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

OperandType format_operand (OperandType operand, Label_Node *head, int pass, int line)
{
   AddressingType addtype;
   int hash, split;
   int i;
   char tmp[80], unformat[80];
   char lastchar, firstchar;
   int length;

   /* make a copy of the original operand */
   strcpy (tmp, operand.orig);
   strcpy (unformat, operand.orig);
   length = strlen(tmp);
   
   for (i=0; i<strlen(tmp); i++)
     tmp[i] = toupper(tmp[i]);
   
   firstchar = tmp[0];
   lastchar = tmp[strlen(operand.orig)-1];
   
   /* If it starts with a hash, assume immediate addressing */
   if (firstchar == '#')
     hash = 1;
   else
     hash = 0;
   
   /* If the label starts with '<' or '>' */
   if (tmp[1] == '<' || firstchar == '<' ||
       tmp[1] == '>' || firstchar == '>')
     split = 1;
   else
     split = 0;
   
   
   /* Assume a label */
   addtype = LAB;
   
   /* If it only contains (a-z A-Z 0-9) assume it's a label */
   /* Unless it's a single 'A' then it's Accumulator addressing */
   /* If the operand only consists of a decimal number it will be */
   /* assumed to be a label. get_value will handle this anyway */
   if (strcmp(tmp, "A") == 0)
     addtype = ACC;
   else if (tmp[hash] != '$' && tmp[hash] != '%')
     {
	for (i=(hash + split); i < strlen (tmp); i++)
	  {
	     if (!isalnum(tmp[i]))
	       {
		  addtype = IMM;
		  i = strlen(tmp);  
	       }
	  }
     }
   else
     addtype = IMM;
     
   
   
   /* If it's a label, handle addressing modes and '<', '>' */
   if (addtype == LAB)
     {
	operand.value = get_value (&operand, &unformat[hash], head, pass, line) & 0xffff;
       	if (hash == 1)
	  {
	     addtype = IMM;
	  }
	else
	  {
	     if (operand.value < 256)
	       addtype = ZP;
	     else
	       addtype = ABS;
	  }
     }
   else if (addtype != ACC)
     /* It's not a label. What is it? */
     {
	/*
	 printf ("%s\n", tmp);
	*/
	
	if (firstchar == '(' && strcmp(&tmp[length-3], "),Y") == 0)
	  addtype = INDY;
	else if (firstchar == '(' && strcmp(&tmp[length-3], ",X)") == 0)
	  addtype = INDX;
	else if (firstchar == '(' && lastchar == ')')
	  addtype = IND;
	else if (firstchar == '#')
	  addtype = IMM;
	else if (strcmp(&tmp[length-2], ",Y") == 0)
	  {
	     tmp[strlen(tmp)-2] = '\0';
	     operand.value = get_value(&operand, unformat, head, pass, line) & 0xffff;
	     if (operand.value < 256)
	       addtype = ZPY;
	     else
	       addtype = ABSY;
	  }
	else if (strcmp(&tmp[length-2], ",X") == 0)
	  {
	     tmp[strlen(tmp)-2] = '\0';
	     operand.value = get_value(&operand, unformat, head, pass, line) & 0xffff;
	     if (operand.value < 256)
	       addtype = ZPX;
	     else
	       addtype = ABSX;
	  }
	else
	  {
	     operand.value = get_value(&operand, unformat, head, pass, line) & 0xffff;
	     if (operand.value < 256)
	       addtype = ZP;
	     else
	       addtype = ABS;
	  }
     }
   
   /* Okay, we know what type it is now. Fill in the blanks */
   operand.addtype = addtype;
   switch (addtype)
     {
      case IMM:
	operand.value = get_value(&operand, &unformat[1], head, pass, line) & 0xff;	
	sprintf (operand.formatted, "#$%.2lX", operand.value);
	strcpy (operand.addtype_text, "Immediate");
	break;
	
      case ABS:
	sprintf (operand.formatted, "$%.4lX", operand.value);
	strcpy (operand.addtype_text, "Absolute");
	break;
	
      case ZP:
	sprintf (operand.formatted, "$%.2lX", operand.value);
	strcpy (operand.addtype_text, "Zero Page");
	break;
	
      case INDX:
	unformat[strlen(tmp)-3] = '\0';
	operand.value = get_value(&operand, &unformat[1], head, pass, line) & 0xff;
	sprintf (operand.formatted, "($%.2lX,X)", operand.value);
	strcpy (operand.addtype_text, "(Indirect,X)");
	break;
	
      case INDY:
	unformat[strlen(tmp)-3] = '\0';
	operand.value = get_value(&operand, &unformat[1], head, pass, line) & 0xff;
	sprintf (operand.formatted, "($%.2lX),Y", operand.value);
	strcpy (operand.addtype_text, "(Indirect),Y");
	break;
	
      case ZPX:
	sprintf (operand.formatted, "$%.2lX,X", operand.value);
	strcpy (operand.addtype_text, "Zero Page,X");
	break;

      case ZPY:
	sprintf (operand.formatted, "$%.2lX,Y", operand.value);
	strcpy (operand.addtype_text, "Zero Page,Y");
	break;

      case ABSX:
      	sprintf (operand.formatted, "$%.4lX,X", operand.value);
	strcpy (operand.addtype_text, "Absolute,X");
	break;
	
      case ABSY:
	sprintf (operand.formatted, "$%.4lX,Y", operand.value);
	strcpy (operand.addtype_text, "Absolute,Y");
	break;
	
      case IND:
	unformat[strlen(tmp)-1] = '\0';
	operand.value = get_value(&operand, &unformat[1], head, pass, line) & 0xffff;
	sprintf (operand.formatted, "($%.4lX)", operand.value);
	strcpy (operand.addtype_text, "(Indirect)");
	break;
	
      case ACC:
	sprintf (operand.formatted, "A");
	operand.value = 0;
	strcpy (operand.addtype_text, "Accumulator");
	break;
	
      case LAB:
	break;
	
      case REL:
	break;
	
      case IMP:
	break;
     }  
   return operand;
}

int get_value (OperandType *operand, char string[30], Label_Node *head, int pass, int line)
{
   enum optype {TEXT, DECIMAL, HEX, BINARY, CHAR, CALC};
   typedef enum optype OperativeType;
   OperativeType opertype;
   int i, split;
   long value;
   char part1[30], part2[30];
   char op;
   
   for (i=0; i<=30; i++)
     part1[i] = part2[i] = '\0';
   
  
   /* Funky recursive bit */
   for (i=0; i<strlen(string); i++)
     {
	if (string[i] != '+' && string[i] != '-')
	  part1[i]=string[i];
	else
	  {
	     op = string[i];
	     strcpy(part2, &string[i+1]);
	     
	     /*
	      printf ("Calc: '%s' (%c) '%s'\n", part1, op, part2);
	      */
	     
	     i=strlen(string);
	     
	     switch (op)
	       {
		case '+':
		  return get_value(operand, part1, head, pass, line) + get_value(operand, part2, head, pass, line);
		  break;
		case '-':
		  return get_value(operand, part1, head, pass, line) - get_value(operand, part2, head, pass, line);
		  break;
	       }
	  }
     }

   if (string[0] == '<' || string[0] == '>')
     split = 1;
   else
     split = 0;
       
   /* If any characters are not 'A-Z' then it's not a label */
   opertype = DECIMAL;
     
   if (string[0] == '$')
     opertype = HEX;   
   else if (string[0] == '%')
     opertype = BINARY;
   else if (string[0] == '\'' && string[2] == '\'')
     opertype = CHAR;
   else
     {
	for (i = split; i < strlen(string); i++)
	  {
	     if (!isdigit(string[i]))
	       opertype = TEXT;
	  }
     }
   
   strcpy (operand->label, "");
   
   switch (opertype)
     {
      case DECIMAL:
	value = strtol (&string[0], NULL, 10);
      	break;
      case BINARY:
	value = strtol(&string[1], NULL, 2);
	break;
      case HEX:
	value = strtol(&string[1], NULL, 16);
	break;
      case CHAR:
	value = (unsigned char) string[1];
	break;
      case TEXT:
	for (i=0; i<strlen(string); i++)
	  string[i] = toupper(string[i]);
	strcpy(operand->label, string);
      	value = find_label_element(head, &string[split]);
	if (value == 0x666666 && pass == 2)
	  {
	     fprintf (stderr, "Unknown label %s in line %d\n", &string[split], line);
	     exit(EXIT_FAILURE);
	  }
	if (string[0] == '<')
	  value = value & 0x00ff;
	else if (string[0] == '>')
	  value = (value & 0xff00) >> 8;
	break;
      default:
	value = 0x6666;
     }
   return value;
}