/*****************************************************************************
 * Copyright (c) 2014-2026 OpenRCT2 developers
 *
 * For a complete list of all authors, please refer to contributors.md
 * Interested in contributing? Visit https://github.com/OpenRCT2/OpenRCT2
 *
 * OpenRCT2 is licensed under the GNU General Public License version 3.
 *****************************************************************************/

#include "ObjectRepository.h"

#include "../Context.h"
#include "../Diagnostic.h"
#include "../OpenRCT2.h"
#include "../PlatformEnvironment.h"
#include "../core/Console.hpp"
#include "../core/DataSerialiser.h"
#include "../core/EnumUtils.hpp"
#include "../core/FileIndex.hpp"
#include "../core/FileStream.h"
#include "../core/Guard.hpp"
#include "../core/IStream.hpp"
#include "../core/Numerics.hpp"
#include "../core/Path.hpp"
#include "../core/String.hpp"
#include "../localisation/LocalisationService.h"
#include "../park/Legacy.h"
#include "../platform/Platform.h"
#include "../sawyer_coding/SawyerChunkReader.h"
#include "../sawyer_coding/SawyerCoding.h"
#include "Object.h"
#include "ObjectFactory.h"

#include <memory>
#include <unordered_map>
#include <vector>

// windows.h defines CP_UTF8
#undef CP_UTF8

namespace OpenRCT2
{
    using namespace OpenRCT2::SawyerCoding;

    struct ObjectEntryHash
    {
        size_t operator()(const RCTObjectEntry& entry) const
        {
            uint32_t hash = 5381;
            for (auto i : entry.name)
            {
                hash = ((hash << 5) + hash) + i;
            }
            return hash;
        }
    };

    struct ObjectEntryEqual
    {
        bool operator()(const RCTObjectEntry& lhs, const RCTObjectEntry& rhs) const
        {
            return memcmp(&lhs.name, &rhs.name, 8) == 0;
        }
    };

    using ObjectIdentifierMap = std::unordered_map<std::string, size_t, String::Hash, std::equal_to<>>;
    using ObjectEntryMap = std::unordered_map<RCTObjectEntry, size_t, ObjectEntryHash, ObjectEntryEqual>;

    class ObjectFileIndex final : public FileIndex<ObjectRepositoryItem>
    {
    private:
        static constexpr uint32_t kMagicNumber = 0x5844494F; // OIDX
        static constexpr uint16_t kVersion = 31;
        static constexpr auto kPattern = "*.dat;*.pob;*.json;*.parkobj";

    public:
        explicit ObjectFileIndex(IObjectRepository& objectRepository, const IPlatformEnvironment& env)
            : FileIndex(
                  "object index", kMagicNumber, kVersion, env.GetFilePath(PathId::cacheObjects), std::string(kPattern),
                  std::vector<std::string>{
                      env.GetDirectoryPath(DirBase::openrct2, DirId::objects),
                      env.GetDirectoryPath(DirBase::user, DirId::objects),
                  })
        {
        }

    public:
        std::optional<ObjectRepositoryItem> Create([[maybe_unused]] int32_t language, const std::string& path) const override
        {
            std::unique_ptr<Object> object = ObjectFactory::CreateObjectFromFile(path, false);

            // All official DAT files have a JSON object counterpart. Avoid loading the obsolete .DAT versions,
            // which can happen if the user copies the official DAT objects to their custom content folder.
            if (object == nullptr
                || (object->GetGeneration() == ObjectGeneration::dat
                    && object->GetObjectEntry().GetSourceGame() != ObjectSourceGame::custom))
            {
                return std::nullopt;
            }

            ObjectRepositoryItem item = {};
            item.Type = object->GetObjectType();
            item.Generation = object->GetGeneration();
            item.Identifier = object->GetIdentifier();
            item.ObjectEntry = object->GetObjectEntry();
            item.Version = object->GetVersion();
            item.Path = path;
            item.Name = object->GetName();
            item.Authors = object->GetAuthors();
            item.Sources = object->GetSourceGames();
            if (object->IsCompatibilityObject())
                item.Flags |= ObjectItemFlags::IsCompatibilityObject;
            object->SetRepositoryItem(&item);
            return item;
        }

    protected:
        void Serialise(DataSerialiser& ds, const ObjectRepositoryItem& item) const override
        {
            ds << item.Type;
            ds << item.Generation;
            ds << item.Identifier;
            ds << item.ObjectEntry;
            ds << item.Path;
            ds << item.Name;

            ds << item.Sources;
            ds << item.Authors;
            ds << item.Flags;

            switch (item.Type)
            {
                case ObjectType::ride:
                    ds << item.RideInfo.RideFlags;
                    ds << item.RideInfo.RideType;
                    break;
                case ObjectType::sceneryGroup:
                {
                    ds << item.SceneryGroupInfo.Entries;
                    break;
                }
                case ObjectType::footpathSurface:
                    ds << item.FootpathSurfaceInfo.Flags;
                    break;
                case ObjectType::peepAnimations:
                    ds << item.PeepAnimationsInfo.PeepType;
                    break;
                default:
                    // Switch processes only ObjectType::ride and ObjectType::sceneryGroup
                    break;
            }
        }

    private:
        bool IsTrackReadOnly(const std::string& path) const
        {
            return String::startsWith(path, SearchPaths[0]) || String::startsWith(path, SearchPaths[1]);
        }
    };

    class ObjectRepository final : public IObjectRepository
    {
        IPlatformEnvironment& _env;
        ObjectFileIndex const _fileIndex;
        std::vector<ObjectRepositoryItem> _items;
        ObjectIdentifierMap _newItemMap;
        ObjectEntryMap _itemMap;

    public:
        explicit ObjectRepository(IPlatformEnvironment& env)
            : _env(env)
            , _fileIndex(*this, env)
        {
        }

        ~ObjectRepository() final
        {
            ClearItems();
        }

        void LoadOrConstruct(int32_t language) override
        {
            ClearItems();
            auto items = _fileIndex.LoadOrBuild(language);
            AddItems(items);
            SortItems();
        }

        void Construct(int32_t language) override
        {
            auto items = _fileIndex.Rebuild(language);
            AddItems(items);
            SortItems();
        }

        size_t GetNumObjects() const override
        {
            return _items.size();
        }

        const ObjectRepositoryItem* GetObjects() const override
        {
            return _items.data();
        }

        const ObjectRepositoryItem* FindObjectLegacy(std::string_view legacyIdentifier) const override
        {
            RCTObjectEntry entry = {};
            entry.SetName(legacyIdentifier);

            auto kvp = _itemMap.find(entry);
            if (kvp != _itemMap.end())
            {
                return &_items[kvp->second];
            }
            return nullptr;
        }

        const ObjectRepositoryItem* FindObject(std::string_view identifier) const override final
        {
            auto kvp = _newItemMap.find(identifier);
            if (kvp != _newItemMap.end())
            {
                return &_items[kvp->second];
            }
            return nullptr;
        }

        const ObjectRepositoryItem* FindObject(const RCTObjectEntry* objectEntry) const override final
        {
            auto kvp = _itemMap.find(*objectEntry);
            if (kvp != _itemMap.end())
            {
                return &_items[kvp->second];
            }
            return nullptr;
        }

        const ObjectRepositoryItem* FindObject(const ObjectEntryDescriptor& entry) const override final
        {
            if (entry.Generation == ObjectGeneration::dat)
                return FindObject(&entry.Entry);

            return FindObject(entry.Identifier);
        }

        std::unique_ptr<Object> LoadObject(const ObjectRepositoryItem* ori) override
        {
            return LoadObject(ori, !gOpenRCT2NoGraphics);
        }

        std::unique_ptr<Object> LoadObject(const ObjectRepositoryItem* ori, bool loadImages) override
        {
            Guard::ArgumentNotNull(ori, GUARD_LINE);

            return ObjectFactory::CreateObjectFromFile(ori->Path, loadImages);
        }

        void RegisterLoadedObject(const ObjectRepositoryItem* ori, std::unique_ptr<Object>&& object) override
        {
            ObjectRepositoryItem* item = &_items[ori->Id];

            Guard::Assert(item->LoadedObject == nullptr, GUARD_LINE);
            item->LoadedObject = std::move(object);
        }

        void UnregisterLoadedObject(const ObjectRepositoryItem* ori, Object* object) override
        {
            ObjectRepositoryItem* item = &_items[ori->Id];
            if (item->LoadedObject.get() == object)
            {
                item->LoadedObject = nullptr;
            }
        }

        void AddObject(const RCTObjectEntry* objectEntry, const void* data, size_t dataSize) override
        {
            utf8 objectName[9];
            ObjectEntryGetNameFixed(objectName, sizeof(objectName), objectEntry);

            // Check that the object is loadable before writing it
            auto object = ObjectFactory::CreateObjectFromLegacyData(objectEntry, data, dataSize);
            if (object == nullptr)
            {
                Console::Error::WriteLine("[%s] Unable to export object.", objectName);
            }
            else
            {
                LOG_VERBOSE("Adding object: [%s]", objectName);
                auto path = GetPathForNewObject(*objectEntry);
                try
                {
                    SaveObject(path, objectEntry, data, dataSize);
                    ScanObject(path);
                }
                catch (const std::exception&)
                {
                    Console::Error::WriteLine("Failed saving object: [%s] to '%s'.", objectName, path.c_str());
                }
            }
        }

        void AddObjectFromFile(
            ObjectGeneration generation, std::string_view objectName, const void* data, size_t dataSize) override
        {
            LOG_VERBOSE("Adding object: [%s]", std::string(objectName).c_str());
            u8string path;
            if (generation == ObjectGeneration::json)
            {
                path = GetPathForNewObject(objectName);
            }
            else
            {
                const RCTObjectEntry* entry = reinterpret_cast<const RCTObjectEntry*>(data);
                path = GetPathForNewObject(*entry);
            }
            try
            {
                File::WriteAllBytes(path, data, dataSize);
                ScanObject(path);
            }
            catch (const std::exception&)
            {
                Console::Error::WriteLine("Failed saving object: [%s] to '%s'.", std::string(objectName).c_str(), path.c_str());
            }
        }

        void ExportPackedObject(IStream* stream) override
        {
            auto chunkReader = SawyerChunkReader(stream);

            // Check if we already have this object
            RCTObjectEntry entry = stream->ReadValue<RCTObjectEntry>();
            if (FindObject(&entry) != nullptr)
            {
                chunkReader.SkipChunk();
            }
            else
            {
                // Read object and save to new file
                std::shared_ptr<SawyerChunk> chunk = chunkReader.ReadChunk();
                AddObject(&entry, chunk->GetData(), chunk->GetLength());
            }
        }

    private:
        void ClearItems()
        {
            _items.clear();
            _newItemMap.clear();
            _itemMap.clear();
        }

        void SortItems()
        {
            std::sort(_items.begin(), _items.end(), [](const ObjectRepositoryItem& a, const ObjectRepositoryItem& b) -> bool {
                return String::compare(a.Name, b.Name) < 0;
            });

            // Fix the IDs
            for (size_t i = 0; i < _items.size(); i++)
            {
                _items[i].Id = i;
            }

            // Rebuild item map
            _itemMap.clear();
            _newItemMap.clear();
            for (size_t i = 0; i < _items.size(); i++)
            {
                RCTObjectEntry entry = _items[i].ObjectEntry;
                _itemMap[entry] = i;
                if (!_items[i].Identifier.empty())
                {
                    _newItemMap[_items[i].Identifier] = i;
                }
            }
        }

        void AddItems(const std::vector<ObjectRepositoryItem>& items)
        {
            size_t numConflicts = 0;
            for (const auto& item : items)
            {
                if (!AddItem(item))
                {
                    numConflicts++;
                }
            }
            if (numConflicts > 0)
            {
                Console::Error::WriteLine("%zu object conflicts found.", numConflicts);
            }
        }

        bool AddItem(const ObjectRepositoryItem& item)
        {
            const auto newIdent = MapToNewObjectIdentifier(item.Identifier);
            if (!newIdent.empty())
            {
                Console::Error::WriteLine("Mixed install detected. Not loading: '%s'", item.Identifier.c_str());
                return false;
            }
            const ObjectRepositoryItem* conflict{};
            if (item.ObjectEntry.name[0] != '\0')
            {
                conflict = FindObject(&item.ObjectEntry);
            }
            if (conflict == nullptr)
            {
                conflict = FindObject(item.Identifier);
            }

            if (conflict == nullptr)
            {
                size_t index = _items.size();
                auto copy = item;
                copy.Id = index;
                _items.push_back(std::move(copy));
                if (!item.Identifier.empty())
                {
                    _newItemMap[item.Identifier] = index;
                }
                if (!item.ObjectEntry.IsEmpty())
                {
                    _itemMap[item.ObjectEntry] = index;
                }
                return true;
            }
            // When there is a conflict between a DAT file and a JSON file, the JSON should take precedence.
            else if (item.Generation == ObjectGeneration::json && conflict->Generation == ObjectGeneration::dat)
            {
                const auto id = conflict->Id;
                const auto oldPath = conflict->Path;
                _items[id] = item;
                _items[id].Id = id;
                if (!item.Identifier.empty())
                {
                    _newItemMap[item.Identifier] = id;
                }

                Console::Error::WriteLine("Object conflict: '%s' was overridden by '%s'", oldPath.c_str(), item.Path.c_str());
                return true;
            }

            Console::Error::WriteLine("Object conflict: '%s'", conflict->Path.c_str());
            Console::Error::WriteLine("               : '%s'", item.Path.c_str());
            return false;
        }

        void ScanObject(const std::string& path)
        {
            auto language = LocalisationService_GetCurrentLanguage();
            if (auto result = _fileIndex.Create(language, path); result.has_value())
            {
                AddItem(result.value());
            }
        }

        // 0x0098DA2C
        static constexpr std::array<ChunkEncoding, 11> kLegacyObjectEntryGroupEncoding = {
            ChunkEncoding::rle, ChunkEncoding::rle, ChunkEncoding::rle,    ChunkEncoding::rle,
            ChunkEncoding::rle, ChunkEncoding::rle, ChunkEncoding::rle,    ChunkEncoding::rle,
            ChunkEncoding::rle, ChunkEncoding::rle, ChunkEncoding::rotate,
        };

        static void SaveObject(
            std::string_view path, const RCTObjectEntry* entry, const void* data, size_t dataSize, bool fixChecksum = true)
        {
            if (fixChecksum)
            {
                uint32_t realChecksum = ObjectCalculateChecksum(entry, data, dataSize);
                if (realChecksum != entry->checksum)
                {
                    char objectName[9];
                    ObjectEntryGetNameFixed(objectName, sizeof(objectName), entry);
                    LOG_VERBOSE("[%s] Incorrect checksum, adding salt bytes...", objectName);

                    // Calculate the value of extra bytes that can be appended to the data so that the
                    // data is then valid for the object's checksum
                    const auto extraBytes = calculateExtraBytesToFixChecksum(realChecksum, entry->checksum);

                    // Create new data blob with appended bytes
                    std::vector<uint8_t> newData;
                    newData.reserve(dataSize + extraBytes.size());

                    const auto dataSpan = std::span(static_cast<const uint8_t*>(data), dataSize);
                    newData.insert(newData.end(), dataSpan.begin(), dataSpan.end());
                    newData.insert(newData.end(), extraBytes.begin(), extraBytes.end());

                    uint32_t newRealChecksum = ObjectCalculateChecksum(entry, newData.data(), newData.size());
                    if (newRealChecksum != entry->checksum)
                    {
                        Console::Error::WriteLine("CalculateExtraBytesToFixChecksum failed to fix checksum.");

                        // Save old data form
                        SaveObject(path, entry, data, dataSize, false);
                    }
                    else
                    {
                        // Save new data form
                        SaveObject(path, entry, newData.data(), newData.size(), false);
                    }
                    return;
                }
            }

            // Encode data
            ObjectType objectType = entry->GetType();
            ChunkHeader chunkHeader;
            chunkHeader.encoding = kLegacyObjectEntryGroupEncoding[EnumValue(objectType)];
            chunkHeader.length = static_cast<uint32_t>(dataSize);
            const auto encodedDataBuffer = std::make_unique_for_overwrite<uint8_t[]>(0x600000);
            const size_t encodedDataSize = WriteChunkBuffer(
                encodedDataBuffer.get(), reinterpret_cast<const uint8_t*>(data), chunkHeader);

            // Save to file
            auto fs = FileStream(std::string(path), FileMode::write);
            fs.Write(entry, sizeof(RCTObjectEntry));
            fs.Write(encodedDataBuffer.get(), encodedDataSize);
        }

        static std::array<uint8_t, 11> calculateExtraBytesToFixChecksum(
            const int32_t currentChecksum, const int32_t targetChecksum)
        {
            std::array<uint8_t, 11> salt{};

            // Work out which bits need to be flipped to make the current checksum match the one in the file
            // The bitwise rotation compensates for the rotation performed during the checksum calculation*/
            int32_t bitsToFlip = targetChecksum ^ ((currentChecksum << 25) | (currentChecksum >> 7));

            // Each set bit encountered during encoding flips one bit of the resulting checksum (so each bit of the checksum is
            // an XOR of bits from the file). Here, we take each bit that should be flipped in the checksum and set one of the
            // bits in the data that maps to it. 11 bytes is the minimum needed to touch every bit of the checksum - with less
            // than that, you wouldn't always be able to make the checksum come out to the desired target
            salt[0] = (bitsToFlip & 0x00000001) << 7;
            salt[1] = ((bitsToFlip & 0x00200000) >> 14);
            salt[2] = ((bitsToFlip & 0x000007F8) >> 3);
            salt[3] = ((bitsToFlip & 0xFF000000) >> 24);
            salt[4] = ((bitsToFlip & 0x00100000) >> 13);
            salt[5] = (bitsToFlip & 0x00000004) >> 2;
            salt[6] = 0;
            salt[7] = ((bitsToFlip & 0x000FF000) >> 12);
            salt[8] = (bitsToFlip & 0x00000002) >> 1;
            salt[9] = (bitsToFlip & 0x00C00000) >> 22;
            salt[10] = (bitsToFlip & 0x00000800) >> 11;

            return salt;
        }

        u8string updateFileName(u8string fileName, u8string extension)
        {
            // Get object directory and create it if it doesn't exist
            auto userObjPath = _env.GetDirectoryPath(DirBase::user, DirId::objects);
            Path::CreateDirectory(userObjPath);

            auto fullPath = Path::Combine(userObjPath, fileName + extension);
            auto counter = 1u;
            while (File::Exists(fullPath))
            {
                counter++;
                fullPath = Path::Combine(
                    userObjPath, String::stdFormat("%s-%02X%s", fileName.c_str(), counter, extension.c_str()));
            }

            return fullPath;
        }

        std::string GetPathForNewObject(const RCTObjectEntry& entry)
        {
            auto fileName = GetFileNameForNewObject(entry);
            auto extension = u8string(u8".DAT");
            return updateFileName(fileName, extension);
        }

        std::string GetPathForNewObject(std::string_view jsonIdentifier)
        {
            // Get object directory and create it if it doesn't exist
            auto userObjPath = _env.GetDirectoryPath(DirBase::user, DirId::objects);
            Path::CreateDirectory(userObjPath);

            // The identifier comes from park data; sanitise the storage path so it stays within the objects directory.
            auto fileName = Platform::SanitiseFilename(jsonIdentifier);
            if (fileName.empty())
            {
                fileName = "object_with_invalid_name";
            }
            auto extension = u8string(u8".parkobj");
            return updateFileName(fileName, extension);
        }

        std::string GetFileNameForNewObject(const RCTObjectEntry& entry)
        {
            utf8 flagsBuffer[10];
            std::snprintf(flagsBuffer, 9, "%08X", entry.flags);
            utf8 checksumBuffer[10];
            std::snprintf(checksumBuffer, 9, "%08X", entry.checksum);

            // Needs to be converted to string first because convertToUtf8() does not properly handle the string view length.
            auto cp1252name = std::string(entry.GetName());
            auto name = String::convertToUtf8(cp1252name, CodePage::cp1252);
            return name + "." + u8string(flagsBuffer) + '.' + u8string(checksumBuffer);
        }
    };

    std::unique_ptr<IObjectRepository> CreateObjectRepository(IPlatformEnvironment& env)
    {
        return std::make_unique<ObjectRepository>(env);
    }

    bool IsObjectCustom(const ObjectRepositoryItem* object)
    {
        Guard::ArgumentNotNull(object);
        switch (object->GetFirstSourceGame())
        {
            case ObjectSourceGame::rct1:
            case ObjectSourceGame::addedAttractions:
            case ObjectSourceGame::loopyLandscapes:
            case ObjectSourceGame::rct2:
            case ObjectSourceGame::wackyWorlds:
            case ObjectSourceGame::timeTwister:
            case ObjectSourceGame::openRCT2Official:
                return false;
            default:
                return true;
        }
    }

    std::unique_ptr<Object> ObjectRepositoryLoadObject(const RCTObjectEntry* objectEntry, bool loadImages)
    {
        std::unique_ptr<Object> object;
        auto& objRepository = GetContext()->GetObjectRepository();
        const ObjectRepositoryItem* ori = objRepository.FindObject(objectEntry);
        if (ori != nullptr)
        {
            object = objRepository.LoadObject(ori, loadImages);
            if (object != nullptr)
            {
                object->Load();
            }
        }
        return object;
    }

    size_t ObjectRepositoryGetItemsCount()
    {
        auto& objectRepository = GetContext()->GetObjectRepository();
        return objectRepository.GetNumObjects();
    }

    const ObjectRepositoryItem* ObjectRepositoryGetItems()
    {
        auto& objectRepository = GetContext()->GetObjectRepository();
        return objectRepository.GetObjects();
    }

    const ObjectRepositoryItem* ObjectRepositoryFindObjectByEntry(const RCTObjectEntry* entry)
    {
        auto& objectRepository = GetContext()->GetObjectRepository();
        return objectRepository.FindObject(entry);
    }

    const ObjectRepositoryItem* ObjectRepositoryFindObjectByName(const char* name)
    {
        auto& objectRepository = GetContext()->GetObjectRepository();
        return objectRepository.FindObjectLegacy(name);
    }

    int32_t ObjectCalculateChecksum(const RCTObjectEntry* entry, const void* data, size_t dataLength)
    {
        const uint8_t* entryBytePtr = reinterpret_cast<const uint8_t*>(entry);

        uint32_t checksum = 0xF369A75B;
        checksum ^= entryBytePtr[0];
        checksum = Numerics::rol32(checksum, 11);
        for (int32_t i = 4; i < 12; i++)
        {
            checksum ^= entryBytePtr[i];
            checksum = Numerics::rol32(checksum, 11);
        }

        const uint8_t* dataBytes = reinterpret_cast<const uint8_t*>(data);
        const size_t dataLength32 = dataLength - (dataLength & 31);
        for (size_t i = 0; i < 32; i++)
        {
            for (size_t j = i; j < dataLength32; j += 32)
            {
                checksum ^= dataBytes[j];
            }
            checksum = Numerics::rol32(checksum, 11);
        }
        for (size_t i = dataLength32; i < dataLength; i++)
        {
            checksum ^= dataBytes[i];
            checksum = Numerics::rol32(checksum, 11);
        }

        return static_cast<int32_t>(checksum);
    }
} // namespace OpenRCT2
