#pragma once

#include "_python.h"
#include "interpreter.h"
#include "helpers.h"

namespace matplotlibcpp {
template<typename Numeric>
bool plot(const std::vector<Numeric> &x, const std::vector<Numeric> &y, const std::map<std::string, std::string>& keywords)
{
    assert(x.size() == y.size());

    // using numpy arrays
    PyObject* xarray = get_array(x);
    PyObject* yarray = get_array(y);

    // construct positional args
    PyObject* args = PyTuple_New(2);
    PyTuple_SetItem(args, 0, xarray);
    PyTuple_SetItem(args, 1, yarray);

    // construct keyword args
    PyObject* kwargs = helpers::to_dict(keywords);

    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_plot, args, kwargs);

    Py_DECREF(args);
    Py_DECREF(kwargs);
    if(res != nullptr) Py_DECREF(res);

    return res != nullptr;
}

template<typename NumericX, typename NumericY>
bool plot(const std::vector<NumericX>& x, const std::vector<NumericY>& y, const std::string& s = "")
{
    assert(x.size() == y.size());

    PyObject* xarray = get_array(x);
    PyObject* yarray = get_array(y);

    PyObject* pystring = PyString_FromString(s.c_str());

    PyObject* plot_args = PyTuple_New(3);
    PyTuple_SetItem(plot_args, 0, xarray);
    PyTuple_SetItem(plot_args, 1, yarray);
    PyTuple_SetItem(plot_args, 2, pystring);

    PyObject* res = PyObject_CallObject(detail::_interpreter::get().s_python_function_plot, plot_args);

    Py_DECREF(plot_args);
    if(res != nullptr) Py_DECREF(res);

    return res != nullptr;
}

template<typename Numeric>
bool named_plot(const std::string& name, const std::vector<Numeric>& y, const std::string& format = "")
{
    PyObject* kwargs = PyDict_New();
    PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));

    PyObject* yarray = get_array(y);

    PyObject* pystring = PyString_FromString(format.c_str());

    PyObject* plot_args = PyTuple_New(2);

    PyTuple_SetItem(plot_args, 0, yarray);
    PyTuple_SetItem(plot_args, 1, pystring);

    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_plot, plot_args, kwargs);

    Py_DECREF(kwargs);
    Py_DECREF(plot_args);
    if (res != nullptr) Py_DECREF(res);

    return res != nullptr;
}

template<typename Numeric>
bool named_plot(const std::string& name, const std::vector<Numeric>& x, const std::vector<Numeric>& y, const std::string& format = "")
{
    PyObject* kwargs = PyDict_New();
    PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));

    PyObject* xarray = get_array(x);
    PyObject* yarray = get_array(y);

    PyObject* pystring = PyString_FromString(format.c_str());

    PyObject* plot_args = PyTuple_New(3);
    PyTuple_SetItem(plot_args, 0, xarray);
    PyTuple_SetItem(plot_args, 1, yarray);
    PyTuple_SetItem(plot_args, 2, pystring);

    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_plot, plot_args, kwargs);

    Py_DECREF(kwargs);
    Py_DECREF(plot_args);
    if (res != nullptr) Py_DECREF(res);

    return res != nullptr;
}

template<typename Numeric>
bool plot(const std::vector<Numeric>& y, const std::string& format = "")
{
    std::vector<Numeric> x(y.size());
    for(size_t i=0; i<x.size(); ++i) x.at(i) = static_cast<Numeric>(i);
    return plot(x,y,format);
}

#if __cplusplus > 199711L || _MSC_VER > 1800
// C++11-exclusive content starts here (variadic plot() and initializer list support)

namespace detail {

template<typename T>
using is_function = typename std::is_function<std::remove_pointer<std::remove_reference<T>>>::type;

template<bool obj, typename T>
struct is_callable_impl;

template<typename T>
struct is_callable_impl<false, T>
{
    typedef is_function<T> type;
}; // a non-object is callable iff it is a function

template<typename T>
struct is_callable_impl<true, T>
{
    struct Fallback { void operator()(); };
    struct Derived : T, Fallback { };

    template<typename U, U> struct Check;

    template<typename U>
    static std::true_type test( ... ); // use a variadic function to make sure (1) it accepts everything and (2) its always the worst match

    template<typename U>
    static std::false_type test( Check<void(Fallback::*)(), &U::operator()>* );

public:
    typedef decltype(test<Derived>(nullptr)) type;
    typedef decltype(&Fallback::operator()) dtype;
    static constexpr bool value = type::value;
}; // an object is callable iff it defines operator()

template<typename T>
struct is_callable
{
    // dispatch to is_callable_impl<true, T> or is_callable_impl<false, T> depending on whether T is of class type or not
    typedef typename is_callable_impl<std::is_class<T>::value, T>::type type;
};

template<typename IsYDataCallable>
struct plot_impl { };

template<>
struct plot_impl<std::false_type>
{
    template<typename IterableX, typename IterableY>
    bool operator()(const IterableX& x, const IterableY& y, const std::string& format)
    {
        // 2-phase lookup for distance, begin, end
        using std::distance;
        using std::begin;
        using std::end;

        auto xs = distance(begin(x), end(x));
        auto ys = distance(begin(y), end(y));
        assert(xs == ys && "x and y data must have the same number of elements!");

        PyObject* xlist = PyList_New(xs);
        PyObject* ylist = PyList_New(ys);
        PyObject* pystring = PyString_FromString(format.c_str());

        auto itx = begin(x), ity = begin(y);
        for(size_t i = 0; i < static_cast<size_t>(xs); ++i) {
            PyList_SetItem(xlist, i, PyFloat_FromDouble(*itx++));
            PyList_SetItem(ylist, i, PyFloat_FromDouble(*ity++));
        }

        PyObject* plot_args = PyTuple_New(3);
        PyTuple_SetItem(plot_args, 0, xlist);
        PyTuple_SetItem(plot_args, 1, ylist);
        PyTuple_SetItem(plot_args, 2, pystring);

        PyObject* res = PyObject_CallObject(detail::_interpreter::get().s_python_function_plot, plot_args);

        Py_DECREF(plot_args);
        if(res != nullptr) Py_DECREF(res);

        return res != nullptr;
    }
};

template<>
struct plot_impl<std::true_type>
{
    template<typename Iterable, typename Callable>
    bool operator()(const Iterable& ticks, const Callable& f, const std::string& format)
    {
        if(begin(ticks) == end(ticks)) return true;

        // We could use additional meta-programming to deduce the correct element type of y,
        // but all values have to be convertible to double anyways
        std::vector<double> y;
        for(auto x : ticks) y.push_back(f(x));
        return plot_impl<std::false_type>()(ticks,y,format);
    }
};

} // end namespace detail

// recursion stop for the above
template<typename... Args>
bool plot() { return true; }

template<typename A, typename B, typename... Args>
bool plot(const A& a, const B& b, const std::string& format, Args... args)
{
    return detail::plot_impl<typename detail::is_callable<B>::type>()(a,b,format) && plot(args...);
}

/*
 * This group of plot() functions is needed to support initializer lists, i.e. calling
 *    plot( {1,2,3,4} )
 */
inline bool plot(const std::vector<double>& x, const std::vector<double>& y, const std::string& format = "") {
    return plot<double,double>(x,y,format);
}

inline bool plot(const std::vector<double>& y, const std::string& format = "") {
    return plot<double>(y,format);
}

inline bool plot(const std::vector<double>& x, const std::vector<double>& y, const std::map<std::string, std::string>& keywords) {
    return plot<double>(x,y,keywords);
}

#endif
} // end namespace matplotlibcpp