/*
 *  nextpnr -- Next Generation Place and Route
 *
 *  Copyright (C) 2018  Clifford Wolf <clifford@clifford.at>
 *  Copyright (C) 2018  David Shah <david@symbioticeda.com>
 *
 *  Permission to use, copy, modify, and/or distribute this software for any
 *  purpose with or without fee is hereby granted, provided that the above
 *  copyright notice and this permission notice appear in all copies.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */

#ifndef COMMON_PYCONTAINERS_H
#define COMMON_PYCONTAINERS_H

#include <boost/python.hpp>
#include <boost/python/suite/indexing/map_indexing_suite.hpp>
#include <boost/python/suite/indexing/vector_indexing_suite.hpp>
#include <stdexcept>
#include <type_traits>
#include <utility>
#include "nextpnr.h"

NEXTPNR_NAMESPACE_BEGIN

using namespace boost::python;

inline void KeyError() { PyErr_SetString(PyExc_KeyError, "Key not found"); }

/*
A wrapper for a Pythonised nextpnr Iterator. The actual class wrapped is a
pair<Iterator, Iterator> containing (current, end)
*/

template <typename T, typename P> struct iterator_wrapper
{
    typedef decltype(*(std::declval<T>())) value_t;

    static value_t next(std::pair<T, T> &iter)
    {
        if (iter.first != iter.second) {
            value_t val = *iter.first;
            ++iter.first;
            return val;
        } else {
            PyErr_SetString(PyExc_StopIteration, "End of range reached");
            boost::python::throw_error_already_set();
            // Should be unreachable, but prevent control may reach end of
            // non-void
            throw std::runtime_error("unreachable");
        }
    }

    static void wrap(const char *python_name)
    {
        class_<std::pair<T, T>>(python_name, no_init)
                .def("__next__", next, P());
    }
};

/*
A wrapper for a nextpnr Range. Ranges should have two functions, begin()
and end() which return iterator-like objects supporting ++, * and !=
Full STL iterator semantics are not required, unlike the standard Boost wrappers
*/

template <typename T, typename P = return_value_policy<return_by_value>>
struct range_wrapper
{
    typedef decltype(std::declval<T>().begin()) iterator_t;

    static std::pair<iterator_t, iterator_t> iter(T &range)
    {
        return std::make_pair(range.begin(), range.end());
    }

    static void wrap(const char *range_name, const char *iter_name)
    {
        class_<T>(range_name, no_init).def("__iter__", iter);
        iterator_wrapper<iterator_t, P>().wrap(iter_name);
    }

    typedef iterator_wrapper<iterator_t, P> iter_wrap;
};

#define WRAP_RANGE(t) range_wrapper<t##Range>().wrap(#t "Range", #t "Iterator")

/*
Wrapper for a pair, allows accessing either using C++-style members (.first and
.second) or as a Python iterable and indexable object
 */
template <typename T1, typename T2> struct pair_wrapper
{
    typedef std::pair<T1, T2> T;

    struct pair_iterator_wrapper
    {
        static object next(std::pair<T &, int> &iter)
        {
            if (iter.second == 0) {
                iter.second++;
                return object(iter.first.first);
            } else if (iter.second == 1) {
                iter.second++;
                return object(iter.first.second);
            } else {
                PyErr_SetString(PyExc_StopIteration, "End of range reached");
                boost::python::throw_error_already_set();
                // Should be unreachable, but prevent control may reach end of
                // non-void
                throw std::runtime_error("unreachable");
            }
        }

        static void wrap(const char *python_name)
        {
            class_<std::pair<T &, int>>(python_name, no_init)
                    .def("__next__", next);
        }
    };

    static object get(T &x, int i)
    {
        if ((i >= 2) || (i < 0))
            KeyError();
        return (i == 1) ? object(x.second) : object(x.first);
    }

    static void set(T &x, int i, object val)
    {
        if ((i >= 2) || (i < 0))
            KeyError();
        if (i == 0)
            x.first = extract<T1>(val);
        if (i == 1)
            x.second = extract<T2>(val);
    }

    static int len(T &x) { return 2; }

    static std::pair<T &, int> iter(T &x)
    {
        return std::make_pair(boost::ref(x), 0);
    };

    static void wrap(const char *pair_name, const char *iter_name)
    {
        pair_iterator_wrapper::wrap(iter_name);
        class_<T>(pair_name, no_init)
                .def("__iter__", iter)
                .def("__len__", len)
                .def("__getitem__", get)
                .def("__setitem__", set, with_custodian_and_ward<1, 2>())
                .def_readwrite("first", &T::first)
                .def_readwrite("second", &T::second);
    }
};

/*
Special case of above for map key/values
 */
template <typename T1, typename T2> struct map_pair_wrapper
{
    typedef std::pair<T1, T2> T;

    struct pair_iterator_wrapper
    {
        static object next(std::pair<T &, int> &iter)
        {
            if (iter.second == 0) {
                iter.second++;
                return object(iter.first.first);
            } else if (iter.second == 1) {
                iter.second++;
                return object(iter.first.second);
            } else {
                PyErr_SetString(PyExc_StopIteration, "End of range reached");
                boost::python::throw_error_already_set();
                // Should be unreachable, but prevent control may reach end of
                // non-void
                throw std::runtime_error("unreachable");
            }
        }

        static void wrap(const char *python_name)
        {
            class_<std::pair<T &, int>>(python_name, no_init)
                    .def("__next__", next);
        }
    };

    static object get(T &x, int i)
    {
        if ((i >= 2) || (i < 0))
            KeyError();
        return (i == 1) ? object(x.second) : object(x.first);
    }

    static int len(T &x) { return 2; }

    static std::pair<T &, int> iter(T &x)
    {
        return std::make_pair(boost::ref(x), 0);
    };

    static void wrap(const char *pair_name, const char *iter_name)
    {
        pair_iterator_wrapper::wrap(iter_name);
        class_<T>(pair_name, no_init)
                .def("__iter__", iter)
                .def("__len__", len)
                .def("__getitem__", get)
                .def_readonly("first", &T::first)
                .def_readwrite("second", &T::second);
    }
};

/*
Wrapper for a map, either an unordered_map, regular map or dict
 */

template <typename T> struct map_wrapper
{
    typedef typename std::remove_cv<
            typename std::remove_reference<typename T::key_type>::type>::type K;
    typedef typename T::mapped_type V;
    typedef typename T::value_type KV;

    static V &get(T &x, K const &i)
    {
        if (x.find(i) != x.end())
            return x.at(i);
        KeyError();
        std::terminate();
    }

    static void set(T &x, K const &i, V const &v) { x[i] = v; }

    static void del(T const &x, K const &i)
    {
        if (x.find(i) != x.end())
            x.erase(i);
        else
            KeyError();
        std::terminate();
    }

    static void wrap(const char *map_name, const char *kv_name,
                     const char *kv_iter_name, const char *iter_name)
    {
        map_pair_wrapper<typename KV::first_type,
                         typename KV::second_type>::wrap(kv_name, kv_iter_name);
        typedef range_wrapper<T, return_value_policy<copy_non_const_reference>>
                rw;
        typename rw::iter_wrap().wrap(iter_name);
        class_<T>(map_name, no_init)
                .def("__iter__", rw::iter)
                .def("__len__", &T::size)
                .def("__getitem__", get, return_internal_reference<>())
                .def("__setitem__", set, with_custodian_and_ward<1, 2>());
    }
};

#define WRAP_MAP(t, name)                                                      \
    map_wrapper<t>().wrap(#name, #name "KeyValue", #name "KeyValueIter",       \
                          #name "Iterator")

NEXTPNR_NAMESPACE_END

#endif