// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
// SPDX-License-Identifier: GPL-3.0-or-later

// SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include <algorithm>
#include <array>
#include <cstddef>
#include <cstring>

#include "common/hex_util.h"
#include "common/logging.h"
#include "common/settings.h"
#ifndef _WIN32
#include "common/string_util.h"
#endif

#include "core/core.h"
#include "core/file_sys/common_funcs.h"
#include "core/file_sys/content_archive.h"
#include "core/file_sys/control_metadata.h"
#include "core/file_sys/ips_layer.h"
#include "core/file_sys/patch_manager.h"
#include "core/file_sys/registered_cache.h"
#include "core/file_sys/romfs.h"
#include "core/file_sys/vfs/vfs_cached.h"
#include "core/file_sys/vfs/vfs_layered.h"
#include "core/file_sys/vfs/vfs_vector.h"
#include "core/hle/service/filesystem/filesystem.h"
#include "core/hle/service/ns/language.h"
#include "core/hle/service/set/settings_server.h"
#include "core/loader/loader.h"
#include "core/loader/nso.h"
#include "core/memory/cheat_engine.h"

namespace FileSys {
namespace {

constexpr u32 SINGLE_BYTE_MODULUS = 0x100;

constexpr std::array<const char*, 14> EXEFS_FILE_NAMES{
    "main",    "main.npdm", "rtld",    "sdk",     "subsdk0", "subsdk1", "subsdk2",
    "subsdk3", "subsdk4",   "subsdk5", "subsdk6", "subsdk7", "subsdk8", "subsdk9",
};

enum class TitleVersionFormat : u8 {
    ThreeElements, ///< vX.Y.Z
    FourElements,  ///< vX.Y.Z.W
};

std::string FormatTitleVersion(u32 version,
                               TitleVersionFormat format = TitleVersionFormat::ThreeElements) {
    std::array<u8, sizeof(u32)> bytes{};
    bytes[0] = static_cast<u8>(version % SINGLE_BYTE_MODULUS);
    for (std::size_t i = 1; i < bytes.size(); ++i) {
        version /= SINGLE_BYTE_MODULUS;
        bytes[i] = static_cast<u8>(version % SINGLE_BYTE_MODULUS);
    }

    if (format == TitleVersionFormat::FourElements) {
        return fmt::format("v{}.{}.{}.{}", bytes[3], bytes[2], bytes[1], bytes[0]);
    }
    return fmt::format("v{}.{}.{}", bytes[3], bytes[2], bytes[1]);
}

// Returns a directory with name matching name case-insensitive. Returns nullptr if directory
// doesn't have a directory with name.
VirtualDir FindSubdirectoryCaseless(const VirtualDir dir, std::string_view name) {
#ifdef _WIN32
    return dir->GetSubdirectory(name);
#else
    const auto subdirs = dir->GetSubdirectories();
    for (const auto& subdir : subdirs) {
        std::string dir_name = Common::ToLower(subdir->GetName());
        if (dir_name == name) {
            return subdir;
        }
    }

    return nullptr;
#endif
}

std::optional<std::vector<Core::Memory::CheatEntry>> ReadCheatFileFromFolder(
    u64 title_id, const PatchManager::BuildID& build_id_, const VirtualDir& base_path, bool upper) {
    const auto build_id_raw = Common::HexToString(build_id_, upper);
    const auto build_id = build_id_raw.substr(0, sizeof(u64) * 2);
    const auto file = base_path->GetFile(fmt::format("{}.txt", build_id));

    if (file == nullptr) {
        LOG_INFO(Common_Filesystem, "No cheats file found for title_id={:016X}, build_id={}",
                 title_id, build_id);
        return std::nullopt;
    }

    std::vector<u8> data(file->GetSize());
    if (file->Read(data.data(), data.size()) != data.size()) {
        LOG_INFO(Common_Filesystem, "Failed to read cheats file for title_id={:016X}, build_id={}",
                 title_id, build_id);
        return std::nullopt;
    }

    const Core::Memory::TextCheatParser parser;
    return parser.Parse(std::string_view(reinterpret_cast<const char*>(data.data()), data.size()));
}

void AppendCommaIfNotEmpty(std::string& to, std::string_view with) {
    if (to.empty()) {
        to += with;
    } else {
        to += ", ";
        to += with;
    }
}

bool IsDirValidAndNonEmpty(const VirtualDir& dir) {
    return dir != nullptr && (!dir->GetFiles().empty() || !dir->GetSubdirectories().empty());
}

bool IsVersionedExternalUpdateDisabled(const std::vector<std::string>& disabled, u32 version) {
    const std::string disabled_key = fmt::format("Update@{}", version);
    return std::find(disabled.cbegin(), disabled.cend(), disabled_key) != disabled.cend() ||
           std::find(disabled.cbegin(), disabled.cend(), "Update") != disabled.cend();
}

std::string GetUpdateVersionStringFromSlot(const ContentProvider* provider, u64 update_tid) {
    if (provider == nullptr) {
        return {};
    }

    auto control_nca = provider->GetEntry(update_tid, ContentRecordType::Control);
    if (control_nca == nullptr ||
        control_nca->GetStatus() != Loader::ResultStatus::Success) {
        return {};
    }

    const auto romfs = control_nca->GetRomFS();
    if (romfs == nullptr) {
        return {};
    }

    const auto extracted = ExtractRomFS(romfs);
    if (extracted == nullptr) {
        return {};
    }

    auto nacp_file = extracted->GetFile("control.nacp");
    if (nacp_file == nullptr) {
        nacp_file = extracted->GetFile("Control.nacp");
    }
    if (nacp_file == nullptr) {
        return {};
    }

    NACP nacp{nacp_file};
    return nacp.GetVersionString();
}
} // Anonymous namespace

PatchManager::PatchManager(u64 title_id_,
                           const Service::FileSystem::FileSystemController& fs_controller_,
                           const ContentProvider& content_provider_)
    : title_id{title_id_}, fs_controller{fs_controller_}, content_provider{content_provider_} {}

PatchManager::~PatchManager() = default;

u64 PatchManager::GetTitleID() const {
    return title_id;
}

VirtualDir PatchManager::PatchExeFS(VirtualDir exefs) const {
    LOG_INFO(Loader, "Patching ExeFS for title_id={:016X}", title_id);

    if (exefs == nullptr)
        return exefs;

    const auto& disabled = Settings::values.disabled_addons[title_id];

    bool update_disabled = true;
    std::optional<u32> enabled_version;
    bool checked_external = false;
    bool checked_manual = false;

    const auto* content_union = static_cast<const ContentProviderUnion*>(&content_provider);
    const auto update_tid = GetUpdateTitleID(title_id);

    if (content_union) {
        // First, check ExternalContentProvider
        const auto* external_provider = content_union->GetExternalProvider();
        if (external_provider) {
            const auto update_versions = external_provider->ListUpdateVersions(update_tid);

            if (!update_versions.empty()) {
                checked_external = true;
                for (const auto& update_entry : update_versions) {
                    if (!IsVersionedExternalUpdateDisabled(disabled, update_entry.version)) {
                        update_disabled = false;
                        enabled_version = update_entry.version;
                        break;
                    }
                }
            }
        }

        // Also check ManualContentProvider (for Android)
        if (!checked_external) {
            const auto* manual_provider = static_cast<const ManualContentProvider*>(
                content_union->GetSlotProvider(ContentProviderUnionSlot::FrontendManual));
            if (manual_provider) {
                const auto manual_update_versions = manual_provider->ListUpdateVersions(update_tid);

                if (!manual_update_versions.empty()) {
                    checked_manual = true;
                    for (const auto& update_entry : manual_update_versions) {
                        if (!IsVersionedExternalUpdateDisabled(disabled, update_entry.version)) {
                            update_disabled = false;
                            enabled_version = update_entry.version;
                            break;
                        }
                    }
                }
            }
        }
    }

    // check for original NAND style
    // Check NAND if: no external updates exist, OR all external updates are disabled
    if (!checked_external && !checked_manual) {
        // Only enable NAND update if it exists AND is not disabled
        // We need to check if an update actually exists in the content provider
        const bool has_nand_update = content_provider.HasEntry(update_tid, ContentRecordType::Program);

        if (has_nand_update) {
            const bool nand_disabled = std::find(disabled.cbegin(), disabled.cend(), "Update (NAND)") != disabled.cend();
            const bool sdmc_disabled = std::find(disabled.cbegin(), disabled.cend(), "Update (SDMC)") != disabled.cend();
            const bool generic_disabled = std::find(disabled.cbegin(), disabled.cend(), "Update") != disabled.cend();

            if (!nand_disabled && !sdmc_disabled && !generic_disabled) {
                update_disabled = false;
            }
        }
    } else if (update_disabled && content_union) {
        const bool nand_disabled = std::find(disabled.cbegin(), disabled.cend(), "Update (NAND)") != disabled.cend();
        const bool sdmc_disabled = std::find(disabled.cbegin(), disabled.cend(), "Update (SDMC)") != disabled.cend();

        if (!nand_disabled || !sdmc_disabled) {
            const auto nand_sdmc_entries = content_union->ListEntriesFilterOrigin(
                std::nullopt, TitleType::Update, ContentRecordType::Program, update_tid);

            for (const auto& [slot, entry] : nand_sdmc_entries) {
                if (slot == ContentProviderUnionSlot::UserNAND ||
                    slot == ContentProviderUnionSlot::SysNAND) {
                    if (!nand_disabled) {
                        update_disabled = false;
                        break;
                    }
                } else if (slot == ContentProviderUnionSlot::SDMC) {
                    if (!sdmc_disabled) {
                        update_disabled = false;
                        break;
                    }
                }
            }
        }
    }

    // Game Updates
    std::unique_ptr<NCA> update = nullptr;

    // If we have a specific enabled version from external provider, use it
    if (enabled_version.has_value() && content_union) {
        const auto* external_provider = content_union->GetExternalProvider();
        if (external_provider) {
            auto file = external_provider->GetEntryForVersion(update_tid, ContentRecordType::Program, *enabled_version);
            if (file != nullptr) {
                update = std::make_unique<NCA>(file);
            }
        }

        // Also try ManualContentProvider
        if (update == nullptr) {
            const auto* manual_provider = static_cast<const ManualContentProvider*>(
                content_union->GetSlotProvider(ContentProviderUnionSlot::FrontendManual));
            if (manual_provider) {
                auto file = manual_provider->GetEntryForVersion(update_tid, ContentRecordType::Program, *enabled_version);
                if (file != nullptr) {
                    update = std::make_unique<NCA>(file);
                }
            }
        }
    }

    // Fallback to regular content provider if no external update was loaded
    if (update == nullptr && !update_disabled) {
        update = content_provider.GetEntry(update_tid, ContentRecordType::Program);
    }

    if (!update_disabled && update != nullptr && update->GetExeFS() != nullptr) {
        LOG_INFO(Loader, "    ExeFS: Update ({}) applied successfully",
                 FormatTitleVersion(content_provider.GetEntryVersion(update_tid).value_or(0)));
        exefs = update->GetExeFS();
    }

    // LayeredExeFS
    const auto load_dir = fs_controller.GetModificationLoadRoot(title_id);
    const auto sdmc_load_dir = fs_controller.GetSDMCModificationLoadRoot(title_id);

    std::vector<VirtualDir> patch_dirs = {sdmc_load_dir};
    if (load_dir != nullptr) {
        const auto load_patch_dirs = load_dir->GetSubdirectories();
        patch_dirs.insert(patch_dirs.end(), load_patch_dirs.begin(), load_patch_dirs.end());
    }

    std::sort(patch_dirs.begin(), patch_dirs.end(),
              [](const VirtualDir& l, const VirtualDir& r) { return l->GetName() < r->GetName(); });

    std::vector<VirtualDir> layers;
    layers.reserve(patch_dirs.size() + 1);
    for (const auto& subdir : patch_dirs) {
        if (std::find(disabled.begin(), disabled.end(), subdir->GetName()) != disabled.end())
            continue;

        auto exefs_dir = FindSubdirectoryCaseless(subdir, "exefs");
        if (exefs_dir != nullptr)
            layers.push_back(std::move(exefs_dir));
    }
    layers.push_back(exefs);

    auto layered = LayeredVfsDirectory::MakeLayeredDirectory(std::move(layers));
    if (layered != nullptr) {
        LOG_INFO(Loader, "    ExeFS: LayeredExeFS patches applied successfully");
        exefs = std::move(layered);
    }

    if (Settings::values.dump_exefs) {
        LOG_INFO(Loader, "Dumping ExeFS for title_id={:016X}", title_id);
        const auto dump_dir = fs_controller.GetModificationDumpRoot(title_id);
        if (dump_dir != nullptr) {
            const auto exefs_dir = GetOrCreateDirectoryRelative(dump_dir, "/exefs");
            VfsRawCopyD(exefs, exefs_dir);
        }
    }

    return exefs;
}

std::vector<VirtualFile> PatchManager::CollectPatches(const std::vector<VirtualDir>& patch_dirs,
                                                      const std::string& build_id) const {
    const auto& disabled = Settings::values.disabled_addons[title_id];
    const auto nso_build_id = fmt::format("{:0<64}", build_id);

    std::vector<VirtualFile> out;
    out.reserve(patch_dirs.size());
    for (const auto& subdir : patch_dirs) {
        if (std::find(disabled.cbegin(), disabled.cend(), subdir->GetName()) != disabled.cend())
            continue;

        auto exefs_dir = FindSubdirectoryCaseless(subdir, "exefs");
        if (exefs_dir != nullptr) {
            for (const auto& file : exefs_dir->GetFiles()) {
                if (file->GetExtension() == "ips") {
                    auto name = file->GetName();

                    const auto this_build_id =
                        fmt::format("{:0<64}", name.substr(0, name.find('.')));
                    if (nso_build_id == this_build_id)
                        out.push_back(file);
                } else if (file->GetExtension() == "pchtxt") {
                    IPSwitchCompiler compiler{file};
                    if (!compiler.IsValid())
                        continue;

                    const auto this_build_id = Common::HexToString(compiler.GetBuildID());
                    if (nso_build_id == this_build_id)
                        out.push_back(file);
                }
            }
        }
    }

    return out;
}

std::vector<u8> PatchManager::PatchNSO(const std::vector<u8>& nso, const std::string& name) const {
    if (nso.size() < sizeof(Loader::NSOHeader)) {
        return nso;
    }

    Loader::NSOHeader header;
    std::memcpy(&header, nso.data(), sizeof(header));

    if (header.magic != Common::MakeMagic('N', 'S', 'O', '0')) {
        return nso;
    }

    const auto build_id_raw = Common::HexToString(header.build_id);
    const auto build_id = build_id_raw.substr(0, build_id_raw.find_last_not_of('0') + 1);

    if (Settings::values.dump_nso) {
        LOG_INFO(Loader, "Dumping NSO for name={}, build_id={}, title_id={:016X}", name, build_id,
                 title_id);
        const auto dump_dir = fs_controller.GetModificationDumpRoot(title_id);
        if (dump_dir != nullptr) {
            const auto nso_dir = GetOrCreateDirectoryRelative(dump_dir, "/nso");
            const auto file = nso_dir->CreateFile(fmt::format("{}-{}.nso", name, build_id));

            file->Resize(nso.size());
            file->WriteBytes(nso);
        }
    }

    LOG_INFO(Loader, "Patching NSO for name={}, build_id={}", name, build_id);

    const auto load_dir = fs_controller.GetModificationLoadRoot(title_id);
    if (load_dir == nullptr) {
        LOG_ERROR(Loader, "Cannot load mods for invalid title_id={:016X}", title_id);
        return nso;
    }

    auto patch_dirs = load_dir->GetSubdirectories();
    std::sort(patch_dirs.begin(), patch_dirs.end(),
              [](const VirtualDir& l, const VirtualDir& r) { return l->GetName() < r->GetName(); });
    const auto patches = CollectPatches(patch_dirs, build_id);

    auto out = nso;
    for (const auto& patch_file : patches) {
        if (patch_file->GetExtension() == "ips") {
            LOG_INFO(Loader, "    - Applying IPS patch from mod \"{}\"",
                     patch_file->GetContainingDirectory()->GetParentDirectory()->GetName());
            const auto patched = PatchIPS(std::make_shared<VectorVfsFile>(out), patch_file);
            if (patched != nullptr)
                out = patched->ReadAllBytes();
        } else if (patch_file->GetExtension() == "pchtxt") {
            LOG_INFO(Loader, "    - Applying IPSwitch patch from mod \"{}\"",
                     patch_file->GetContainingDirectory()->GetParentDirectory()->GetName());
            const IPSwitchCompiler compiler{patch_file};
            const auto patched = compiler.Apply(std::make_shared<VectorVfsFile>(out));
            if (patched != nullptr)
                out = patched->ReadAllBytes();
        }
    }

    if (out.size() < sizeof(Loader::NSOHeader)) {
        return nso;
    }

    std::memcpy(out.data(), &header, sizeof(header));
    return out;
}

bool PatchManager::HasNSOPatch(const BuildID& build_id_, std::string_view name) const {
    const auto build_id_raw = Common::HexToString(build_id_);
    const auto build_id = build_id_raw.substr(0, build_id_raw.find_last_not_of('0') + 1);

    LOG_INFO(Loader, "Querying NSO patch existence for build_id={}, name={}", build_id, name);

    const auto load_dir = fs_controller.GetModificationLoadRoot(title_id);
    if (load_dir == nullptr) {
        LOG_ERROR(Loader, "Cannot load mods for invalid title_id={:016X}", title_id);
        return false;
    }

    auto patch_dirs = load_dir->GetSubdirectories();
    std::sort(patch_dirs.begin(), patch_dirs.end(),
              [](const VirtualDir& l, const VirtualDir& r) { return l->GetName() < r->GetName(); });

    return !CollectPatches(patch_dirs, build_id).empty();
}

std::vector<Core::Memory::CheatEntry> PatchManager::CreateCheatList(const BuildID& build_id_) const {
    const auto load_dir = fs_controller.GetModificationLoadRoot(title_id);
    if (load_dir == nullptr) {
        LOG_ERROR(Loader, "Cannot load mods for invalid title_id={:016X}", title_id);
        return {};
    }

    const auto& disabled = Settings::values.disabled_addons[title_id];
    auto patch_dirs = load_dir->GetSubdirectories();
    std::sort(patch_dirs.begin(), patch_dirs.end(), [](auto const& l, auto const& r) { return l->GetName() < r->GetName(); });

    // <mod dir> / <folder> / cheats / <build id>.txt
    std::vector<Core::Memory::CheatEntry> out;
    for (const auto& subdir : patch_dirs) {
        if (std::find(disabled.cbegin(), disabled.cend(), subdir->GetName()) == disabled.cend()) {
            if (auto cheats_dir = FindSubdirectoryCaseless(subdir, "cheats"); cheats_dir != nullptr) {
                if (auto const res = ReadCheatFileFromFolder(title_id, build_id_, cheats_dir, true))
                    std::copy(res->begin(), res->end(), std::back_inserter(out));
                if (auto const res = ReadCheatFileFromFolder(title_id, build_id_, cheats_dir, false))
                    std::copy(res->begin(), res->end(), std::back_inserter(out));
            }
        }
    }
    // Uncareless user-friendly loading of patches (must start with 'cheat_')
    // <mod dir> / <cheat file>.txt
    for (auto const& f : load_dir->GetFiles()) {
        auto const name = f->GetName();
        if (name.starts_with("cheat_") && std::find(disabled.cbegin(), disabled.cend(), name) == disabled.cend()) {
            std::vector<u8> data(f->GetSize());
            if (f->Read(data.data(), data.size()) == data.size()) {
                const Core::Memory::TextCheatParser parser;
                auto const res = parser.Parse(std::string_view(reinterpret_cast<const char*>(data.data()), data.size()));
                std::copy(res.begin(), res.end(), std::back_inserter(out));
            } else {
                LOG_INFO(Common_Filesystem, "Failed to read cheats file for title_id={:016X}", title_id);
            }
        }
    }
    return out;
}

static void ApplyLayeredFS(VirtualFile& romfs, u64 title_id, ContentRecordType type,
                           const Service::FileSystem::FileSystemController& fs_controller) {
    const auto load_dir = fs_controller.GetModificationLoadRoot(title_id);
    const auto sdmc_load_dir = fs_controller.GetSDMCModificationLoadRoot(title_id);
    if ((type != ContentRecordType::Program && type != ContentRecordType::Data &&
         type != ContentRecordType::HtmlDocument) ||
        (load_dir == nullptr && sdmc_load_dir == nullptr)) {
        return;
    }

    const auto& disabled = Settings::values.disabled_addons[title_id];
    std::vector<VirtualDir> patch_dirs = load_dir->GetSubdirectories();
    if (std::find(disabled.cbegin(), disabled.cend(), "SDMC") == disabled.cend()) {
        patch_dirs.push_back(sdmc_load_dir);
    }
    std::sort(patch_dirs.begin(), patch_dirs.end(),
              [](const VirtualDir& l, const VirtualDir& r) { return l->GetName() < r->GetName(); });

    std::vector<VirtualDir> layers;
    std::vector<VirtualDir> layers_ext;
    layers.reserve(patch_dirs.size() + 1);
    layers_ext.reserve(patch_dirs.size() + 1);
    for (const auto& subdir : patch_dirs) {
        if (std::find(disabled.cbegin(), disabled.cend(), subdir->GetName()) != disabled.cend()) {
            continue;
        }

        auto romfs_dir = FindSubdirectoryCaseless(subdir, "romfs");
        if (romfs_dir != nullptr)
            layers.emplace_back(std::make_shared<CachedVfsDirectory>(std::move(romfs_dir)));

        // Support for romfslite introduced in Atmosphere 1.9.5
        auto romfslite_dir = FindSubdirectoryCaseless(subdir, "romfslite");
        if (romfslite_dir != nullptr)
            layers.emplace_back(std::make_shared<CachedVfsDirectory>(std::move(romfslite_dir)));

        auto ext_dir = FindSubdirectoryCaseless(subdir, "romfs_ext");
        if (ext_dir != nullptr)
            layers_ext.emplace_back(std::make_shared<CachedVfsDirectory>(std::move(ext_dir)));

        if (type == ContentRecordType::HtmlDocument) {
            auto manual_dir = FindSubdirectoryCaseless(subdir, "manual_html");
            if (manual_dir != nullptr)
                layers.emplace_back(std::make_shared<CachedVfsDirectory>(std::move(manual_dir)));
        }
    }

    // When there are no layers to apply, return early as there is no need to rebuild the RomFS
    if (layers.empty() && layers_ext.empty()) {
        return;
    }

    auto extracted = ExtractRomFS(romfs);
    if (extracted == nullptr) {
        return;
    }

    layers.emplace_back(std::move(extracted));

    auto layered = LayeredVfsDirectory::MakeLayeredDirectory(std::move(layers));
    auto layered_ext = LayeredVfsDirectory::MakeLayeredDirectory(std::move(layers_ext));
    if (layered == nullptr && layered_ext == nullptr) {
        return;
    }

    auto packed = CreateRomFS(std::move(layered), std::move(layered_ext));
    if (packed == nullptr) {
        return;
    }

    LOG_INFO(Loader, "    RomFS: LayeredFS patches applied successfully");
    romfs = std::move(packed);
}

VirtualFile PatchManager::PatchRomFS(const NCA* base_nca, VirtualFile base_romfs,
                                     ContentRecordType type, VirtualFile packed_update_raw,
                                     bool apply_layeredfs) const {
    const auto log_string = fmt::format("Patching RomFS for title_id={:016X}, type={:02X}",
                                        title_id, static_cast<u8>(type));
    if (type == ContentRecordType::Program || type == ContentRecordType::Data) {
        LOG_INFO(Loader, "{}", log_string);
    } else {
        LOG_DEBUG(Loader, "{}", log_string);
    }

    auto romfs = base_romfs;

    // Game Updates
    const auto update_tid = GetUpdateTitleID(title_id);
    const auto& disabled = Settings::values.disabled_addons[title_id];

    bool update_disabled = true;
    std::optional<u32> enabled_version;
    VirtualFile update_raw = nullptr;
    bool checked_external = false;
    bool checked_manual = false;

    const auto* content_union = static_cast<const ContentProviderUnion*>(&content_provider);
    if (content_union) {
        // First, check ExternalContentProvider
        const auto* external_provider = content_union->GetExternalProvider();
        if (external_provider) {
            const auto update_versions = external_provider->ListUpdateVersions(update_tid);

            if (!update_versions.empty()) {
                checked_external = true;
                for (const auto& update_entry : update_versions) {
                    if (!IsVersionedExternalUpdateDisabled(disabled, update_entry.version)) {
                        update_disabled = false;
                        enabled_version = update_entry.version;
                        update_raw = external_provider->GetEntryForVersion(update_tid, type, update_entry.version);
                        break;
                    }
                }
            }
        }

        if (!checked_external) {
            const auto* manual_provider = static_cast<const ManualContentProvider*>(
                content_union->GetSlotProvider(ContentProviderUnionSlot::FrontendManual));
            if (manual_provider) {
                const auto manual_update_versions = manual_provider->ListUpdateVersions(update_tid);

                if (!manual_update_versions.empty()) {
                    checked_manual = true;
                    for (const auto& update_entry : manual_update_versions) {
                        if (!IsVersionedExternalUpdateDisabled(disabled, update_entry.version)) {
                            update_disabled = false;
                            enabled_version = update_entry.version;
                            update_raw = manual_provider->GetEntryForVersion(update_tid, type, update_entry.version);
                            break;
                        }
                    }
                }
            }
        }
    }

    if (!checked_external && !checked_manual) {
        const bool nand_disabled = std::find(disabled.cbegin(), disabled.cend(), "Update (NAND)") != disabled.cend();
        const bool sdmc_disabled = std::find(disabled.cbegin(), disabled.cend(), "Update (SDMC)") != disabled.cend();
        const bool generic_disabled = std::find(disabled.cbegin(), disabled.cend(), "Update") != disabled.cend();

        if (!nand_disabled && !sdmc_disabled && !generic_disabled) {
            update_disabled = false;
        }
        if (!update_disabled) {
            update_raw = content_provider.GetEntryRaw(update_tid, type);
        }
    } else if (update_disabled && content_union) {
        const bool nand_disabled = std::find(disabled.cbegin(), disabled.cend(), "Update (NAND)") != disabled.cend();
        const bool sdmc_disabled = std::find(disabled.cbegin(), disabled.cend(), "Update (SDMC)") != disabled.cend();

        if (!nand_disabled || !sdmc_disabled) {
            const auto nand_sdmc_entries = content_union->ListEntriesFilterOrigin(
                std::nullopt, TitleType::Update, type, update_tid);

            for (const auto& [slot, entry] : nand_sdmc_entries) {
                if (slot == ContentProviderUnionSlot::UserNAND ||
                    slot == ContentProviderUnionSlot::SysNAND) {
                    if (!nand_disabled) {
                        update_disabled = false;
                        update_raw = content_provider.GetEntryRaw(update_tid, type);
                        break;
                    }
                } else if (slot == ContentProviderUnionSlot::SDMC) {
                    if (!sdmc_disabled) {
                        update_disabled = false;
                        update_raw = content_provider.GetEntryRaw(update_tid, type);
                        break;
                    }
                }
            }
        }
    }

    if (!update_disabled && update_raw != nullptr && base_nca != nullptr) {
        const auto new_nca = std::make_shared<NCA>(update_raw, base_nca);
        if (new_nca->GetStatus() == Loader::ResultStatus::Success &&
            new_nca->GetRomFS() != nullptr) {
            LOG_INFO(Loader, "    RomFS: Update ({}) applied successfully",
                     enabled_version.has_value() ? FormatTitleVersion(*enabled_version) :
                     FormatTitleVersion(content_provider.GetEntryVersion(update_tid).value_or(0)));
            romfs = new_nca->GetRomFS();
        }
    } else if (!update_disabled && packed_update_raw != nullptr && base_nca != nullptr) {
        const auto new_nca = std::make_shared<NCA>(packed_update_raw, base_nca);
        if (new_nca->GetStatus() == Loader::ResultStatus::Success &&
            new_nca->GetRomFS() != nullptr) {
            LOG_INFO(Loader, "    RomFS: Update (PACKED) applied successfully");
            romfs = new_nca->GetRomFS();
        }
    }

    // LayeredFS
    if (apply_layeredfs) {
        ApplyLayeredFS(romfs, title_id, type, fs_controller);
    }

    return romfs;
}

std::vector<Patch> PatchManager::GetPatches(VirtualFile update_raw) const {
    if (title_id == 0) {
        return {};
    }

    std::vector<Patch> out;
    const auto& disabled = Settings::values.disabled_addons[title_id];

    // Game Updates
    const auto update_tid = GetUpdateTitleID(title_id);

    std::vector<Patch> external_update_patches;

    const auto* content_union = static_cast<const ContentProviderUnion*>(&content_provider);

    if (content_union) {
        // First, check ExternalContentProvider for updates
        const auto* external_provider = content_union->GetExternalProvider();
        if (external_provider) {
            const auto update_versions = external_provider->ListUpdateVersions(update_tid);

            for (const auto& update_entry : update_versions) {
                std::string version_str = update_entry.version_string;
                if (version_str.empty()) {
                    version_str = FormatTitleVersion(update_entry.version);
                }

                const auto update_disabled =
                    IsVersionedExternalUpdateDisabled(disabled, update_entry.version);

                Patch update_patch = {.enabled = !update_disabled,
                                      .name = "Update",
                                      .version = version_str,
                                      .type = PatchType::Update,
                                      .program_id = title_id,
                                      .title_id = update_tid,
                                      .source = PatchSource::External,
                                      .numeric_version = update_entry.version};

                external_update_patches.push_back(update_patch);
            }
        }

        const auto* manual_provider = static_cast<const ManualContentProvider*>(
            content_union->GetSlotProvider(ContentProviderUnionSlot::FrontendManual));
        if (manual_provider && external_update_patches.empty()) {
            const auto manual_update_versions = manual_provider->ListUpdateVersions(update_tid);

            for (const auto& update_entry : manual_update_versions) {
                std::string version_str = update_entry.version_string;
                if (version_str.empty()) {
                    version_str = FormatTitleVersion(update_entry.version);
                }

                const auto update_disabled =
                    IsVersionedExternalUpdateDisabled(disabled, update_entry.version);


                Patch update_patch = {.enabled = !update_disabled,
                                      .name = "Update",
                                      .version = version_str,
                                      .type = PatchType::Update,
                                      .program_id = title_id,
                                      .title_id = update_tid,
                                      .source = PatchSource::External,
                                      .numeric_version = update_entry.version};

                external_update_patches.push_back(update_patch);
            }
        }

        if (external_update_patches.size() > 1) {
            bool found_enabled = false;
            for (auto& patch : external_update_patches) {
                if (patch.enabled) {
                    if (found_enabled) {
                        patch.enabled = false;
                    } else {
                        found_enabled = true;
                    }
                }
            }
        }

        for (auto& patch : external_update_patches) {
            out.push_back(std::move(patch));
        }

        const auto all_updates = content_union->ListEntriesFilterOrigin(
            std::nullopt, std::nullopt, ContentRecordType::Program, update_tid);

        for (const auto& [slot, entry] : all_updates) {
            (void)entry;
            if (slot == ContentProviderUnionSlot::External ||
                slot == ContentProviderUnionSlot::FrontendManual) {
                continue;
            }

            PatchSource source_type = PatchSource::Unknown;
            std::string source_suffix;

            switch (slot) {
                case ContentProviderUnionSlot::UserNAND:
                case ContentProviderUnionSlot::SysNAND:
                    source_type = PatchSource::NAND;
                    source_suffix = " (NAND)";
                    break;
                case ContentProviderUnionSlot::SDMC:
                    source_type = PatchSource::SDMC;
                    source_suffix = " (SDMC)";
                    break;
                default:
                    break;
            }

            std::string version_str;
            u32 numeric_ver = 0;
            const auto* slot_provider = content_union->GetSlotProvider(slot);
            version_str = GetUpdateVersionStringFromSlot(slot_provider, update_tid);

            if (slot_provider != nullptr) {
                const auto slot_ver = slot_provider->GetEntryVersion(update_tid);
                if (slot_ver.has_value()) {
                    numeric_ver = *slot_ver;
                    if (version_str.empty() && numeric_ver != 0) {
                        version_str = FormatTitleVersion(numeric_ver);
                    }
                }
            }

            std::string patch_name = "Update" + source_suffix;

            bool update_disabled =
                std::find(disabled.cbegin(), disabled.cend(), patch_name) != disabled.cend();

            Patch update_patch = {.enabled = !update_disabled,
                                  .name = patch_name,
                                  .version = version_str,
                                  .type = PatchType::Update,
                                  .program_id = title_id,
                                  .title_id = update_tid,
                                  .source = source_type,
                                  .numeric_version = numeric_ver};

            out.push_back(update_patch);
        }
    } else {
        PatchManager update{update_tid, fs_controller, content_provider};
        const auto metadata = update.GetControlMetadata();
        const auto& nacp = metadata.first;

        bool update_disabled =
            std::find(disabled.cbegin(), disabled.cend(), "Update") != disabled.cend();
        Patch update_patch = {.enabled = !update_disabled,
                              .name = "Update",
                              .version = "",
                              .type = PatchType::Update,
                              .program_id = title_id,
                              .title_id = title_id,
                              .source = PatchSource::Unknown,
                              .numeric_version = 0};

        if (nacp != nullptr) {
            update_patch.version = nacp->GetVersionString();
            out.push_back(update_patch);
        } else {
            if (content_provider.HasEntry(update_tid, ContentRecordType::Program)) {
                const auto meta_ver = content_provider.GetEntryVersion(update_tid);
                if (meta_ver.value_or(0) == 0) {
                    out.push_back(update_patch);
                } else {
                    update_patch.version = FormatTitleVersion(*meta_ver);
                    update_patch.numeric_version = *meta_ver;
                    out.push_back(update_patch);
                }
            } else if (update_raw != nullptr) {
                update_patch.version = "PACKED";
                update_patch.source = PatchSource::Packed;
                out.push_back(update_patch);
            }
        }
    }

    // General Mods (LayeredFS and IPS)
    const auto mod_dir = fs_controller.GetModificationLoadRoot(title_id);
    if (mod_dir != nullptr) {
        for (auto const& f : mod_dir->GetFiles())
            if (auto const name = f->GetName(); name.starts_with("cheat_")) {
                auto const mod_disabled = std::find(disabled.begin(), disabled.end(), name) != disabled.end();
                out.push_back({
                    .enabled = !mod_disabled,
                    .name = name,
                    .version = "Cheats",
                    .type = PatchType::Mod,
                    .program_id = title_id,
                    .title_id = title_id,
                    .source = PatchSource::Unknown,
                    .location = f->GetFullPath(),
                });
            }

        for (const auto& mod : mod_dir->GetSubdirectories()) {
            std::string types;

            const auto exefs_dir = FindSubdirectoryCaseless(mod, "exefs");
            if (IsDirValidAndNonEmpty(exefs_dir)) {
                bool ips = false;
                bool ipswitch = false;
                bool layeredfs = false;

                for (const auto& file : exefs_dir->GetFiles()) {
                    if (file->GetExtension() == "ips") {
                        ips = true;
                    } else if (file->GetExtension() == "pchtxt") {
                        ipswitch = true;
                    } else if (std::find(EXEFS_FILE_NAMES.begin(), EXEFS_FILE_NAMES.end(),
                                         file->GetName()) != EXEFS_FILE_NAMES.end()) {
                        layeredfs = true;
                                         }
                }

                if (ips)
                    AppendCommaIfNotEmpty(types, "IPS");
                if (ipswitch)
                    AppendCommaIfNotEmpty(types, "IPSwitch");
                if (layeredfs)
                    AppendCommaIfNotEmpty(types, "LayeredExeFS");
            }
            if (IsDirValidAndNonEmpty(FindSubdirectoryCaseless(mod, "romfs")) ||
                IsDirValidAndNonEmpty(FindSubdirectoryCaseless(mod, "romfslite")))
                AppendCommaIfNotEmpty(types, "LayeredFS");
            if (IsDirValidAndNonEmpty(FindSubdirectoryCaseless(mod, "romfs_ext")))
                AppendCommaIfNotEmpty(types, "ExtLayeredFS");
            if (IsDirValidAndNonEmpty(FindSubdirectoryCaseless(mod, "cheats")))
                AppendCommaIfNotEmpty(types, "Cheats");

            if (types.empty())
                continue;

            const auto mod_disabled = std::find(disabled.begin(), disabled.end(), mod->GetName()) != disabled.end();
            out.push_back({.enabled = !mod_disabled,
                           .name = mod->GetName(),
                           .version = types,
                           .type = PatchType::Mod,
                           .program_id = title_id,
                           .title_id = title_id,
                           .source = PatchSource::Unknown,
                           .location = mod->GetFullPath()});
        }
    }

    // SDMC mod directory (RomFS LayeredFS)
    const auto sdmc_mod_dir = fs_controller.GetSDMCModificationLoadRoot(title_id);
    if (sdmc_mod_dir != nullptr) {
        std::string types;
        if (IsDirValidAndNonEmpty(FindSubdirectoryCaseless(sdmc_mod_dir, "exefs")))
            AppendCommaIfNotEmpty(types, "LayeredExeFS");
        if (IsDirValidAndNonEmpty(FindSubdirectoryCaseless(sdmc_mod_dir, "romfs")) ||
            IsDirValidAndNonEmpty(FindSubdirectoryCaseless(sdmc_mod_dir, "romfslite")))
            AppendCommaIfNotEmpty(types, "LayeredFS");
        if (IsDirValidAndNonEmpty(FindSubdirectoryCaseless(sdmc_mod_dir, "romfs_ext")))
            AppendCommaIfNotEmpty(types, "ExtLayeredFS");

        if (!types.empty()) {
            const auto mod_disabled =
                std::find(disabled.begin(), disabled.end(), "SDMC") != disabled.end();
            out.push_back({.enabled = !mod_disabled,
                           .name = "SDMC",
                           .version = types,
                           .type = PatchType::Mod,
                           .program_id = title_id,
                           .title_id = title_id,
                           .source = PatchSource::Unknown});
        }
    }

    // DLC
    std::vector<ContentProviderEntry> dlc_match;
    bool has_external_dlc = false;
    bool has_nand_dlc = false;
    bool has_sdmc_dlc = false;
    bool has_other_dlc = false;
    const auto dlc_entries_with_origin =
        content_union->ListEntriesFilterOrigin(std::nullopt, TitleType::AOC, ContentRecordType::Data);

    dlc_match.reserve(dlc_entries_with_origin.size());
    for (const auto& [slot, entry] : dlc_entries_with_origin) {
        const auto base_tid = GetBaseTitleID(entry.title_id);
        const bool matches_base = base_tid == title_id;
        if (!matches_base) {
            LOG_DEBUG(Loader, "DLC {:016X} base {:016X} doesn't match title {:016X}",
                      entry.title_id, base_tid, title_id);
            continue;
        }

        const auto* slot_provider = content_union->GetSlotProvider(slot);
        if (slot_provider == nullptr) {
            continue;
        }

        auto nca = slot_provider->GetEntry(entry);
        if (!nca) {
            LOG_DEBUG(Loader, "Failed to get NCA for DLC {:016X}", entry.title_id);
            continue;
        }

        const auto status = nca->GetStatus();
        if (status != Loader::ResultStatus::Success) {
            LOG_DEBUG(Loader, "DLC {:016X} NCA has status {}", entry.title_id,
                      static_cast<int>(status));
            continue;
        }

        switch (slot) {
            case ContentProviderUnionSlot::External:
            case ContentProviderUnionSlot::FrontendManual:
                has_external_dlc = true;
                break;
            case ContentProviderUnionSlot::UserNAND:
            case ContentProviderUnionSlot::SysNAND:
                has_nand_dlc = true;
                break;
            case ContentProviderUnionSlot::SDMC:
                has_sdmc_dlc = true;
                break;
            default:
                has_other_dlc = true;
                break;
        }
        dlc_match.push_back(entry);
    }

    if (!dlc_match.empty()) {
        // Ensure sorted so DLC IDs show in order.
        std::sort(dlc_match.begin(), dlc_match.end());

        std::string list;
        for (size_t i = 0; i < dlc_match.size() - 1; ++i)
            list += fmt::format("{}, ", dlc_match[i].title_id & 0x7FF);

        list += fmt::format("{}", dlc_match.back().title_id & 0x7FF);

        const auto dlc_disabled =
            std::find(disabled.begin(), disabled.end(), "DLC") != disabled.end();
        PatchSource dlc_source = PatchSource::Unknown;
        if (has_external_dlc && !has_nand_dlc && !has_sdmc_dlc && !has_other_dlc) {
            dlc_source = PatchSource::External;
        } else if (has_nand_dlc && !has_external_dlc && !has_sdmc_dlc && !has_other_dlc) {
            dlc_source = PatchSource::NAND;
        } else if (has_sdmc_dlc && !has_external_dlc && !has_nand_dlc && !has_other_dlc) {
            dlc_source = PatchSource::SDMC;
        }

        out.push_back({.enabled = !dlc_disabled,
                       .name = "DLC",
                       .version = std::move(list),
                       .type = PatchType::DLC,
                       .program_id = title_id,
                       .title_id = dlc_match.back().title_id,
                       .source = dlc_source});
    }

    return out;
}

std::optional<u32> PatchManager::GetGameVersion() const {
    const auto update_tid = GetUpdateTitleID(title_id);
    if (content_provider.HasEntry(update_tid, ContentRecordType::Program)) {
        return content_provider.GetEntryVersion(update_tid);
    }

    return content_provider.GetEntryVersion(title_id);
}

PatchManager::Metadata PatchManager::GetControlMetadata() const {
    const auto base_control_nca = content_provider.GetEntry(title_id, ContentRecordType::Control);
    if (base_control_nca == nullptr) {
        return {};
    }

    return ParseControlNCA(*base_control_nca);
}

PatchManager::Metadata PatchManager::ParseControlNCA(const NCA& nca) const {
    const auto base_romfs = nca.GetRomFS();
    if (base_romfs == nullptr) {
        return {};
    }

    const auto romfs = PatchRomFS(&nca, base_romfs, ContentRecordType::Control);
    if (romfs == nullptr) {
        return {};
    }

    const auto extracted = ExtractRomFS(romfs);
    if (extracted == nullptr) {
        return {};
    }

    auto nacp_file = extracted->GetFile("control.nacp");
    if (nacp_file == nullptr) {
        nacp_file = extracted->GetFile("Control.nacp");
    }

    auto nacp = nacp_file == nullptr ? nullptr : std::make_unique<NACP>(nacp_file);

    // Get language code from settings
    const auto language_code = Service::Set::GetLanguageCodeFromIndex(
        static_cast<u32>(Settings::values.language_index.GetValue()));

    // Convert to application language and get priority list
    const auto application_language =
        Service::NS::ConvertToApplicationLanguage(language_code)
            .value_or(Service::NS::ApplicationLanguage::AmericanEnglish);
    const auto language_priority_list =
        Service::NS::GetApplicationLanguagePriorityList(application_language);

    // Convert to language names
    auto priority_language_names = FileSys::LANGUAGE_NAMES; // Copy
    if (language_priority_list) {
        for (size_t i = 0; i < priority_language_names.size(); ++i) {
            // Relies on FileSys::LANGUAGE_NAMES being in the same order as
            // Service::NS::ApplicationLanguage
            const auto language_index = static_cast<u8>(language_priority_list->at(i));

            if (language_index < FileSys::LANGUAGE_NAMES.size()) {
                priority_language_names[i] = FileSys::LANGUAGE_NAMES[language_index];
            } else {
                // Not a catastrophe, unlikely to happen
                LOG_WARNING(Loader, "Invalid language index {}", language_index);
            }
        }
    }

    // Get first matching icon
    VirtualFile icon_file;
    for (const auto& language : priority_language_names) {
        icon_file = extracted->GetFile(std::string("icon_").append(language).append(".dat"));
        if (icon_file != nullptr) {
            break;
        }
    }

    return {std::move(nacp), icon_file};
}
} // namespace FileSys
