#include <iostream>
#include <vector>
#include <math.h>
#include "Expression.hpp"
#include "Operator.hpp"
#include "EquationSystem.hpp"

using namespace std;

struct Variable : public Operator<float> {
  Variable(const std::string& x)
    : _value(x) { }
  const float eval(const vector<Expression<float> >& v, const map<string, float>& m) const {
    //assert(v.size() == 0);
    return m.find(_value)->second;
  }
  private:
  std::string _value;
};

struct Const : public Operator<float> {
  Const(const float& x)
    : _value(x) { }
  const float eval(const vector<Expression<float> >& v, const map<string, float>& m) const {
    //assert(v.size() == 0);
    return _value;
  }
  private:
  float _value;
};

struct Plus : public Operator<float> {
  Plus(const float& x)
    : _value(x) { }
  const float eval(const vector<Expression<float> >& v, const map<string, float>& m) const {
    //assert(v.size() == 1);
    return _value + v[0].eval(m);
  }
  private:
  float _value;
};

struct Mult : public Operator<float> {
  Mult(const float& x)
    : _value(x) { }
  const float eval(const vector<Expression<float> >& v, const map<string, float>& m) const {
    //assert(v.size() == 1);
    return _value * v[0].eval(m);
  }
  private:
  float _value;
};

Expression<float> constant(float x) {
  return Expression<float>(new Const(x), vector<Expression<float> >());
}
Expression<float> variable(string x) {
  return Expression<float>(new Variable(x), vector<Expression<float> >());
}
Expression<float> add(float a, Expression<float> b) {
  vector<Expression<float> > args;
  args.push_back(b);
  return Expression<float>(new Plus(a), args);
}
Expression<float> Max(Expression<float> a, Expression<float> b) {
  vector<Expression<float> > args;
  args.push_back(a);
  args.push_back(b);
  return Expression<float>(new Maximum<float>(), args);
}
Expression<float> Min(Expression<float> a, Expression<float> b) {
  vector<Expression<float> > args;
  args.push_back(a);
  args.push_back(b);
  return Expression<float>(new Minimum<float>(), args);
}

int main () {
  typedef Expression<float> E;
  typedef vector<E> Args;
  Args empty;

  EquationSystem<float> test;

  // problem:
  // x = max(y, 10)
  // y = 10 * x

  test.add("x1", Max(constant(0),
                     Min(add(-1, variable("x1")),
                         variable("x2"))));
  test.add("x2", Max(constant(0),
                     Max(add(5, variable("x1")),
                         variable("x1"))));
  test.add("x3", Max(constant(0),
                     Max(add(1, variable("x3")),
                         add(0, variable("x1")))));

  map<string, float> m = test.solveBF(-INFINITY);
  cout << m["x1"] << endl;
  cout << m["x2"] << endl;
  cout << m["x3"] << endl;

  m = test.maxStrategy(m).solveBF(-INFINITY);
  cout << m["x1"] << endl;
  cout << m["x2"] << endl;
  cout << m["x3"] << endl;


  /*Args xArgs;
  xArgs.push_back(E(new Variable("x"), empty));
  xArgs.push_back(E(new Const(10), empty));
  test.add("x", E(new Maximum<float>(), xArgs));

  Args yArgs;
  yArgs.push_back(E(new Variable("x"), empty));
  test.add("y", E(new Mult(10), yArgs));

  map<string, float> m = test.solveBF(-INFINITY);
  cout << m["x"] << endl;
  cout << m["y"] << endl;

  map<string,float> assignment;
  assignment["x"] = -INFINITY;
  assignment["y"] = -INFINITY;
  map<string, float> result = test.maxStrategy(assignment).solveBF(INFINITY);
  cout << result["x"] << endl;
  cout << result["y"] << endl;


  assignment["x"] = 12;
  cout << E(new Maximum<float>(), xArgs).maxStrategyEager(assignment).eval(assignment) << endl;*/
  return 0;
}