/*
 * Copyright (c) Atmosphère-NX
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#pragma once
#include <stratosphere.hpp>

namespace ams::lmem::impl {

    constexpr inline u32 ExpHeapMagic    = util::ReverseFourCC<'E','X','P','H'>::Code;
    constexpr inline u32 FrameHeapMagic  = util::ReverseFourCC<'F','R','M','H'>::Code;
    constexpr inline u32 UnitHeapMagic   = util::ReverseFourCC<'U','N','T','H'>::Code;

    class ScopedHeapLock {
        NON_COPYABLE(ScopedHeapLock);
        NON_MOVEABLE(ScopedHeapLock);
        private:
            HeapHandle m_handle;
        public:
            explicit ScopedHeapLock(HeapHandle h) : m_handle(h) {
                if (m_handle->option & CreateOption_ThreadSafe) {
                    os::LockSdkMutex(std::addressof(m_handle->mutex));
                }
            }

            ~ScopedHeapLock() {
                if (m_handle->option & CreateOption_ThreadSafe) {
                    os::UnlockSdkMutex(std::addressof(m_handle->mutex));
                }
            }
    };

    constexpr inline MemoryRange MakeMemoryRange(void *address, size_t size) {
        return MemoryRange{ .address = reinterpret_cast<uintptr_t>(address), .size = size };
    }

    constexpr inline void *GetHeapStartAddress(HeapHandle handle) {
        return handle->heap_start;
    }

    constexpr inline size_t GetPointerDifference(const void *start, const void *end) {
        return reinterpret_cast<uintptr_t>(end) - reinterpret_cast<uintptr_t>(start);
    }

    constexpr inline size_t GetPointerDifference(uintptr_t start, uintptr_t end) {
        return end - start;
    }

    void InitializeHeapHead(HeapHead *out, u32 magic, void *start, void *end, u32 option);
    void FinalizeHeap(HeapHead *heap);
    bool ContainsAddress(HeapHandle handle, const void *address);
    size_t GetHeapTotalSize(HeapHandle handle);

    /* Debug Fill */
    u32 GetDebugFillValue(FillType type);
    u32 SetDebugFillValue(FillType type, u32 value);

    inline void FillMemory(void *dst, u32 fill_value, size_t size) {
        /* All heap blocks must be at least 32-bit aligned. */
        AMS_ASSERT(util::IsAligned(reinterpret_cast<uintptr_t>(dst), alignof(u32)));
        AMS_ASSERT(util::IsAligned(size, sizeof(u32)));
        for (size_t i = 0; i < size / sizeof(fill_value); i++) {
            reinterpret_cast<u32 *>(dst)[i] = fill_value;
        }
    }

    inline void FillUnallocatedMemory(HeapHead *heap, void *address, size_t size) {
        if (heap->option & CreateOption_DebugFill) {
            FillMemory(address, impl::GetDebugFillValue(FillType_Unallocated), size);
        }
    }

    inline void FillAllocatedMemory(HeapHead *heap, void *address, size_t size) {
        if (heap->option & CreateOption_ZeroClear) {
            FillMemory(address, 0, size);
        } else if (heap->option & CreateOption_DebugFill) {
            FillMemory(address, impl::GetDebugFillValue(FillType_Allocated), size);
        }
    }

    inline void FillFreedMemory(HeapHead *heap, void *address, size_t size) {
        if (heap->option & CreateOption_DebugFill) {
            FillMemory(address, impl::GetDebugFillValue(FillType_Freed), size);
        }
    }

}