/* Copyright (C) 2016 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. 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 2 of the License, or
 * (at your option) any later version.
 *
 * 0 A.D. 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 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */
#include "ps/GameSetup/Config.h"

// Use the macro below to define types that will be passed by value to C++ functions.
// NOTE: References are used just to avoid superfluous copy constructor calls
// in the script wrapper code. They cannot be used as out-parameters.
// They are const T& by default to avoid confusion about this, especially
// because sometimes the function is not just exposed to scripts, but also
// called from C++ code.

template <typename T> struct ScriptInterface::MaybeRef
{
	typedef const T& Type;
};

#define PASS_BY_VALUE_IN_NATIVE_WRAPPER(T) \
template <> struct ScriptInterface::MaybeRef<T> \
{ \
	typedef T Type; \
}; \

PASS_BY_VALUE_IN_NATIVE_WRAPPER(JS::HandleValue)
PASS_BY_VALUE_IN_NATIVE_WRAPPER(bool)
PASS_BY_VALUE_IN_NATIVE_WRAPPER(int)
PASS_BY_VALUE_IN_NATIVE_WRAPPER(uint8_t)
PASS_BY_VALUE_IN_NATIVE_WRAPPER(uint16_t)
PASS_BY_VALUE_IN_NATIVE_WRAPPER(uint32_t)
PASS_BY_VALUE_IN_NATIVE_WRAPPER(fixed)
PASS_BY_VALUE_IN_NATIVE_WRAPPER(float)
PASS_BY_VALUE_IN_NATIVE_WRAPPER(double)

#undef PASS_BY_VALUE_IN_NATIVE_WRAPPER

// This works around a bug in Visual Studio 2013 (error C2244 if ScriptInterface:: is included in the
// type specifier of MaybeRef<T>::Type for parameters inside the member function declaration).
// It's probably the bug described here, but I'm not quite sure (at least the example there still 
// cause error C2244):
// https://connect.microsoft.com/VisualStudio/feedback/details/611863/vs2010-c-fails-with-error-c2244-gcc-4-3-4-compiles-ok
//
// TODO: When dropping support for VS 2013, check if this bug is still present in the supported
// Visual Studio versions (replace the macro definitions in NativeWrapperDecls.h with these ones, 
// remove them from here and check if this causes error C2244 when compiling.
#undef NUMBERED_LIST_TAIL_MAYBE_REF
#undef NUMBERED_LIST_BALANCED_MAYBE_REF
#undef TYPED_ARGS_MAYBE_REF
#define NUMBERED_LIST_TAIL_MAYBE_REF(z, i, data) , typename ScriptInterface::MaybeRef<data##i>::Type
#define NUMBERED_LIST_BALANCED_MAYBE_REF(z, i, data) BOOST_PP_COMMA_IF(i) typename ScriptInterface::MaybeRef<data##i>::Type
#define TYPED_ARGS_MAYBE_REF(z, i, data) , typename ScriptInterface::MaybeRef<T##i>::Type a##i

// (NativeWrapperDecls.h set up a lot of the macros we use here)

// ScriptInterface_NativeWrapper<T>::call(cx, rval, fptr, args...) will call fptr(cbdata, args...),
// and if T != void then it will store the result in rval:

// Templated on the return type so void can be handled separately
template <typename R>
struct ScriptInterface_NativeWrapper {
	#define OVERLOADS(z, i, data) \
		template<TYPENAME_T0_HEAD(z,i)  typename F> \
		static void call(JSContext* cx, JS::MutableHandleValue rval, F fptr  T0_A0_MAYBE_REF(z,i)) { \
			ScriptInterface::AssignOrToJSValUnrooted<R>(cx, rval, fptr(ScriptInterface::GetScriptInterfaceAndCBData(cx) A0_TAIL(z,i))); \
		}

	BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
	#undef OVERLOADS
};

// Overloaded to ignore the return value from void functions
template <>
struct ScriptInterface_NativeWrapper<void> {
	#define OVERLOADS(z, i, data) \
		template<TYPENAME_T0_HEAD(z,i)  typename F> \
		static void call(JSContext* cx, JS::MutableHandleValue /*rval*/, F fptr  T0_A0_MAYBE_REF(z,i)) { \
			fptr(ScriptInterface::GetScriptInterfaceAndCBData(cx) A0_TAIL(z,i)); \
		}
	BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
	#undef OVERLOADS
};

// Same idea but for method calls:

template <typename R, typename TC>
struct ScriptInterface_NativeMethodWrapper {
	#define OVERLOADS(z, i, data) \
		template<TYPENAME_T0_HEAD(z,i)  typename F> \
		static void call(JSContext* cx, JS::MutableHandleValue rval, TC* c, F fptr  T0_A0_MAYBE_REF(z,i)) { \
			ScriptInterface::AssignOrToJSValUnrooted<R>(cx, rval, (c->*fptr)( A0(z,i) )); \
		}

	BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
	#undef OVERLOADS
};

template <typename TC>
struct ScriptInterface_NativeMethodWrapper<void, TC> {
	#define OVERLOADS(z, i, data) \
		template<TYPENAME_T0_HEAD(z,i)  typename F> \
		static void call(JSContext* /*cx*/, JS::MutableHandleValue /*rval*/, TC* c, F fptr  T0_A0_MAYBE_REF(z,i)) { \
			(c->*fptr)( A0(z,i) ); \
		}
	BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
	#undef OVERLOADS
};

// Fast natives don't trigger the hook we use for profiling, so explicitly
// notify the profiler when these functions are being called.
// ScriptInterface_impl::Register stores the name in a reserved slot.
#define SCRIPT_PROFILE \
	if (g_ScriptProfilingEnabled) \
	{ \
		std::string name = "(unknown)"; \
		JS::RootedString str(cx, JS_GetFunctionId(JS_ValueToFunction(cx, args.calleev()))); \
		if (str) \
		{ \
			JS::RootedValue strVal(cx, JS::StringValue(str)); \
			ScriptInterface::FromJSVal(cx, strVal, name); \
		} \
		CProfileSampleScript profile(StringFlyweight(name).get().c_str()); \
	}

// JSFastNative-compatible function that wraps the function identified in the template argument list
#define OVERLOADS(z, i, data) \
	template <typename R, TYPENAME_T0_HEAD(z,i)  R (*fptr) ( ScriptInterface::CxPrivate* T0_TAIL_MAYBE_REF(z,i) )> \
	bool ScriptInterface::call(JSContext* cx, uint argc, jsval* vp) { \
		JS::CallArgs args = JS::CallArgsFromVp(argc, vp); \
		JSAutoRequest rq(cx); \
		SCRIPT_PROFILE \
		BOOST_PP_REPEAT_##z (i, CONVERT_ARG, ~) \
		JS::RootedValue rval(cx); \
		ScriptInterface_NativeWrapper<R>::template call<T0_HEAD(z,i) R( ScriptInterface::CxPrivate* T0_TAIL_MAYBE_REF(z,i))>(cx, &rval, fptr  A0_TAIL(z,i)); \
		args.rval().set(rval); \
		return !ScriptInterface::IsExceptionPending(cx); \
	}
BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
#undef OVERLOADS

// Same idea but for methods
#define OVERLOADS(z, i, data) \
	template <typename R, TYPENAME_T0_HEAD(z,i)  JSClass* CLS, typename TC, R (TC::*fptr) ( T0_MAYBE_REF(z,i) )> \
	bool ScriptInterface::callMethod(JSContext* cx, uint argc, jsval* vp) { \
		JS::CallArgs args = JS::CallArgsFromVp(argc, vp); \
		JSAutoRequest rq(cx); \
		SCRIPT_PROFILE \
		JS::RootedObject thisObj(cx, JS_THIS_OBJECT(cx, vp)); \
		if (ScriptInterface::GetClass(thisObj) != CLS) return false; \
		TC* c = static_cast<TC*>(ScriptInterface::GetPrivate(thisObj)); \
		if (! c) return false; \
		BOOST_PP_REPEAT_##z (i, CONVERT_ARG, ~) \
		JS::RootedValue rval(cx); \
		ScriptInterface_NativeMethodWrapper<R, TC>::template call<T0_HEAD(z,i) R (TC::*)(T0_MAYBE_REF(z,i))>(cx, &rval, c, fptr A0_TAIL(z,i)); \
		args.rval().set(rval); \
		return !ScriptInterface::IsExceptionPending(cx); \
	}
BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
#undef OVERLOADS

#define ASSIGN_OR_TO_JS_VAL(z, i, data) AssignOrToJSVal(cx, argv.handleAt(i), a##i);

#define OVERLOADS(z, i, data) \
template<typename R TYPENAME_T0_TAIL(z, i)> \
bool ScriptInterface::CallFunction(JS::HandleValue val, const char* name, T0_A0_CONST_REF(z,i) R& ret) \
{ \
	JSContext* cx = GetContext(); \
	JSAutoRequest rq(cx); \
	JS::RootedValue jsRet(cx); \
	JS::AutoValueVector argv(cx); \
	argv.resize(i); \
	BOOST_PP_REPEAT_##z (i, ASSIGN_OR_TO_JS_VAL, ~) \
	bool ok = CallFunction_(val, name, argv, &jsRet); \
	if (!ok) \
		return false; \
	return FromJSVal(cx, jsRet, ret); \
}
BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
#undef OVERLOADS

#define OVERLOADS(z, i, data) \
template<typename R TYPENAME_T0_TAIL(z, i)> \
bool ScriptInterface::CallFunction(JS::HandleValue val, const char* name, T0_A0_CONST_REF(z,i) JS::Rooted<R>* ret) \
{ \
	JSContext* cx = GetContext(); \
	JSAutoRequest rq(cx); \
	JS::MutableHandle<R> jsRet(ret); \
	JS::AutoValueVector argv(cx); \
	argv.resize(i); \
	BOOST_PP_REPEAT_##z (i, ASSIGN_OR_TO_JS_VAL, ~) \
	bool ok = CallFunction_(val, name, argv, jsRet); \
	if (!ok) \
		return false; \
	return true; \
}
BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
#undef OVERLOADS

#define OVERLOADS(z, i, data) \
template<typename R TYPENAME_T0_TAIL(z, i)> \
bool ScriptInterface::CallFunction(JS::HandleValue val, const char* name, T0_A0_CONST_REF(z,i) JS::MutableHandle<R> ret) \
{ \
	JSContext* cx = GetContext(); \
	JSAutoRequest rq(cx); \
	JS::AutoValueVector argv(cx); \
	argv.resize(i); \
	BOOST_PP_REPEAT_##z (i, ASSIGN_OR_TO_JS_VAL, ~) \
	bool ok = CallFunction_(val, name, argv, ret); \
	if (!ok) \
		return false; \
	return true; \
}
BOOST_PP_REPEAT(SCRIPT_INTERFACE_MAX_ARGS, OVERLOADS, ~)
#undef OVERLOADS
#undef ASSIGN_OR_TO_JS_VAL

// Clean up our mess
#undef SCRIPT_PROFILE
#undef NUMBERED_LIST_HEAD
#undef NUMBERED_LIST_TAIL
#undef NUMBERED_LIST_TAIL_MAYBE_REF
#undef NUMBERED_LIST_BALANCED
#undef NUMBERED_LIST_BALANCED_MAYBE_REF
#undef TYPED_ARGS
#undef TYPED_ARGS_MAYBE_REF
#undef TYPED_ARGS_CONST_REF
#undef CONVERT_ARG
#undef TYPENAME_T0_HEAD
#undef TYPENAME_T0_TAIL
#undef T0
#undef T0_MAYBE_REF
#undef T0_HEAD
#undef T0_TAIL
#undef T0_TAIL_MAYBE_REF
#undef T0_A0
#undef T0_A0_MAYBE_REF
#undef T0_A0_CONST_REF
#undef A0
#undef A0_TAIL