#include <stdio.h>

#include "ampl/ampl_c.h"

int main(int argc, char **argv) {
  // Create an AMPL instance
  AMPL *ampl;
  AMPL_CALL(AMPL_Create(&ampl));

  /*
  // If the AMPL installation directory is not in the system search path:
  AMPL_ENVIRONMENT *env;
  AMPL_EnvironmentCreateWithBin(&env, "full path to the AMPL installation directory","");
  AMPL_CALL(AMPL_CreateWithEnv(&ampl, env));
  */

  if (argc > 1) AMPL_CALL(AMPL_SetOption(ampl, "solver", argv[1]));

  // Read the model and data files.
  const char *modelDirectory = argc == 3 ? argv[2] : "../models";
  char mod[256];
  char dat[256];
  sprintf(mod, "%s%s", modelDirectory, "/diet/diet.mod");
  sprintf(dat, "%s%s", modelDirectory, "/diet/diet.dat");

  AMPL_CALL(AMPL_Read(ampl, mod));
  AMPL_CALL(AMPL_ReadData(ampl, dat));

  // Solve
  AMPL_CALL(AMPL_Solve(ampl, "", ""));

  // Get objective entity value by AMPL name
  double value;
  AMPL_CALL(AMPL_GetValueNumeric(ampl, "Total_Cost", &value));
  printf("Objective is: %f\n", value);

  // Reassign data - specific instances
  const char *foods[] = {"BEEF", "HAM"};
  double costs[] = {5.01, 4.55};

  for (size_t i = 0; i < 2; i++) {
    AMPL_TUPLE *tuple;
    AMPL_TupleCreateString(&tuple, 1, &foods[i]);
    AMPL_CALL(AMPL_ParameterInstanceSetNumericValue(ampl, "cost", tuple, costs[i]));
    AMPL_TupleFree(&tuple);
  }
  printf("Increased costs of beef and ham.\n");

  // Resolve and display objective
  AMPL_CALL(AMPL_Solve(ampl, "", ""));
  AMPL_CALL(AMPL_GetValueNumeric(ampl, "Total_Cost", &value));
  printf("New objective is: %f\n", value);

  // Reassign data - all instances
  const double elements[8] = {3, 5, 5, 6, 1, 2, 5.01, 4.55};
  AMPL_CALL(AMPL_ParameterSetArgsDoubleValues(ampl, "cost", 8, elements));
  printf("Updated all costs.\n");

  // Resolve and display objective
  AMPL_CALL(AMPL_Solve(ampl, "", ""));
  AMPL_CALL(AMPL_GetValueNumeric(ampl, "Total_Cost", &value));
  printf("New objective is: %f\n", value);

  // Get the values of the variable Buy in a dataframe object
  AMPL_DATAFRAME *dataframe;
  char *dataframe_string;
  AMPL_CALL(AMPL_EntityGetValues(ampl, "Buy", NULL, 0, &dataframe));
  AMPL_DataFrameToString(dataframe, &dataframe_string);

  // Print them
  printf("%s\n", dataframe_string);
  AMPL_StringFree(&dataframe_string);
  AMPL_DataFrameFree(&dataframe);

  // Get the values of an expression into a DataFrame object
  const char *expr[] = {"{j in FOOD} 100*Buy[j]/Buy[j].ub"};
  AMPL_CALL(AMPL_GetData(ampl, expr, 1, &dataframe));
  AMPL_CALL(AMPL_DataFrameToString(dataframe, &dataframe_string));

  // Print them
  printf("%s\n", dataframe_string);
  AMPL_StringFree(&dataframe_string);
  AMPL_DataFrameFree(&dataframe);

  //AMPL_EnvironmentFree(&env);
  AMPL_Free(&ampl);

  return 0;
}