#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "buff.h"
#include <ctype.h>

#define FW 0
#define BW 1

line_t *b_start = NULL;
line_t *b_end = NULL;
line_t *cur = NULL;
int num = 0;
int pos = 0;
/* addr1 is the last address, while addr2 is the previous one */
int addr1, addr2;
char *fname, mod=0, lc;
line_t* marks[26] = {NULL};


const char* skip_blank(const char **c){

  while (isblank(**c)) (*c)++;
  return *c;
}


int get_addr(const char **cmd){

  int addr, n, got, d;
  char sign = 1, comma = 0, semic = 0, DIR = FW;
  const char *c;
  line_t *p;
  
  addr1 = addr2 = -1;
  c = *cmd;
  while(*c){
    c = skip_blank(&c);
    n = 0;
    got = 0;
    if (isdigit(*c)){
      while (isdigit(*c)){
        got = 1;
        n = n * 10 + *c - '0', c++;
      }
      if (got){
        addr1 = n;
      }
    }
    else {
      switch(*c){
      case '.': /* cur line*/
        addr1 = pos;
        break;
      case '$': /* last line */
        addr1 = num;
        break;
      case ',': /* range 1 */ /* refactor to set addr2 = addr1 */
        fprintf(stderr, "    >>>> comma: addr1: %d addr2: %d pos: %d\n", addr1, addr2, pos);
        comma = 1;
        if (addr1 == -1){
          (*cmd)++;
          return -1;
        }
        addr2 = addr1;
        addr1 = -1;
        break;
      case ';': /* range 2*/
        semic = 1;
        if (addr1 == -1){
          return -1;
        }
        addr2 = addr1;
        break;
      case '?': DIR = BW;
      case '/': /* match */
        c++;
        addr = match((char**) &c, DIR);
        DIR = FW;
        if (addr == -1){
          return -1;
        }
        addr1 = addr;
        fprintf(stderr, "    match (%d): addr1: %d addr2: %d pos: %d\n", DIR, addr1, addr2, pos);
        break;
      case '\'': /* mark */
        fprintf(stderr, "    >>>> address is a mark!!!\n");
        c++;
        d = *c - 'a';
        if (d < 0 || d > 26){
          E;
          return -1;
        }
        p = marks[*c - 'a'];
        if (!p)
          E;
        else
          addr = get_lineno(p);
        if (addr < 0)
          marks[*c - 'a'] = NULL;
        addr1 = addr;
        break;
      case '-': sign = -1;
      case '+':
        fprintf(stderr, "    >>>> +/-: addr1: %d addr2: %d pos: %d\n", addr1, addr2, pos);
        /* the assignment below breaks stuff like 1++++ */
        if (addr1 < 0)
          addr1 = pos;
        c ++;
        c = skip_blank(&c);
        if (! isdigit(*c)){
          addr1 += sign;
        }
        else{
          n = 0;
          while(isdigit(*c)){
            n = 10 * n + *c - '0', c++;
          }
          addr1 += sign * n;
        }
        c--;
        fprintf(stderr, "    >>>>AT_EXIT  +/-: addr1: %d addr2: %d pos: %d\n", addr1, addr2, pos);
        sign = +1;
        break;
      default:
        goto check;
      }
      c++;
    }
  }

 check:
  *cmd = c;
  
  fprintf(stderr, "  >>> get_addr: addr1: %d addr2: %d\n", addr1, addr2);

  if (addr1 > num || addr2 > num)
    return -2;
  
  if (addr2 == -1){
    if (comma){
      addr1 = num;
      addr2 = 1;
      return 2;
    }
    if (semic){
      addr1 = num;
      addr2 = pos;
      return 2;
    }
    if (addr1 == -1){
      addr1 = addr2 = pos;
      return -1;
    }
    return 1;
  }
  return 2;
}


int get_fname(char **cmd){
  
  static char b[4096];
  int s, n;
  
  n = sscanf(*cmd, "%s", b);
  if (n <1 )
    return 0;
  fprintf(stderr, " >>> read fname: %s\n", b);
  s = strlen(b);
  if (s){
    fname = realloc(fname, (s+1) * sizeof(char));
    memcpy(fname, b, s+1);
    return 1;
  }
  return -1;
}


void main_loop(){
  
  char *cmd, *c;
  int ret, addr, tmp1, tmp2;
  char p, move, app;
  
  cmd = malloc(256 * sizeof(char));
  c = cmd;
  
  while(1){
    p = 0; move = 0, app = 0;
    fgets(cmd, 255, stdin);
    
    ret = get_addr((const char **) &cmd);
    
    fprintf(stderr,">>> *** pos: %d ret: %d ***\n", pos, ret);
    if (ret) {
      fprintf(stderr, ">>>   *** addr1: %d, addr2= %d***\n", addr1, addr2);
    }

    
    switch(cmd[0]){
    case 'a':
      if (addr1 > -1)
        move_to_line(addr1, 0);
      else
        addr1 = pos;
      append_lines();
      break;
    case 'c':
      if (addr1 > -1)
        move_to_line(addr1,0);
      CHECKADDR;
      delete_lines();
      addr1 = addr2 = pos;
      append_lines();
    case 'd':
      if (ret == -1 )
        addr2 = 1, addr1=num;
      CHECKADDR;
      if (addr1 == 0){
        E; break;
      }
      delete_lines();
      break;
    case 'E': mod = 0;
    case 'e':
      if (mod){
        if (lc != 'e'){
          E;
          break;
        }
      }
      cmd++;
      skip_blank((const char**)&cmd);
      if (cmd[0] == '!')
        //read_command();
        ;
      else
        if(get_fname(&cmd) >=0)
          read_file();
        else{
          perror(fname);
          E;
        }
      break;
    case 'f':
      if (ret > 0)
        E;
      else{
        cmd += 1;
        if (get_fname(&cmd)>=0)
          printf("%s\n", fname);
        else{
          perror(fname);
          E;
        }
      }
      break;
    case 'i':
      if (addr1 > -1)
        move_to_line(addr1, 0);
      else
        addr1 = pos;
      CHECKADDR;
      insert_lines();
      break;
    case 'k':
      cmd ++;
      if (addr1==-1)
        addr1 = pos;
      if (mark(cmd))
        E;
      break;
    case 'n': p = 1;
    case 'p':
      if (ret == 2){
        CHECKADDR;
        print_lines(p);
      }
      else  if (ret == 1){
        move_to_line(addr1, 0);
        print_cur_line(p);
      }
      else if (ret == -1){
        addr2=1, addr1=num;
        print_lines(p);
      }
      else
        E;
      break;
    case '\0':
    case '\n':
      fprintf(stderr, ">>>> void command\n");
      if (ret == -1 ){
        if (cur -> next){
          cur = cur -> next, pos += 1;
          print_cur_line(0);
        }
        else
          E;
      }
      else {
        if (addr1 <=num)
          move_to_line(addr1, 1);
        else if (addr2 <=pos)
          print_cur_line(p);
        else
          E;
      }
      break;
    case 'Q': mod = 0;
    case 'q':
      fprintf(stderr, "    >>>> q: mod: %d lc: %c\n", mod, lc);
      if (mod){
        if (lc == 'q')
          goto cleanup;
        else {
          E;
          break;
        }
      }
      goto cleanup;
      break;
    case 'm':  move = 1;
    case 't':
      cmd +=1;
      if (ret <2)
        addr2 = addr1;
      CHECKADDR;
      tmp1=addr1, tmp2=addr2;
      if(get_addr((const char**)&cmd) == 1){
        addr = addr1;
        addr1 = tmp1, addr2 = tmp2;
        transfer_lines(addr, move);
      }
      else
        E;
      move = 0;
      break;
    case 'W': app = 1;
    case 'w':
      cmd += 1;
      get_fname(&cmd);
      if (!fname)
        E;
      else{
        if (write_lines(app)){
          perror(fname);
          E;
        }
      }
      break;
    case '!':
      cmd += 1;
      system(cmd);
      printf("!\n");
      /* exec_command(cmd, stdout); */
      break;
    case '=':
      if (addr1 == -1)
        addr1 = num;
      print_lineno();
      break;
    case 'h': /* not impl. */
    case 'H': /* not impl. */
    case '#':
      break;
    default:
      if (cmd[0])
        fprintf(stderr, ">>> **** unknown command: '%c'****\n", cmd[0]);
      E;
    }
    lc = cmd[0];
    cmd = c;
  }
 cleanup:
  free(c);
  return;
}



int main(int argc, char *argv[]){

  FILE *fin;

  fname = NULL;
  if (argc > 1){
    fname = malloc((strlen(argv[1])+1) * sizeof(char));
    memcpy(fname, argv[1], strlen(argv[1]) + 1);
    if (read_file())
      perror(fname);
  }
  main_loop();
  addr1 = num, addr2 = 1;
  if (num>0) delete_lines();
  free(fname);
}