// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

#include "common/common.h"

#include "core/mem_map.h"
#include "core/hle/kernel/shared_memory.h"

namespace Kernel {

class SharedMemory : public Object {
public:
    std::string GetTypeName() const override { return "SharedMemory"; }

    static Kernel::HandleType GetStaticHandleType() {  return Kernel::HandleType::SharedMemory; }
    Kernel::HandleType GetHandleType() const override { return Kernel::HandleType::SharedMemory; }

    u32 base_address;                   ///< Address of shared memory block in RAM
    MemoryPermission permissions;       ///< Permissions of shared memory block (SVC field)
    MemoryPermission other_permissions; ///< Other permissions of shared memory block (SVC field)
    std::string name;                   ///< Name of shared memory object (optional)
};

////////////////////////////////////////////////////////////////////////////////////////////////////

/**
 * Creates a shared memory object
 * @param handle Handle of newly created shared memory object
 * @param name Name of shared memory object
 * @return Pointer to newly created shared memory object
 */
SharedMemory* CreateSharedMemory(Handle& handle, const std::string& name) {
    SharedMemory* shared_memory = new SharedMemory;
    handle = Kernel::g_object_pool.Create(shared_memory);
    shared_memory->name = name;
    return shared_memory;
}

Handle CreateSharedMemory(const std::string& name) {
    Handle handle;
    CreateSharedMemory(handle, name);
    return handle;
}

/**
 * Maps a shared memory block to an address in system memory
 * @param handle Shared memory block handle
 * @param address Address in system memory to map shared memory block to
 * @param permissions Memory block map permissions (specified by SVC field)
 * @param other_permissions Memory block map other permissions (specified by SVC field)
 * @return Result of operation, 0 on success, otherwise error code
 */
ResultCode MapSharedMemory(u32 handle, u32 address, MemoryPermission permissions,
    MemoryPermission other_permissions) {

    if (address < Memory::SHARED_MEMORY_VADDR || address >= Memory::SHARED_MEMORY_VADDR_END) {
        LOG_ERROR(Kernel_SVC, "cannot map handle=0x%08X, address=0x%08X outside of shared mem bounds!",
            handle, address);
        return ResultCode(ErrorDescription::InvalidAddress, ErrorModule::Kernel,
                ErrorSummary::InvalidArgument, ErrorLevel::Permanent);
    }
    SharedMemory* shared_memory = Kernel::g_object_pool.Get<SharedMemory>(handle);
    if (shared_memory == nullptr) return InvalidHandle(ErrorModule::Kernel);

    shared_memory->base_address = address;
    shared_memory->permissions = permissions;
    shared_memory->other_permissions = other_permissions;

    return RESULT_SUCCESS;
}

ResultVal<u8*> GetSharedMemoryPointer(Handle handle, u32 offset) {
    SharedMemory* shared_memory = Kernel::g_object_pool.Get<SharedMemory>(handle);
    if (shared_memory == nullptr) return InvalidHandle(ErrorModule::Kernel);

    if (0 != shared_memory->base_address)
        return MakeResult<u8*>(Memory::GetPointer(shared_memory->base_address + offset));

    LOG_ERROR(Kernel_SVC, "memory block handle=0x%08X not mapped!", handle);
    // TODO(yuriks): Verify error code.
    return ResultCode(ErrorDescription::InvalidAddress, ErrorModule::Kernel,
            ErrorSummary::InvalidState, ErrorLevel::Permanent);
}

} // namespace