#include <cstdio>
#include <iostream>

#include "stack.h"

int getOperandos(Stack& pS, int* n1, int* n2) {

	if( pS.isEmpty() )	{
		std::cerr<<"Error: empty stack !!!\n";
		return 0;
	}
	*n2 = pS.pop();

	if( pS.isEmpty() )	{
		pS.push(*n2);
		std::cerr<<"Error: two operands needed !!!\n";
		return 0;
	}
	*n1 = pS.pop();

	return 1;
}

int main(void) {

	// Construct a Stack with LE implementation - factoryMethod
    Stack* pS = Stack::create(Stack::STACK_LE);
	// Construct a Stack with VE implementation - factoryMethod
	// Stack* pS = Stack::create(Stack::STACK_VE);

	while( 1 ) {
		char line[31];
		int i;
		std::cout<<"\ncalc-pol> ";
		std::cin>>line;
		if( sscanf_s(line, " %d", &i, sizeof(i))==1 ) {
			pS->push(i);  // Empilha operando ...
		}
		else              // Verifica se eh operador ... 
		{
			int n1, n2;
			char operador;
			sscanf_s(line, "%c", &operador, sizeof(char));
			switch(operador)
			{
				case '+':
					if ( getOperandos(*pS, &n1, &n2) ) 
						pS->push(n1+n2);
					break;
				case '-':
					if ( getOperandos(*pS, &n1, &n2) ) 
						pS->push(n1-n2);
					break;
				case '/':
					if ( getOperandos(*pS, &n1, &n2) )
					{
						if( n2 != 0 ) {
							pS->push(n1/n2);
						}
						else {
							std::cout<<"Error: colud not divide by zero !!!\n";
                            pS->push(n1);
                            pS->push(n2);
						}
					}
					break;
				case '*':
					if (getOperandos(*pS, &n1, &n2)) pS->push(n1*n2);
					break;
				case 'q':
					exit(0);
				default:
					std::cout<<"Error: Invalid operand or operator op=[ "<<operador<<" ] !!!\n";
			}
		}

		// Imprime a pilha 
        std::cout<<"\nPrinting Stack-1 -----------------------------\n";
        StackIterator *it1 = pS->iterator();
		while( ! it1->fim() ) {
          std::cout<<" pilha: "<<it1->prox();
		}
        std::cout<<"\n";

        std::cout<<"\nPrinting Stack-2 -----------------------------\n";
        StackIterator *it2 = pS->iterator();
        it2->percorre();
        std::cout<<"\n";

	} // Fim while( 1 )
}