/***************************************************************************
 * file name   : assembler.c                                               *
 * author      :                                                *
 * description : This program will assemble a .ASM file into a .OBJ file   *
 *               This program will use the "asm_parser" library to achieve *
 *			     its functionality.										   * 
 *                                                                         *
 ***************************************************************************
 *
 */

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

int main(int argc, char **argv) {
  if (argc < 2) {
    printf("Usage: %s <assembly_file.asm>\n", argv[0]);
    return 1;
  }
  char *filename = argv[1];  // name of ASM file
  char program[ROWS][COLS];  // ASM file line-by-line
  char program_bin_str[ROWS][17];  // instructions converted to a binary string
  unsigned short int program_bin[ROWS];  // instructions in binary (HEX)
  int num_lines = read_asm_file(filename, program);
  if (num_lines != 0) {
    return num_lines;  // Return error code from read_asm_file
  }
  int instr_count = 0;
  for (int i = 0; i < ROWS && program[i][0] != '\0'; i++) {
    char *line = program[i];
    char instr_bin_str[17] = {0};
    int ret = parse_instruction(line, instr_bin_str);
    if (ret == 0) {
      strcpy(program_bin_str[instr_count], instr_bin_str);
      unsigned short int bin = str_to_bin(instr_bin_str);
      if (bin == 6) {  // Error code from str_to_bin
        printf("Error on line %d: %s\n", i + 1, line);
        return 6;
      }
      // if program_bin is full, return error
      if (instr_count >= ROWS) {
        printf("Error: Program too large\n");
        return 0;
      }
      program_bin[instr_count] = bin;
      instr_count++;
    } else {
      printf("Error on line %d: %s\n", i + 1, line);
      return ret;
    }
    // ret == 0 means successful parsing
  }
  // Write the object file
  char obj_filename[256];
  strcpy(obj_filename, filename);
  char *dot = strrchr(obj_filename, '.');
  if (dot != NULL) {
    strcpy(dot, ".obj");
  } else {
    strcat(obj_filename, ".obj");
  }
  int ret = write_obj_file(obj_filename, program_bin, instr_count);
  if (ret != 0) {
    return ret;  // Return error code from write_obj_file
  }
  printf("Successfully assembled %s to %s\n", filename, obj_filename);
  return 0;
}