/**

GDevelop - Function Extension
Copyright (c) 2008-2016 Florian Rival (Florian.Rival@gmail.com)
This project is released under the MIT License.
*/

#include "GDCpp/Extensions/ExtensionBase.h"

#include "GDCore/Events/CodeGeneration/ExpressionsCodeGeneration.h"
#include "GDCore/Events/CodeGeneration/EventsCodeGenerationContext.h"
#include "GDCore/Events/CodeGeneration/EventsCodeGenerator.h"
#include "GDCore/Events/Tools/EventsCodeNameMangler.h"
#include "GDCpp/Extensions/CppPlatform.h"
#include "GDCpp/Runtime/Project/Project.h"
#include "GDCpp/Runtime/Project/Layout.h"
#include "GDCpp/Runtime/CommonTools.h"
#if defined(GD_IDE_ONLY)
#include "GDCore/Events/Parsers/ExpressionParser.h"
#include "GDCore/Events/Instruction.h"
#endif
#include "FunctionEvent.h"


/**
 * \brief This class declares information about the extension.
 */
class Extension : public ExtensionBase
{
public:

    /**
     * Constructor of an extension declares everything the extension contains: objects, actions, conditions and expressions.
     */
    Extension()
    {
        SetExtensionInformation("Function",
                              _("Function events"),
                              _("This Extension allows you to use events that behave like functions."),
                              "Florian Rival",
                              "Open source (MIT License)");

        #if defined(GD_IDE_ONLY)

        AddAction("LaunchFunction",
            _("Launch a function"),
            _("Launch a function"),
            _("Launch _PARAM0_ (_PARAM1_, _PARAM2_, _PARAM3_, _PARAM4_, _PARAM5_, _PARAM6_, _PARAM7_)"),
            _("Functions"),
            "res/actions/function24.png",
            "res/actions/function.png")
            .AddParameter("", _("Name of the function"))
            .AddParameter("string", _("Parameter 1"), "", true)
            .AddParameter("string", _("Parameter 2"), "", true)
            .AddParameter("string", _("Parameter 3"), "", true)
            .AddParameter("string", _("Parameter 4"), "", true)
            .AddParameter("string", _("Parameter 5"), "", true)
            .AddParameter("string", _("Parameter 6"), "", true)
            .AddParameter("string", _("Parameter 7"), "", true)
            .codeExtraInformation.SetCustomCodeGenerator([](gd::Instruction & instruction, gd::EventsCodeGenerator & codeGenerator, gd::EventsCodeGenerationContext & context) {
                gd::String functionName = instruction.GetParameter(0).GetPlainString();
                const gd::Project & project = codeGenerator.GetProject();
                const gd::Layout & layout = codeGenerator.GetLayout();

                const FunctionEvent * functionEvent = FunctionEvent::SearchForFunctionInEvents(project, layout.GetEvents(), functionName);
                if ( !functionEvent )
                {
                    std::cout << "Function \""+functionName+"\" not found!" << std::endl;
                    return "//Function \""+functionName+"\" not found.\n";
                }

                codeGenerator.AddGlobalDeclaration("void "+FunctionEvent::MangleFunctionName(layout, *functionEvent)+"(RuntimeContext *, std::map <gd::String, std::vector<RuntimeObject*> *>, std::vector<gd::String> &);\n");
                gd::String code;

                //Generate code for objects passed as arguments
                gd::String objectsAsArgumentCode;
                {
                    objectsAsArgumentCode += "runtimeContext->ClearObjectListsMap()";
                    std::vector<gd::String> realObjects = codeGenerator.ExpandObjectsName(functionEvent->GetObjectsPassedAsArgument(), context);
                    for (std::size_t i = 0;i<realObjects.size();++i)
                    {
                        context.EmptyObjectsListNeeded(realObjects[i]);
                        objectsAsArgumentCode += ".AddObjectListToMap(\""+codeGenerator.ConvertToString(realObjects[i])+"\", "+ManObjListName(realObjects[i])+")";
                    }
                    objectsAsArgumentCode += ".ReturnObjectListsMap()";
                }

                //Generate code for evaluating parameters
                code += "std::vector<gd::String> functionParameters;\n";
                for (std::size_t i = 1;i<8;++i)
                {
                    gd::String parameterCode;
                    gd::CallbacksForGeneratingExpressionCode callbacks(parameterCode, codeGenerator, context);
                    gd::ExpressionParser parser(instruction.GetParameter(i).GetPlainString());
                    parser.ParseStringExpression(CppPlatform::Get(), project, layout, callbacks);
                    if (parameterCode.empty()) parameterCode = "\"\"";

                    code += "functionParameters.push_back("+parameterCode+");\n";
                }

                code += FunctionEvent::MangleFunctionName(layout, *functionEvent)+"(runtimeContext, "+objectsAsArgumentCode+", functionParameters);\n";
                return code;
            });

        AddEvent("Function",
            _("Function"),
            _("Function event : An event that can only be launched by the action named \"Launch a function\""),
            "",
            "res/function.png",
            std::make_shared<FunctionEvent>())
            .SetCodeGenerator([](gd::BaseEvent & event_, gd::EventsCodeGenerator & codeGenerator,
                gd::EventsCodeGenerationContext & /* The function has nothing to do with the current context */){
                FunctionEvent & event = dynamic_cast<FunctionEvent&>(event_);
                const gd::Layout & layout = codeGenerator.GetLayout();

                //Declaring function prototype.
                codeGenerator.AddGlobalDeclaration("void "+FunctionEvent::MangleFunctionName(layout, event)+"(RuntimeContext *, std::map <gd::String, std::vector<RuntimeObject*> *>, std::vector<gd::String> &);\n");

                //Generating function code:
                gd::String functionCode;
                functionCode += "\nvoid "+FunctionEvent::MangleFunctionName(layout, event)+"(RuntimeContext * runtimeContext, std::map <gd::String, std::vector<RuntimeObject*> *> objectsListsMap, std::vector<gd::String> & currentFunctionParameters)\n{\n";

                gd::EventsCodeGenerationContext callerContext;
                {
                    std::vector<gd::String> realObjects = codeGenerator.ExpandObjectsName(event.GetObjectsPassedAsArgument(), callerContext);
                    for (std::size_t i = 0;i<realObjects.size();++i)
                    {
                        callerContext.EmptyObjectsListNeeded(realObjects[i]);
                        functionCode += "std::vector<RuntimeObject*> "+ManObjListName(realObjects[i]) + ";\n";
                        functionCode += "if ( objectsListsMap[\""+realObjects[i]+"\"] != NULL ) "+ManObjListName(realObjects[i])+" = *objectsListsMap[\""+realObjects[i]+"\"];\n";
                    }
                }
                functionCode += "{";

                gd::EventsCodeGenerationContext context;
                context.InheritsFrom(callerContext);

                //Generating function body code
                gd::String conditionsCode = codeGenerator.GenerateConditionsListCode(event.GetConditions(), context);
                gd::String actionsCode = codeGenerator.GenerateActionsListCode(event.GetActions(), context);
                gd::String subeventsCode = codeGenerator.GenerateEventsListCode(event.GetSubEvents(), context);

                functionCode += codeGenerator.GenerateObjectsDeclarationCode(context);
                gd::String ifPredicat = "true";
                for (std::size_t i = 0;i<event.GetConditions().size();++i)
                    ifPredicat += " && condition"+gd::String::From(i)+"IsTrue";

                functionCode += conditionsCode;
                functionCode += "if (" +ifPredicat+ ")\n";
                functionCode += "{\n";
                functionCode += actionsCode;
                if ( event.HasSubEvents() ) //Sub events
                {
                    functionCode += "\n{\n";
                    functionCode += subeventsCode;
                    functionCode += "}\n";
                }
                functionCode += "}\n";

                functionCode += "}\n"; //Context end
                functionCode += "}\n"; //Function end
                codeGenerator.AddCustomCodeOutsideMain(functionCode);

                return "";
            });

        AddStrExpression("Parameter",
            _("Parameter of the current function"),
            _("Return the text contained in a parameter of the currently-launched function"),
            _("Function"),
            "res/function.png")
            .AddParameter("expression", _("Index of the parameter (Parameters start at 0!)"))
            .codeExtraInformation.SetCustomCodeGenerator([](const std::vector<gd::Expression> & parameters, gd::EventsCodeGenerator & codeGenerator, gd::EventsCodeGenerationContext & context) {
                codeGenerator.AddIncludeFile("Function/FunctionTools.h");
                const gd::Project & game = codeGenerator.GetProject();
                const gd::Layout & scene = codeGenerator.GetLayout();

                //Ensure currentFunctionParameters vector is always existing.
                gd::String mainFakeParameters = "std::vector<gd::String> currentFunctionParameters;\n";
                if (codeGenerator.GetCustomCodeInMain().find(mainFakeParameters) == gd::String::npos)
                    codeGenerator.AddCustomCodeInMain(mainFakeParameters);

                //Generate code for evaluating index
                gd::String expression;
                gd::CallbacksForGeneratingExpressionCode callbacks(expression, codeGenerator, context);
                gd::ExpressionParser parser(parameters[0].GetPlainString());
                if (!parser.ParseMathExpression(codeGenerator.GetPlatform(), game, scene, callbacks) || expression.empty()) expression = "0";

                gd::String code;

                code += "GDpriv::FunctionTools::GetSafelyStringFromVector(currentFunctionParameters, "+expression+")";

                return code;
            });
        #endif

        GD_COMPLETE_EXTENSION_COMPILATION_INFORMATION();
    };
};

/**
 * Used by GDevelop to create the extension class
 * -- Do not need to be modified. --
 */
extern "C" ExtensionBase * GD_EXTENSION_API CreateGDExtension() {
    return new Extension;
}