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

#include <map>
#include <memory>
#include <utility>
#include <vector>

#include "common/common_types.h"
#include "common/logging/log.h"

#include "core/hle/config_mem.h"
#include "core/hle/kernel/memory.h"
#include "core/hle/kernel/vm_manager.h"
#include "core/hle/result.h"
#include "core/hle/shared_page.h"
#include "core/memory.h"
#include "core/memory_setup.h"

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

namespace Kernel {

static MemoryRegionInfo memory_regions[3];

/// Size of the APPLICATION, SYSTEM and BASE memory regions (respectively) for each sytem
/// memory configuration type.
static const u32 memory_region_sizes[8][3] = {
    // Old 3DS layouts
    {0x04000000, 0x02C00000, 0x01400000}, // 0
    { /* This appears to be unused. */ }, // 1
    {0x06000000, 0x00C00000, 0x01400000}, // 2
    {0x05000000, 0x01C00000, 0x01400000}, // 3
    {0x04800000, 0x02400000, 0x01400000}, // 4
    {0x02000000, 0x04C00000, 0x01400000}, // 5

    // New 3DS layouts
    {0x07C00000, 0x06400000, 0x02000000}, // 6
    {0x0B200000, 0x02E00000, 0x02000000}, // 7
};

void MemoryInit(u32 mem_type) {
    // TODO(yuriks): On the n3DS, all o3DS configurations (<=5) are forced to 6 instead.
    ASSERT_MSG(mem_type <= 5, "New 3DS memory configuration aren't supported yet!");
    ASSERT(mem_type != 1);

    // The kernel allocation regions (APPLICATION, SYSTEM and BASE) are laid out in sequence, with
    // the sizes specified in the memory_region_sizes table.
    VAddr base = 0;
    for (int i = 0; i < 3; ++i) {
        memory_regions[i].base = base;
        memory_regions[i].size = memory_region_sizes[mem_type][i];
        memory_regions[i].linear_heap_memory = std::make_shared<std::vector<u8>>();

        base += memory_regions[i].size;
    }

    // We must've allocated the entire FCRAM by the end
    ASSERT(base == Memory::FCRAM_SIZE);

    using ConfigMem::config_mem;
    config_mem.app_mem_type = mem_type;
    // app_mem_malloc does not always match the configured size for memory_region[0]: in case the
    // n3DS type override is in effect it reports the size the game expects, not the real one.
    config_mem.app_mem_alloc = memory_region_sizes[mem_type][0];
    config_mem.sys_mem_alloc = memory_regions[1].size;
    config_mem.base_mem_alloc = memory_regions[2].size;
}

void MemoryShutdown() {
    for (auto& region : memory_regions) {
        region.base = 0;
        region.size = 0;
        region.linear_heap_memory = nullptr;
    }
}

MemoryRegionInfo* GetMemoryRegion(MemoryRegion region) {
    switch (region) {
    case MemoryRegion::APPLICATION:
        return &memory_regions[0];
    case MemoryRegion::SYSTEM:
        return &memory_regions[1];
    case MemoryRegion::BASE:
        return &memory_regions[2];
    default:
        UNREACHABLE();
    }
}

}

namespace Memory {

namespace {

struct MemoryArea {
    u32 base;
    u32 size;
    const char* name;
};

// We don't declare the IO regions in here since its handled by other means.
static MemoryArea memory_areas[] = {
    {SHARED_MEMORY_VADDR, SHARED_MEMORY_SIZE,     "Shared Memory"}, // Shared memory
    {VRAM_VADDR,          VRAM_SIZE,              "VRAM"},          // Video memory (VRAM)
    {DSP_RAM_VADDR,       DSP_RAM_SIZE,           "DSP RAM"},       // DSP memory
    {TLS_AREA_VADDR,      TLS_AREA_SIZE,          "TLS Area"},      // TLS memory
};

/// Represents a block of memory mapped by ControlMemory/MapMemoryBlock
struct MemoryBlock {
    MemoryBlock() : handle(0), base_address(0), address(0), size(0), operation(0), permissions(0) {
    }
    u32 handle;
    u32 base_address;
    u32 address;
    u32 size;
    u32 operation;
    u32 permissions;

    const u32 GetVirtualAddress() const{
        return base_address + address;
    }
};

static std::map<u32, MemoryBlock> heap_map;
static std::map<u32, MemoryBlock> heap_linear_map;

}

u32 MapBlock_Heap(u32 size, u32 operation, u32 permissions) {
    MemoryBlock block;

    block.base_address  = HEAP_VADDR;
    block.size          = size;
    block.operation     = operation;
    block.permissions   = permissions;

    if (heap_map.size() > 0) {
        const MemoryBlock last_block = heap_map.rbegin()->second;
        block.address = last_block.address + last_block.size;
    }
    heap_map[block.GetVirtualAddress()] = block;

    return block.GetVirtualAddress();
}

u32 MapBlock_HeapLinear(u32 size, u32 operation, u32 permissions) {
    MemoryBlock block;

    block.base_address  = LINEAR_HEAP_VADDR;
    block.size          = size;
    block.operation     = operation;
    block.permissions   = permissions;

    if (heap_linear_map.size() > 0) {
        const MemoryBlock last_block = heap_linear_map.rbegin()->second;
        block.address = last_block.address + last_block.size;
    }
    heap_linear_map[block.GetVirtualAddress()] = block;

    return block.GetVirtualAddress();
}

void Init() {
    InitMemoryMap();
    LOG_DEBUG(HW_Memory, "initialized OK");
}

void InitLegacyAddressSpace(Kernel::VMManager& address_space) {
    using namespace Kernel;

    for (MemoryArea& area : memory_areas) {
        auto block = std::make_shared<std::vector<u8>>(area.size);
        address_space.MapMemoryBlock(area.base, std::move(block), 0, area.size, MemoryState::Private).Unwrap();
    }

    auto cfg_mem_vma = address_space.MapBackingMemory(CONFIG_MEMORY_VADDR,
            (u8*)&ConfigMem::config_mem, CONFIG_MEMORY_SIZE, MemoryState::Shared).MoveFrom();
    address_space.Reprotect(cfg_mem_vma, VMAPermission::Read);

    auto shared_page_vma = address_space.MapBackingMemory(SHARED_PAGE_VADDR,
            (u8*)&SharedPage::shared_page, SHARED_PAGE_SIZE, MemoryState::Shared).MoveFrom();
    address_space.Reprotect(shared_page_vma, VMAPermission::Read);
}

void Shutdown() {
    heap_map.clear();
    heap_linear_map.clear();

    LOG_DEBUG(HW_Memory, "shutdown OK");
}

} // namespace
