#include "il2cpp-config.h"
#include "metadata/GenericMetadata.h"
#include "metadata/GenericMethod.h"
#include "metadata/GenericSharing.h"
#include "metadata/Il2CppGenericMethodCompare.h"
#include "metadata/Il2CppGenericMethodHash.h"
#include "os/Mutex.h"
#include "utils/Memory.h"
#include "vm/Class.h"
#include "vm/Exception.h"
#include "vm/GenericClass.h"
#include "vm/MetadataAlloc.h"
#include "vm/MetadataCache.h"
#include "vm/MetadataLock.h"
#include "vm/Method.h"
#include "vm/Runtime.h"
#include "vm/Type.h"
#include "utils/Il2CppHashMap.h"
#include "il2cpp-class-internals.h"
#include "il2cpp-runtime-metadata.h"
#include "il2cpp-runtime-stats.h"
#include <string>

using il2cpp::metadata::GenericMetadata;
using il2cpp::metadata::GenericSharing;
using il2cpp::os::FastAutoLock;
using il2cpp::vm::Class;
using il2cpp::vm::GenericClass;
using il2cpp::vm::MetadataCalloc;
using il2cpp::vm::MetadataCache;
using il2cpp::vm::Method;
using il2cpp::vm::Runtime;
using il2cpp::vm::Type;

namespace il2cpp
{
namespace metadata
{
    typedef Il2CppHashMap<const Il2CppGenericMethod*, MethodInfo*, Il2CppGenericMethodHash, Il2CppGenericMethodCompare> Il2CppGenericMethodMap;
    static Il2CppGenericMethodMap s_GenericMethodMap;

    static void AGenericMethodWhichIsTooDeeplyNestedWasInvoked()
    {
        vm::Exception::Raise(vm::Exception::GetMaximumNestedGenericsException());
    }

    static void AGenericMethodWhichIsTooDeeplyNestedWasInvokedInvoker(Il2CppMethodPointer ptr, const MethodInfo* method, void* obj, void** args, void* ret)
    {
        AGenericMethodWhichIsTooDeeplyNestedWasInvoked();
    }

    const MethodInfo* GenericMethod::GetMethod(const Il2CppGenericMethod* gmethod, bool copyMethodPtr)
    {
        FastAutoLock lock(&il2cpp::vm::g_MetadataLock);

        // This can be NULL only when we have hit the generic recursion depth limit.
        if (gmethod == NULL)
        {
            MethodInfo* newMethod = (MethodInfo*)MetadataCalloc(1, sizeof(MethodInfo));
            newMethod->methodPointer = AGenericMethodWhichIsTooDeeplyNestedWasInvoked;
            newMethod->invoker_method = AGenericMethodWhichIsTooDeeplyNestedWasInvokedInvoker;
            return newMethod;
        }

        Il2CppGenericMethodMap::const_iterator iter = s_GenericMethodMap.find(gmethod);
        if (iter != s_GenericMethodMap.end())
            return iter->second;

        if (copyMethodPtr)
        {
            Il2CppGenericMethod *newGMethod = vm::MetadataAllocGenericMethod();
            newGMethod->methodDefinition = gmethod->methodDefinition;
            newGMethod->context = gmethod->context;
            gmethod = newGMethod;
        }

        const MethodInfo* methodDefinition = gmethod->methodDefinition;
        Il2CppClass* declaringClass = methodDefinition->klass;
        if (gmethod->context.class_inst)
        {
            IL2CPP_ASSERT(!declaringClass->generic_class);
            Il2CppGenericClass* genericClassDeclaringType = GenericMetadata::GetGenericClass(methodDefinition->klass, gmethod->context.class_inst);
            declaringClass = GenericClass::GetClass(genericClassDeclaringType);

            // we may fail if we cannot construct generic type
            if (!declaringClass)
                return NULL;
        }
        MethodInfo* newMethod = (MethodInfo*)MetadataCalloc(1, sizeof(MethodInfo));

        // we set this here because the initialization may recurse and try to retrieve the same generic method
        // this is safe because we *always* take the lock when retrieving the MethodInfo from a generic method.
        // if we move lock to only if MethodInfo needs constructed then we need to revisit this since we could return a partially initialized MethodInfo
        s_GenericMethodMap.insert(std::make_pair(gmethod, newMethod));

        newMethod->klass = declaringClass;
        newMethod->flags = methodDefinition->flags;
        newMethod->iflags = methodDefinition->iflags;
        newMethod->slot = methodDefinition->slot;
        newMethod->name = methodDefinition->name;
        newMethod->is_generic = false;
        newMethod->is_inflated = true;
        newMethod->token = methodDefinition->token;

        newMethod->return_type = GenericMetadata::InflateIfNeeded(methodDefinition->return_type, &gmethod->context, true);

        newMethod->parameters_count = methodDefinition->parameters_count;
        newMethod->parameters = GenericMetadata::InflateParameters(methodDefinition->parameters, methodDefinition->parameters_count, &gmethod->context, true);

        newMethod->genericMethod = gmethod;

        if (!gmethod->context.method_inst)
        {
            if (methodDefinition->is_generic)
                newMethod->is_generic = true;

            if (!declaringClass->generic_class)
            {
                newMethod->genericContainerHandle = methodDefinition->genericContainerHandle;
            }

            newMethod->methodMetadataHandle = methodDefinition->methodMetadataHandle;
        }
        else
        {
            // we only need RGCTX for generic instance methods
            newMethod->rgctx_data = GenericMetadata::InflateRGCTX(gmethod->methodDefinition->klass->image, gmethod->methodDefinition->token, &gmethod->context);
        }

        newMethod->methodPointer = MetadataCache::GetMethodPointer(methodDefinition, &gmethod->context);
        if (newMethod->methodPointer)
            newMethod->invoker_method = MetadataCache::GetInvokerMethodPointer(methodDefinition, &gmethod->context);
        else
            newMethod->invoker_method = Runtime::GetMissingMethodInvoker();

        ++il2cpp_runtime_stats.inflated_method_count;

        return newMethod;
    }

    const Il2CppGenericContext* GenericMethod::GetContext(const Il2CppGenericMethod* gmethod)
    {
        return &gmethod->context;
    }

    static std::string FormatGenericArguments(const Il2CppGenericInst* inst)
    {
        std::string output;
        if (inst)
        {
            output.append("<");
            for (size_t i = 0; i < inst->type_argc; ++i)
            {
                if (i != 0)
                    output.append(", ");
                output.append(Type::GetName(inst->type_argv[i], IL2CPP_TYPE_NAME_FORMAT_FULL_NAME));
            }
            output.append(">");
        }

        return output;
    }

    std::string GenericMethod::GetFullName(const Il2CppGenericMethod* gmethod)
    {
        const MethodInfo* method = gmethod->methodDefinition;
        std::string output;
        output.append(Type::GetName(&gmethod->methodDefinition->klass->byval_arg, IL2CPP_TYPE_NAME_FORMAT_FULL_NAME));
        output.append(FormatGenericArguments(gmethod->context.class_inst));
        output.append("::");
        output.append(Method::GetName(method));
        output.append(FormatGenericArguments(gmethod->context.method_inst));

        return output;
    }

    void GenericMethod::ClearStatics()
    {
        s_GenericMethodMap.clear();
    }
} /* namespace vm */
} /* namespace il2cpp */
