/*******************************************************************************
 *
 * TRIQS: a Toolbox for Research in Interacting Quantum Systems
 *
 * Copyright (C) 2011-2014 by O. Parcollet
 *
 * TRIQS is free software: you can redistribute it and/or modify it under the
 * terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 *
 * TRIQS is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * TRIQS. If not, see <http://www.gnu.org/licenses/>.
 *
 ******************************************************************************/
#pragma once
#include "../common.hpp"
#include "../range.hpp"
#include "./mem_layout.hpp"
#include "../permutation.hpp"
#include <triqs/utility/mini_vector.hpp>
#include "../../impl/exceptions.hpp"
#include <iostream>
#include <sstream>

namespace triqs {
namespace arrays {
 namespace indexmaps {
  namespace cuboid {
   using namespace triqs::arrays::permutations;

   /// Standard hyper_rectangular domain for arrays
   template <int Rank> class domain_t {
    using n_uple = mini_vector<size_t, Rank>;
    n_uple lengths_;
    friend class boost::serialization::access;
    template <class Archive> void serialize(Archive &ar, const unsigned int version) {
     ar &TRIQS_MAKE_NVP("dimensions", lengths_);
    }

    public:
    static constexpr unsigned int rank = Rank;
    using index_value_type = n_uple;

    domain_t() = default;
    domain_t(const domain_t &C) = default;
    domain_t(domain_t &&C) = default;
    domain_t &operator=(domain_t const &) = default;
    domain_t &operator=(domain_t &&x) = default;

    domain_t(n_uple lengths) : lengths_(std::move(lengths)) {}
    domain_t(mini_vector<int, Rank> const &lengths) : lengths_(lengths) {}
    domain_t(std::vector<std::size_t> const &l) : lengths_() {
     if (!(l.size() == Rank))
      TRIQS_RUNTIME_ERROR << "cuboid domain_t construction : vector size incorrect : got " << l.size() << " while expected "
                          << Rank;
     lengths_ = n_uple(l);
    }
    template <typename... T> domain_t(size_t i0, T... t) : lengths_(i0, t...) {}

    size_t number_of_elements() const { return lengths_.product_of_elements(); }
    bool operator==(domain_t const &X) const { return this->lengths_ == X.lengths_; }
    bool operator!=(domain_t const &X) const { return !(*this == X); }
    n_uple const &lengths() const &{ return lengths_; }
    n_uple lengths() && { return lengths_; }
    /** Generates the value of the indices of a cuboid_domain.  */
    static constexpr ull_t iteration_order_default = permutations::identity(Rank);
    template <ull_t IterationOrder = iteration_order_default> class gal_generator {
     using indices_type = index_value_type;
     const domain_t *dom;
     indices_type indices_tuple;
     bool atend;

     public:
     gal_generator(const domain_t &P, bool atEnd = false) : dom(&P), atend(atEnd) {}
     bool operator==(const gal_generator &IT2) const {
      assert((IT2.dom == dom));
      return ((IT2.atend == atend));
     }
     bool operator!=(const gal_generator &IT2) const { return (!operator==(IT2)); }
     indices_type const &operator*() const { return indices_tuple; }
     explicit operator bool() const { return !atend; }
     gal_generator &operator++() {
      assert(!atend);
      atend = advance_impl(std::integral_constant<int, 0>());
      return *this;
     }

     private:
     template <int r> bool advance_impl(std::integral_constant<int, r>) {
      constexpr int p = permutations::apply(IterationOrder, r);
      if (indices_tuple[p] < dom->lengths()[p] - 1) {
       ++(indices_tuple[p]);
       return false;
      }
      indices_tuple[p] = 0;
      return advance_impl(std::integral_constant<int, r + 1>());
     }
     bool advance_impl(std::integral_constant<int, rank>) { return true; }
    };

    using generator = gal_generator<>;

    generator begin() const { return generator(*this, false); }
    generator end() const { return generator(*this, true); }
    /* End of generator */

    // Check that key in in the domain
    template <class KeyType> void assert_key_in_domain(KeyType const &key) const {
     std::stringstream fs;
     bool res = key_check_impl(std::integral_constant<int, 0>(), key, this->lengths_, fs);
     if (!res) TRIQS_ARRAYS_KEY_ERROR << " key out of domain \n" << fs.str();
    }
    template <int r, class KeyType>
    bool key_check_impl(std::integral_constant<int, r>, KeyType const &key, n_uple const &L, std::stringstream &fs) const {
     bool cond = ((size_t(std::get<r>(key)) < L[r]));
     if (!cond) fs << "key [" << r << "] = " << std::get<r>(key) << " is not within [0," << L[r] << "[\n";
     return key_check_impl(std::integral_constant<int, r + 1>(), key, L, fs) && cond;
    }
    template <class KeyType>
    bool key_check_impl(std::integral_constant<int, rank>, KeyType const &, n_uple const &, std::stringstream &) const {
     return true;
    }

    // Check that key in in the domain : variadic form. No need for speed optimisation here, it is just for debug
    template <typename... Args> void assert_key_in_domain_v(Args const &... args) const {
     assert_key_in_domain(std::make_tuple(args...));
    }

    friend std::ostream &operator<<(std::ostream &out, domain_t const &x) {
     return out << "Cuboid of rank " << x.rank << " and dimensions " << x.lengths();
    }
   };
  }
 }

 template <typename... U> indexmaps::cuboid::domain_t<sizeof...(U)> make_cuboid_domain(U... u) {
  return {size_t(u)...};
 }

 using matrix_shape_t = indexmaps::cuboid::domain_t<2>;
 using vector_shape_t = indexmaps::cuboid::domain_t<1>;
}
}