/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */

/*
 *  Main authors:
 *     Guido Tack <guido.tack@monash.edu>
 */

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef __MINIZINC_HASH_HH__
#define __MINIZINC_HASH_HH__

#include <minizinc/ast.hh>
#include <minizinc/exception.hh>

#include <unordered_map>
#include <unordered_set>

namespace MiniZinc {

/// Hash class for expressions
struct ExpressionHash {
  size_t operator()(const Expression* e) const { return Expression::hash(e); }
};

/// Equality test for expressions
struct ExpressionEq {
  bool operator()(const Expression* e0, const Expression* e1) const {
    return Expression::equal(e0, e1);
  }
};

/// Hash map from expression to \a T
template <class T>
class ExpressionMap {
protected:
  /// The underlying map implementation
  std::unordered_map<Expression*, T, ExpressionHash, ExpressionEq> _m;

public:
  /// Iterator type
  typedef
      typename std::unordered_map<Expression*, T, ExpressionHash, ExpressionEq>::iterator iterator;
  /// Insert mapping from \a e to \a t
  iterator insert(Expression* e, const T& t) {
    assert(e != NULL);
    return _m.insert(std::pair<Expression*, T>(e, t)).first;
  }
  /// Find \a e in map
  iterator find(Expression* e) { return _m.find(e); }
  /// Begin of iterator
  iterator begin(void) { return _m.begin(); }
  /// End of iterator
  iterator end(void) { return _m.end(); }
  /// Remove binding of \a e from map
  void remove(Expression* e) { _m.erase(e); }
  /// Remove all elements from the map
  void clear(void) { _m.clear(); }
};

/// Equality test for identifiers
struct IdEq {
  bool operator()(const Id* e0, const Id* e1) const {
    if (e0->idn() == e1->idn()) {
      if (e0->idn() == -1) return e0->v() == e1->v();
      return true;
    }
    return false;
  }
};

/// Hash map from identifier to \a T
template <class T>
class IdMap {
protected:
  /// The underlying map implementation
  std::unordered_map<Id*, T, ExpressionHash, IdEq> _m;

public:
  /// Iterator type
  typedef typename std::unordered_map<Id*, T, ExpressionHash, IdEq>::iterator iterator;
  /// Insert mapping from \a e to \a t
  void insert(Id* e, const T& t) {
    assert(e != NULL);
    _m.insert(std::pair<Id*, T>(e, t));
  }
  /// Find \a e in map
  iterator find(Id* e) { return _m.find(e); }
  /// Begin of iterator
  iterator begin(void) { return _m.begin(); }
  /// End of iterator
  iterator end(void) { return _m.end(); }
  /// Remove binding of \a e from map
  void remove(Id* e) { _m.erase(e); }
  /// Return number of elements in the map
  int size(void) const { return _m.size(); }
  /// Remove all elements from the map
  void clear(void) { _m.clear(); }
  T& get(Id* ident) {
    iterator it = find(ident);
    //       assert(it != _m.end());
    if (_m.end() == it) {  // Changing so it stays in Release version
      std::string msg = "Id ";
      //         if (ident)                 // could be a segfault...
      //           msg += ident->v().c_str();
      msg += " not found";
      throw InternalError(msg);
    }
    return it->second;
  }
};

/// Hash class for KeepAlive objects
struct KAHash {
  size_t operator()(const KeepAlive& e) const { return Expression::hash(e()); }
};

/// Equality test for KeepAlive objects
struct KAEq {
  bool operator()(const KeepAlive& e0, const KeepAlive& e1) const {
    return Expression::equal(e0(), e1());
  }
};

/// Hash map from KeepAlive to \a T
template <class T>
class KeepAliveMap {
protected:
  /// The underlying map implementation
  std::unordered_map<KeepAlive, T, KAHash, KAEq> _m;

public:
  /// Iterator type
  typedef typename std::unordered_map<KeepAlive, T, KAHash, KAEq>::iterator iterator;
  /// Insert mapping from \a e to \a t
  void insert(KeepAlive& e, const T& t) {
    assert(e() != NULL);
    _m.insert(std::pair<KeepAlive, T>(e, t));
  }
  /// Find \a e in map
  iterator find(KeepAlive& e) { return _m.find(e); }
  /// Begin of iterator
  iterator begin(void) { return _m.begin(); }
  /// End of iterator
  iterator end(void) { return _m.end(); }
  /// Remove binding of \a e from map
  void remove(KeepAlive& e) { _m.erase(e); }
  void clear() { _m.clear(); }
  template <class D>
  void dump(void) {
    for (iterator i = _m.begin(); i != _m.end(); ++i) {
      std::cerr << D::k(i->first()) << ": " << D::d(i->second) << std::endl;
    }
  }
};

class ExpressionSetIter
    : public std::unordered_set<Expression*, ExpressionHash, ExpressionEq>::iterator {
protected:
  bool _empty;
  typedef std::unordered_set<Expression*, ExpressionHash, ExpressionEq>::iterator Iter;

public:
  ExpressionSetIter(void) : _empty(false) {}
  ExpressionSetIter(bool) : _empty(true) {}
  ExpressionSetIter(const Iter& i) : Iter(i), _empty(false) {}
  bool operator==(const ExpressionSetIter& i) const {
    return (_empty && i._empty) || static_cast<const Iter&>(*this) == static_cast<const Iter&>(i);
  }
  bool operator!=(const ExpressionSetIter& i) const { return !operator==(i); }
};

/// Hash set for expressions
class ExpressionSet {
protected:
  /// The underlying set implementation
  std::unordered_set<Expression*, ExpressionHash, ExpressionEq> _s;

public:
  /// Insert \a e
  void insert(Expression* e) {
    assert(e != NULL);
    _s.insert(e);
  }
  /// Find \a e in map
  ExpressionSetIter find(Expression* e) { return _s.find(e); }
  /// Begin of iterator
  ExpressionSetIter begin(void) { return _s.begin(); }
  /// End of iterator
  ExpressionSetIter end(void) { return _s.end(); }
  /// Remove binding of \a e from map
  void remove(Expression* e) { _s.erase(e); }
  bool contains(Expression* e) { return find(e) != end(); }
  /// Remove all elements from the map
  void clear(void) { _s.clear(); }
  bool isEmpty(void) const { return _s.begin() == _s.end(); }
};

}  // namespace MiniZinc

#endif