/*

  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

  and by

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

  Contributors Ch. Lauter, S. Chevillard

  christoph.lauter@ens-lyon.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 <unistd.h> /* execve, fork, daemon */
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <stdio.h>
#include <sys/wait.h>
#include <dlfcn.h>
#include <gmp.h>
#include <mpfr.h>
#include "expression.h"
#include "external.h"
#include "plot.h"
#include "infnorm.h"
#include "general.h"
#include "printf.h"
#include "signalhandling.h"

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

#define READ_BUFFER_SIZE 2048

extern int fileNumber;

int bashExecute(char *command) {
  int i;
  deferSignalHandling();
  fflush(NULL);
  i = system(command);
  fflush(NULL);
  resumeSignalHandling();
  return WEXITSTATUS(i);
}

char *evaluateStringAsBashCommand(char *command, char *input) {
  char *res;
  int okay, errorOnInput;
  int pipesToBash[2];
  int pipesFromBash[2];
  pid_t pid;
  int childStatus;
  char readBuffer[READ_BUFFER_SIZE];
  int readLen;
  char *buf;
  int len;
  int i;

  if ((command == NULL) || (strlen(command) == 0)) {
    printMessage(1,SOLLYA_MSG_NO_COMMAND_PROVIDED,"Warning in bashevaluate: no command provided\n");
    return NULL;
  }

  res = NULL;
  okay = 0;
  deferSignalHandling();
  fflush(NULL);
  resumeSignalHandling();

  /* Create two unnamed pipes */
  if ((input != NULL) && (pipe(pipesToBash) == -1)) {
    /* Error creating the pipe */
    printMessage(1,SOLLYA_MSG_ERROR_WHILE_CREATING_A_PIPE,"Warning in bashevaluate: error while creating a pipe");
  } else {
    if (pipe(pipesFromBash) == -1) {
      /* Error creating the pipe */
      printMessage(1, SOLLYA_MSG_ERROR_WHILE_CREATING_A_PIPE, "Warning in bashevaluate: error while creating a pipe");
    } else {
      /* Fork
      //
      // Flush before forking
      */
      deferSignalHandling();
      fflush(NULL);
      parserFlushInput();
      resumeSignalHandling();
      if ((pid = fork()) == -1) {
	/* Error forking */
	printMessage(1, SOLLYA_MSG_ERROR_WHILE_FORKING, "Warning in bashevaluate: error while forking");
      } else {
	/* Fork worked */
	if (pid == 0) {
	  /* I am the child
	  //
	  // Close the unneeded ends of the pipes.
	  */
	  if (input != NULL) close(pipesToBash[1]);
	  close(pipesFromBash[0]);

	  /* Connect my input and output to the pipe
	   */
	  if (input != NULL) {
	    if (sollya_dup2(pipesToBash[0],0) == -1) {
	      _exit(1);
	    }
	  }
	  if (sollya_dup2(pipesFromBash[1],1) == -1) {
	    _exit(1);
	  }

	  /* Execute bash
	   */
	  deferSignalHandling();
	  fflush(NULL);
	  execlp("sh","sh","-c",command,(char *) NULL);
	  fflush(NULL);
	  resumeSignalHandling();

	  _exit(1);
	} else {
	  /* I am the father
	  //
	  // Close the unneeded ends of the pipes.
	  */
	  if (input != NULL) close(pipesToBash[0]);
	  close(pipesFromBash[1]);

	  /* Do my job
	   */
	  errorOnInput = 0;
	  if (input != NULL) {
	    if (write(pipesToBash[1],input,
		      strlen(input) * sizeof(char)) == -1) {
	      printMessage(1,SOLLYA_MSG_UNABLE_TO_WRITE_TO_BASH,"Warning in bashevaluate: unable to write to bash");
	      errorOnInput = 1;
	    }
	    close(pipesToBash[1]);
	  }

	  deferSignalHandling();
	  fflush(NULL);
	  resumeSignalHandling();

	  if (!errorOnInput) {
	    do {
	      readLen = read(pipesFromBash[0],readBuffer,READ_BUFFER_SIZE);
	      if (readLen > 0) {
		if (res == NULL) {
		  res = safeCalloc(readLen + 1, sizeof(char));
		  buf = res;
		} else {
		  len = strlen(res);
		  buf = safeCalloc(len + readLen + 1, sizeof(char));
		  strcpy(buf,res);
		  safeFree(res);
		  res = buf;
		  buf += len;
		}
		for (i=0;i<readLen;i++) {
		  *buf = (readBuffer[i] == '\0') ? '?' : readBuffer[i];
		  buf++;
		}
	      }
	    } while (readLen == READ_BUFFER_SIZE);

	    /* Wait for my child to exit */
	    wait(&childStatus);

	    /* Read the rest of the pipe if it filled up again after
	       having been emptied already.
	    */
	    do {
	      readLen = read(pipesFromBash[0],readBuffer,READ_BUFFER_SIZE);
	      if (readLen > 0) {
		if (res == NULL) {
		  res = safeCalloc(readLen + 1, sizeof(char));
		  buf = res;
		} else {
		  len = strlen(res);
		  buf = safeCalloc(len + readLen + 1, sizeof(char));
		  strcpy(buf,res);
		  safeFree(res);
		  res = buf;
		  buf += len;
		}
		for (i=0;i<readLen;i++) {
		  *buf = (readBuffer[i] == '\0') ? '?' : readBuffer[i];
		  buf++;
		}
	      }
	    } while (readLen == READ_BUFFER_SIZE);

	    if (WEXITSTATUS(childStatus) != 0) {
	      printMessage(1, SOLLYA_MSG_THE_EXIT_CODE_OF_CHILD_PROCESS_IS, "Warning in bashevaluate: the exit code of the child process is %d.\n", WEXITSTATUS(childStatus));
	    } else {
	      printMessage(2, SOLLYA_MSG_THE_EXIT_CODE_OF_CHILD_PROCESS_IS, "Information in bashevaluate: the exit code of the child process is %d.\n", WEXITSTATUS(childStatus));
	    }

	    close(pipesFromBash[0]);

	    okay = 1;
	    if (res == NULL) {
	      res = safeCalloc(2, sizeof(char));
	    }
	    len = strlen(res);
	    if (len >= 1) {
	      if (res[len-1] == '\n') res[len-1] = '\0';
	    }
	  }
	}
      }
    }
  }

  if (!okay) {
    if (res != NULL) safeFree(res);
    res = NULL;
  }

  deferSignalHandling();
  fflush(NULL);
  parserFlushInput();
  resumeSignalHandling();

  return res;
}


void externalPlot(char *library, mpfr_t a, mpfr_t b, mp_prec_t samplingPrecision, int random, node *func, int mode, mp_prec_t prec, char *name, int type) {
  void *descr;
  void  (*myFunction)(mpfr_t, mpfr_t);
  char *error;
  mpfr_t x_h,x,y,temp,perturb,ulp,min_value;
  double xd, yd;
  FILE *file;
  gmp_randstate_t state;
  char *gplotname;
  char *dataname;
  char *outputname;
  int n;
  char *gnuplotname;

  gnuplotname = getGnuplotName();

  if(samplingPrecision > prec) {
    printMessage(1,SOLLYA_MSG_SAMPLING_PREC_MUST_BE_LOWER_THAN_CURR_PREC,"Error: you must use a sampling precision lower than the current precision\n");
    return;
  }

  descr = dlopen(library, RTLD_NOW);
  if (descr==NULL) {
    printMessage(1,SOLLYA_MSG_EXTERNALPLOT_COULD_NOT_OPEN_A_LIBRARY, "Error: the given library (%s) is not available (%s)!\n",library,dlerror());
    return;
  }

  dlerror(); /* Clear any existing error */
  myFunction = (void (*)(mpfr_t, mpfr_t)) dlsym(descr, "f");
  if ((error = dlerror()) != NULL) {
    printMessage(1, SOLLYA_MSG_EXTERNALPLOT_DID_NOT_FIND_FUNCTION_F, "Error: the function f cannot be found in library %s (%s)\n",library,error);
    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);
  }


  /* Beginning of the interesting part of the code */
  file = fopen(gplotname, "w");
  if (file == NULL) {
    printMessage(1,SOLLYA_MSG_COULD_NOT_OPEN_PLOT_FILE,"Error: the file %s requested by plot could not be opened for writing: ",gplotname);
    printMessage(1,SOLLYA_MSG_CONTINUATION,"\"%s\".\n",strerror(errno));
    return;
  }
  sollyaFprintf(file, "# Gnuplot script generated by %s\n",PACKAGE_NAME);
  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", sollya_mpfr_get_d(a, GMP_RNDD),sollya_mpfr_get_d(b, GMP_RNDU));
  sollyaFprintf(file, "plot \"%s\" using 1:2 with dots t \"\"\n",dataname);
  if ((name==NULL) || (type==PLOTFILE)) {
    sollyaFprintf(file,"pause mouse close\n");
  }
  fclose(file);

  file = fopen(dataname, "w");
  if (file == NULL) {
    printMessage(1,SOLLYA_MSG_COULD_NOT_OPEN_PLOT_FILE,"Error: the file %s requested by plot could not be opened for writing: ",dataname);
    printMessage(1,SOLLYA_MSG_CONTINUATION,"\"%s\".\n",strerror(errno));
    return;
  }

  gmp_randinit_default (state);

  mpfr_init2(x_h,samplingPrecision);
  mpfr_init2(perturb, prec);
  mpfr_init2(x,prec);
  mpfr_init2(y,prec);
  mpfr_init2(temp,prec);
  mpfr_init2(ulp,prec);
  mpfr_init2(min_value,53);

  mpfr_sub(min_value, b, a, GMP_RNDN);
  mpfr_div_2ui(min_value, min_value, 12, GMP_RNDN);

  mpfr_set(x_h,a,GMP_RNDD);

  while(mpfr_less_p(x_h,b)) {
    mpfr_set(x, x_h, GMP_RNDN); /* exact */

    if (mpfr_zero_p(x_h)) {
      mpfr_set(x_h, min_value, GMP_RNDU);
    }
    else {
      if (mpfr_cmpabs(x_h, min_value) < 0) mpfr_set_d(x_h, 0., GMP_RNDN);
      else mpfr_nextabove(x_h);
    }

    if(random) {
      mpfr_sub(ulp, x_h, x, GMP_RNDN);
      mpfr_urandomb(perturb, state);
      mpfr_mul(perturb, perturb, ulp, GMP_RNDN);
      mpfr_add(x, x, perturb, GMP_RNDN);
    }

    if (mpfr_zero_p(x)) {
      mpfr_mul(x,x,x,GMP_RNDN); /* (+/- 0)^2 = + 0 */
    }
    (*myFunction)(temp,x);
    evaluateFaithful(y, func, x,prec);
    mpfr_sub(temp, temp, y, GMP_RNDN);
    if(mode==RELATIVE) mpfr_div(temp, temp, y, GMP_RNDN);
    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);
    if (!mpfr_number_p(temp)) {
      printMessage(2,SOLLYA_MSG_A_FUNCTION_COULD_NOT_BE_PLOTTED_AT_A_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(temp, GMP_RNDN);
    if (yd >= MAX_VALUE_GNUPLOT) yd = MAX_VALUE_GNUPLOT;
    if (yd <= -MAX_VALUE_GNUPLOT) yd = -MAX_VALUE_GNUPLOT;
    sollyaFprintf(file, "\t%1.50e\n", yd);
  }

  fclose(file);

  /* End of the interesting part.... */

  dlclose(descr);
  mpfr_clear(x);
  mpfr_clear(y);
  mpfr_clear(x_h);
  mpfr_clear(temp);
  mpfr_clear(perturb);
  mpfr_clear(ulp);
  mpfr_clear(min_value);

  deferSignalHandling();
  fflush(NULL);
  parserFlushInput();
  resumeSignalHandling();
  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);
	  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) {
      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);
  gmp_randclear(state);
  return;
}