/*
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.
*/

/*
meankondo

A simple tool to compute the renormalization group flow for Fermionic hierarchical models

*/


#include <stdio.h>
#include <stdlib.h>

// pre-compiler definitions
#include "definitions.cpp"

// various arrays
#include "array.h"

// list of fields
#include "fields.h"
// numbers
#include "number.h"
// polynomials
#include "polynomial.h"
// list of rccs
#include "idtable.h"
// grouped representation of polynomials
#include "grouped_polynomial.h"
// command line parser
#include "cli_parser.h"
// parse input file
#include "parse_file.h"
// means
#include "mean.h"
// various string operations
#include "istring.h"

// read cli arguments
int read_args_meankondo(int argc,const char* argv[], Str_Array* str_args, Meankondo_Options* opts);
// print usage message
int print_usage_meankondo();
// compute flow
int compute_flow(Str_Array str_args, Meankondo_Options opts);
// compute the flow equation
int compute_flow_equation(Polynomial init_poly, Id_Table idtable, Fields_Table fields, Polynomial_Matrix propagator, Groups groups, int threads, Grouped_Polynomial* flow_equation);


int main (int argc, const char* argv[]){
  // string arguments
  Str_Array str_args;
  // options
  Meankondo_Options opts;

  // read command-line arguments
  read_args_meankondo(argc,argv,&str_args,&opts);

  // warning message if representing rational numbers as floats
#ifdef RATIONAL_AS_FLOAT
  fprintf(stderr,"info: representing rational numbers using floats\n");
#endif

  compute_flow(str_args, opts);

  //free memory
  free_Str_Array(str_args);
  return(0);
}


// parse command-line arguments
#define CP_FLAG_THREADS 1
int read_args_meankondo(int argc,const char* argv[], Str_Array* str_args, Meankondo_Options* opts){
  int i;
  // pointers
  char* ptr;
  // file to read the polynomial from in flow mode
  const char* file="";
  // flag that indicates what argument is being read
  int flag=0;
  // whether a file was specified on the command-line
  int exists_file=0;


  // defaults
  // single thread
  (*opts).threads=1;
  // do not chain
  (*opts).chain=0;

  // loop over arguments
  for(i=1;i<argc;i++){
    // flag
    if(argv[i][0]=='-'){
      for(ptr=((char*)argv[i])+1;*ptr!='\0';ptr++){
	switch(*ptr){
	// threads
	case 't':
	  flag=CP_FLAG_THREADS;
	  break;
	// chain
	case 'C':
	  (*opts).chain=1;
	  break;
	// print version
	case 'v':
	  printf("meankondo " VERSION "\n");
	  exit(1);
	  break;
	default:
	  print_usage_meankondo();
	  exit(-1);
	  break;
	}
      }
    }
    // threads
    else if(flag==CP_FLAG_THREADS){
      sscanf(argv[i],"%d",&((*opts).threads));
      flag=0;
    }
    // read file name from command-line
    else{
      file=argv[i];
      exists_file=1;
    }
  }

  read_config_file(str_args, file, 1-exists_file);

  return(0);
}

// print usage message
int print_usage_meankondo(){
  printf("\nusage:\n   meankondo [-t threads] [-C] <filename>\n\n");
  return(0);
}


// compute the renormalization group flow
int compute_flow(Str_Array str_args, Meankondo_Options opts){
  int i;
  // index of the entry in the input file
  int arg_index;
  // header of the entry
  Char_Array arg_header;
  // list of fields
  Fields_Table fields;
  // their propagator
  Polynomial_Matrix propagator;
  // initial polynomial
  Polynomial init_poly;
  // list of rccs
  Id_Table idtable;
  // groups of independent fields
  Groups groups;
  // flow equation
  Grouped_Polynomial flow_equation;


  // parse fields
  arg_index=find_str_arg("fields", str_args);
  if(arg_index<0){
    fprintf(stderr,"error: no fields entry in the configuration file\n");
    exit(-1);
  }
  else{
    parse_input_fields(str_args.strs[arg_index],&fields);
  }

  // parse id table
  arg_index=find_str_arg("id_table", str_args);
  if(arg_index<0){
    fprintf(stderr,"error: no id table entry in the configuration file\n");
    exit(-1);
  }
  else{
    parse_input_id_table(str_args.strs[arg_index],&idtable, fields);
  }

  // parse symbols
  arg_index=find_str_arg("symbols", str_args);
  if(arg_index>=0){
    parse_input_symbols(str_args.strs[arg_index],&fields);
  }
  else{
    init_Symbols(&(fields.symbols),1);
  }

  // parse input polynomial
  arg_index=find_str_arg("input_polynomial", str_args);
  if(arg_index>=0){
    parse_input_polynomial(str_args.strs[arg_index],&init_poly, fields);
  }
  else{
    fprintf(stderr,"error: no input polynomial entry in the configuration file\n");
    exit(-1);
  }

  // propagator
  arg_index=find_str_arg("propagator", str_args);
  if(arg_index<0){
    fprintf(stderr,"error: no propagator entry in the configuration file\n");
    exit(-1);
  }
  else{
    parse_input_propagator(str_args.strs[arg_index],&propagator, fields);
  }

  // parse identities
  arg_index=find_str_arg("identities", str_args);
  if(arg_index>=0){
    parse_input_identities(str_args.strs[arg_index],&fields);
  }
  else{
    init_Identities(&(fields.ids),1);
  }

  // parse groups
  arg_index=find_str_arg("groups", str_args);
  if(arg_index>=0){
    parse_input_groups(str_args.strs[arg_index],&groups);
  }
  else{
    init_Groups(&groups, 1);
  }

  // flow equation
  compute_flow_equation(init_poly, idtable, fields, propagator, groups, opts.threads, &flow_equation);
  free_Polynomial(init_poly);
  free_Polynomial_Matrix(propagator);
  free_Fields_Table(fields);
  free_Groups(groups);

  // if chain then print config file
  if(opts.chain==1){
    for(i=0;i<str_args.length;i++){
      // check whether to print the str_arg
      get_str_arg_title(str_args.strs[i], &arg_header);
      if (\
	str_cmp(arg_header.str, "symbols")==0 &&\
	str_cmp(arg_header.str, "groups")==0 &&\
	str_cmp(arg_header.str, "fields")==0 &&\
	str_cmp(arg_header.str, "identities")==0 &&\
	str_cmp(arg_header.str, "propagator")==0 &&\
	str_cmp(arg_header.str, "input_polynomial")==0 &&\
	str_cmp(arg_header.str, "id_table")==0 ){
	  printf("%s\n&\n",str_args.strs[i].str);
      }
      free_Char_Array(arg_header);
    }
    // print flow equation
    printf("#!flow_equation\n");
  }

  // print flow equation
  grouped_polynomial_print(flow_equation,'%','%');

  // free memory
  free_Id_Table(idtable);
  free_Grouped_Polynomial(flow_equation);
  return(0);
}


// compute the flow equation
int compute_flow_equation(Polynomial init_poly, Id_Table idtable, Fields_Table fields, Polynomial_Matrix propagator, Groups groups, int threads, Grouped_Polynomial* flow_equation){
  // expectation
  Polynomial exp_poly;

  polynomial_cpy(init_poly,&exp_poly);

  // average
  if(threads>1){
    polynomial_mean_multithread(&exp_poly, fields, propagator, groups, threads);
  }
  else{
    polynomial_mean(&exp_poly, fields, propagator, groups);
  }
    
  // grouped representation of expanded_poly
  group_polynomial(exp_poly,flow_equation,idtable, fields);
  free_Polynomial(exp_poly);

  return(0);
}