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



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;


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

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


int get_addr(const char **cmd){

  int addr, n, got;
  char sign = 0, comma = 0, semic = 0;
  const char *c;
  
  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){
        if (addr1 > -1 )
          addr2 = addr1;
        addr1 = n;
      }
    }
    else {
      switch(*c){
      case '.':
        if (addr1 > -1)
          addr2 = addr1;
        addr1 = pos;
        break;
      case '$':
        if (addr1 > -1)
          addr2 = addr1;
        addr1 = num;
        break;
      case ',':
        comma = 1;
        if (addr1 ==-1)
          addr2 = 1, addr1=num;
        else if (addr1 < addr2){
          *cmd = c++;
          return -1; 
        }
        break;
      case ';':
        semic = 1;
        if (addr1 == -1)
          addr2 = pos, addr1=num;
        else if (addr1 < addr2){
          *cmd = c++;
          return -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 (addr1 == -1){
    if (comma){
      addr1 = num;
      addr2 = 1;
      return 2;
    }
    if (semic){
      addr1 = num;
      addr2 = pos;
      return 2;
    }
    addr1 = addr2 = pos;
    return 0;
  }
  if (addr2 == -1){
    if (comma || semic){
      addr2 = addr1;
      return 2;
    }
    addr2 = pos;
    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;
  char p;
  
  cmd = malloc(256 * sizeof(char));
  c = cmd;
  
  while(1){
    p = 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);
      append_lines();
      break;
    case 'c':
      if (addr1 > -1)
        move_to_line(addr1,0);
      delete_lines();
      addr1 = addr2 = pos;
      append_lines();
    case 'd':
      if (ret == -1){
        E;
        break;
      }
      if (ret == 2){
        CHECKADDR;
      }
      if (ret == 1)
        addr2 = addr1;
      delete_lines();
      break;
    case 'e':
      cmd += 1;
      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);
      insert_lines();
      break;
    case 'n': p = 1;
    case 'p':
      if (ret == 2){
        CHECKADDR;
        print_lines(p);
      }
      else  if (ret == 1) 
        move_to_line(addr2, 1);
      else if (ret == 0)
        print_cur_line(p);
      else if (ret == -1){
        addr1 = num;
        addr2 = 1;
        move_to_line(addr2,0);
        print_lines(p);
      }
      else
        E;
      break;
    case '\n':
      if (addr1 > -1 && addr1 <=pos)
        move_to_line(addr1, 1);
      else if (addr2 <=pos)
        print_cur_line(p);
      else
        E;
      break;
    case 'q':
      goto cleanup;
      break;
    case 'w':
      cmd +=1;
      get_fname(&cmd);
      if (!fname)
        E;
      else{
        if (write_lines()){
          perror(fname);
          E;
        }
      }
      break;
    case '=':
      if (addr1 == -1)
        addr1 = num;
      print_lineno();
      break;
    default:
      if (cmd[0])
        fprintf(stderr, ">>> **** unknown command: '%c'****\n", cmd[0]);
      E;
    }
  }
 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())
      fclose(fin);
    else{
      perror(fname);
    }
  }
  main_loop();
  addr1 = pos, addr2 = 1;
  delete_lines();
  free(fname);
}