o3de/Code/Framework/AzFramework/AzFramework/IO/LocalFileIO.cpp

/*
 * Copyright (c) Contributors to the Open 3D Engine Project.
 * For complete copyright and license terms please see the LICENSE at the root of this distribution.
 *
 * SPDX-License-Identifier: Apache-2.0 OR MIT
 *
 */
#include <AzFramework/IO/LocalFileIO.h>
#include <sys/stat.h>
#include <AzCore/IO/SystemFile.h>
#include <AzCore/IO/IOUtils.h>
#include <AzCore/IO/Path/Path.h>
#include <AzCore/Casting/numeric_cast.h>
#include <AzCore/Casting/lossy_cast.h>
#include <AzCore/std/containers/fixed_unordered_set.h>
#include <AzCore/std/functional.h>
#include <AzCore/std/string/conversions.h>
#include <AzCore/std/string/string_view.h>
#include <AzCore/StringFunc/StringFunc.h>
#include <AzCore/Utils/Utils.h>
#include <cctype>

namespace AZ
{
    namespace IO
    {
        const HandleType LocalHandleStartValue = 1000000; //start the local file io handles at 1 million

        LocalFileIO::LocalFileIO()
        {
            m_nextHandle = LocalHandleStartValue;
        }

        LocalFileIO::~LocalFileIO()
        {
            AZStd::lock_guard<AZStd::recursive_mutex> lock(m_openFileGuard);
            while (!m_openFiles.empty())
            {
                const auto& handlePair = *m_openFiles.begin();
                Close(handlePair.first);
            }

            AZ_Assert(m_openFiles.empty(), "Trying to shutdown filing system with files still open");
        }

        Result LocalFileIO::Open(const char* filePath, OpenMode mode, HandleType& fileHandle)
        {
            char resolvedPath[AZ_MAX_PATH_LEN];
            ResolvePath(filePath, resolvedPath, AZ_MAX_PATH_LEN);

            AZ::IO::UpdateOpenModeForReading(mode);

            // Generate open modes for SystemFile
            int systemFileMode = TranslateOpenModeToSystemFileMode(resolvedPath, mode);
            bool write = AnyFlag(mode & (OpenMode::ModeWrite | OpenMode::ModeUpdate | OpenMode::ModeAppend));
            if (write)
            {
                CheckInvalidWrite(resolvedPath);
            }

            {
                AZStd::lock_guard<AZStd::recursive_mutex> lock(m_openFileGuard);

                fileHandle = GetNextHandle();

                // Construct a new SystemFile in the map (SystemFiles don't copy/move very well).
                auto newPair = m_openFiles.emplace(fileHandle);
                // Check for successful insert
                if (!newPair.second)
                {
                    fileHandle = InvalidHandle;
                    return ResultCode::Error;
                }
                // Attempt to open the newly created file
                if (newPair.first->second.Open(resolvedPath, systemFileMode, 0))
                {
                    return ResultCode::Success;
                }
                else
                {
                    // Remove file, it's not actually open
                    m_openFiles.erase(fileHandle);
                    // On failure, ensure the fileHandle returned is invalid
                    //  some code does not check return but handle value (equivalent to checking for nullptr FILE*)
                    fileHandle = InvalidHandle;
                    return ResultCode::Error;
                }
            }
        }

        Result LocalFileIO::Close(HandleType fileHandle)
        {
            auto filePointer = GetFilePointerFromHandle(fileHandle);
            if (!filePointer)
            {
                return ResultCode::Error_HandleInvalid;
            }

            filePointer->Close();

            {
                AZStd::lock_guard<AZStd::recursive_mutex> lock(m_openFileGuard);
                m_openFiles.erase(fileHandle);
            }
            return ResultCode::Success;
        }

        Result LocalFileIO::Read(HandleType fileHandle, void* buffer, AZ::u64 size, bool failOnFewerThanSizeBytesRead, AZ::u64* bytesRead)
        {
            auto filePointer = GetFilePointerFromHandle(fileHandle);
            if (!filePointer)
            {
                return ResultCode::Error_HandleInvalid;
            }

            SystemFile::SizeType readResult = filePointer->Read(size, buffer);

            if (bytesRead)
            {
                *bytesRead = aznumeric_cast<AZ::u64>(readResult);
            }

            if (static_cast<AZ::u64>(readResult) != size)
            {
                if (failOnFewerThanSizeBytesRead)
                {
                    return ResultCode::Error;
                }

                // Reading less than desired is valid if ferror is not set
                AZ_Assert(Eof(fileHandle), "End of file unexpectedly reached before all data was read");
            }

            return ResultCode::Success;
        }

        Result LocalFileIO::Write(HandleType fileHandle, const void* buffer, AZ::u64 size, AZ::u64* bytesWritten)
        {
            auto filePointer = GetFilePointerFromHandle(fileHandle);
            if (!filePointer)
            {
                return ResultCode::Error_HandleInvalid;
            }

            SystemFile::SizeType writeResult = filePointer->Write(buffer, size);

            if (bytesWritten)
            {
                *bytesWritten = writeResult;
            }

            if (static_cast<AZ::u64>(writeResult) != size)
            {
                return ResultCode::Error;
            }

            return ResultCode::Success;
        }

        Result LocalFileIO::Flush(HandleType fileHandle)
        {
            auto filePointer = GetFilePointerFromHandle(fileHandle);
            if (!filePointer)
            {
                return ResultCode::Error_HandleInvalid;
            }

            filePointer->Flush();

            return ResultCode::Success;
        }

        Result LocalFileIO::Tell(HandleType fileHandle, AZ::u64& offset)
        {
            auto filePointer = GetFilePointerFromHandle(fileHandle);
            if (!filePointer)
            {
                return ResultCode::Error_HandleInvalid;
            }

            SystemFile::SizeType resultValue = filePointer->Tell();
            if (resultValue == -1)
            {
                return ResultCode::Error;
            }

            offset = static_cast<AZ::u64>(resultValue);
            return ResultCode::Success;
        }

        Result LocalFileIO::Seek(HandleType fileHandle, AZ::s64 offset, SeekType type)
        {
            auto filePointer = GetFilePointerFromHandle(fileHandle);
            if (!filePointer)
            {
                return ResultCode::Error_HandleInvalid;
            }

            SystemFile::SeekMode mode = SystemFile::SF_SEEK_BEGIN;
            if (type == SeekType::SeekFromCurrent)
            {
                mode = SystemFile::SF_SEEK_CURRENT;
            }
            else if (type == SeekType::SeekFromEnd)
            {
                mode = SystemFile::SF_SEEK_END;
            }

            filePointer->Seek(offset, mode);

            return ResultCode::Success;
        }

        Result LocalFileIO::Size(HandleType fileHandle, AZ::u64& size)
        {
            auto filePointer = GetFilePointerFromHandle(fileHandle);
            if (!filePointer)
            {
                return ResultCode::Error_HandleInvalid;
            }

            size = filePointer->Length();
            return ResultCode::Success;
        }

        Result LocalFileIO::Size(const char* filePath, AZ::u64& size)
        {
            char resolvedPath[AZ_MAX_PATH_LEN];
            ResolvePath(filePath, resolvedPath, AZ_MAX_PATH_LEN);

            size = SystemFile::Length(resolvedPath);
            if (!size)
            {
                return SystemFile::Exists(resolvedPath) ? ResultCode::Success : ResultCode::Error;
            }

            return ResultCode::Success;
        }

        bool LocalFileIO::IsReadOnly(const char* filePath)
        {
            char resolvedPath[AZ_MAX_PATH_LEN];
            ResolvePath(filePath, resolvedPath, AZ_MAX_PATH_LEN);

            return !SystemFile::IsWritable(resolvedPath);
        }

        bool LocalFileIO::Eof(HandleType fileHandle)
        {
            auto filePointer = GetFilePointerFromHandle(fileHandle);
            if (!filePointer)
            {
                return false;
            }

            return filePointer->Eof();
        }

        AZ::u64 LocalFileIO::ModificationTime(const char* filePath)
        {
            char resolvedPath[AZ_MAX_PATH_LEN];
            ResolvePath(filePath, resolvedPath, AZ_MAX_PATH_LEN);

            return SystemFile::ModificationTime(resolvedPath);
        }

        AZ::u64 LocalFileIO::ModificationTime(HandleType fileHandle)
        {
            auto filePointer = GetFilePointerFromHandle(fileHandle);
            if (!filePointer)
            {
                return 0;
            }

            return filePointer->ModificationTime();
        }

        bool LocalFileIO::Exists(const char* filePath)
        {
            char resolvedPath[AZ_MAX_PATH_LEN];
            ResolvePath(filePath, resolvedPath, AZ_MAX_PATH_LEN);

            return SystemFile::Exists(resolvedPath);
        }

        bool LocalFileIO::IsDirectory(const char* filePath)
        {
            char resolvedPath[AZ_MAX_PATH_LEN];
            ResolvePath(filePath, resolvedPath, AZ_MAX_PATH_LEN);

            return SystemFile::IsDirectory(resolvedPath);
        }

        void LocalFileIO::CheckInvalidWrite([[maybe_unused]] const char* path)
        {
#if defined(AZ_ENABLE_TRACING)
            const char* assetAliasPath = GetAlias("@products@");
            if (path && assetAliasPath)
            {
                const AZ::IO::PathView pathView(path);
                if (pathView.IsRelativeTo(assetAliasPath))
                {
                    AZ_Error("FileIO", false, "You may not alter data inside the asset cache.  Please check the call stack and consider writing into the source asset folder instead.\n"
                        "Attempted write location: %s", path);
                }
            }
#endif
        }

        Result LocalFileIO::Remove(const char* filePath)
        {
            char resolvedPath[AZ_MAX_PATH_LEN];

            ResolvePath(filePath, resolvedPath, AZ_MAX_PATH_LEN);

            CheckInvalidWrite(resolvedPath);

            if (IsDirectory(resolvedPath))
            {
                return ResultCode::Error;
            }

            return SystemFile::Delete(resolvedPath) ? ResultCode::Success : ResultCode::Error;
        }

        Result LocalFileIO::Rename(const char* originalFilePath, const char* newFilePath)
        {
            char resolvedOldPath[AZ_MAX_PATH_LEN];
            char resolvedNewPath[AZ_MAX_PATH_LEN];

            ResolvePath(originalFilePath, resolvedOldPath, AZ_MAX_PATH_LEN);
            ResolvePath(newFilePath, resolvedNewPath, AZ_MAX_PATH_LEN);

            CheckInvalidWrite(resolvedNewPath);

            if (!SystemFile::Rename(resolvedOldPath, resolvedNewPath))
            {
                return ResultCode::Error;
            }

            return ResultCode::Success;
        }

        SystemFile* LocalFileIO::GetFilePointerFromHandle(HandleType fileHandle)
        {
            AZStd::lock_guard<AZStd::recursive_mutex> lock(m_openFileGuard);
            auto openFileIterator = m_openFiles.find(fileHandle);
            if (openFileIterator != m_openFiles.end())
            {
                SystemFile& file = openFileIterator->second;
                return &file;
            }
            return nullptr;
        }

        HandleType LocalFileIO::GetNextHandle()
        {
            return m_nextHandle++;
        }

        static ResultCode DestroyPath_Recurse(LocalFileIO* fileIO, const char* filePath)
        {
            // this is a deltree command.  It needs to eat everything.  Even files.
            ResultCode res = ResultCode::Success;

            fileIO->FindFiles(filePath, "*", [&](const char* iterPath) -> bool
                {
                    // depth first recurse into directories!

                    // note:  findFiles returns full path names.

                    if (fileIO->IsDirectory(iterPath))
                    {
                        // recurse.
                        if (DestroyPath_Recurse(fileIO, iterPath) != ResultCode::Success)
                        {
                            res = ResultCode::Error;
                            return false; // stop the find files.
                        }
                    }
                    else
                    {
                        // if its a file, remove it
                        if (fileIO->Remove(iterPath) != ResultCode::Success)
                        {
                            res = ResultCode::Error;
                            return false; // stop the find files.
                        }
                    }
                    return true; // continue the find files
                });

            if (res != ResultCode::Success)
            {
                return res;
            }

            // now that we've finished recursing, rmdir on the folder itself
            return AZ::IO::SystemFile::DeleteDir(filePath) ? ResultCode::Success : ResultCode::Error;
        }

        Result LocalFileIO::DestroyPath(const char* filePath)
        {
            char resolvedPath[AZ_MAX_PATH_LEN];
            ResolvePath(filePath, resolvedPath, AZ_MAX_PATH_LEN);

            bool pathExists = Exists(resolvedPath);
            if (!pathExists)
            {
                return ResultCode::Success;
            }

            if (pathExists && (!IsDirectory(resolvedPath)))
            {
                return ResultCode::Error;
            }

            return DestroyPath_Recurse(this, resolvedPath);
        }

        static void ToUnixSlashes(char* path, AZ::u64 size)
        {
            auto PrevAndCurrentCharIsPathSeparator = [](const char prev, const char next) -> bool
            {
                constexpr AZStd::string_view pathSeparator = "/";
                const bool prevIsPathSeparator = pathSeparator.find_first_of(prev) != AZStd::string_view::npos;
                const bool nextIsPathSeparator = pathSeparator.find_first_of(next) != AZStd::string_view::npos;
                return prevIsPathSeparator && nextIsPathSeparator;
            };

            size_t copyOffset = 0;
            for (size_t i = 0; i < size && path[i] != '\0'; i++)
            {
                if (path[i] == '\\')
                {
                    path[i] = '/';
                }

                // Replace runs of path separators with one path separator
#if AZ_TRAIT_USE_WINDOWS_FILE_API
                // Network file systems for Windows based APIs start with consecutive path separators
                // so skip over the first character in this case
                constexpr size_t duplicateSeparatorStartOffet = 1;
#else
                constexpr size_t duplicateSeparatorStartOffet = 0;
#endif
                if (i > duplicateSeparatorStartOffet)
                {
                    if (PrevAndCurrentCharIsPathSeparator(path[i - 1], path[i]))
                    {
                        continue;
                    }
                }

                // If the copy offset is different than the iteration index of the path, then copy over it over
                if (copyOffset != i)
                {
                    path[copyOffset] = path[i];
                }

                ++copyOffset;
            }

            // Null-terminate the path again in case duplicate slashes were collapsed
            path[copyOffset] = '\0';

        }

        bool LocalFileIO::ResolvePath(const char* path, char* resolvedPath, AZ::u64 resolvedPathSize) const
        {
            if (resolvedPath == nullptr || resolvedPathSize == 0)
            {
                return false;
            }

            resolvedPath[0] = '\0';

            if (path == nullptr)
            {
                return false;
            }

            if (AZ::IO::PathView(path).HasRootPath())
            {
                size_t pathLen = strlen(path);
                if (pathLen + 1 < resolvedPathSize)
                {
                    azstrncpy(resolvedPath, resolvedPathSize, path, pathLen + 1);

                    //see if the absolute path matches the resolved value of @products@, if it does lowercase the relative part
                    LowerIfBeginsWith(resolvedPath, resolvedPathSize, GetAlias("@products@"));

                    ToUnixSlashes(resolvedPath, resolvedPathSize);
                    return true;
                }
                else
                {
                    return false;
                }
            }

            constexpr AZStd::string_view productAssetAlias = "@products@";
            // Add plus one for the path separator: <alias>/<path>
            constexpr size_t MaxPathSizeWithProductAssetAlias = AZ::IO::MaxPathLength + productAssetAlias.size() + 1;
            using RootedPathString = AZStd::fixed_string<MaxPathSizeWithProductAssetAlias>;
            RootedPathString rootedPathBuffer;
            const char* rootedPath = path;
            // if the path does not begin with an alias, then it is assumed to begin with @products@
            if (path[0] != '@')
            {
                if (GetAlias("@products@"))
                {

                    if (const size_t requiredSize = productAssetAlias.size() + strlen(path) + 1;
                        requiredSize > rootedPathBuffer.capacity())
                    {
                        AZ_Error("FileIO", false, "Prepending the %.*s alias to the input path results in a path longer than the"
                            " AZ::IO::MaxPathLength + the alias size of %zu. The size of the potential failed path is %zu",
                            AZ_STRING_ARG(productAssetAlias), rootedPathBuffer.capacity(), requiredSize)
                    }
                    else
                    {
                        rootedPathBuffer = RootedPathString::format("%.*s/%s", AZ_STRING_ARG(productAssetAlias), path);
                    }
                }
                else
                {
                    if (ConvertToAbsolutePath(path, rootedPathBuffer.data(), rootedPathBuffer.capacity()))
                    {
                        // Recalculate the internal string length
                        rootedPathBuffer.resize_no_construct(AZStd::char_traits<char>::length(rootedPathBuffer.data()));
                    }
                }
                rootedPath = rootedPathBuffer.c_str();
            }

            if (ResolveAliases(rootedPath, resolvedPath, resolvedPathSize))
            {
                ToUnixSlashes(resolvedPath, resolvedPathSize);
                return true;
            }

            return false;
        }

        bool LocalFileIO::ResolvePath(AZ::IO::FixedMaxPath& resolvedPath, const AZ::IO::PathView& path) const
        {
            if (AZ::IO::FixedMaxPathString fixedPath{ path.Native() };
                ResolvePath(fixedPath.c_str(), resolvedPath.Native().data(), resolvedPath.Native().capacity()))
            {
                // Update the null-terminator offset
                resolvedPath.Native().resize_no_construct(AZStd::char_traits<char>::length(resolvedPath.Native().data()));
                return true;
            }

            return false;
        }

        void LocalFileIO::SetAlias(const char* key, const char* path)
        {
            char fullPath[AZ_MAX_PATH_LEN];
            ConvertToAbsolutePath(path, fullPath, AZ_MAX_PATH_LEN);

            m_aliases[key] = fullPath;
        }

        const char* LocalFileIO::GetAlias(const char* key) const
        {
            if (const auto it = m_aliases.find(key); it != m_aliases.end())
            {
                return it->second.c_str();
            }
            else if (const auto deprecatedIt = m_deprecatedAliases.find(key);
                deprecatedIt != m_deprecatedAliases.end())
            {
                AZ_Error("FileIO", false, R"(Alias "%s" is deprecated. Please use alias "%s" instead)",
                    key, deprecatedIt->second.c_str());
                AZStd::string_view aliasValue = deprecatedIt->second;
                // Contains the list of aliases resolved so far
                // If max_size is hit, than an error is logged and nullptr is returned
                using VisitedAliasSet = AZStd::fixed_unordered_set<AZStd::string_view, 8, 8>;
                VisitedAliasSet visitedAliasSet;
                while (aliasValue.starts_with("@"))
                {
                    if (visitedAliasSet.contains(aliasValue))
                    {
                        AZ_Error("FileIO", false, "Cycle found with for alias %.*s when trying to resolve deprecated alias %s",
                            AZ_STRING_ARG(aliasValue), key);
                        return nullptr;
                    }

                    if(visitedAliasSet.size() == visitedAliasSet.max_size())
                    {
                        AZ_Error("FileIO", false, "Unable to resolve path to deprecated alias %s within %zu steps",
                            key, visitedAliasSet.max_size());
                        return nullptr;
                    }

                    // Add the current alias value to the visited set
                    visitedAliasSet.emplace(aliasValue);

                    // Check if the alias value corresponds to another alias
                    if (auto resolvedIter = m_aliases.find(aliasValue); resolvedIter != m_aliases.end())
                    {
                        aliasValue = resolvedIter->second;
                    }
                    else if (resolvedIter = m_deprecatedAliases.find(aliasValue);
                        resolvedIter != m_deprecatedAliases.end())
                    {
                        aliasValue = resolvedIter->second;
                    }
                    else
                    {
                        return nullptr;
                    }
                }

                return aliasValue.data();
            }
            return nullptr;
        }

        void LocalFileIO::ClearAlias(const char* key)
        {
            m_aliases.erase(key);
        }

        void LocalFileIO::SetDeprecatedAlias(AZStd::string_view oldAlias, AZStd::string_view newAlias)
        {
            m_deprecatedAliases[oldAlias] = newAlias;
        }

        AZStd::optional<AZ::u64> LocalFileIO::ConvertToAliasBuffer(char* outBuffer, AZ::u64 outBufferLength, AZStd::string_view inBuffer) const
        {
            size_t longestMatch = 0;
            size_t bufStringLength = inBuffer.size();
            AZStd::string_view longestAlias;

            for (const auto& [alias, resolvedAlias] : m_aliases)
            {
                // here we are making sure that the buffer being passed in has enough space to include the alias in it.
                // we are trying to find the LONGEST match, meaning of the following two examples, the second should 'win'
                // File:  g:/O3DE/dev/files/morefiles/blah.xml
                // Alias1 links to 'g:/O3DE/dev/'
                // Alias2 links to 'g:/O3DE/dev/files/morefiles'
                // so returning Alias2 is preferred as it is more specific, even though alias1 includes it.
                // note that its not possible for this to be matched if the string is shorter than the length of the alias itself so we skip
                // strings that are shorter than the alias's mapped path without checking.
                if ((longestMatch == 0) || (resolvedAlias.size() > longestMatch) && (resolvedAlias.size() <= bufStringLength))
                {
                    // Check if the input path is relative to the alias value
                    if (AZ::IO::PathView(inBuffer).IsRelativeTo(AZ::IO::PathView(resolvedAlias)))
                    {
                        longestMatch = resolvedAlias.size();
                        longestAlias = alias;
                    }
                }
            }
            if (!longestAlias.empty())
            {
                // rearrange the buffer to have
                // [alias][old path]
                size_t aliasSize = longestAlias.size();
                size_t charsToAbsorb = longestMatch;
                size_t remainingData = bufStringLength - charsToAbsorb;
                size_t finalStringSize = aliasSize + remainingData;
                if (finalStringSize >= outBufferLength)
                {
                    AZ_Error("FileIO", false, "Alias %.*s cannot fit in output buffer. The output buffer is too small (max len %lu, actual len %zu)",
                        aznumeric_cast<int>(longestAlias.size()), longestAlias.data(), outBufferLength, finalStringSize);
                    // avoid buffer overflow, return original untouched
                    return AZStd::nullopt;
                }

                // move the remaining piece of the string:
                memmove(outBuffer + aliasSize, inBuffer.data() + charsToAbsorb, remainingData);
                // copy the alias
                memcpy(outBuffer, longestAlias.data(), aliasSize);
                /// add a null
                outBuffer[finalStringSize] = 0;
                return finalStringSize;
            }

            // If the input and output buffer are different, copy over the input buffer to the output buffer
            if (outBuffer != inBuffer.data())
            {
                if (inBuffer.size() >= outBufferLength)
                {
                    AZ_Error("FileIO", false, R"(Path "%.*s" cannot fit in output buffer. The output buffer is too small (max len %llu, actual len %zu))",
                        aznumeric_cast<int>(inBuffer.size()), inBuffer.data(), outBufferLength, inBuffer.size());
                    return AZStd::nullopt;
                }
                size_t finalStringSize = inBuffer.copy(outBuffer, outBufferLength);
                outBuffer[finalStringSize] = 0;
            }
            return bufStringLength;
        }

        AZStd::optional<AZ::u64> LocalFileIO::ConvertToAlias(char* inOutBuffer, AZ::u64 bufferLength) const
        {
            return ConvertToAliasBuffer(inOutBuffer, bufferLength, inOutBuffer);
        }

        bool LocalFileIO::ConvertToAlias(AZ::IO::FixedMaxPath& convertedPath, const AZ::IO::PathView& pathView) const
        {
            AZStd::optional<AZ::u64> convertedPathSize =
                ConvertToAliasBuffer(convertedPath.Native().data(), convertedPath.Native().capacity(), pathView.Native());
            if (convertedPathSize)
            {
                // Force update of AZStd::fixed_string m_size member to set correct null-terminator offset
                convertedPath.Native().resize_no_construct(*convertedPathSize);
                return true;
            }

            return false;
        }

        bool LocalFileIO::ResolveAliases(const char* path, char* resolvedPath, AZ::u64 resolvedPathSize) const
        {
            AZ_Assert(path && path[0] != '%', "%% is deprecated, @ is the only valid alias token");
            AZStd::string_view pathView(path);

            const auto found = AZStd::find_if(m_aliases.begin(), m_aliases.end(),
                [pathView](const auto& alias)
                {
                    return pathView.starts_with(alias.first);
                });

            using string_view_pair = AZStd::pair<AZStd::string_view, AZStd::string_view>;
            auto [aliasKey, aliasValue] = (found != m_aliases.end()) ? string_view_pair(*found)
                                                                     : string_view_pair{};

            size_t requiredResolvedPathSize = pathView.size() - aliasKey.size() + aliasValue.size() + 1;
            AZ_Assert(path != resolvedPath, "ResolveAliases does not support inplace update of the path");
            AZ_Assert(resolvedPathSize >= requiredResolvedPathSize, "Resolved path size %llu not large enough. It needs to be %zu",
                resolvedPathSize, requiredResolvedPathSize);
            // we assert above, but we also need to properly handle the case when the resolvedPath buffer size
            // is too small to copy the source into.
            if (path == resolvedPath || (resolvedPathSize < requiredResolvedPathSize))
            {
                return false;
            }

            // Skip past the alias key in the pathView
            // must ensure that we are replacing the entire folder name, not a partial (e.g. @GAME01@/ vs @GAME0@/)
            if (AZStd::string_view postAliasView = pathView.substr(aliasKey.size());
                !aliasKey.empty() && (postAliasView.empty() || postAliasView.starts_with('/') || postAliasView.starts_with('\\')))
            {
                // Copy over resolved alias path first
                size_t resolvedPathLen = 0;
                aliasValue.copy(resolvedPath, aliasValue.size());
                resolvedPathLen += aliasValue.size();
                // Append the post alias path next
                postAliasView.copy(resolvedPath + resolvedPathLen, postAliasView.size());
                resolvedPathLen += postAliasView.size();
                // Null-Terminated the resolved path
                resolvedPath[resolvedPathLen] = '\0';

                // If the path started with one of the "asset cache" path aliases, lowercase the path
                const char* projectPlatformCacheAliasPath = GetAlias("@products@");

                const bool lowercasePath = projectPlatformCacheAliasPath != nullptr && AZ::StringFunc::StartsWith(resolvedPath, projectPlatformCacheAliasPath);

                if (lowercasePath)
                {
                    // Lowercase only the relative part after the replaced alias.
                    AZStd::to_lower(resolvedPath + aliasValue.size(), resolvedPath + resolvedPathLen);
                }

                // Replace any backslashes with posix slashes
                AZStd::replace(resolvedPath, resolvedPath + resolvedPathLen, AZ::IO::WindowsPathSeparator, AZ::IO::PosixPathSeparator);
                return true;
            }
            else
            {
                // The input path doesn't start with an available, copy it directly to the resolved path
                pathView.copy(resolvedPath, pathView.size());
                // Null-Terminated the resolved path
                resolvedPath[pathView.size()] = '\0';
            }
            // warn on failing to resolve an alias
            AZ_Warning("LocalFileIO::ResolveAlias", path && path[0] != '@', "Failed to resolve an alias: %s", path ? path : "(null)");
            return false;
        }

        bool LocalFileIO::ReplaceAlias(AZ::IO::FixedMaxPath& replacedAliasPath, const AZ::IO::PathView& path) const
        {
            if (path.empty())
            {
                replacedAliasPath = path;
                return true;
            }

            AZStd::string_view pathStrView = path.Native();
            for (const auto& [aliasKey, aliasValue] : m_aliases)
            {
                if (AZ::StringFunc::StartsWith(pathStrView, aliasKey))
                {
                    // Add to the size of result path by the resolved alias length - the alias key length
                    AZStd::string_view postAliasView = pathStrView.substr(aliasKey.size());
                    size_t requiredFixedMaxPathSize = postAliasView.size();
                    requiredFixedMaxPathSize += aliasValue.size();

                    // The replaced alias path is greater than 1024 characters, return false
                    if (requiredFixedMaxPathSize > replacedAliasPath.Native().max_size())
                    {
                        return false;
                    }
                    replacedAliasPath.Native() = AZ::IO::FixedMaxPathString(AZStd::string_view{ aliasValue });
                    replacedAliasPath.Native() += postAliasView;
                    return true;
                }
            }

            if (pathStrView.size() > replacedAliasPath.Native().max_size())
            {
                return false;
            }

            replacedAliasPath = path;
            return true;
        }

        bool LocalFileIO::GetFilename(HandleType fileHandle, char* filename, AZ::u64 filenameSize) const
        {
            AZStd::lock_guard<AZStd::recursive_mutex> lock(m_openFileGuard);
            auto fileIt = m_openFiles.find(fileHandle);
            if (fileIt != m_openFiles.end())
            {
                azstrncpy(filename, filenameSize, fileIt->second.Name(), filenameSize);
                return true;
            }
            return false;
        }

        bool LocalFileIO::LowerIfBeginsWith(char* inOutBuffer, AZ::u64 bufferLen, const char* alias) const
        {
            if (alias)
            {
                AZ::u64 aliasLen = azlossy_caster(strlen(alias));
                if (azstrnicmp(inOutBuffer, alias, aliasLen) == 0)
                {
                    for (AZ::u64 i = aliasLen; i < bufferLen && inOutBuffer[i] != '\0'; ++i)
                    {
                        inOutBuffer[i] = static_cast<char>(std::tolower(static_cast<int>(inOutBuffer[i])));
                    }

                    return true;
                }
            }

            return false;
        }

        AZStd::string LocalFileIO::RemoveTrailingSlash(const AZStd::string& pathStr)
        {
            if (pathStr.empty() || (pathStr[pathStr.length() - 1] != '/' && pathStr[pathStr.length() - 1] != '\\'))
            {
                return pathStr;
            }

            return pathStr.substr(0, pathStr.length() - 1);
        }

        AZStd::string LocalFileIO::CheckForTrailingSlash(const AZStd::string& pathStr)
        {
            if (pathStr.empty() || pathStr[pathStr.length() - 1] == '/')
            {
                return pathStr;
            }

            if (pathStr[pathStr.length() - 1] == '\\')
            {
                return pathStr.substr(0, pathStr.length() - 1) + "/";
            }

            return pathStr + "/";
        }

        bool LocalFileIO::ConvertToAbsolutePath(const char* path, char* absolutePath, AZ::u64 maxLength) const
        {
            return AZ::Utils::ConvertToAbsolutePath(path, absolutePath, maxLength);
        }
    } // namespace IO
} // namespace AZ