// file: lecture_18/example.cc
//
// generate a sinewave to a file
//

// include files
//
//#include "example.h"

// main program
//
int main(int argc, char** argv) {

  int joe;

  {
    int mary;
  }

  float* s = {1, 2, 3};
  long i = s[i] + log(x) + j / k;

  char c = 'a';
  long ii = (long)c;

  float* x;
  long joe = (long)(long*)x;
  


  /*
  // check the number of command line arguments
  //
  if (argc < NARGS) {
    fprintf(stdout, "**> insufficient number of arguments (%d)\n", argc);
    return(1);
  }

  // process the command line arguments
  //
  float amplitude = atof(argv[1]);
  float frequency = atof(argv[2]);
  float phase = atof(argv[3]);
  float sample_frequency = atof(argv[4]);
  float duration = atof(argv[5]);
  char* ofname = argv[6];

  // echo the input parameters
  //
  fprintf(stdout, "sample_frequency = %f Hz\n", sample_frequency);

  // not a good way: loop over all samples
  //
  float time_increment = 1.0 / sample_frequency;
  for (float ctime = 0; ctime < duration; ctime += time_increment) {
    float sum = amplitude * sin(2.0 * M_PI * frequency * ctime + phase / 360.0);
  }

  // convert time to samples
  //
  long N = (long)round(duration * sample_frequency);
  fprintf(stdout, "the number of samples is %d\n", N);

  // loop over the number of samples and generate a sinewave
  //
  float sample_period = 1.0 / sample_frequency;
  float sine_const = 2.0 * M_PI * frequency * sample_period;
  for (long i = 0; i < N; i++) {

    // calculate a value
    //
    float sum = amplitude * sin(sine_const * (float)i);
  }

  /*
  // open the file again
  //
  FILE* fp = fopen(argv[1], "r");
  if (fp == (FILE*)NULL) {
    fprintf(stdout, "**> error opening file\n");
    return(-1);
  }

  // process the command line arguments
  //
  float sample_frequency = atof(argv[2]);
  fprintf(stdout, "sample_frequency = %f Hz\n", sample_frequency);

  // get the size by seeking to the end
  //
  fseek(fp, (long)0, SEEK_END);
  long end_pos = ftell(fp);
  long N = end_pos / sizeof(short int);
  rewind(fp);
  fprintf(stdout, "%s: number of samples = %ld\n", argv[1], N);

  // declare a buffer size
  //
  long M = 10;
  short int mybuf[N];

  fprintf(stdout, "<---->\n");
  fprintf(stdout, "... reading back in groups of %d\n", M);

  //  long nbytes_elem = fread(mybuf, sizeof(short int), N * 10, fp);
  //fprintf(stdout, "number of elements read = %d\n", nbytes_elem);

  long i = 0;
  long nelem_read = 0;
  while ((nelem_read = fread(&mybuf[i], sizeof(short int), M, fp)) > 0) {
    if (nelem_read != M) {
      fprintf(stdout, "**> warning: end of file\n");
    }
    fprintf(stdout, "(%d) (%f secs): %f %f %f\n",
	    i, (float)i / sample_frequency,
	    (float)mybuf[i], (float)mybuf[i+1], (float)mybuf[i+2]);
    i += M;
  }

  // close the file
  //
  fclose(fp);
  
  //--------------------------------------------------------------------
  // get the command line arguments
  //
  FILE* fp = fopen(argv[1], "w");
  if (fp == (FILE*)NULL) {
    fprintf(stdout, "error opening file\n");
    return(-1);
  }

  float amplitude = atof(argv[2]);
  fprintf(stdout, "amplitude = %f units\n", amplitude);

  float frequency = atof(argv[3]);
  fprintf(stdout, "frequency = %f Hz\n", frequency);

  float total_time = atof(argv[4]);
  fprintf(stdout, "total time = %f secs\n", total_time);

  float sample_frequency = atof(argv[5]);
  fprintf(stdout, "sample_frequency = %f Hz\n", sample_frequency);

  // not a good way: loop over all samples
  //
  float time_increment = 1.0 / sample_frequency;
  for (float ctime = 0; ctime < total_time; ctime += time_increment) {
    fprintf(stdout, "ctime = %f\n", ctime);
  }

  // convert time to samples
  //
  long N = (long)round(total_time * sample_frequency);
  fprintf(stdout, "the number of samples is %d\n", N);

  // loop over the number of samples and generate a sinewave
  //
  float sample_period = 1.0 / sample_frequency;
  float sine_const = 2.0 * M_PI * frequency * sample_period;
  for (long i = 0; i < N; i++) {

    // calculate a value
    //
    float sum = amplitude * sin(sine_const * (float)i);

    // write this to a file
    //
    short int ival = (short int)round(SCALE * sum);
    //short int ival = round(sum);
    fprintf(stdout, "(%d) (%f secs): %f (%d)\n", i, (float)i / sample_frequency, sum, ival);
    if (fwrite(&ival, sizeof(short int), 1, fp) != 1) {
      fprintf(stdout, "*> error writing data (%d %f %d)\n", i, sum, ival);
    }
  }

  // close the file
  //
  fclose(fp);

  // open the file again
  //
  FILE* fp2 = fopen(argv[1], "r");
  if (fp2 == (FILE*)NULL) {
    fprintf(stdout, "error opening file\n");
    return(-1);
  }

  fprintf(stdout, "<---->\n");
  fprintf(stdout, "... reading back ...\n");
  long i = 0;
  short int jval;

  do while {
  };
  

  while (fread(&jval, sizeof(short int), 1, fp2) == 1) {
    fprintf(stdout, "(%d) (%f secs): %f (%d)\n", i, (float)i / sample_frequency,
	    (float)jval, jval);
    i++;
  }

  // close the file
  //
  fclose(fp2);

  // check the number of arguments
  //
  if (argc < 7) {
    fprintf(stdout, "%s: insuffficient number of arguments (%d)\n",
	    argv[0], argc);
    exit(-1);
  }
  
  */
  // grab the last argument
  //
  char grade = argv[1][0];
  fprintf(stdout, "the input was: %c [%d]\n", grade, grade);

  // convert the input to uppercase
  //
  char tmp_grade = toupper(grade);
  
  // test for its value using if/else if
  //
  fprintf(stdout, "using if/else if:\n");

  if ((tmp_grade == 'A') || (tmp_grade == 'Z')) {
    fprintf(stdout, "%c: Excellent!\n", tmp_grade);
  }
  else if (tmp_grade == 'B') {
    fprintf(stdout, "%c: Well done\n", tmp_grade);
  }
  /*
  else if (tmp_grade == 'C') {
    fprintf(stdout, "%c: Satisfactory\n", tmp_grade);
  }
  else if (tmp_grade == 'D') {
    fprintf(stdout, "%c: You passed\n", tmp_grade);
  }
  else if (tmp_grade == 'F') {
    fprintf(stdout, "%c: Better try again\n", tmp_grade);
  }
  */
  else {
    fprintf(stdout, "%c: Invalid tmp_grade\n", tmp_grade);
  }

  // switch statement
  //
  fprintf(stdout, "using switch:\n");

  switch(tmp_grade) {
  case 'A':
  case 'Z':
    fprintf(stdout, "%c: Excellent!\n", tmp_grade);
    break;
  case 'B':
  case 'C':
    fprintf(stdout, "%c: Well done\n", tmp_grade);
    break;
  case 'D':
    fprintf(stdout, "%c: You passed\n", tmp_grade);
    break;
  case 'F':
    fprintf(stdout, "%c: Better try again\n", tmp_grade);
    break;
  default:
    fprintf(stdout, "%c: Invalid grade\n", tmp_grade);
  }
  
  // try a number
  //
  int tmp_num = atoi(argv[2]);

  switch(tmp_num) {
  case 3:
    fprintf(stdout, "the perfect number...\n");
    break;
  case 27:
    fprintf(stdout, "my favorite number...\n");
    break;
  default:
    fprintf(stdout, "what is wrong with you!...\n");
  }

  // exit gracefully
  //
  return 0;
}