// -*- 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