/*
Copyright 2015 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"



// compute flow numerically, no exponentials
//    inputs: flow_equation
//            init, niter, tol (the allowed error at each step), ls (whether to display the results in terms of ls), display_mode (what to print)
int numerical_flow(Grouped_Polynomial flow_equation, RCC init, Labels labels, int niter, long double tol, int display_mode){
  // running coupling contants
  RCC rccs=init;
  int i,j;

  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
    printf("%5d  ",0);
    for(j=0;j<rccs.length;j++){
      printf("% 14.7Le  ",rccs.values[j]);
    }
    printf("\n");
  }

  for(i=0;i<niter;i++){
    // compute a single step
    step_flow(&rccs, flow_equation, tol);
    // convert ls to alphas
    if(display_mode==DISPLAY_NUMERICAL){
      // print the result
      printf("%5d  ",i+1);
      for(j=0;j<rccs.length;j++){
	printf("% 14.7Le  ",rccs.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){
    RCC_print(rccs);
  }

  return(0);
}

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

  init_Int_Array(&computed, (*rccs).length);

  // 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);
      // if the new rcc is too small, then ignore it
      if(fabs(new_rccs[i])<tol){
	new_rccs[i]=0.;
      }
      (*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);
      // if the new rcc is too small, then ignore it
      if(fabs(new_rccs[i])<tol){
	new_rccs[i]=0.;
      }
    }
  }

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

  // free memory
  free_Int_Array(computed);
  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);
}