS_THAN_2_TO_MINUS_PREC,"Information: function image proven to be less than 2^(-%d) on point %s = %v\nThis point will be plotted as the midpoint of the proof interval.\n",(int)p,((variablename == NULL) ? "_x_" : variablename),x);
	  }
	  if (!mpfr_number_p(y)) {
	    printMessage(2,SOLLYA_MSG_PLOT_FUNC_UNDEFINED_OR_UNSTABLE_AT_POINT,"Information: function undefined or not evaluable in point %s = %v\nThis point will not be plotted.\n",((variablename == NULL) ? "_x_" : variablename),x);
	  }
	  yd = sollya_mpfr_get_d(y, GMP_RNDN);
	  if (!(yd-yd == 0.0)) overflow = 1;
	  if (yd >= MAX_VALUE_GNUPLOT) {
	    yd = MAX_VALUE_GNUPLOT;
	    overflow = 1;
	  }
	  if (yd <= -MAX_VALUE_GNUPLOT) {
	    yd = -MAX_VALUE_GNUPLOT;
	    overflow = 1;
	  }
	  sollyaFprintf(file, "\t%1.50e", yd);

	  list = list->next;
	}
	sollyaFprintf(file,"\n");

	mpfr_add(current_x, current_x,step,GMP_RNDU);
	mpfr_urandomb(perturb, random_state); mpfr_mul_2ui(perturb, perturb, 1, GMP_RNDN);
	mpfr_sub_ui(perturb, perturb, 1, GMP_RNDN); mpfr_div_2ui(perturb, perturb, 2, GMP_RNDN);
	mpfr_mul(perturb, perturb, step, GMP_RNDN); /* perturb \in [-step/4; step/4] */
	mpfr_add(x, current_x, perturb, GMP_RNDU);
      }

      mpfr_clear(cutoff);
      mpfr_clear(perturb);
      mpfr_clear(current_x);
      gmp_randclear(random_state);

      fclose(file);

      if (overflow)
	printMessage(1, SOLLYA_MSG_PLOT_OVERFLOW_OCCURRED_ON_CONVERSION_TO_DOUBLE, "Warning: an overflow occurred in a conversion mpfr to double while plotting.\n");

      if (flush) {
	printMessage(1,SOLLYA_MSG_PLOT_NOT_FAITHFULLY_EVALUATED_AT_SOME_POINT,"Warning: the evaluation of the image on at least one point of at least one function has not been faithfully accurate.\n");
      }
    }
  }

  mpfr_clear(x); mpfr_clear(y); mpfr_clear(step);

  deferSignalHandling();
  fflush(NULL);
  parserFlushInput();
  resumeSignalHandling();
  if (plotPossible) {
    if ((name==NULL) || (type==PLOTFILE)) {
      if (fork()==0) { /* The daemon call could fail (and will on certain Cygwin), in which case a double fork yields (almost (mod HUP etc.)) the same result. If daemon works, the fork has no effect */
	if (daemon(1,0) == 0) { /* We want the prompt to return, so we need a daemon. We need to connect that daemon to /dev/null, which we do by setting the 2nd arg to zero */
	  if (fork() == 0) { /* We need a child of the daemon that waits for gnuplot to remove the file */
	    execlp(gnuplotname, gnuplotname, gplotname, NULL);
	    perror("An error occurred when calling gnuplot ");
	    exit(1);
	  } else {
	    wait(NULL);
	    sleep(1);
	    if (name == NULL) {
	      remove(gplotname);
	      remove(dataname);
	    }
	    sleep(1);
	    exit(0);
	  }
	} else {
	  fprintf(stderr, "Could not create a daemon for gnuplot\n");
	  if (fork() == 0) { /* We could not create a daemon but we still want a child to wait for us */
	    execlp(gnuplotname, gnuplotname, gplotname, NULL);
	    perror("An error occurred when calling gnuplot ");
	    exit(1);
	  } else {
	    wait(NULL);
	    sleep(2);
	    exit(0);
	  }	  
	}
      }
      else {
	wait(NULL);
	sleep(1);
      }
    }
    else { /* Case we have an output: no daemon */
      if (fork()==0) { /* We do not need no daemon so no stupid double/triple fork. This fork is necessary just to spawn the new process */
	execlp(gnuplotname, gnuplotname, gplotname, NULL);
	perror("An error occurred when calling gnuplot ");
	exit(1);
      }
      else {
	wait(NULL);
	if(type==PLOTPOSTSCRIPT) {
	  remove(gplotname);
	  remove(dataname);
	}
	sleep(1);
      }
    }
  }
  
  deferSignalHandling();
  fflush(NULL);
  parserFlushInput();
  resumeSignalHandling();


  safeFree(gplotname);
  safeFree(dataname);
  safeFree(outputname);
  return;
}

void removePlotFiles(void) {
  int i;
  char *name;
  int n;

  n = sollya_snprintf(NULL, 0, "%s/%s%s-%04d", getTempDir(), PACKAGE_NAME, getUniqueId(), NUMBEROFFILES);
  name = (char *)safeCalloc(n+5, sizeof(char));

  for(i=0;i<NUMBEROFFILES;i++) {
    sollya_snprintf(name, n+3, "%s/%s%s-%04d.p",getTempDir(), PACKAGE_NAME, getUniqueId(), i);
    remove(name);
    sollya_snprintf(name, n+5, "%s/%s%s-%04d.dat",getTempDir(),PACKAGE_NAME,getUniqueId(), i);
    remove(name);
  }

  safeFree(name);
  return;
}


void asciiPlotTree(node *tree, mpfr_t a, mpfr_t b, mp_prec_t prec) {
  mpfr_t y, x, step, minValue, maxValue;
  int sizeX, sizeY, i, k, drawXAxis, drawYAxis, xAxis, yAxis;
#if defined(TIOCGWINSZ) && defined(STDOUT_FILENO) && defined(HAVE_SYS_IOCTL_H)
#if defined(__CYGWIN__)
  struct winsize {
    unsigned short  ws_row;     /* rows in characters */
    unsigned short  ws_col;     /* columns in characters */
    unsigned short  ws_xpixel;  /* horizontal size in pixels (not used) */
    unsigned short  ws_ypixel;  /* vertical size in pixels (not used) */
  } size;
#else
  struct winsize size;
#endif
#endif
  mpfr_t *values;
  char **lines;
  char *curr;
  int oldColor;

  mpfr_init2(y,prec);
  if ((mpfr_cmp(a,b) == 0) || isConstant(tree)) {
    evaluateFaithful(y,tree,a,prec);
    if (!mpfr_number_p(y)) {
      printMessage(1,SOLLYA_MSG_CONSTANT_EXPR_CANNOT_BE_EVALUATED_AT_ALL,"Warning: this constant function is not evaluable by this tool.\n");
    }
    printValue(&y);
    sollyaPrintf("\n");
    mpfr_clear(y);
    return;
  }


#if defined(TIOCGWINSZ) && defined(STDOUT_FILENO) && defined(HAVE_SYS_IOCTL_H)
  if ((eliminatePromptBackup == 1) && (!libraryMode)) {
    sizeX = 77;
    sizeY = 25;
  } else {
    if (ioctl(STDOUT_FILENO, TIOCGWINSZ, (char *) &size) >= 0) {
      sizeX = size.ws_col;
      sizeY = size.ws_row;
      if ((sizeX < 2) || (sizeY < 2)) {
	sizeX = 77;
	sizeY = 25;
      }
      if (sizeX > 500) sizeX = 500;
      if (sizeY > 500) sizeY = 500;
    } else {
      sizeX = 77;
      sizeY = 25;
    }
  }
#else
  sizeX = 77;
  sizeY = 25;
#endif

  values = (mpfr_t *) safeCalloc(sizeX-1,sizeof(mpfr_t));
  for (i=0;i<sizeX-1;i++) {
    mpfr_init2(values[i],2*prec);
  }

  mpfr_init2(x,prec);
  mpfr_init2(step,prec);
  mpfr_sub(step,b,a,GMP_RNDN);
  mpfr_set_si(x,sizeX-2,GMP_RNDN);
  mpfr_div(step,step,x,GMP_RNDN);


  for (i=0;i<sizeX-1;i++) {
    mpfr_set_si(x,i,GMP_RNDN);
    mpfr_mul(x,x,step,GMP_RNDN);
    mpfr_add(x,x,a,GMP_RNDN);

    evaluateFaithful(values[i],tree,x,prec);
    if (!mpfr_number_p(values[i])) {
      mpfr_set_d(values[i],0.0,GMP_RNDN);
    }
  }

  mpfr_init2(minValue,prec);
  mpfr_init2(maxValue,prec);
  mpfr_set(minValue,values[0],GMP_RNDN);
  mpfr_set(maxValue,values[0],GMP_RNDN);
  for (i=1;i<sizeX-1;i++) {
    if (mpfr_cmp(values[i],minValue) < 0) {
      mpfr_set(minValue, values[i], GMP_RNDN);
    }
    if (mpfr_cmp(values[i],maxValue) > 0) {
      mpfr_set(maxValue, values[i], GMP_RNDN);
    }
  }

  drawXAxis = 0; drawYAxis = 0; xAxis = 0; yAxis = 0;
  if (mpfr_sgn(minValue) != mpfr_sgn(maxValue)) {
    drawXAxis = 1;
    mpfr_neg(x,minValue,GMP_RNDN);
    mpfr_sub(y,maxValue,minValue,GMP_RNDN);
    mpfr_div(x,x,y,GMP_RNDN);
    mpfr_mul_si(x,x,sizeY-2,GMP_RNDN);
    xAxis = mpfr_get_si(x,GMP_RNDN);
    if (xAxis < 0) xAxis = 0;
    if (xAxis > (sizeY - 2)) xAxis = sizeY - 2;
  }

  if (mpfr_sgn(a) != mpfr_sgn(b)) {
    drawYAxis = 1;
    mpfr_neg(x,a,GMP_RNDN);
    mpfr_div(x,x,step,GMP_RNDN);
    yAxis = mpfr_get_si(x,GMP_RNDN);
    if (yAxis < 0) yAxis = 0;
    if (yAxis > (sizeX - 2)) yAxis = 2;
  }

  for (i=0;i<sizeX-1;i++) {
    mpfr_sub(values[i],values[i],minValue,GMP_RNDN);
  }
  mpfr_sub(maxValue,maxValue,minValue,GMP_RNDN);
  for (i=0;i<sizeX-1;i++) {
    mpfr_div(values[i],values[i],maxValue,GMP_RNDN);
    mpfr_mul_si(values[i],values[i],sizeY-2,GMP_RNDN);
  }

  lines = (char **) safeCalloc(sizeY,sizeof(char *));
  for (k=0;k<sizeY-1;k++) {
    lines[k] = (char *) safeCalloc(sizeX,sizeof(char));
    for (i=0;i<sizeX-1;i++)
      lines[k][i] = ' ';
  }

  if (drawXAxis) {
    for (i=0;i<sizeX-1;i++)
      lines[(sizeY - 2) - xAxis][i] = '-';
  }

  if (drawYAxis) {
    for (k=0;k<sizeY-1;k++)
      lines[k][yAxis] = '|';
  }

  if (drawXAxis && drawYAxis) {
    lines[(sizeY - 2) - xAxis][yAxis] = '+';
  }

  for (i=0;i<sizeX-1;i++) {
    k = mpfr_get_si(values[i],GMP_RNDN);
    if (k < 0) k = 0;
    if (k > (sizeY - 2)) k = sizeY - 2;
    lines[(sizeY - 2) - k][i] = 'x';
  }

  saveMode();
  for (k=0;k<sizeY-1;k++) {
    curr = lines[k];
    while (*curr != '\0') {
      if (*curr != 'x')
	sollyaPrintf("%c",*(curr++));
      else {
	oldColor = getDisplayColor();
	redMode();
	sollyaPrintf("%c",*(curr++));
	setDisplayColor(oldColor);
      }
    }
    sollyaPrintf("\n");
  }

  restoreMode();

  for (k=0;k<sizeY-1;k++) safeFree(lines[k]);
  safeFree(lines);
  mpfr_clear(minValue);
  mpfr_clear(maxValue);
  mpfr_clear(y);
  mpfr_clear(x);
  mpfr_clear(step);
  for (i=0;i<sizeX-1;i++) {
    mpfr_clear(values[i]);
  }
  safeFree(values);
  return;
}