#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "parc.h"

#define BUFSIZE 10

void usage();
void parse(FILE* in, FILE* out);
void scheme(FILE* in, FILE* out);
char* eval(char* expr);

int main(int argv, char** argc) {
  FILE *in, *out;

  if (argv < 3) {
    usage();
    return 0;
  }

  in = fopen(argc[1], "r");
  out = fopen(argc[2], "w");

  parse(in, out);

  fclose(in);
  fclose(out);
  return 0;
}

void usage() {
  printf("2 Args\n");
}

void parse(FILE* in, FILE* out) {
  char tmp;

  while ( (tmp = fgetc(in)) != EOF )
    if (tmp == '$')
      scheme(in, out);
    else
      fputc(tmp, out);
}

void scheme(FILE* in, FILE* out) {
  char *str=NULL,
    tmp,
    buf[BUFSIZE];
  int i=0, si=0;

  while ( (tmp = fgetc(in)) != EOF &&
          tmp != '$') {
    if (i == BUFSIZE) {
      str = realloc(str, (si+i)*sizeof(char));
      strncat(str+si, buf, i);
      si += i;
      i=0;
    }

    buf[i++] = tmp;
  }
  str = realloc(str, si);
  strncat(str+si, buf, i);

  printf("%s", str);
  for (i=0;str[i] != '\0';i++)
    printf("%d ", (int)str[i]);
  printf("\n");

  fputs(eval(str), out);
  free(str);
}

struct margs {
  char** argv;
  int argc;
};

struct margs split(char* expr) {
  struct margs args;
  char *cpy, *tmp;
  int i;
  cpy = malloc(20*sizeof(char));

  strcpy(cpy, expr);
const char delims[] = "( )\t\n\r";

#define ARGV args.argv
#define ARGC args.argc

  ARGV = malloc(BUFSIZE*sizeof(char*));
  ARGC=0;
  while ( (tmp = strtok(cpy, delims)) != NULL ) {
    cpy = NULL;

    ARGV[ARGC++] = tmp;
  }


#undef ARGV
#undef ARGC

  return args;
}

char* eval(char* expr) { /* Need Not Free expr */
  struct margs args = split(expr);
  char* (*func)(int, char**);
  int i;
  char *tmp;

  printf("%s", expr);
  for (i=0;expr[i] != '\0';i++)
    printf("%d ", (int)expr[i]);
  printf("\n");


  tmp = _add(args.argc, args.argv);

  for (i=0;tmp[i] != '\0';i++)
    printf("%d ", (int)tmp[i]);
  printf("\n");

  return tmp;
}

/************ FUNCS FROM HEADER ************/

char* _add(int argc, char** argv) {
  int i, len=0, rlen = 4*argc, slen;
  char* ret = malloc(rlen+sizeof(char));

  for (i=1;i<argc;i++) {
    if (len == 0)
      ret[len++] = '(';

    if (len+ (slen = strlen(argv[i])) >= rlen-2) {
      rlen += (rlen-len)*(argc-i)*4;
      ret = realloc(ret, rlen*sizeof(char));
    }

    strcat(ret+len, argv[i]);
    //free(argv[i]);
    len += slen;
    if (i+1<argc)
      ret[len++] = '+';
  }
  if (len==0) {
    free(ret);
    return NULL;
  }

  ret[len++] = ')';
  ret[len++] = '\0';
  ret = realloc(ret, len*sizeof(char));
  free(argv);
  return ret;
}


char* _sub(int argc, char** argv) {
  int i, len=0, rlen = 4*argc, slen;
  char* ret = malloc(rlen+sizeof(char));

  for (i=1;i<argc;i++) {
    if (len == 0)
      ret[len++] = '(';
if (len+ (slen = strlen(argv[i])) >= rlen-2) {
      rlen += (rlen-len)*(argc-i)*4;
      ret = realloc(ret, rlen*sizeof(char));
    }

    strcat(ret+len, argv[i]);
    len += slen;
    ret[len++] = '-';
  }
  if (len==0) {
    free(ret);
    return NULL;
  }

  ret[len++] = ')';
  ret = realloc(ret, len*sizeof(char));
  return ret;
}


char* _mult(int argc, char** argv) {
  int i, len=0, rlen = 4*argc, slen;
  char* ret = malloc(rlen+sizeof(char));

  for (i=1;i<argc;i++) {
    if (len == 0)
      ret[len++] = '(';

    if (len+ (slen = strlen(argv[i])) >= rlen-2) {
      rlen += (rlen-len)*(argc-i)*4;
      ret = realloc(ret, rlen*sizeof(char));
    }

    strcat(ret+len, argv[i]);
    len += slen;
    ret[len++] = '*';
  }
  if (len==0) {
    free(ret);
    return NULL;
  }
  ret[len++] = ')';
  ret = realloc(ret, len*sizeof(char));
  return ret;
}