/*
Copyright 2015-2022 Ian Jauslin

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

#include "flow.h"

#include <stdio.h>
#include <stdlib.h>
#include "tools.h"
#include "math.h"
#include "definitions.cpp"
#include "number.h"
#include "array.h"
#include "coefficient.h"
#include "rcc.h"
#include "grouped_polynomial.h"


// compute flow numerically, no exponentials
int numerical_flow(Grouped_Polynomial flow_equation, RCC init, Grouped_Polynomial postprocess_flow_equation, Labels labels, int niter, int display_mode){
  // running coupling contants
  RCC rccs=init;
  // for printing
  RCC rcc_print;
  int i,j;

  // init printing rcc
  init_RCC(&rcc_print, rccs.length);

  if(display_mode==DISPLAY_NUMERICAL){
    // print labels
    printf("%5s  ","n");
    for(j=0;j<rccs.length;j++){
      print_label(rccs.indices[j], labels);
    }
    printf("\n\n");

    // print initial values
    RCC_cpy_noinit(rccs,&rcc_print);
    if(postprocess_flow_equation.length>0){
      // ignore constants
      for(j=0;j<rcc_print.length;j++){
	if(rcc_print.indices[j]<0){
	  rcc_print.values[j]=1.;
	}
      }
      evaleq(rcc_print, rcc_print, postprocess_flow_equation);
    }
    printf("%5d  ",0);
    for(j=0;j<rcc_print.length;j++){
      // use constants from rcc
      if(rcc_print.indices[j]<0){
	printf("% 14.7Le  ",rccs.values[j]);
      }
      else{
	printf("% 14.7Le  ",rcc_print.values[j]);
      }
    }
    printf("\n");
  }

  for(i=0;i<niter;i++){
    // compute a single step
    step_flow(&rccs, flow_equation);

    // print
    if(postprocess_flow_equation.length>0){
      RCC_cpy_noinit(rccs,&rcc_print);
      // ignore constants
      for(j=0;j<rcc_print.length;j++){
	if(rcc_print.indices[j]<0){
	  rcc_print.values[j]=1.;
	}
      }
      evaleq(rcc_print, rcc_print, postprocess_flow_equation);
    }
    else{
      RCC_cpy_noinit(rccs,&rcc_print);
    }
    if(display_mode==DISPLAY_NUMERICAL){
      // print the result
      printf("%5d  ",i+1);
      for(j=0;j<rcc_print.length;j++){
	// use constants from rcc
	if(rcc_print.indices[j]<0){
	  printf("% 14.7Le  ",rccs.values[j]);
	}
	else{
	  printf("% 14.7Le  ",rcc_print.values[j]);
	}
      }
      printf("\n");
    }
  }

  if(display_mode==DISPLAY_NUMERICAL){
    // print labels
    printf("\n");
    printf("%5s  ","n");
    for(j=0;j<rccs.length;j++){
      print_label(rccs.indices[j], labels);
    }
    printf("\n\n");
  }

  if(display_mode==DISPLAY_FINAL){
    if(postprocess_flow_equation.length>0){
      RCC_cpy_noinit(rccs,&rcc_print);
      // ignore constants
      for(j=0;j<rcc_print.length;j++){
	if(rcc_print.indices[j]<0){
	  rcc_print.values[j]=1.;
	}
      }
      evaleq(rcc_print, rcc_print, postprocess_flow_equation);
    }
    else{
      RCC_cpy_noinit(rccs,&rcc_print);
    }
    RCC_print(rcc_print);
  }

  free_RCC(rcc_print);

  return(0);
}

// single step in the flow no exponentials
int step_flow(RCC* rccs, Grouped_Polynomial flow_equation){
  int i;
  long double* new_rccs=calloc((*rccs).length,sizeof(long double));

  // initialize vectors to 0
  for(i=0;i<(*rccs).length;i++){
    new_rccs[i]=0.;
  }

  // compute the constants first
  for(i=0;i<flow_equation.length;i++){
    if(flow_equation.indices[i]<0){
      evalcoef(*rccs, flow_equation.coefs[i], new_rccs+i);
      (*rccs).values[i]=new_rccs[i];
    }
  }

  // for each equation
  for(i=0;i<flow_equation.length;i++){
    if(flow_equation.indices[i]>=0){
      evalcoef(*rccs, flow_equation.coefs[i], new_rccs+i);
    }
  }

  // copy results to rccs
  for(i=0;i<(*rccs).length;i++){
    (*rccs).values[i]=new_rccs[i];
  }

  // free memory
  free(new_rccs);
  return(0);
}


// print the label of an rcc (takes constants and derivatives into account)
int print_label(int index, Labels labels){
  int i;
  int nderivs;
  int posin_labels;
  Char_Array label;

  // constant term
  if(index<0){
    nderivs=-index/DOFFSET;
    for (i=0;i<12-nderivs;i++){
      printf(" ");
    }
    for(i=0;i<nderivs;i++){
      printf("d");
    }
    printf("C%d  ",-index-nderivs*DOFFSET);
  }
  else{
    nderivs=index/DOFFSET;
    posin_labels=intlist_find_err(labels.indices, labels.length, index-nderivs*DOFFSET);
    label=labels.labels[posin_labels];
    for (i=0;i<14-label.length-nderivs;i++){
      printf(" ");
    }
    for(i=0;i<nderivs;i++){
      printf("d");
    }
    printf("%s  ",char_array_to_str_noinit(labels.labels+posin_labels));
  }

  return(0);
}