axmol/extensions/scripting/lua-bindings/manual/platform/ios/LuaObjcBridge.mm

/****************************************************************************
 Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
 Copyright (c) 2022 Bytedance Inc.

 https://axmolengine.github.io/

 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.
 ****************************************************************************/

#include "scripting/lua-bindings/manual/platform/ios/LuaObjcBridge.h"
#include <Foundation/Foundation.h>

NS_AX_BEGIN

void LuaObjcBridge::luaopen_luaoc(lua_State* L)
{
    s_luaState = L;
    lua_newtable(L);
    lua_pushstring(L, "callStaticMethod");
    lua_pushcfunction(L, LuaObjcBridge::callObjcStaticMethod);
    lua_rawset(L, -3);
    lua_setglobal(L, "LuaObjcBridge");
}

static void luaTableToObjcDictionary(lua_State* L, NSMutableDictionary* dict, NSString* key)
{
    NSMutableDictionary* dict2 = [[NSMutableDictionary alloc] init];
    lua_pushnil(L);
    while (lua_next(L, -2))
    {
        NSString* key2 = nil;
        int keyType    = lua_type(L, -2);
        if (keyType == LUA_TSTRING)
            key2 = [NSString stringWithCString:lua_tostring(L, -2) encoding:NSUTF8StringEncoding];
        else if (keyType == LUA_TNUMBER)
            key2 = [[NSNumber numberWithInt:lua_tonumber(L, -2)] stringValue];
        else
        {
            lua_pop(L, 1);
            continue;
        }

        switch (lua_type(L, -1))
        {
        case LUA_TNUMBER:
            [dict2 setObject:[NSNumber numberWithFloat:lua_tonumber(L, -1)] forKey:key2];
            break;

        case LUA_TBOOLEAN:
            [dict2 setObject:[NSNumber numberWithBool:lua_toboolean(L, -1)] forKey:key2];
            break;

        case LUA_TSTRING:
            [dict2 setObject:[NSString stringWithCString:lua_tostring(L, -1) encoding:NSUTF8StringEncoding]
                      forKey:key2];
            break;
        case LUA_TTABLE:
            luaTableToObjcDictionary(L, dict2, key2);
            break;
        }
        lua_pop(L, 1);
    }

    [dict setObject:dict2 forKey:key];
}

/**
 className
 methodName
 args
 */
int LuaObjcBridge::callObjcStaticMethod(lua_State* L)
{
    if (lua_gettop(L) != 3 || !lua_isstring(L, -3) || !lua_isstring(L, -2))
    {
        lua_pushboolean(L, 0);
        lua_pushinteger(L, kLuaBridgeErrorInvalidParameters);
        return 2;
    }

    const char* className  = lua_tostring(L, -3);
    const char* methodName = lua_tostring(L, -2);
    if (!className || !methodName)
    {
        lua_pushboolean(L, 0);
        lua_pushinteger(L, kLuaBridgeErrorInvalidParameters);
        return 2;
    }

    Class targetClass = NSClassFromString([NSString stringWithCString:className encoding:NSUTF8StringEncoding]);
    if (!targetClass)
    {
        lua_pushboolean(L, 0);
        lua_pushinteger(L, kLuaBridgeErrorClassNotFound);
        return 2;
    }

    SEL methodSel;
    bool hasArguments = lua_istable(L, -1);
    if (hasArguments)
    {
        NSString* methodName_ = [NSString stringWithCString:methodName encoding:NSUTF8StringEncoding];
        methodName_           = [NSString stringWithFormat:@"%@:", methodName_];
        methodSel             = NSSelectorFromString(methodName_);
    }
    else
    {
        methodSel = NSSelectorFromString([NSString stringWithCString:methodName encoding:NSUTF8StringEncoding]);
    }
    if (methodSel == (SEL)0)
    {
        lua_pushboolean(L, 0);
        lua_pushinteger(L, kLuaBridgeErrorMethodNotFound);
        return 2;
    }

    NSMethodSignature* methodSig = [targetClass methodSignatureForSelector:(SEL)methodSel];
    if (methodSig == nil)
    {
        lua_pushboolean(L, 0);
        lua_pushinteger(L, kLuaBridgeErrorMethodSignature);
        return 2;
    }

    @try
    {
        NSInvocation* invocation = [NSInvocation invocationWithMethodSignature:methodSig];
        [invocation setTarget:targetClass];
        [invocation setSelector:methodSel];
        NSUInteger returnLength = [methodSig methodReturnLength];
        const char* returnType  = [methodSig methodReturnType];

        if (hasArguments)
        {
            NSMutableDictionary* dict = [NSMutableDictionary dictionary];
            lua_pushnil(L);
            while (lua_next(L, -2))
            {
                NSString* key = [NSString stringWithCString:lua_tostring(L, -2) encoding:NSUTF8StringEncoding];

                switch (lua_type(L, -1))
                {
                case LUA_TNUMBER:
                    [dict setObject:[NSNumber numberWithFloat:lua_tonumber(L, -1)] forKey:key];
                    break;

                case LUA_TBOOLEAN:
                    [dict setObject:[NSNumber numberWithBool:lua_toboolean(L, -1)] forKey:key];
                    break;

                case LUA_TSTRING:
                    [dict setObject:[NSString stringWithCString:lua_tostring(L, -1) encoding:NSUTF8StringEncoding]
                             forKey:key];
                    break;

                case LUA_TTABLE:
                    luaTableToObjcDictionary(L, dict, key);
                    break;

                case LUA_TFUNCTION:
                    int functionId = retainLuaFunction(L, -1, NULL);
                    [dict setObject:[NSNumber numberWithInt:functionId] forKey:key];
                    break;
                }

                lua_pop(L, 1);
            }

            [invocation setArgument:&dict atIndex:2];
            [invocation invoke];
        }
        else
        {
            [invocation invoke];
        }

        lua_pushboolean(L, 1);
        if (returnLength > 0)
        {
            if (strcmp(returnType, @encode(id)) == 0)
            {
                id ret;
                [invocation getReturnValue:&ret];
                pushValue(L, ret);
            }
            else if (strcmp(returnType, @encode(BOOL)) == 0)  // BOOL
            {
                char ret;
                [invocation getReturnValue:&ret];
                lua_pushboolean(L, ret);
            }
            else if (strcmp(returnType, @encode(int)) == 0)  // int
            {
                int ret;
                [invocation getReturnValue:&ret];
                lua_pushinteger(L, ret);
            }
            else if (strcmp(returnType, @encode(float)) == 0)  // float
            {
                float ret;
                [invocation getReturnValue:&ret];
                lua_pushnumber(L, ret);
            }
            else
            {
                NSLog(@"not support return type = %s", returnType);
                lua_pushnil(L);
            }
        }
        else
        {
            lua_pushnil(L);
        }
        return 2;
    }
    @catch (NSException* exception)
    {
        NSLog(@"EXCEPTION THROW: %@", exception);
        lua_pushboolean(L, 0);
        lua_pushinteger(L, kLuaBridgeErrorExceptionOccurred);
        return 2;
    }
}

void LuaObjcBridge::pushValue(lua_State* L, void* val)
{
    id oval = (id)val;
    if (oval == nil)
    {
        lua_pushnil(L);
    }
    else if ([oval isKindOfClass:[NSNumber class]])
    {
        NSNumber* number       = (NSNumber*)oval;
        const char* numberType = [number objCType];
        if (strcmp(numberType, @encode(BOOL)) == 0)
        {
            lua_pushboolean(L, [number boolValue]);
        }
        else if (strcmp(numberType, @encode(int)) == 0)
        {
            lua_pushinteger(L, [number intValue]);
        }
        else
        {
            lua_pushnumber(L, [number floatValue]);
        }
    }
    else if ([oval isKindOfClass:[NSString class]])
    {
        lua_pushstring(L, [oval cStringUsingEncoding:NSUTF8StringEncoding]);
    }
    else if ([oval isKindOfClass:[NSDictionary class]])
    {
        lua_newtable(L);

        for (id key in oval)
        {
            const char* key_ = [[NSString stringWithFormat:@"%@", key] cStringUsingEncoding:NSUTF8StringEncoding];
            lua_pushstring(L, key_);
            pushValue(L, [oval objectForKey:key]);
            lua_rawset(L, -3);
        }

        return;
    }
    else
    {
        lua_pushstring(L, [[NSString stringWithFormat:@"%@", oval] cStringUsingEncoding:NSUTF8StringEncoding]);
    }
}

NS_AX_END