// The MIT License (MIT)

// Copyright (c) 2013-2016 Rappt1101010z, ThePhD and contributors

// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files (the "Software"), to deal in
// the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software is furnished to do so,
// subject to the following conditions:

// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

#ifndef SOL_CALL_HPP
#define SOL_CALL_HPP

#include "wrapper.hpp"
#include "property.hpp"
#include "stack.hpp"

namespace sol { 
namespace call_detail {
	
	template <bool b, typename F>
	inline decltype(auto) pick(std::integral_constant<bool, b>, F&& f) {
		return std::forward<F>(f);
	}

	template <typename R, typename W>
	inline auto& pick(std::true_type, property_wrapper<R, W>& f) {
		return f.read;
	}

	template <typename R, typename W>
	inline auto& pick(std::false_type, property_wrapper<R, W>& f) {
		return f.write;
	}

	template <typename T, typename List>
	struct void_call;

	template <typename T, typename... Args>
	struct void_call<T, types<Args...>> {
		static void call(Args...) {}
	};

	template <typename T, int additional_pop = 0>
	struct constructor_match {
		T* obj;

		constructor_match(T* obj) : obj(obj) {}

		template <typename Fx, std::size_t I, typename... R, typename... Args>
		int operator()(types<Fx>, index_value<I>, types<R...> r, types<Args...> a, lua_State* L, int, int start) const {
			detail::default_construct func{};
			return stack::call_into_lua<additional_pop, false>(r, a, L, start, func, obj);
		}
	};

	template <typename T>
	inline int destruct(lua_State* L) {
		T* obj = stack::get<non_null<T*>>(L, 1);
		std::allocator<T> alloc{};
		alloc.destroy(obj);
		return 0;
	}
	
	namespace overload_detail {
		template <std::size_t... M, typename Match, typename... Args>
		inline int overload_match_arity(sol::types<>, std::index_sequence<>, std::index_sequence<M...>, Match&&, lua_State* L, int, int, Args&&...) {
			return luaL_error(L, "sol: no matching function call takes this number of arguments and the specified types");
		}

		template <typename Fx, typename... Fxs, std::size_t I, std::size_t... In, std::size_t... M, typename Match, typename... Args>
		inline int overload_match_arity(sol::types<Fx, Fxs...>, std::index_sequence<I, In...>, std::index_sequence<M...>, Match&& matchfx, lua_State* L, int fxarity, int start, Args&&... args) {
			typedef lua_bind_traits<meta::unqualified_t<Fx>> traits;
			typedef meta::tuple_types<typename traits::return_type> return_types;
			typedef typename traits::free_args_list args_list;
			typedef typename args_list::indices args_indices;
			// compile-time eliminate any functions that we know ahead of time are of improper arity
			if (meta::find_in_pack_v<index_value<traits::free_arity>, index_value<M>...>::value) {
				return overload_match_arity(types<Fxs...>(), std::index_sequence<In...>(), std::index_sequence<M...>(), std::forward<Match>(matchfx), L, fxarity, start, std::forward<Args>(args)...);
			}
			if (traits::free_arity != fxarity) {
				return overload_match_arity(types<Fxs...>(), std::index_sequence<In...>(), std::index_sequence<traits::arity, M...>(), std::forward<Match>(matchfx), L, fxarity, start, std::forward<Args>(args)...);
			}
			if (!stack::stack_detail::check_types<true>().check(args_list(), args_indices(), L, start, no_panic)) {
				return overload_match_arity(types<Fxs...>(), std::index_sequence<In...>(), std::index_sequence<M...>(), std::forward<Match>(matchfx), L, fxarity, start, std::forward<Args>(args)...);
			}
			return matchfx(types<Fx>(), index_value<I>(), return_types(), args_list(), L, fxarity, start, std::forward<Args>(args)...);
		}
	} // overload_detail

	template <typename... Functions, typename Match, typename... Args>
	inline int overload_match_arity(Match&& matchfx, lua_State* L, int fxarity, int start, Args&&... args) {
		return overload_detail::overload_match_arity(types<Functions...>(), std::make_index_sequence<sizeof...(Functions)>(), std::index_sequence<>(), std::forward<Match>(matchfx), L, fxarity, start, std::forward<Args>(args)...);
	}

	template <typename... Functions, typename Match, typename... Args>
	inline int overload_match(Match&& matchfx, lua_State* L, int start, Args&&... args) {
		int fxarity = lua_gettop(L) - (start - 1);
		return overload_match_arity<Functions...>(std::forward<Match>(matchfx), L, fxarity, start, std::forward<Args>(args)...);
	}

	template <typename T, typename... TypeLists, typename Match, typename... Args>
	inline int construct(Match&& matchfx, lua_State* L, int fxarity, int start, Args&&... args) {
		// use same overload resolution matching as all other parts of the framework
		return overload_match_arity<decltype(void_call<T, TypeLists>::call)...>(std::forward<Match>(matchfx), L, fxarity, start, std::forward<Args>(args)...);
	}

	template <typename T, typename... TypeLists>
	inline int construct(lua_State* L) {
		static const auto& meta = usertype_traits<T>::metatable;
		int argcount = lua_gettop(L);
		call_syntax syntax = argcount > 0 ? stack::get_call_syntax(L, meta, 1) : call_syntax::dot;
		argcount -= static_cast<int>(syntax);

		T** pointerpointer = reinterpret_cast<T**>(lua_newuserdata(L, sizeof(T*) + sizeof(T)));
		T*& referencepointer = *pointerpointer;
		T* obj = reinterpret_cast<T*>(pointerpointer + 1);
		referencepointer = obj;
		reference userdataref(L, -1);
		userdataref.pop();

		construct<T, TypeLists...>(constructor_match<T>(obj), L, argcount, 1 + static_cast<int>(syntax));

		userdataref.push();
		luaL_getmetatable(L, &meta[0]);
		if (stack::get<type>(L) == type::nil) {
			lua_pop(L, 1);
			return luaL_error(L, "sol: unable to get usertype metatable");
		}

		lua_setmetatable(L, -2);
		return 1;
	}

	template <typename F, bool is_index, bool is_variable, typename = void>
	struct agnostic_lua_call_wrapper {
		static int var_call(std::true_type, lua_State* L, F f) {
			typedef wrapper<meta::unqualified_t<F>> wrap;
			typedef typename wrap::returns_list returns_list;
			typedef typename wrap::free_args_list args_list;
			typedef typename wrap::caller caller;
			return stack::call_into_lua<is_index ? 1 : 2>(returns_list(), args_list(), L, is_index ? 2 : 3, caller(), f);
		}

		static int var_call(std::false_type, lua_State* L, F f) {
			typedef wrapper<meta::unqualified_t<F>> wrap;
			typedef typename wrap::free_args_list args_list;
			typedef typename wrap::returns_list returns_list;
			typedef typename wrap::caller caller;
			return stack::call_into_lua(returns_list(), args_list(), L, 1, caller(), f);
		}

		static int call(lua_State* L, F f) {
			return var_call(std::integral_constant<bool, is_variable>(), L, f);
		}
	};

	template <typename F, bool is_index, bool is_variable>
	struct agnostic_lua_call_wrapper<F, is_index, is_variable, std::enable_if_t<std::is_member_function_pointer<F>::value>> {
		static int call(lua_State* L, F f) {
			typedef wrapper<meta::unqualified_t<F>> wrap;
			typedef typename wrap::returns_list returns_list;
			typedef typename wrap::args_list args_list;
			typedef typename wrap::caller caller;
			typedef typename wrap::object_type object_type;

#ifdef SOL_SAFE_USERTYPE
			object_type* o = stack::get<object_type*>(L, 1);
			if (o == nullptr) {
				return luaL_error(L, "sol: received null for 'self' argument (use ':' for accessing member functions, make sure member variables are preceeded by the actual object with '.' syntax)");
			}
			return stack::call_into_lua<is_variable ? 2 : 1>(returns_list(), args_list(), L, is_variable ? 3 : 2, caller(), f, *o);
#else
			object_type& o = stack::get<object_type&>(L, 1);
			return stack::call_into_lua<is_variable ? 2 : 1>(returns_list(), args_list(), L, is_variable ? 3 : 2, caller(), f);
#endif // Safety
		}
	};

	template <bool is_index, bool is_variable, typename C>
	struct agnostic_lua_call_wrapper<lua_r_CFunction, is_index, is_variable, C> {
		static int call(lua_State* L, lua_r_CFunction f) {
			return f(L);
		}
	};

	template <bool is_index, bool is_variable, typename C>
	struct agnostic_lua_call_wrapper<lua_CFunction, is_index, is_variable, C> {
		static int call(lua_State* L, lua_CFunction f) {
			return f(L);
		}
	};

	template <bool is_index, bool is_variable, typename C>
	struct agnostic_lua_call_wrapper<no_prop, is_index, is_variable, C> {
		static int call(lua_State* L, no_prop) {
			return luaL_error(L, is_index ? "sol: cannot read from a writeonly property" : "sol: cannot write to a readonly property");
		}
	};

	template <typename F, bool is_variable>
	struct agnostic_lua_call_wrapper<F, false, is_variable, std::enable_if_t<std::is_member_object_pointer<F>::value>> {
		typedef sol::lua_bind_traits<F> traits_type;

		static int call_assign(std::true_type, lua_State* L, F f) {
			typedef wrapper<meta::unqualified_t<F>> wrap;
			typedef typename wrap::args_list args_list;
			typedef typename wrap::object_type object_type;
			typedef typename wrap::caller caller;
#ifdef SOL_SAFE_USERTYPE
			object_type* o = stack::get<object_type*>(L, 1);
			if (o == nullptr) {
				if (is_variable) {
					return luaL_error(L, "sol: received nil for 'self' argument (bad '.' access?)");
				}
				return luaL_error(L, "sol: received nil for 'self' argument (pass 'self' as first argument)");
			}
			return stack::call_into_lua<is_variable ? 2 : 1>(types<void>(), args_list(), L, is_variable ? 3 : 2, caller(), f, *o);
#else
			object_type& o = stack::get<object_type&>(L, 1);
			return stack::call_into_lua<is_variable ? 2 : 1>(types<void>(), args_list(), L, is_variable ? 3 : 2, caller(), f, o);
#endif // Safety
		}

		static int call_assign(std::false_type, lua_State* L, F) {
			return luaL_error(L, "sol: cannot write to this variable: copy assignment/constructor not available");
		}

		static int call_const(std::false_type, lua_State* L, F f) {
			typedef typename traits_type::return_type R;
			return call_assign(std::is_assignable<std::add_lvalue_reference_t<meta::unqualified_t<R>>, R>(), L, f);
		}

		static int call_const(std::true_type, lua_State* L, F) {
			return luaL_error(L, "sol: cannot write to a readonly (const) variable");
		}

		static int call(lua_State* L, F f) {
			return call_const(std::is_const<typename traits_type::return_type>(), L, f);
		}
	};

	template <typename F, bool is_variable>
	struct agnostic_lua_call_wrapper<F, true, is_variable, std::enable_if_t<std::is_member_object_pointer<F>::value>> {
		typedef sol::lua_bind_traits<F> traits_type;

		static int call(lua_State* L, F f) {
			typedef wrapper<meta::unqualified_t<F>> wrap;
			typedef typename wrap::object_type object_type;
			typedef typename wrap::returns_list returns_list;
			typedef typename wrap::caller caller;
#ifdef SOL_SAFE_USERTYPE
			object_type* o = stack::get<object_type*>(L, 1);
			if (o == nullptr) {
				if (is_variable) {
					return luaL_error(L, "sol: 'self' argument is nil (bad '.' access?)");
				}
				return luaL_error(L, "sol: 'self' argument is nil (pass 'self' as first argument)");
			}
			return stack::call_into_lua<is_variable ? 2 : 1>(returns_list(), types<>(), L, is_variable ? 3 : 2, caller(), f, *o);
#else
			object_type& o = stack::get<object_type&>(L, 1);
			return stack::call_into_lua<is_variable ? 2 : 1>(returns_list(), types<>(), L, is_variable ? 3 : 2, caller(), f, o);
#endif // Safety
		}
	};

	template <bool is_index, bool is_variable, typename C>
	struct agnostic_lua_call_wrapper<no_construction, is_index, is_variable, C> {
		static int call(lua_State* L, no_construction&) {
			return luaL_error(L, "sol: cannot call this constructor (tagged as non-constructible)");
		}
	};

	template <typename... Args, bool is_index, bool is_variable, typename C>
	struct agnostic_lua_call_wrapper<bases<Args...>, is_index, is_variable, C> {
		static int call(lua_State* L, bases<Args...>&) {
			// Uh. How did you even call this, lul
			return 0;
		}
	};

	template <typename T, typename F, bool is_index, bool is_variable, typename = void>
	struct lua_call_wrapper : agnostic_lua_call_wrapper<F, is_index, is_variable> {};

	template <typename T, typename... Args, bool is_index, bool is_variable, typename C>
	struct lua_call_wrapper<T, sol::constructor_list<Args...>, is_index, is_variable, C> {
		typedef sol::constructor_list<Args...> F;

		static int call(lua_State* L, F&) {
			static const auto& metakey = usertype_traits<T>::metatable;
			int argcount = lua_gettop(L);
			call_syntax syntax = argcount > 0 ? stack::get_call_syntax(L, metakey, 1) : call_syntax::dot;
			argcount -= static_cast<int>(syntax);

			T** pointerpointer = reinterpret_cast<T**>(lua_newuserdata(L, sizeof(T*) + sizeof(T)));
			reference userdataref(L, -1);
			T*& referencepointer = *pointerpointer;
			T* obj = reinterpret_cast<T*>(pointerpointer + 1);
			referencepointer = obj;
			
			construct<T, Args...>(constructor_match<T, 1>(obj), L, argcount, 1 + static_cast<int>(syntax));

			userdataref.push();
			luaL_getmetatable(L, &metakey[0]);
			if (stack::get<type>(L) == type::nil) {
				lua_pop(L, 1);
				return luaL_error(L, "sol: unable to get usertype metatable");
			}

			lua_setmetatable(L, -2);
			return 1;
		}
	};

	template <typename T, typename... Cxs, bool is_index, bool is_variable, typename C>
	struct lua_call_wrapper<T, sol::constructor_wrapper<Cxs...>, is_index, is_variable, C> {
		typedef sol::constructor_wrapper<Cxs...> F;

		struct onmatch {
			template <typename Fx, std::size_t I, typename... R, typename... Args>
			int operator()(types<Fx>, index_value<I>, types<R...> r, types<Args...> a, lua_State* L, int, int start, F& f) {
				T** pointerpointer = reinterpret_cast<T**>(lua_newuserdata(L, sizeof(T*) + sizeof(T)));
				reference userdataref(L, -1);
				T*& referencepointer = *pointerpointer;
				T* obj = reinterpret_cast<T*>(pointerpointer + 1);
				referencepointer = obj;

				auto& func = std::get<I>(f.set);
				stack::call_into_lua<1, false>(r, a, L, start, func, detail::implicit_wrapper<T>(obj));

				userdataref.push();
				luaL_getmetatable(L, &usertype_traits<T>::metatable[0]);
				if (stack::get<type>(L) == type::nil) {
					lua_pop(L, 1);
					std::string err = "sol: unable to get usertype metatable for ";
					err += usertype_traits<T>::name;
					return luaL_error(L, err.c_str());
				}
				lua_setmetatable(L, -2);

				return 1;
			}
		};

		static int call(lua_State* L, F& f) {
			call_syntax syntax = stack::get_call_syntax(L, usertype_traits<T>::metatable);
			int syntaxval = static_cast<int>(syntax);
			int argcount = lua_gettop(L) - syntaxval;
			return construct<T, meta::pop_front_type_t<meta::function_args_t<Cxs>>...>(onmatch(), L, argcount, 1 + syntaxval, f);
		}

	};

	template <typename T, typename Fx, bool is_index, bool is_variable>
	struct lua_call_wrapper<T, sol::destructor_wrapper<Fx>, is_index, is_variable, std::enable_if_t<std::is_void<Fx>::value>> {
		typedef sol::destructor_wrapper<Fx> F;

		static int call(lua_State* L, F&) {
			return destruct<T>(L);
		}
	};

	template <typename T, typename Fx, bool is_index, bool is_variable>
	struct lua_call_wrapper<T, sol::destructor_wrapper<Fx>, is_index, is_variable, std::enable_if_t<!std::is_void<Fx>::value>> {
		typedef sol::destructor_wrapper<Fx> F;

		static int call(lua_State* L, F& f) {
			T* obj = stack::get<non_null<T*>>(L);
			f.fx(detail::implicit_wrapper<T>(obj));
			return 0;
		}
	};

	template <typename T, typename... Fs, bool is_index, bool is_variable, typename C>
	struct lua_call_wrapper<T, overload_set<Fs...>, is_index, is_variable, C> {
		typedef overload_set<Fs...> F;

		struct on_match {
			template <typename Fx, std::size_t I, typename... R, typename... Args>
			int operator()(types<Fx>, index_value<I>, types<R...>, types<Args...>, lua_State* L, int, int, F& fx) {
				auto& f = std::get<I>(fx.set);
				return lua_call_wrapper<T, Fx, is_index, is_variable>{}.call(L, f);
			}
		};

		static int call(lua_State* L, F& fx) {
			return overload_match_arity<Fs...>(on_match(), L, lua_gettop(L), 1, fx);
		}
	};

	template <typename T, bool is_index, bool is_variable, typename Fx>
	int call_wrapped(lua_State* L, Fx&& fx) {
		return lua_call_wrapper<T, meta::unqualified_t<Fx>, is_index, is_variable>{}.call(L, std::forward<Fx>(fx));
	}

	template <typename T, typename = void>
	struct is_var_bind : std::false_type {};

	template <typename T>
	struct is_var_bind<T, std::enable_if_t<std::is_member_object_pointer<T>::value>> : std::true_type {};

	template <>
	struct is_var_bind<no_prop> : std::true_type {};

	template <typename R, typename W>
	struct is_var_bind<property_wrapper<R, W>> : std::true_type {};

} // call_detail

template <typename T>
struct is_variable_binding : call_detail::is_var_bind<meta::unqualified_t<T>> {};

template <typename T>
struct is_function_binding : meta::neg<is_variable_binding<T>> {};

} // sol

#endif // SOL_CALL_HPP