// -*- C++ -*- //

#ifndef HUGO_MAPS_H

#define HUGO_MAPS_H

///\file

///\brief Miscellaneous property maps

///

///\todo This file has the same name as the concept file in skeletons,

/// and this is not easily detectable in docs...

#include <map>

namespace hugo {

  /// Null map. (aka DoNothingMap)

  /// If you have to provide a map only for its type definitions,

  /// or if you have to provide a writable map, but will not use the

  /// data written to it...

  template<typename K, typename T>

  class NullMap

  {

  public:

    typedef K KeyType;

    typedef T ValueType;

    T operator[](const K&) const { return T(); }

    void set(const K&, const T&) {}

  };

  /// Constant map.

  /// This is a readable map which assignes a specified value to each key.

  /// In other aspects it is equivalent to the \ref NullMap

  template<typename K, typename T>

  class ConstMap

  {

    T v;

  public:

    typedef K KeyType;

    typedef T ValueType;

    ConstMap() {}

    ConstMap(const T &_v) : v(_v) {}

    T operator[](const K&) const { return v; }

    void set(const K&, const T&) {}

    template<typename T1>

    struct rebind {

      typedef ConstMap<K,T1> other;

    };

    template<typename T1>

    ConstMap(const ConstMap<K,T1> &, const T &_v) : v(_v) {}

  };

  /// \c std::map wrapper

  /// This is essentially a wrapper for \c std::map. With addition that

  /// you can specify a default value different from \c ValueType() .

  ///

  /// \todo Provide allocator parameter...

  template <typename Key, typename T, typename Compare = std::less<Key> >

  class StdMap : public std::map<Key,T,Compare> {

    typedef std::map<Key,T,Compare> parent;

    T v;

    typedef typename parent::value_type PairType;

  public:

    typedef Key KeyType;

    typedef T ValueType;

    typedef T& ReferenceType;

    typedef const T& ConstReferenceType;

    StdMap() : v() {}

    /// Constructor with specified default value

    StdMap(const T& _v) : v(_v) {}

    /// \brief Constructs the map from an appropriate std::map.

    ///

    /// \warning Inefficient: copies the content of \c m !

    StdMap(const parent &m) : parent(m) {}

    /// \brief Constructs the map from an appropriate std::map, and explicitly

    /// specifies a default value.

    ///

    /// \warning Inefficient: copies the content of \c m !

    StdMap(const parent &m, const T& _v) : parent(m), v(_v) {}

    template<typename T1, typename Comp1>

    StdMap(const StdMap<Key,T1,Comp1> &m, const T &_v) { FIXME; }

    ReferenceType operator[](const Key &k) {

      return insert(PairType(k,v)).first -> second;

    }

    ConstReferenceType operator[](const Key &k) const {

      typename parent::iterator i = lower_bound(__k);

      if (i == end() || key_comp()(k, (*i).first))

	return v;

      return (*i).second;

    }

    void set(const Key &k, const T &t) {

      parent::operator[](k) = t;

    }

    /// Changes the default value of the map.

    /// \return Returns the previous default value.

    ///

    /// \warning The value of some keys (which has alredy been queried, but

    /// the value has been unchanged from the default) may change!

    T setDefault(const T &_v) { T old=v; v=_v; return old; }

    template<typename T1>

    struct rebind {

      typedef StdMap<Key,T1,Compare> other;

    };

  };

}

#endif // HUGO_MAPS_H