// -*- c++ -*- //

 #ifndef HUGO_ITER_MAP

 #define HUGO_ITER_MAP

 #include <vector>

 #include <algorithm>

 // for uint8_t

 #include <stdint.h>

 // for memset

 #include <cstring>

 namespace hugo {

   /// \todo Decide whether we need all the range checkings!!!

   template<typename KeyIntMap, uint8_t N>

   class IterableMap {

   public:

     typedef typename KeyIntMap::KeyType KeyType;

     typedef uint8_t ValueType;

     typedef typename std::vector<KeyType>::const_iterator iterator;

   protected:

     KeyIntMap &base;

     std::vector<KeyType> data;

     size_t bounds[N];

     uint8_t find(size_t a) const {

       uint8_t n=0;

       for(; n<N && bounds[n]<=a; ++n);

       return n;

     }

     void half_swap(size_t &a, size_t b) {

       if(a != b) {

 	base.set(data[b],a);

 	data[a] = data[b];

 	a = b;

       }

     }

     size_t move(size_t a, uint8_t m, uint8_t n) {

       if(m != n) {

 	size_t orig_a = a;

 	KeyType orig_key = data[a];

 	while(m > n) {

 	  --m;

 	  half_swap(a, bounds[m]++);

 	}

 	while(m < n) {

 	  half_swap(a, --bounds[m]);

 	  ++m;

 	}

 	if(a != orig_a) {

 	  base.set(orig_key, a);

 	  data[a]=orig_key;

 	}

       }

       return a;

     }

   public:

     IterableMap(KeyIntMap &_base) : base(_base) {

       memset(bounds, 0, sizeof(bounds));

       //    for(int i=0; i<N; ++i) { bounds[i]=0; }

     }

     uint8_t operator[](const KeyType& k) const {

       return find(base[k]);

     }

     void set(const KeyType& k, uint8_t n) {

       size_t a = base[k];

       if(a < bounds[N-1]) {

 	base.set(k, move(a, find(a), n));

       }

     }

     void insert(const KeyType& k, uint8_t n) {

       if(n<N) {

 	data.push_back(k);

 	base.set(k, move(bounds[N-1]++, N-1, n));

       }

     }

     iterator begin(uint8_t n) const {

       if(n < N)

 	return data.begin() + (n ? bounds[n-1] : 0);

       else

 	return data.end();

     }

     iterator end(uint8_t n) const {

       if(n < N)

 	return data.begin() + bounds[n];

       else

 	return data.end();

     }

     size_t size(uint8_t n) const {

       if(n < N)

 	return bounds[n] - (n ? bounds[n-1] : 0);

       else

 	return 0;

     }

     size_t size() const {

       // assert(bounds[N-1] == data.size());

       return bounds[N-1];

     }

   };

 }

 #endif