#include "Command.h"

void FindOrderCommand::findZeros() {
  for ( list< list<Node> >::const_iterator ptr = graph.getAdjList().begin();
        ptr != graph.getAdjList().end();
        ++ptr ) {
    list<Node>::const_iterator thisClass = ptr->begin();
    if (0 == indegrees[thisClass->getName()]) {
      Node node = *thisClass;
      zeros.push(node);
    }
  }// for
}// findZeros

void FindOrderCommand::execute() {
  findZeros();

  while (!zeros.empty()) {
    order.push(zeros.front());
    list< list<Node> >::const_iterator ptr = graph.getAdjList().begin();
    while (ptr->front().getName() != zeros.front().getName())  { ++ptr; }
    list<Node>::const_iterator zeroClass = ptr->begin();
    if (ptr->size() > 1) {
      ++zeroClass;
      while (zeroClass != ptr->end()) {
        list< list<Node> >::iterator ptr2 = graph.getAdjList().begin();
        while (ptr2->front().getName() != zeroClass->getName())  { ++ptr2; }
        indegrees[ptr2->front().getName()] -= 1;
        if (indegrees[ptr2->front().getName()] == 0) {
          Node node = ptr2->front();
          zeros.push(node);
        }// if
        ++zeroClass;
      }// while
    }// if
    zeros.pop();
  }// while
}// findOrder

stack<Node> FindOrderCommand::getOrder() {
  return order;
}// getOrder