/*
** Copyright (c) 2018 Valve Corporation
** Copyright (c) 2018 LunarG, Inc.
**
** Permission is hereby granted, free of charge, to any person obtaining a
** copy of this software and associated documentation files (the "Software"),
** to deal in the Software without restriction, including without limitation
** the rights to use, copy, modify, merge, publish, distribute, sublicense,
** and/or sell copies of the Software, and to permit persons to whom the
** Software is furnished to do so, subject to the following conditions:
**
** The above copyright notice and this permission notice shall be included in
** all copies or substantial portions of the Software.
**
** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
** AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
** FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
** DEALINGS IN THE SOFTWARE.
*/

#ifndef GFXRECON_UTIL_PLATFORM_H
#define GFXRECON_UTIL_PLATFORM_H

#include "util/defines.h"

#include <cstdint>
#include <cstdio>
#include <cstring>
#include <ctime>
#include <cwchar>
#include <string>
#include <thread>
#include <vector>

#if defined(WIN32)
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#include <direct.h>
#else // WIN32
#include <dlfcn.h>
#include <errno.h>
#include <pthread.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
#include <signal.h>
#include <sys/mman.h>
#endif // WIN32

GFXRECON_BEGIN_NAMESPACE(gfxrecon)
GFXRECON_BEGIN_NAMESPACE(util)
GFXRECON_BEGIN_NAMESPACE(platform)

enum FileSeekOrigin
{
    FileSeekCurrent = SEEK_CUR,
    FileSeekEnd     = SEEK_END,
    FileSeekSet     = SEEK_SET
};

#if defined(__ANDROID__)
const int32_t kMaxPropertyLength = 255;
#endif

#if defined(WIN32)

typedef DWORD   pid_t;
typedef HMODULE LibraryHandle;

inline pid_t GetCurrentProcessId()
{
    return ::GetCurrentProcessId();
}

inline uint64_t GetCurrentThreadId()
{
    return ::GetCurrentThreadId();
}

inline void TriggerDebugBreak()
{
    __debugbreak();
}

inline LibraryHandle OpenLibrary(const char* name)
{
    return LoadLibraryA(name);
}

inline void CloseLibrary(LibraryHandle handle)
{
    FreeLibrary(handle);
}

inline void* GetProcAddress(LibraryHandle handle, const char* name)
{
    return ::GetProcAddress(handle, name);
}

inline std::string GetEnv(const char* name)
{
    try
    {
        // value_size DOES include the null terminator, so for any set variable
        // will always be at least 1. If it's 0, the variable wasn't set.
        DWORD value_size = GetEnvironmentVariableA(name, nullptr, 0);
        if (value_size != 0)
        {
            // Max environment variable size (including null terminator).
            const size_t kMaxEnvSize = 8196;
            char         return_value[kMaxEnvSize];
            GetEnvironmentVariableA(name, return_value, value_size);
            return std::string(return_value);
        }
    }
    catch (...)
    {
        // Something bad happened during alloc or function call.
    }
    return std::string("");
}

inline int32_t MemoryCopy(void* destination, size_t destination_size, const void* source, size_t source_size)
{
    return memcpy_s(destination, destination_size, source, source_size);
}

inline int32_t MemoryCompare(const void* memory_1, const void* memory_2, size_t compare_size)
{
    return memcmp(memory_1, memory_2, compare_size);
}

inline int32_t StringCompareNoCase(const char* string_1, const char* string_2)
{
    return _stricmp(string_1, string_2);
}

inline int32_t StringCompareNoCase(const wchar_t* string_1, const wchar_t* string_2)
{
    return _wcsicmp(string_1, string_2);
}

inline int32_t StringCompareNoCase(const char* string_1, const char* string_2, size_t compare_size)
{
    return _strnicmp(string_1, string_2, compare_size);
}

inline int32_t StringCompareNoCase(const wchar_t* string_1, const wchar_t* string_2, size_t compare_size)
{
    return _wcsnicmp(string_1, string_2, compare_size);
}

inline int32_t StringCopy(char* destination, size_t destination_size, const char* source, size_t source_size)
{
    return strncpy_s(destination, destination_size, source, source_size);
}

inline int32_t StringCopy(wchar_t* destination, size_t destination_size, const wchar_t* source, size_t source_size)
{
    return wcsncpy_s(destination, destination_size, source, source_size);
}

inline int32_t FileOpen(FILE** stream, const char* filename, const char* mode)
{
    return static_cast<int32_t>(fopen_s(stream, filename, mode));
}

inline int64_t FileTell(FILE* stream)
{
    return _ftelli64(stream);
}

inline bool FileSeek(FILE* stream, int64_t offset, FileSeekOrigin origin)
{
    int32_t result = _fseeki64(stream, offset, origin);
    return (result == 0);
}

inline size_t FileWriteNoLock(const void* buffer, size_t element_size, size_t element_count, FILE* stream)
{
    return _fwrite_nolock(buffer, element_size, element_count, stream);
}

inline size_t FileReadNoLock(void* buffer, size_t element_size, size_t element_count, FILE* stream)
{
    return _fread_nolock(buffer, element_size, element_count, stream);
}

inline int32_t FileVprintf(FILE* stream, const char* format, va_list vlist)
{
    return vfprintf_s(stream, format, vlist);
}

inline int32_t LocalTime(tm* local_time, const time_t* timer)
{
    return static_cast<int32_t>(localtime_s(local_time, timer));
}

inline int32_t GMTime(tm* gm_time, const time_t* timer)
{
    return static_cast<int32_t>(gmtime_s(gm_time, timer));
}

inline int32_t MakeDirectory(const char* filename)
{
    return _mkdir(filename);
}

inline size_t GetSystemPageSize()
{
    SYSTEM_INFO sSysInfo;
    GetSystemInfo(&sSysInfo);
    return sSysInfo.dwPageSize;
}

inline void* AllocateRawMemory(size_t aligned_size, bool use_write_watch = false)
{
    assert(aligned_size > 0);

    if (aligned_size > 0)
    {
        DWORD flags = MEM_RESERVE | MEM_COMMIT;

        if (use_write_watch)
        {
            flags |= MEM_WRITE_WATCH;
        }

        return VirtualAlloc(nullptr, aligned_size, flags, PAGE_READWRITE);
    }

    return nullptr;
}

inline void FreeRawMemory(void* memory, size_t aligned_size)
{
    assert(memory != nullptr);

    GFXRECON_UNREFERENCED_PARAMETER(aligned_size);
    VirtualFree(memory, 0, MEM_RELEASE);
}

inline int GetSystemLastErrorCode()
{
    return GetLastError();
}

#else // !defined(WIN32)

// Error value indicating string was truncated
#define STRUNCATE 80

typedef void* LibraryHandle;

inline pid_t GetCurrentProcessId()
{
    return getpid();
}

inline uint64_t GetCurrentThreadId()
{
    return static_cast<uint64_t>(syscall(SYS_gettid));
}

inline void TriggerDebugBreak()
{
    raise(SIGTRAP);
}

inline LibraryHandle OpenLibrary(const char* name)
{
    return dlopen(name, RTLD_NOW | RTLD_LOCAL);
}

inline void CloseLibrary(LibraryHandle handle)
{
    dlclose(handle);
}

inline void* GetProcAddress(LibraryHandle handle, const char* name)
{
    return dlsym(handle, name);
}

inline std::string GetEnv(const char* name)
{
    std::string env_value;

#if defined(__ANDROID__)
    std::string command = "getprop ";
    command += name;

    FILE* pipe = popen(command.c_str(), "r");
    if (pipe != nullptr)
    {
        char result[kMaxPropertyLength];
        result[0] = '\0';

        fgets(result, kMaxPropertyLength, pipe);
        pclose(pipe);

        size_t count = strcspn(result, "\r\n");
        if (count > 0)
        {
            env_value = std::string(result, count);
        }
    }
#else
    const char* ret_value = getenv(name);
    if (nullptr != ret_value)
    {
        env_value = ret_value;
    }
#endif

    return env_value;
}

inline int32_t MemoryCopy(void* destination, size_t destination_size, const void* source, size_t source_size)
{
    if (source_size > destination_size)
    {
        std::memcpy(destination, source, destination_size);
        return STRUNCATE;
    }
    else
    {
        std::memcpy(destination, source, source_size);
        return 0;
    }
}

inline int32_t MemoryCompare(const void* memory_1, const void* memory_2, size_t compare_size)
{
    return memcmp(memory_1, memory_2, compare_size);
}

inline int32_t StringCompareNoCase(const char* string_1, const char* string_2)
{
    return strcasecmp(string_1, string_2);
}

inline int32_t StringCompareNoCase(const wchar_t* string_1, const wchar_t* string_2)
{
    return wcscasecmp(string_1, string_2);
}

inline int32_t StringCompareNoCase(const char* string_1, const char* string_2, size_t compare_size)
{
    return strncasecmp(string_1, string_2, compare_size);
}

inline int32_t StringCompareNoCase(const wchar_t* string_1, const wchar_t* string_2, size_t compare_size)
{
    return wcsncasecmp(string_1, string_2, compare_size);
}

inline int32_t StringCopy(char* destination, size_t destination_size, const char* source, size_t source_size)
{
    if (source_size > destination_size)
    {
        strncpy(destination, source, destination_size);
        return STRUNCATE;
    }
    else
    {
        strncpy(destination, source, source_size);
        return 0;
    }
}

inline int32_t StringCopy(wchar_t* destination, size_t destination_size, const wchar_t* source, size_t source_size)
{
    if (source_size > destination_size)
    {
        wcsncpy(destination, source, destination_size);
        return STRUNCATE;
    }
    else
    {
        wcsncpy(destination, source, source_size);
        return 0;
    }
}

inline int32_t FileOpen(FILE** stream, const char* filename, const char* mode)
{
    if (stream == nullptr)
    {
        return EINVAL;
    }

    FILE* result = fopen(filename, mode);
    if (result != nullptr)
    {
        (*stream) = result;
        return 0;
    }
    else
    {
        return errno;
    }
}

inline int64_t FileTell(FILE* stream)
{
    return ftello(stream);
}

inline bool FileSeek(FILE* stream, int64_t offset, FileSeekOrigin origin)
{
    int32_t result = fseeko(stream, offset, origin);
    return (result == 0);
}

inline size_t FileWriteNoLock(const void* buffer, size_t element_size, size_t element_count, FILE* stream)
{
#if defined(__ANDROID__) && (__ANDROID_API__ < 28)
    return fwrite(buffer, element_size, element_count, stream);
#else
    return fwrite_unlocked(buffer, element_size, element_count, stream);
#endif
}

inline size_t FileReadNoLock(void* buffer, size_t element_size, size_t element_count, FILE* stream)
{
#if defined(__ANDROID__) && (__ANDROID_API__ < 28)
    return fread(buffer, element_size, element_count, stream);
#else
    return fread_unlocked(buffer, element_size, element_count, stream);
#endif
}

inline int32_t FileVprintf(FILE* stream, const char* format, va_list vlist)
{
    return vfprintf(stream, format, vlist);
}

inline int32_t LocalTime(tm* local_time, const time_t* timer)
{
#if defined(__ANDROID__) || defined(__USE_POSIX)
    tm* result = localtime_r(timer, local_time);
    return (result != nullptr) ? 0 : errno;
#else
    if (local_time == nullptr)
    {
        return EINVAL;
    }

    tm* result = localtime(timer);
    if (result != nullptr)
    {
        (*local_time) = (*result);
        return 0;
    }
    else
    {
        return errno;
    }
#endif
}

inline int32_t GMTime(tm* gm_time, const time_t* timer)
{
#if defined(__ANDROID__) || defined(__USE_POSIX)
    tm* result = gmtime_r(timer, gm_time);
    return (result != nullptr) ? 0 : errno;
#else
    if (gm_time == nullptr)
    {
        return EINVAL;
    }

    tm* result = gmtime(timer);
    if (result != nullptr)
    {
        (*gm_time) = (*result);
        return 0;
    }
    else
    {
        return errno;
    }
#endif
}

inline int32_t MakeDirectory(const char* filename)
{
    return mkdir(filename, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
}

inline size_t GetSystemPageSize()
{
    return getpagesize();
}

// Memory allocation without extra space for private info like with new or malloc
inline void* AllocateRawMemory(size_t aligned_size, bool use_write_watch = false)
{
    assert(aligned_size > 0);

    if (aligned_size > 0)
    {
        void* memory = mmap(nullptr, aligned_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

        if (memory == MAP_FAILED)
        {
            return nullptr;
        }

        return memory;
    }

    return nullptr;
}

inline void FreeRawMemory(void* memory, size_t aligned_size)
{
    assert(memory != nullptr);

    munmap(memory, aligned_size);
}

inline int GetSystemLastErrorCode()
{
    return errno;
}

#endif // WIN32

inline size_t GetAlignedSize(size_t size, size_t align_to)
{
    size_t extra = size & (align_to - 1); // size % system_page_size_
    if (extra != 0)
    {
        // Adjust the size to be a multiple of the system page size.
        size = size - extra + align_to;
    }

    return size;
}

inline LibraryHandle OpenLibrary(const std::vector<std::string>& name_list)
{
    for (const auto& name : name_list)
    {
        const auto handle = OpenLibrary(name.c_str());
        if (handle != nullptr)
        {
            return handle;
        }
    }
    return nullptr;
}

inline size_t StringLength(const char* s)
{
    return strlen(s);
}

inline size_t StringLength(const wchar_t* s)
{
    return wcslen(s);
}

inline int32_t StringCompare(const char* string_1, const char* string_2)
{
    return strcmp(string_1, string_2);
}

inline int32_t StringCompare(const wchar_t* string_1, const wchar_t* string_2)
{
    return wcscmp(string_1, string_2);
}

inline int32_t StringCompare(const char* string_1, const char* string_2, size_t compare_size)
{
    return strncmp(string_1, string_2, compare_size);
}

inline int32_t StringCompare(const wchar_t* string_1, const wchar_t* string_2, size_t compare_size)
{
    return wcsncmp(string_1, string_2, compare_size);
}

inline int32_t FilePuts(const char* char_string, FILE* stream)
{
    return fputs(char_string, stream);
}

inline int32_t FileFlush(FILE* stream)
{
    return fflush(stream);
}

inline size_t FileWrite(const void* buffer, size_t element_size, size_t element_count, FILE* stream)
{
    return fwrite(buffer, element_size, element_count, stream);
}

inline size_t FileRead(void* buffer, size_t element_size, size_t element_count, FILE* stream)
{
    return fread(buffer, element_size, element_count, stream);
}

inline int32_t SetFileBufferSize(FILE* stream, size_t buffer_size)
{
    return setvbuf(stream, nullptr, (buffer_size == 0) ? _IONBF : _IOFBF, buffer_size);
}

inline int32_t FileClose(FILE* stream)
{
    return fclose(stream);
}

// Align an address/offset value to a given number of bytes. Requires static alignment value.
template <uint64_t Alignment, typename T>
inline T AlignValue(T original)
{
    // Validate inputs.
    static_assert(std::is_unsigned<T>::value, "Value to align must be unsigned.");
    static_assert(std::numeric_limits<T>::max() > Alignment, "Alignment value is too large.");
    static_assert((Alignment > 0) && (((Alignment - 1) & Alignment) == 0), "Alignment must be a power of two.");

    T alignment_t = static_cast<T>(Alignment);
    return (original + (alignment_t - 1)) & ~(alignment_t - 1);
}

GFXRECON_END_NAMESPACE(platform)
GFXRECON_END_NAMESPACE(util)
GFXRECON_END_NAMESPACE(gfxrecon)

#endif // GFXRECON_UTIL_PLATFORM_H