#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;
unsigned int num = 0;
unsigned int pos = 0;
/* addr1 is the lasr address, while addr2 is the previous one */
int addr1, addr2;



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;
  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 < addr2){
          *cmd = c;
          return -1; 
        }
        break;
      default:
        goto check;
      }
      c++;
    }
  }
 check:
  *cmd = c;

  if (addr1 == -1){
    if (comma){
      addr1 = num;
      addr2 = 1;
      return 2;
    }
    addr1 = addr2 = pos;
    return 0;
  }
  if (addr2 == -1){
    addr2 = pos;
    return 1;
  }
  return 2;
}


void main_loop(){
  
  char *cmd;
  int ret;
  char p;
  
  cmd = malloc(256 * sizeof(char));
  
  while(1){
    p = 0;
    fgets(cmd, 255, stdin);
    
    ret = get_addr((const char **) &cmd);
    
    printf(">>> *** pos: %d address: %d ***\n", pos, ret);
    if (ret) {
      printf(">>>   *** addr1: %d, addr2= %d***\n", addr1, addr2);
    }

    switch(cmd[0]){
    case 'i':
      if (addr1 > -1)
        move_to_line(addr1, 0);
      insert_lines();
      break;
    case 'a':
      if (addr1 > -1)
        move_to_line(addr1, 0);
      append_lines();
      break;
    case 'd':
      delete_lines();
      break;
    case 'n': p = 1;
    case 'p':
      if (ret == 2)
        if (addr1 < addr2){
          printf("?\n");
          break;
        }
        else
          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);
      }
      break;
    case '\n':
      if (addr1 > -1)
        move_to_line(addr1, 1);
      else
        print_cur_line(p);
      break;
    case 'q':
      exit(0);
      break;
    case '=':
      if (addr1 == -1)
        addr1 = num;
      print_lineno();
      break;
    default:
      printf(">>> **** unknown command: '%c'****\n", cmd[0])
      ;
    }
  }
}



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

  FILE *fin;
  
  if (argc < 2){
    printf("Usage: %s <filein>\n", argv[0]);
    exit(1);
  }
  
  if ((fin = fopen(argv[1], "r+"))){
    read_lines(fin);
  }
  else{
    printf("Error opening file %s\n", argv[1]);
  }
  
  main_loop();
}