// Copyright 2013 Dolphin Emulator Project / 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

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

#ifdef _WIN32
#include <windows.h>
// Windows.h needs to be included before psapi.h
#include <psapi.h>
#include "common/common_funcs.h"
#include "common/string_util.h"
#else
#include <cstdlib>
#include <sys/mman.h>
#endif

#if !defined(_WIN32) && defined(ARCHITECTURE_x86_64) && !defined(MAP_32BIT)
#include <unistd.h>
#define PAGE_MASK (getpagesize() - 1)
#define round_page(x) ((((unsigned long)(x)) + PAGE_MASK) & ~(PAGE_MASK))
#endif

// This is purposely not a full wrapper for virtualalloc/mmap, but it
// provides exactly the primitive operations that Dolphin needs.

void* AllocateExecutableMemory(size_t size, bool low) {
#if defined(_WIN32)
    void* ptr = VirtualAlloc(nullptr, size, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
#else
    static char* map_hint = nullptr;
#if defined(ARCHITECTURE_x86_64) && !defined(MAP_32BIT)
    // This OS has no flag to enforce allocation below the 4 GB boundary,
    // but if we hint that we want a low address it is very likely we will
    // get one.
    // An older version of this code used MAP_FIXED, but that has the side
    // effect of discarding already mapped pages that happen to be in the
    // requested virtual memory range (such as the emulated RAM, sometimes).
    if (low && (!map_hint))
        map_hint = (char*)round_page(512 * 1024 * 1024); /* 0.5 GB rounded up to the next page */
#endif
    void* ptr = mmap(map_hint, size, PROT_READ | PROT_WRITE | PROT_EXEC,
                     MAP_ANON | MAP_PRIVATE
#if defined(ARCHITECTURE_x86_64) && defined(MAP_32BIT)
                         | (low ? MAP_32BIT : 0)
#endif
                         ,
                     -1, 0);
#endif /* defined(_WIN32) */

#ifdef _WIN32
    if (ptr == nullptr) {
#else
    if (ptr == MAP_FAILED) {
        ptr = nullptr;
#endif
        LOG_ERROR(Common_Memory, "Failed to allocate executable memory");
    }
#if !defined(_WIN32) && defined(ARCHITECTURE_x86_64) && !defined(MAP_32BIT)
    else {
        if (low) {
            map_hint += size;
            map_hint = (char*)round_page(map_hint); /* round up to the next page */
        }
    }
#endif

#if EMU_ARCH_BITS == 64
    if ((u64)ptr >= 0x80000000 && low == true)
        LOG_ERROR(Common_Memory, "Executable memory ended up above 2GB!");
#endif

    return ptr;
}

void* AllocateMemoryPages(size_t size) {
#ifdef _WIN32
    void* ptr = VirtualAlloc(nullptr, size, MEM_COMMIT, PAGE_READWRITE);
#else
    void* ptr = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);

    if (ptr == MAP_FAILED)
        ptr = nullptr;
#endif

    if (ptr == nullptr)
        LOG_ERROR(Common_Memory, "Failed to allocate raw memory");

    return ptr;
}

void* AllocateAlignedMemory(size_t size, size_t alignment) {
#ifdef _WIN32
    void* ptr = _aligned_malloc(size, alignment);
#else
    void* ptr = nullptr;
#ifdef ANDROID
    ptr = memalign(alignment, size);
#else
    if (posix_memalign(&ptr, alignment, size) != 0)
        LOG_ERROR(Common_Memory, "Failed to allocate aligned memory");
#endif
#endif

    if (ptr == nullptr)
        LOG_ERROR(Common_Memory, "Failed to allocate aligned memory");

    return ptr;
}

void FreeMemoryPages(void* ptr, size_t size) {
    if (ptr) {
#ifdef _WIN32
        if (!VirtualFree(ptr, 0, MEM_RELEASE))
            LOG_ERROR(Common_Memory, "FreeMemoryPages failed!\n{}", GetLastErrorMsg());
#else
        munmap(ptr, size);
#endif
    }
}

void FreeAlignedMemory(void* ptr) {
    if (ptr) {
#ifdef _WIN32
        _aligned_free(ptr);
#else
        free(ptr);
#endif
    }
}

void WriteProtectMemory(void* ptr, size_t size, bool allowExecute) {
#ifdef _WIN32
    DWORD oldValue;
    if (!VirtualProtect(ptr, size, allowExecute ? PAGE_EXECUTE_READ : PAGE_READONLY, &oldValue))
        LOG_ERROR(Common_Memory, "WriteProtectMemory failed!\n{}", GetLastErrorMsg());
#else
    mprotect(ptr, size, allowExecute ? (PROT_READ | PROT_EXEC) : PROT_READ);
#endif
}

void UnWriteProtectMemory(void* ptr, size_t size, bool allowExecute) {
#ifdef _WIN32
    DWORD oldValue;
    if (!VirtualProtect(ptr, size, allowExecute ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE,
                        &oldValue))
        LOG_ERROR(Common_Memory, "UnWriteProtectMemory failed!\n{}", GetLastErrorMsg());
#else
    mprotect(ptr, size,
             allowExecute ? (PROT_READ | PROT_WRITE | PROT_EXEC) : PROT_WRITE | PROT_READ);
#endif
}

std::string MemUsage() {
#ifdef _WIN32
#pragma comment(lib, "psapi")
    DWORD processID = GetCurrentProcessId();
    HANDLE hProcess;
    PROCESS_MEMORY_COUNTERS pmc;
    std::string Ret;

    // Print information about the memory usage of the process.

    hProcess = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, processID);
    if (nullptr == hProcess)
        return "MemUsage Error";

    if (GetProcessMemoryInfo(hProcess, &pmc, sizeof(pmc)))
        Ret = fmt::format("{} K", Common::ThousandSeparate(pmc.WorkingSetSize / 1024, 7));

    CloseHandle(hProcess);
    return Ret;
#else
    return "";
#endif
}
