#include "il2cpp-config.h"

#if IL2CPP_TARGET_WINDOWS

#include "WindowsHelpers.h"

#undef CopyFile
#undef DeleteFile
#undef MoveFile
#undef ReplaceFile
#undef GetFileAttributes
#undef SetFileAttributes
#undef CreatePipe

#include "os/File.h"
#include "utils/Expected.h"
#include "utils/Il2CppError.h"
#include "utils/StringUtils.h"
#include "utils/PathUtils.h"

#if IL2CPP_TARGET_WINRT
#include "os/BrokeredFileSystem.h"
#endif

#include <stdint.h>

static inline int FileWin32ErrorToErrorCode(DWORD win32ErrorCode)
{
    return win32ErrorCode;
}

namespace il2cpp
{
namespace os
{
#if IL2CPP_TARGET_WINDOWS_DESKTOP
    utils::Expected<bool> File::Isatty(FileHandle* fileHandle)
    {
        DWORD mode;
        return GetConsoleMode((HANDLE)fileHandle, &mode) != 0;
    }

#elif IL2CPP_TARGET_WINDOWS_GAMES
    utils::Expected<bool> File::Isatty(FileHandle* fileHandle)
    {
        return utils::Il2CppError(utils::NotSupported, "Console functions are not supported on Windows Games platforms.");
    }

#endif

#if IL2CPP_TARGET_WINDOWS_DESKTOP || IL2CPP_TARGET_WINDOWS_GAMES
    FileHandle* File::GetStdInput()
    {
        return (FileHandle*)GetStdHandle(STD_INPUT_HANDLE);
    }

    FileHandle* File::GetStdError()
    {
        return (FileHandle*)GetStdHandle(STD_ERROR_HANDLE);
    }

    FileHandle* File::GetStdOutput()
    {
        return (FileHandle*)GetStdHandle(STD_OUTPUT_HANDLE);
    }

#endif // IL2CPP_TARGET_WINDOWS_DESKTOP || IL2CPP_TARGET_WINDOWS_GAMES

    utils::Expected<bool> File::CreatePipe(FileHandle** read_handle, FileHandle** write_handle)
    {
        int error;
        return CreatePipe(read_handle, write_handle, &error);
    }

    utils::Expected<bool> File::CreatePipe(FileHandle** read_handle, FileHandle** write_handle, int* error)
    {
        SECURITY_ATTRIBUTES attr;

        attr.nLength = sizeof(SECURITY_ATTRIBUTES);
        attr.bInheritHandle = TRUE;
        attr.lpSecurityDescriptor = NULL;

        bool ret = ::CreatePipe((PHANDLE)read_handle, (PHANDLE)write_handle, &attr, 0);

        if (ret == FALSE)
        {
            *error = GetLastError();
            /* FIXME: throw an exception? */
            return false;
        }

        return true;
    }

#if !IL2CPP_TARGET_WINDOWS_GAMES
    UnityPalFileAttributes File::GetFileAttributes(const std::string& path, int *error)
    {
        const UTF16String utf16Path(utils::StringUtils::Utf8ToUtf16(path.c_str()));
        WIN32_FILE_ATTRIBUTE_DATA fileAttributes;

        BOOL result = ::GetFileAttributesExW((LPCWSTR)utf16Path.c_str(), GetFileExInfoStandard, &fileAttributes);
        if (result == FALSE)
        {
            auto lastError = ::GetLastError();

#if IL2CPP_TARGET_WINRT
            if (lastError == ERROR_ACCESS_DENIED)
                return BrokeredFileSystem::GetFileAttributesW(utf16Path, error);
#endif

            *error = FileWin32ErrorToErrorCode(lastError);
            return static_cast<UnityPalFileAttributes>(INVALID_FILE_ATTRIBUTES);
        }

        *error = kErrorCodeSuccess;
        return static_cast<UnityPalFileAttributes>(fileAttributes.dwFileAttributes);
    }

#endif // !IL2CPP_TARGET_WINDOWS_GAMES

    bool File::SetFileAttributes(const std::string& path, UnityPalFileAttributes attributes, int* error)
    {
        const UTF16String utf16Path(utils::StringUtils::Utf8ToUtf16(path.c_str()));

        *error = kErrorCodeSuccess;
        if (::SetFileAttributesW((LPCWSTR)utf16Path.c_str(), attributes))
            return true;

        auto lastError = ::GetLastError();

#if IL2CPP_TARGET_WINRT
        if (lastError == ERROR_ACCESS_DENIED)
            return BrokeredFileSystem::SetFileAttributesW(utf16Path, attributes, error);
#endif

        *error = FileWin32ErrorToErrorCode(lastError);
        return false;
    }

    static inline int64_t HighAndLowToInt64(uint32_t high, uint32_t low)
    {
        return ((uint64_t)high << 32) + low;
    }

    static inline int64_t FileTimeToInt64(const FILETIME& fileTime)
    {
        return HighAndLowToInt64(fileTime.dwHighDateTime, fileTime.dwLowDateTime);
    }

    bool File::GetFileStat(const std::string& path, il2cpp::os::FileStat * stat, int* error)
    {
        *error = kErrorCodeSuccess;
        const UTF16String utf16Path(utils::StringUtils::Utf8ToUtf16(path.c_str()));

        WIN32_FILE_ATTRIBUTE_DATA data;
        if (!::GetFileAttributesExW((LPCWSTR)utf16Path.c_str(), GetFileExInfoStandard, &data))
        {
            auto lastError = ::GetLastError();

#if IL2CPP_TARGET_WINRT
            if (lastError == ERROR_ACCESS_DENIED)
                return BrokeredFileSystem::GetFileStat(path, utf16Path, stat, error);
#endif

            *error = FileWin32ErrorToErrorCode(lastError);
            return false;
        }

        stat->name = il2cpp::utils::PathUtils::Basename(path);
        stat->attributes = data.dwFileAttributes;
        stat->creation_time = FileTimeToInt64(data.ftCreationTime);
        stat->last_access_time = FileTimeToInt64(data.ftLastAccessTime);
        stat->last_write_time = FileTimeToInt64(data.ftLastWriteTime);
        stat->length = HighAndLowToInt64(data.nFileSizeHigh, data.nFileSizeLow);
        return true;
    }

    FileType File::GetFileType(FileHandle* handle)
    {
        int result = ::GetFileType((HANDLE)handle);
        /*if (result == FILE_TYPE_UNKNOWN)
        {
            *error = GetLastError();
        }*/
        return (FileType)result;
    }

    bool File::CopyFile(const std::string& src, const std::string& dest, bool overwrite, int* error)
    {
        const UTF16String utf16Src(utils::StringUtils::Utf8ToUtf16(src.c_str()));
        const UTF16String utf16Dest(utils::StringUtils::Utf8ToUtf16(dest.c_str()));

        *error = kErrorCodeSuccess;

        if (::CopyFileW((LPWSTR)utf16Src.c_str(), (LPWSTR)utf16Dest.c_str(), overwrite ? FALSE : TRUE))
            return true;

        auto lastError = ::GetLastError();

#if IL2CPP_TARGET_WINRT
        if (lastError == ERROR_ACCESS_DENIED)
            return BrokeredFileSystem::CopyFileW(utf16Src, utf16Dest, overwrite, error);
#endif

        *error = FileWin32ErrorToErrorCode(lastError);
        return false;
    }

    bool File::MoveFile(const std::string& src, const std::string& dest, int* error)
    {
        const UTF16String utf16Src(utils::StringUtils::Utf8ToUtf16(src.c_str()));
        const UTF16String utf16Dest(utils::StringUtils::Utf8ToUtf16(dest.c_str()));

        *error = kErrorCodeSuccess;

        if (::MoveFileExW((LPWSTR)utf16Src.c_str(), (LPWSTR)utf16Dest.c_str(), MOVEFILE_COPY_ALLOWED))
            return true;

        auto lastError = ::GetLastError();

#if IL2CPP_TARGET_WINRT
        if (lastError == ERROR_ACCESS_DENIED)
            return BrokeredFileSystem::MoveFileW(utf16Src, utf16Dest, error);
#endif

        *error = FileWin32ErrorToErrorCode(lastError);
        return false;
    }

    bool File::DeleteFile(const std::string& path, int *error)
    {
        *error = kErrorCodeSuccess;
        const UTF16String utf16Path(utils::StringUtils::Utf8ToUtf16(path.c_str()));
        if (::DeleteFileW((LPWSTR)utf16Path.c_str()))
            return true;

        auto lastError = ::GetLastError();

#if IL2CPP_TARGET_WINRT
        if (lastError == ERROR_ACCESS_DENIED)
        {
            *error = BrokeredFileSystem::DeleteFileW(utf16Path);
            return *error == kErrorCodeSuccess;
        }
#endif

        *error = FileWin32ErrorToErrorCode(lastError);
        return false;
    }

    bool File::ReplaceFile(const std::string& sourceFileName, const std::string& destinationFileName, const std::string& destinationBackupFileName, bool ignoreMetadataErrors, int* error)
    {
        const UTF16String utf16Src(utils::StringUtils::Utf8ToUtf16(sourceFileName.c_str()));
        const UTF16String utf16Dest(utils::StringUtils::Utf8ToUtf16(destinationFileName.c_str()));
        const UTF16String utf16Backup(utils::StringUtils::Utf8ToUtf16(destinationBackupFileName.c_str()));

        *error = kErrorCodeSuccess;

        DWORD flags = REPLACEFILE_WRITE_THROUGH;
        if (ignoreMetadataErrors)
            flags |= REPLACEFILE_IGNORE_MERGE_ERRORS;

        if (::ReplaceFileW((LPWSTR)utf16Dest.c_str(), (LPWSTR)utf16Src.c_str(), utf16Backup.empty() ? NULL : (LPWSTR)utf16Backup.c_str(), flags, NULL, NULL))
            return true;

        *error = FileWin32ErrorToErrorCode(::GetLastError());
        return false;
    }

    static inline int MonoToWindowsOpenMode(int monoOpenMode)
    {
        switch (monoOpenMode)
        {
            case kFileModeCreateNew:
                return CREATE_NEW;

            case kFileModeCreate:
                return CREATE_ALWAYS;

            case kFileModeOpen:
                return OPEN_EXISTING;

            case kFileModeOpenOrCreate:
            case kFileModeAppend:
                return OPEN_ALWAYS;

            case kFileModeTruncate:
                return TRUNCATE_EXISTING;

            default:
                Assert(false && "Unknown mono open mode");
                IL2CPP_UNREACHABLE;
        }
    }

    static inline int MonoToWindowsAccessMode(int monoAccessMode)
    {
        switch (monoAccessMode)
        {
            case kFileAccessRead:
                return GENERIC_READ;

            case kFileAccessWrite:
                return GENERIC_WRITE;

            case kFileAccessExecute:
                return GENERIC_EXECUTE;

            case kFileAccessReadWrite:
                return GENERIC_READ | GENERIC_WRITE;

            case kFileAccessReadWriteExecute:
                return GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE;

            default:
                return 0;
        }
    }

    static inline DWORD MonoOptionsToWindowsFlagsAndAttributes(const std::string& path, int options)
    {
        DWORD flagsAndAttributes;

        if (options != 0)
        {
            if (options & kFileOptionsEncrypted)
                flagsAndAttributes = FILE_ATTRIBUTE_ENCRYPTED;
            else
                flagsAndAttributes = FILE_ATTRIBUTE_NORMAL;
            if (options & kFileOptionsDeleteOnClose)
                flagsAndAttributes |= FILE_FLAG_DELETE_ON_CLOSE;
            if (options & kFileOptionsSequentialScan)
                flagsAndAttributes |= FILE_FLAG_SEQUENTIAL_SCAN;
            if (options & kFileOptionsRandomAccess)
                flagsAndAttributes |= FILE_FLAG_RANDOM_ACCESS;

            if (options & kFileOptionsWriteThrough)
                flagsAndAttributes |= FILE_FLAG_WRITE_THROUGH;
        }
        else
        {
            flagsAndAttributes = FILE_ATTRIBUTE_NORMAL;
        }

        int error;
        UnityPalFileAttributes currentAttributes = File::GetFileAttributes(path, &error);

        if (currentAttributes != INVALID_FILE_ATTRIBUTES && (currentAttributes & FILE_ATTRIBUTE_DIRECTORY))
            flagsAndAttributes |= FILE_FLAG_BACKUP_SEMANTICS; // Required to open a directory

        return flagsAndAttributes;
    }

    FileHandle* File::Open(const std::string& path, int openMode, int accessMode, int shareMode, int options, int *error)
    {
        const UTF16String utf16Path(utils::StringUtils::Utf8ToUtf16(path.c_str()));

        openMode = MonoToWindowsOpenMode(openMode);
        accessMode = MonoToWindowsAccessMode(accessMode);
        DWORD flagsAndAttributes = MonoOptionsToWindowsFlagsAndAttributes(path, options);

        HANDLE handle = ::CreateFileW((LPCWSTR)utf16Path.c_str(), accessMode, shareMode, NULL, openMode, flagsAndAttributes, NULL);

        if (INVALID_HANDLE_VALUE == handle)
        {
            auto lastError = ::GetLastError();
#if IL2CPP_TARGET_WINRT
            if (lastError == ERROR_ACCESS_DENIED)
                return BrokeredFileSystem::Open(utf16Path, accessMode, shareMode, openMode, flagsAndAttributes, error);
#endif

            *error = FileWin32ErrorToErrorCode(lastError);
            return (FileHandle*)INVALID_HANDLE_VALUE;
        }

        *error = kErrorCodeSuccess;
        return (FileHandle*)handle;
    }

    bool File::Close(FileHandle* handle, int *error)
    {
        *error = kErrorCodeSuccess;
        if (CloseHandle((HANDLE)handle))
            return true;

        *error = FileWin32ErrorToErrorCode(::GetLastError());
        return false;
    }

    bool File::SetFileTime(FileHandle* handle, int64_t creation_time, int64_t last_access_time, int64_t last_write_time, int* error)
    {
        FILE_BASIC_INFO fileInfo;

        fileInfo.CreationTime.QuadPart = creation_time;
        fileInfo.LastAccessTime.QuadPart = last_access_time;
        fileInfo.LastWriteTime.QuadPart = last_write_time;
        fileInfo.ChangeTime.QuadPart = 0; // 0 means don't change anything
        fileInfo.FileAttributes = 0; // 0 means don't change anything

        if (SetFileInformationByHandle(handle, FileBasicInfo, &fileInfo, sizeof(FILE_BASIC_INFO)) == FALSE)
        {
            *error = GetLastError();
            return false;
        }

        *error = kErrorCodeSuccess;
        return true;
    }

    int64_t File::GetLength(FileHandle* handle, int *error)
    {
        *error = kErrorCodeSuccess;
        LARGE_INTEGER size;
        if (!::GetFileSizeEx((HANDLE)handle, &size))
        {
            *error = FileWin32ErrorToErrorCode(::GetLastError());
            return 0;
        }
        return size.QuadPart;
    }

#if !IL2CPP_USE_GENERIC_FILE
    bool File::Truncate(FileHandle* handle, int *error)
    {
        *error = kErrorCodeSuccess;
        if (!::SetEndOfFile((HANDLE)handle))
        {
            *error = FileWin32ErrorToErrorCode(::GetLastError());
            return false;
        }
        return true;
    }

#endif // IL2CPP_USE_GENERIC_FILE

    bool File::SetLength(FileHandle* handle, int64_t length, int *error)
    {
        *error = kErrorCodeSuccess;
        LARGE_INTEGER zeroOffset = { 0 };
        LARGE_INTEGER requestedOffset = { 0 };
        requestedOffset.QuadPart = length;
        LARGE_INTEGER initialPosition = { 0 };

        // set position to 0 from current to retrieve current position
        if (!::SetFilePointerEx((HANDLE)handle, zeroOffset, &initialPosition, FILE_CURRENT))
        {
            *error = FileWin32ErrorToErrorCode(::GetLastError());
            return false;
        }

        // seek to requested length
        if (!::SetFilePointerEx((HANDLE)handle, requestedOffset, NULL, FILE_BEGIN))
        {
            *error = FileWin32ErrorToErrorCode(::GetLastError());
            return false;
        }

        // set requested length
        if (!::SetEndOfFile((HANDLE)handle))
        {
            *error = FileWin32ErrorToErrorCode(::GetLastError());
            return false;
        }

        // restore original position
        if (!::SetFilePointerEx((HANDLE)handle, initialPosition, NULL, FILE_BEGIN))
        {
            *error = FileWin32ErrorToErrorCode(::GetLastError());
            return false;
        }

        return true;
    }

    int64_t File::Seek(FileHandle* handle, int64_t offset, int origin, int *error)
    {
        *error = kErrorCodeSuccess;
        LARGE_INTEGER distance;
        distance.QuadPart = offset;
        LARGE_INTEGER position = { 0 };
        if (!::SetFilePointerEx((HANDLE)handle, distance, &position, origin))
            *error = FileWin32ErrorToErrorCode(::GetLastError());

        return position.QuadPart;
    }

    int File::Read(FileHandle* handle, char *dest, int count, int *error)
    {
        *error = kErrorCodeSuccess;
        DWORD bytesRead = 0;
        if (!::ReadFile(handle, dest, count, &bytesRead, NULL))
            *error = FileWin32ErrorToErrorCode(::GetLastError());

        return bytesRead;
    }

    int32_t File::Write(FileHandle* handle, const char* buffer, int count, int *error)
    {
        int32_t written;

        BOOL success = WriteFile((HANDLE)handle, buffer, count, (LPDWORD)&written, NULL);

        if (!success)
        {
            DWORD originalError = GetLastError();
            if (originalError == ERROR_INVALID_PARAMETER)
            {
                // Maybe this is an async file write, so try with those parameters.
                OVERLAPPED overlapped = {0};
                success = WriteFile((HANDLE)handle, buffer, count, NULL, &overlapped);
                if (success != 0 || GetLastError() == ERROR_IO_PENDING)
                {
                    success = TRUE;
                    // The async write succeeded. Now get the number of bytes written.
#if IL2CPP_TARGET_WINDOWS_DESKTOP
                    if (GetOverlappedResult((HANDLE)handle, &overlapped, (LPDWORD)&written, TRUE) == 0)
#else
                    if (GetOverlappedResultEx((HANDLE)handle, &overlapped, (LPDWORD)&written, INFINITE, FALSE) == 0)
#endif
                    {
                        // Oops, we could not get the number of bytes writen, so return an error.
                        *error = GetLastError();
                        return -1;
                    }
                }
            }

            if (!success)
            {
                *error = originalError;
                return -1;
            }
        }

        return written;
    }

    bool File::Flush(FileHandle* handle, int* error)
    {
        *error = kErrorCodeSuccess;
        if (FlushFileBuffers((HANDLE)handle))
            return true;

        *error = FileWin32ErrorToErrorCode(::GetLastError());

        return false;
    }

    void File::Lock(FileHandle* handle,  int64_t position, int64_t length, int* error)
    {
        *error = kErrorCodeSuccess;

        OVERLAPPED overlapped;
        ZeroMemory(&overlapped, sizeof(overlapped));

        overlapped.Offset = position & 0xFFFFFFFF;
        overlapped.OffsetHigh = position >> 32;

        LARGE_INTEGER lengthUnion;
        lengthUnion.QuadPart = length;

        if (!::LockFileEx((HANDLE)handle, LOCKFILE_FAIL_IMMEDIATELY, 0, lengthUnion.LowPart, lengthUnion.HighPart, &overlapped))
            *error = FileWin32ErrorToErrorCode(::GetLastError());
    }

    void File::Unlock(FileHandle* handle,  int64_t position, int64_t length, int* error)
    {
        *error = kErrorCodeSuccess;

        OVERLAPPED overlapped;
        ZeroMemory(&overlapped, sizeof(overlapped));

        overlapped.Offset = position & 0xFFFFFFFF;
        overlapped.OffsetHigh = position >> 32;

        LARGE_INTEGER lengthUnion;
        lengthUnion.QuadPart = length;

        if (!::UnlockFileEx((HANDLE)handle, 0, lengthUnion.LowPart, lengthUnion.HighPart, &overlapped))
            *error = FileWin32ErrorToErrorCode(::GetLastError());
    }

    utils::Expected<bool> File::DuplicateHandle(FileHandle* source_process_handle, FileHandle* source_handle, FileHandle* target_process_handle,
        FileHandle** target_handle, int access, int inherit, int options, int* error)
    {
        /* This is only used on Windows */

        //MONO_PREPARE_BLOCKING;
        BOOL ret = ::DuplicateHandle((HANDLE)source_process_handle, (HANDLE)source_handle, (HANDLE)target_process_handle, (LPHANDLE)target_handle, access, inherit, options);
        //MONO_FINISH_BLOCKING;

        if (ret == FALSE)
        {
            *error = GetLastError();
            /* FIXME: throw an exception? */
            return false;
        }

        return true;
    }

    static bool ends_with(const std::string& value, const std::string& ending)
    {
        if (value.length() >= ending.length())
            return value.compare(value.length() - ending.length(), ending.length(), ending) == 0;
        return false;
    }

    utils::Expected<bool> File::IsExecutable(const std::string& path)
    {
        return ends_with(path, "exe");
    }

    bool File::Cancel(FileHandle* handle)
    {
        return CancelIoEx((HANDLE)handle, NULL);
    }
}
}

#endif