eloqstore-sys 1.1.0

#include "eloqstore_capi.h"

#include <cstring>
#include <memory>
#include <mutex>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>

#include "eloq_store.h"
#include "kv_options.h"
#include "types.h"

using eloqstore::BatchWriteRequest;
using eloqstore::EloqStore;
using eloqstore::FloorRequest;
using eloqstore::KvError;
using eloqstore::KvOptions;
using eloqstore::ReadRequest;
using eloqstore::ScanRequest;
using eloqstore::TableIdent;
using eloqstore::WriteDataEntry;
using eloqstore::WriteOp;

// ============================================================
// Thread-local storage for error messages (no mutex: each thread
// has its own copy, and typical usage is sequential set-then-get)
// ============================================================
static thread_local std::string g_last_error_message;

static void set_last_error(const std::string &msg)
{
    g_last_error_message = msg;
}

static void clear_last_error()
{
    g_last_error_message.clear();
}

// ============================================================
// Owned scan result storage (avoids dangling pointers into request)
// ============================================================
struct OwnedScanResult
{
    std::vector<CScanEntry> entries;
    std::vector<uint8_t> key_value_buffer;
};
static std::mutex g_scan_result_mutex;
static std::unordered_map<CScanResult *, std::unique_ptr<OwnedScanResult>>
    g_owned_scan_results;

// ============================================================
// Error code conversion
// ============================================================
static CEloqStoreStatus kv_error_to_c(KvError err)
{
    switch (err)
    {
    case KvError::NoError:
        return CEloqStoreStatus_Ok;
    case KvError::InvalidArgs:
        return CEloqStoreStatus_InvalidArgs;
    case KvError::NotFound:
        return CEloqStoreStatus_NotFound;
    case KvError::NotRunning:
        return CEloqStoreStatus_NotRunning;
    case KvError::Corrupted:
        return CEloqStoreStatus_Corrupted;
    case KvError::EndOfFile:
        return CEloqStoreStatus_EndOfFile;
    case KvError::OutOfSpace:
        return CEloqStoreStatus_OutOfSpace;
    case KvError::OutOfMem:
        return CEloqStoreStatus_OutOfMem;
    case KvError::OpenFileLimit:
        return CEloqStoreStatus_OpenFileLimit;
    case KvError::TryAgain:
        return CEloqStoreStatus_TryAgain;
    case KvError::Busy:
        return CEloqStoreStatus_Busy;
    case KvError::Timeout:
        return CEloqStoreStatus_Timeout;
    case KvError::NoPermission:
        return CEloqStoreStatus_NoPermission;
    case KvError::CloudErr:
        return CEloqStoreStatus_CloudErr;
    case KvError::IoFail:
        return CEloqStoreStatus_IoFail;
    case KvError::ExpiredTerm:
        return CEloqStoreStatus_ExpiredTerm;
    case KvError::OssInsufficientStorage:
        return CEloqStoreStatus_OssInsufficientStorage;
    case KvError::AlreadyExists:
        return CEloqStoreStatus_AlreadyExists;
    default:
        return CEloqStoreStatus_InvalidArgs;
    }
}

// Store C++ objects to handle mapping (for flattened API)
static std::mutex g_request_mutex;
static thread_local ReadRequest *g_last_read_req = nullptr;
static thread_local FloorRequest *g_last_floor_req = nullptr;

extern "C"
{
    // ============================================================
    // Options API (using new naming)
    // ============================================================

    CEloqStoreHandle CEloqStore_Options_Create(void)
    {
        clear_last_error();
        try
        {
            return reinterpret_cast<CEloqStoreHandle>(new KvOptions());
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return nullptr;
        }
    }

    void CEloqStore_Options_Destroy(CEloqStoreHandle opts)
    {
        if (opts)
        {
            delete reinterpret_cast<KvOptions *>(opts);
        }
    }

    void CEloqStore_Options_SetNumThreads(CEloqStoreHandle opts, uint16_t n)
    {
        if (opts)
            reinterpret_cast<KvOptions *>(opts)->num_threads = n;
    }

    void CEloqStore_Options_SetBufferPoolSize(CEloqStoreHandle opts,
                                              uint64_t size)
    {
        if (opts)
            reinterpret_cast<KvOptions *>(opts)->buffer_pool_size = size;
    }

    void CEloqStore_Options_SetDataPageSize(CEloqStoreHandle opts,
                                            uint16_t size)
    {
        if (opts)
            reinterpret_cast<KvOptions *>(opts)->data_page_size = size;
    }

    void CEloqStore_Options_SetManifestLimit(CEloqStoreHandle opts,
                                             uint32_t limit)
    {
        if (opts)
            reinterpret_cast<KvOptions *>(opts)->manifest_limit = limit;
    }

    void CEloqStore_Options_SetFdLimit(CEloqStoreHandle opts, uint32_t limit)
    {
        if (opts)
            reinterpret_cast<KvOptions *>(opts)->fd_limit = limit;
    }

    void CEloqStore_Options_SetPagesPerFileShift(CEloqStoreHandle opts,
                                                 uint8_t shift)
    {
        if (opts)
            reinterpret_cast<KvOptions *>(opts)->pages_per_file_shift = shift;
    }

    void CEloqStore_Options_SetOverflowPointers(CEloqStoreHandle opts,
                                                uint8_t n)
    {
        if (opts)
            reinterpret_cast<KvOptions *>(opts)->overflow_pointers = n;
    }

    void CEloqStore_Options_SetDataAppendMode(CEloqStoreHandle opts,
                                              bool enable)
    {
        if (opts)
            reinterpret_cast<KvOptions *>(opts)->data_append_mode = enable;
    }

    void CEloqStore_Options_SetEnableCompression(CEloqStoreHandle opts,
                                                 bool enable)
    {
        if (opts)
            reinterpret_cast<KvOptions *>(opts)->enable_compression = enable;
    }

    void CEloqStore_Options_AddStorePath(CEloqStoreHandle opts,
                                         const char *path)
    {
        if (opts && path)
            reinterpret_cast<KvOptions *>(opts)->store_path.push_back(path);
    }

    void CEloqStore_Options_SetCloudStorePath(CEloqStoreHandle opts,
                                              const char *path)
    {
        if (opts && path)
            reinterpret_cast<KvOptions *>(opts)->cloud_store_path = path;
    }

    void CEloqStore_Options_SetCloudProvider(CEloqStoreHandle opts,
                                             const char *provider)
    {
        if (opts && provider)
            reinterpret_cast<KvOptions *>(opts)->cloud_provider = provider;
    }

    void CEloqStore_Options_SetCloudRegion(CEloqStoreHandle opts,
                                           const char *region)
    {
        if (opts && region)
            reinterpret_cast<KvOptions *>(opts)->cloud_region = region;
    }

    void CEloqStore_Options_SetCloudCredentials(CEloqStoreHandle opts,
                                                const char *access_key,
                                                const char *secret_key)
    {
        if (opts)
        {
            if (access_key)
                reinterpret_cast<KvOptions *>(opts)->cloud_access_key =
                    access_key;
            if (secret_key)
                reinterpret_cast<KvOptions *>(opts)->cloud_secret_key =
                    secret_key;
        }
    }

    void CEloqStore_Options_SetCloudAutoCredentials(CEloqStoreHandle opts,
                                                    bool enable)
    {
        if (opts)
            reinterpret_cast<KvOptions *>(opts)->cloud_auto_credentials =
                enable;
    }

    void CEloqStore_Options_SetCloudVerifySsl(CEloqStoreHandle opts,
                                              bool verify)
    {
        if (opts)
            reinterpret_cast<KvOptions *>(opts)->cloud_verify_ssl = verify;
    }

    bool CEloqStore_Options_LoadFromIni(CEloqStoreHandle opts, const char *path)
    {
        clear_last_error();
        if (!opts || !path)
        {
            set_last_error("Invalid options or ini path");
            return false;
        }
        try
        {
            return reinterpret_cast<KvOptions *>(opts)->LoadFromIni(path) == 0;
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return false;
        }
    }

    bool CEloqStore_Options_Validate(CEloqStoreHandle opts)
    {
        if (!opts)
            return false;
        return EloqStore::ValidateOptions(*reinterpret_cast<KvOptions *>(opts));
    }

    // ============================================================
    // Engine lifecycle
    // ============================================================

    CEloqStoreHandle CEloqStore_Create(CEloqStoreHandle options)
    {
        clear_last_error();
        if (!options)
        {
            set_last_error("Invalid options: null pointer");
            return nullptr;
        }
        try
        {
            auto *store =
                new EloqStore(*reinterpret_cast<KvOptions *>(options));
            return reinterpret_cast<CEloqStoreHandle>(store);
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return nullptr;
        }
    }

    void CEloqStore_Destroy(CEloqStoreHandle store)
    {
        if (store)
        {
            delete reinterpret_cast<EloqStore *>(store);
        }
    }

    CEloqStoreStatus CEloqStore_Start(CEloqStoreHandle store)
    {
        clear_last_error();
        if (!store)
        {
            return CEloqStoreStatus_InvalidArgs;
        }
        try
        {
            auto err = reinterpret_cast<EloqStore *>(store)->Start(
                eloqstore::MainBranchName, 0);
            if (err != KvError::NoError)
            {
                set_last_error("Failed to start store");
            }
            return kv_error_to_c(err);
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return CEloqStoreStatus_InvalidArgs;
        }
    }

    CEloqStoreStatus CEloqStore_StartWithBranch(CEloqStoreHandle store,
                                                const char *branch,
                                                uint64_t term,
                                                uint32_t partition_group_id)
    {
        clear_last_error();
        if (!store)
        {
            return CEloqStoreStatus_InvalidArgs;
        }
        try
        {
            std::string_view branch_name =
                branch != nullptr ? std::string_view(branch)
                                  : std::string_view(eloqstore::MainBranchName);
            auto err = reinterpret_cast<EloqStore *>(store)->Start(
                branch_name, term, partition_group_id);
            if (err != KvError::NoError)
            {
                set_last_error("Failed to start store");
            }
            return kv_error_to_c(err);
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return CEloqStoreStatus_InvalidArgs;
        }
    }

    void CEloqStore_Stop(CEloqStoreHandle store)
    {
        if (store)
        {
            reinterpret_cast<EloqStore *>(store)->Stop();
        }
    }

    bool CEloqStore_IsStopped(CEloqStoreHandle store)
    {
        return store ? reinterpret_cast<EloqStore *>(store)->IsStopped() : true;
    }

    // ============================================================
    // Table identifier
    // ============================================================

    CTableIdentHandle CEloqStore_TableIdent_Create(const char *table_name,
                                                   uint32_t partition_id)
    {
        clear_last_error();
        if (!table_name)
        {
            set_last_error("Invalid table name: null pointer");
            return nullptr;
        }
        try
        {
            return reinterpret_cast<CTableIdentHandle>(
                new TableIdent(table_name, partition_id));
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return nullptr;
        }
    }

    void CEloqStore_TableIdent_Destroy(CTableIdentHandle ident)
    {
        if (ident)
        {
            delete reinterpret_cast<TableIdent *>(ident);
        }
    }

    const char *CEloqStore_TableIdent_GetName(CTableIdentHandle ident)
    {
        if (!ident)
            return nullptr;
        // Return a pointer to the internal std::string's buffer.
        // The pointer is valid as long as the TableIdent object exists and is
        // not modified. Callers should copy the string immediately if they need
        // to keep it beyond the lifetime of the TableIdent object or if they
        // may call GetName again.
        return reinterpret_cast<TableIdent *>(ident)->tbl_name_.c_str();
    }

    uint32_t CEloqStore_TableIdent_GetPartition(CTableIdentHandle ident)
    {
        return ident ? reinterpret_cast<TableIdent *>(ident)->partition_id_ : 0;
    }

    // ============================================================
    // Flattened write API (simple operations)
    // Implemented using BatchWriteRequest
    // ============================================================

    CEloqStoreStatus CEloqStore_Put(CEloqStoreHandle store,
                                    CTableIdentHandle table,
                                    const uint8_t *key,
                                    size_t key_len,
                                    const uint8_t *value,
                                    size_t value_len,
                                    uint64_t timestamp)
    {
        clear_last_error();
        if (!store || !table || !key || key_len == 0)
        {
            return CEloqStoreStatus_InvalidArgs;
        }

        auto *cpp_store = reinterpret_cast<EloqStore *>(store);
        auto *cpp_table = reinterpret_cast<TableIdent *>(table);

        try
        {
            // Create temporary BatchWriteRequest to execute Put
            std::vector<WriteDataEntry> batch;
            WriteDataEntry entry;
            entry.key_ =
                std::string(reinterpret_cast<const char *>(key), key_len);
            if (value && value_len > 0)
            {
                entry.val_ = std::string(reinterpret_cast<const char *>(value),
                                         value_len);
            }
            entry.timestamp_ = timestamp;
            entry.expire_ts_ = 0;
            entry.op_ = WriteOp::Upsert;
            batch.push_back(std::move(entry));

            BatchWriteRequest req;
            req.SetArgs(*cpp_table, std::move(batch));

            cpp_store->ExecSync(&req);
            return kv_error_to_c(req.Error());
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return CEloqStoreStatus_InvalidArgs;
        }
    }

    CEloqStoreStatus CEloqStore_Delete(CEloqStoreHandle store,
                                       CTableIdentHandle table,
                                       const uint8_t *key,
                                       size_t key_len,
                                       uint64_t timestamp)
    {
        clear_last_error();
        if (!store || !table || !key || key_len == 0)
        {
            return CEloqStoreStatus_InvalidArgs;
        }

        auto *cpp_store = reinterpret_cast<EloqStore *>(store);
        auto *cpp_table = reinterpret_cast<TableIdent *>(table);

        try
        {
            // Create temporary BatchWriteRequest to execute Delete
            std::vector<WriteDataEntry> batch;
            WriteDataEntry entry;
            entry.key_ =
                std::string(reinterpret_cast<const char *>(key), key_len);
            entry.val_ = "";
            entry.timestamp_ = timestamp;
            entry.expire_ts_ = 0;
            entry.op_ = WriteOp::Delete;
            batch.push_back(std::move(entry));

            BatchWriteRequest req;
            req.SetArgs(*cpp_table, std::move(batch));

            cpp_store->ExecSync(&req);
            return kv_error_to_c(req.Error());
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return CEloqStoreStatus_InvalidArgs;
        }
    }

    // ============================================================
    // Batch write API
    // ============================================================

    CEloqStoreStatus CEloqStore_PutBatch(CEloqStoreHandle store,
                                         CTableIdentHandle table,
                                         const uint8_t *const *keys,
                                         const size_t *key_lens,
                                         const uint8_t *const *values,
                                         const size_t *value_lens,
                                         size_t count,
                                         uint64_t timestamp)
    {
        clear_last_error();
        if (!store || !table || !keys || !key_lens || count == 0)
        {
            return CEloqStoreStatus_InvalidArgs;
        }

        auto *cpp_store = reinterpret_cast<EloqStore *>(store);
        auto *cpp_table = reinterpret_cast<TableIdent *>(table);

        try
        {
            std::vector<WriteDataEntry> batch;
            batch.reserve(count);

            for (size_t i = 0; i < count; ++i)
            {
                WriteDataEntry entry;
                entry.key_ = std::string(
                    reinterpret_cast<const char *>(keys[i]), key_lens[i]);
                if (values && value_lens && value_lens[i] > 0)
                {
                    entry.val_ =
                        std::string(reinterpret_cast<const char *>(values[i]),
                                    value_lens[i]);
                }
                else
                {
                    entry.val_ = "";
                }
                entry.timestamp_ = timestamp;
                entry.expire_ts_ = 0;
                entry.op_ = WriteOp::Upsert;
                batch.push_back(std::move(entry));
            }

            BatchWriteRequest req;
            req.SetArgs(*cpp_table, std::move(batch));

            cpp_store->ExecSync(&req);
            return kv_error_to_c(req.Error());
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return CEloqStoreStatus_InvalidArgs;
        }
    }

    CEloqStoreStatus CEloqStore_PutEntries(CEloqStoreHandle store,
                                           CTableIdentHandle table,
                                           const CWriteEntry *entries,
                                           size_t count)
    {
        clear_last_error();
        if (!store || !table || !entries || count == 0)
        {
            return CEloqStoreStatus_InvalidArgs;
        }

        auto *cpp_store = reinterpret_cast<EloqStore *>(store);
        auto *cpp_table = reinterpret_cast<TableIdent *>(table);

        try
        {
            std::vector<WriteDataEntry> batch;
            batch.reserve(count);

            for (size_t i = 0; i < count; ++i)
            {
                WriteDataEntry entry;
                entry.key_ =
                    std::string(reinterpret_cast<const char *>(entries[i].key),
                                entries[i].key_len);
                if (entries[i].value && entries[i].value_len > 0)
                {
                    entry.val_ = std::string(
                        reinterpret_cast<const char *>(entries[i].value),
                        entries[i].value_len);
                }
                else
                {
                    entry.val_ = "";
                }
                entry.timestamp_ = entries[i].timestamp;
                entry.expire_ts_ = entries[i].expire_ts;
                entry.op_ = static_cast<WriteOp>(entries[i].op);
                batch.push_back(std::move(entry));
            }

            BatchWriteRequest req;
            req.SetArgs(*cpp_table, std::move(batch));

            cpp_store->ExecSync(&req);
            return kv_error_to_c(req.Error());
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return CEloqStoreStatus_InvalidArgs;
        }
    }

    CEloqStoreStatus CEloqStore_DeleteBatch(CEloqStoreHandle store,
                                            CTableIdentHandle table,
                                            const uint8_t *const *keys,
                                            const size_t *key_lens,
                                            size_t count,
                                            uint64_t timestamp)
    {
        clear_last_error();
        if (!store || !table || !keys || !key_lens || count == 0)
        {
            return CEloqStoreStatus_InvalidArgs;
        }

        auto *cpp_store = reinterpret_cast<EloqStore *>(store);
        auto *cpp_table = reinterpret_cast<TableIdent *>(table);

        try
        {
            std::vector<WriteDataEntry> batch;
            batch.reserve(count);

            for (size_t i = 0; i < count; ++i)
            {
                WriteDataEntry entry;
                entry.key_ = std::string(
                    reinterpret_cast<const char *>(keys[i]), key_lens[i]);
                entry.val_ = "";
                entry.timestamp_ = timestamp;
                entry.expire_ts_ = 0;
                entry.op_ = WriteOp::Delete;
                batch.push_back(std::move(entry));
            }

            BatchWriteRequest req;
            req.SetArgs(*cpp_table, std::move(batch));

            cpp_store->ExecSync(&req);
            return kv_error_to_c(req.Error());
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return CEloqStoreStatus_InvalidArgs;
        }
    }

    // ============================================================
    // Flattened read API (simple operations)
    // Implemented using ReadRequest/FloorRequest
    // ============================================================

    CEloqStoreStatus CEloqStore_Get(CEloqStoreHandle store,
                                    CTableIdentHandle table,
                                    const uint8_t *key,
                                    size_t key_len,
                                    CGetResult *out_result)
    {
        clear_last_error();
        if (!store || !table || !key || key_len == 0 || !out_result)
        {
            return CEloqStoreStatus_InvalidArgs;
        }

        auto *cpp_store = reinterpret_cast<EloqStore *>(store);
        auto *cpp_table = reinterpret_cast<TableIdent *>(table);

        try
        {
            // Create temporary ReadRequest to execute Get
            ReadRequest req;
            req.SetArgs(
                *cpp_table,
                std::string(reinterpret_cast<const char *>(key), key_len));

            cpp_store->ExecSync(&req);
            auto err = req.Error();

            if (err == KvError::NoError)
            {
                uint8_t *value_copy = new uint8_t[req.value_.size()];
                std::memcpy(value_copy, req.value_.data(), req.value_.size());
                out_result->value = value_copy;
                out_result->value_len = req.value_.size();
                out_result->timestamp = req.ts_;
                out_result->expire_ts = req.expire_ts_;
                out_result->found = true;
                out_result->owns_value = true;
            }
            else if (err == KvError::NotFound)
            {
                out_result->value = nullptr;
                out_result->value_len = 0;
                out_result->timestamp = 0;
                out_result->expire_ts = 0;
                out_result->found = false;
                out_result->owns_value = false;
            }
            else
            {
                return kv_error_to_c(err);
            }
            return CEloqStoreStatus_Ok;
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return CEloqStoreStatus_InvalidArgs;
        }
    }

    CEloqStoreStatus CEloqStore_GetInto(CEloqStoreHandle store,
                                        CTableIdentHandle table,
                                        const uint8_t *key,
                                        size_t key_len,
                                        uint8_t *out_value,
                                        size_t out_capacity,
                                        CGetResult *out_result)
    {
        clear_last_error();
        if (!store || !table || !key || key_len == 0 || !out_result)
        {
            return CEloqStoreStatus_InvalidArgs;
        }

        auto *cpp_store = reinterpret_cast<EloqStore *>(store);
        auto *cpp_table = reinterpret_cast<TableIdent *>(table);

        try
        {
            ReadRequest req;
            req.SetArgs(
                *cpp_table,
                std::string(reinterpret_cast<const char *>(key), key_len));

            cpp_store->ExecSync(&req);
            auto err = req.Error();

            if (err == KvError::NoError)
            {
                out_result->value_len = req.value_.size();
                out_result->timestamp = req.ts_;
                out_result->expire_ts = req.expire_ts_;
                out_result->found = true;

                if (req.value_.size() > out_capacity)
                {
                    out_result->value = nullptr;
                    set_last_error("output buffer too small for value");
                    return CEloqStoreStatus_OutOfSpace;
                }

                if (req.value_.size() > 0)
                {
                    if (!out_value)
                    {
                        set_last_error(
                            "output buffer is null for non-empty value");
                        return CEloqStoreStatus_InvalidArgs;
                    }
                    std::memcpy(
                        out_value, req.value_.data(), req.value_.size());
                }
                out_result->value = out_value;
                out_result->owns_value = false;
            }
            else if (err == KvError::NotFound)
            {
                out_result->value = nullptr;
                out_result->value_len = 0;
                out_result->timestamp = 0;
                out_result->expire_ts = 0;
                out_result->found = false;
                out_result->owns_value = false;
            }
            else
            {
                return kv_error_to_c(err);
            }
            return CEloqStoreStatus_Ok;
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return CEloqStoreStatus_InvalidArgs;
        }
    }

    CEloqStoreStatus CEloqStore_Exists(CEloqStoreHandle store,
                                       CTableIdentHandle table,
                                       const uint8_t *key,
                                       size_t key_len,
                                       bool *out_exists)
    {
        clear_last_error();
        if (!store || !table || !key || key_len == 0 || !out_exists)
        {
            return CEloqStoreStatus_InvalidArgs;
        }

        auto *cpp_store = reinterpret_cast<EloqStore *>(store);
        auto *cpp_table = reinterpret_cast<TableIdent *>(table);

        try
        {
            ReadRequest req;
            req.SetArgs(
                *cpp_table,
                std::string(reinterpret_cast<const char *>(key), key_len));
            cpp_store->ExecSync(&req);
            if (req.Error() == KvError::NoError)
            {
                *out_exists = true;
                return CEloqStoreStatus_Ok;
            }
            if (req.Error() == KvError::NotFound)
            {
                *out_exists = false;
                return CEloqStoreStatus_Ok;
            }
            set_last_error("Exists query failed");
            return kv_error_to_c(req.Error());
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return CEloqStoreStatus_InvalidArgs;
        }
    }

    CEloqStoreStatus CEloqStore_Floor(CEloqStoreHandle store,
                                      CTableIdentHandle table,
                                      const uint8_t *key,
                                      size_t key_len,
                                      CFloorResult *out_result)
    {
        clear_last_error();
        if (!store || !table || !key || key_len == 0 || !out_result)
        {
            return CEloqStoreStatus_InvalidArgs;
        }

        auto *cpp_store = reinterpret_cast<EloqStore *>(store);
        auto *cpp_table = reinterpret_cast<TableIdent *>(table);

        try
        {
            // Create temporary FloorRequest to execute Floor
            FloorRequest req;
            req.SetArgs(
                *cpp_table,
                std::string(reinterpret_cast<const char *>(key), key_len));

            cpp_store->ExecSync(&req);
            auto err = req.Error();

            if (err == KvError::NoError)
            {
                uint8_t *key_copy = new uint8_t[req.floor_key_.size()];
                std::memcpy(
                    key_copy, req.floor_key_.data(), req.floor_key_.size());
                uint8_t *value_copy = new uint8_t[req.value_.size()];
                std::memcpy(value_copy, req.value_.data(), req.value_.size());
                out_result->key = key_copy;
                out_result->key_len = req.floor_key_.size();
                out_result->value = value_copy;
                out_result->value_len = req.value_.size();
                out_result->timestamp = req.ts_;
                out_result->expire_ts = req.expire_ts_;
                out_result->found = true;
            }
            else if (err == KvError::NotFound)
            {
                out_result->key = nullptr;
                out_result->key_len = 0;
                out_result->value = nullptr;
                out_result->value_len = 0;
                out_result->timestamp = 0;
                out_result->expire_ts = 0;
                out_result->found = false;
            }
            else
            {
                return kv_error_to_c(err);
            }
            return CEloqStoreStatus_Ok;
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return CEloqStoreStatus_InvalidArgs;
        }
    }

    // ============================================================
    // Scan request API (complex operations - preserve Request pattern)
    // ============================================================

    CScanRequestHandle CEloqStore_ScanRequest_Create(void)
    {
        clear_last_error();
        try
        {
            return reinterpret_cast<CScanRequestHandle>(new ScanRequest());
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return nullptr;
        }
    }

    void CEloqStore_ScanRequest_Destroy(CScanRequestHandle req)
    {
        if (req)
        {
            delete reinterpret_cast<ScanRequest *>(req);
        }
    }

    void CEloqStore_ScanRequest_SetTable(CScanRequestHandle req,
                                         CTableIdentHandle table)
    {
        if (req && table)
        {
            reinterpret_cast<ScanRequest *>(req)->SetArgs(
                *reinterpret_cast<TableIdent *>(table), "", "", true, false);
        }
    }

    void CEloqStore_ScanRequest_SetRange(CScanRequestHandle req,
                                         const uint8_t *begin_key,
                                         size_t begin_key_len,
                                         bool begin_inclusive,
                                         const uint8_t *end_key,
                                         size_t end_key_len,
                                         bool end_inclusive)
    {
        if (req)
        {
            auto *cpp_req = reinterpret_cast<ScanRequest *>(req);
            std::string begin_str, end_str;
            if (begin_key && begin_key_len > 0)
            {
                begin_str.assign(reinterpret_cast<const char *>(begin_key),
                                 begin_key_len);
            }
            if (end_key && end_key_len > 0)
            {
                end_str.assign(reinterpret_cast<const char *>(end_key),
                               end_key_len);
            }
            // Apply range: call SetArgs again with currently set table, write
            // begin/end
            cpp_req->SetArgs(cpp_req->TableId(),
                             begin_str,
                             end_str,
                             begin_inclusive,
                             end_inclusive);
        }
    }

    void CEloqStore_ScanRequest_SetPagination(CScanRequestHandle req,
                                              size_t max_entries,
                                              size_t max_size)
    {
        if (req)
        {
            reinterpret_cast<ScanRequest *>(req)->SetPagination(max_entries,
                                                                max_size);
        }
    }

    void CEloqStore_ScanRequest_SetPrefetch(CScanRequestHandle req,
                                            size_t num_pages)
    {
        if (req)
        {
            reinterpret_cast<ScanRequest *>(req)->SetPrefetchPageNum(num_pages);
        }
    }

    CEloqStoreStatus CEloqStore_ExecScan(CEloqStoreHandle store,
                                         CScanRequestHandle req,
                                         CScanResult *out_result)
    {
        clear_last_error();
        if (!store || !req || !out_result)
        {
            return CEloqStoreStatus_InvalidArgs;
        }

        auto *cpp_store = reinterpret_cast<EloqStore *>(store);
        auto *cpp_req = reinterpret_cast<ScanRequest *>(req);

        try
        {
            cpp_store->ExecSync(cpp_req);
            auto err = cpp_req->Error();
            if (err != KvError::NoError && err != KvError::NotFound)
            {
                return kv_error_to_c(err);
            }

            const auto &entries = cpp_req->Entries();
            auto [count, size] = cpp_req->ResultSize();

            // Free any previous owned result for this pointer (avoid leak if
            // caller reuses)
            {
                std::lock_guard<std::mutex> lock(g_scan_result_mutex);
                g_owned_scan_results.erase(out_result);
            }
            auto owned = std::make_unique<OwnedScanResult>();
            owned->entries.reserve(entries.size());
            owned->key_value_buffer.reserve(static_cast<size_t>(size) +
                                            entries.size() * 2 *
                                                sizeof(size_t));
            for (const auto &entry : entries)
            {
                const size_t key_len = entry.key_.size();
                const size_t value_len = entry.value_.size();
                const size_t key_off = owned->key_value_buffer.size();
                owned->key_value_buffer.insert(
                    owned->key_value_buffer.end(),
                    reinterpret_cast<const uint8_t *>(entry.key_.data()),
                    reinterpret_cast<const uint8_t *>(entry.key_.data()) +
                        key_len);
                const size_t value_off = owned->key_value_buffer.size();
                owned->key_value_buffer.insert(
                    owned->key_value_buffer.end(),
                    reinterpret_cast<const uint8_t *>(entry.value_.data()),
                    reinterpret_cast<const uint8_t *>(entry.value_.data()) +
                        value_len);
                CScanEntry e;
                e.key = owned->key_value_buffer.data() + key_off;
                e.key_len = key_len;
                e.value = owned->key_value_buffer.data() + value_off;
                e.value_len = value_len;
                e.timestamp = entry.timestamp_;
                e.expire_ts = entry.expire_ts_;
                owned->entries.push_back(e);
            }
            out_result->entries = owned->entries.data();
            out_result->num_entries = owned->entries.size();
            out_result->total_size = size;
            out_result->has_more = cpp_req->HasRemaining();
            {
                std::lock_guard<std::mutex> lock(g_scan_result_mutex);
                g_owned_scan_results[out_result] = std::move(owned);
            }
            return CEloqStoreStatus_Ok;
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return CEloqStoreStatus_InvalidArgs;
        }
    }

    void CEloqStore_FreeScanResult(CScanResult *result)
    {
        if (result)
        {
            std::lock_guard<std::mutex> lock(g_scan_result_mutex);
            g_owned_scan_results.erase(result);
            result->entries = nullptr;
            result->num_entries = 0;
            result->total_size = 0;
            result->has_more = false;
        }
    }

    // ============================================================
    // BatchWrite request API (complex operations - preserve Request pattern)
    // ============================================================

    CBatchWriteHandle CEloqStore_BatchWrite_Create(void)
    {
        clear_last_error();
        try
        {
            return reinterpret_cast<CBatchWriteHandle>(new BatchWriteRequest());
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return nullptr;
        }
    }

    void CEloqStore_BatchWrite_Destroy(CBatchWriteHandle req)
    {
        if (req)
        {
            delete reinterpret_cast<BatchWriteRequest *>(req);
        }
    }

    void CEloqStore_BatchWrite_SetTable(CBatchWriteHandle req,
                                        CTableIdentHandle table)
    {
        if (req && table)
        {
            std::vector<WriteDataEntry> batch;
            reinterpret_cast<BatchWriteRequest *>(req)->SetArgs(
                *reinterpret_cast<TableIdent *>(table), std::move(batch));
        }
    }

    void CEloqStore_BatchWrite_AddEntry(CBatchWriteHandle req,
                                        const uint8_t *key,
                                        size_t key_len,
                                        const uint8_t *value,
                                        size_t value_len,
                                        uint64_t timestamp,
                                        CWriteOp op,
                                        uint64_t expire_ts)
    {
        if (req && key && key_len > 0)
        {
            auto *cpp_req = reinterpret_cast<BatchWriteRequest *>(req);
            WriteDataEntry entry;
            entry.key_ =
                std::string(reinterpret_cast<const char *>(key), key_len);
            if (value && value_len > 0)
            {
                entry.val_ = std::string(reinterpret_cast<const char *>(value),
                                         value_len);
            }
            entry.timestamp_ = timestamp;
            entry.op_ = static_cast<WriteOp>(op);
            entry.expire_ts_ = expire_ts;
            cpp_req->batch_.push_back(std::move(entry));
        }
    }

    void CEloqStore_BatchWrite_Clear(CBatchWriteHandle req)
    {
        if (req)
            reinterpret_cast<BatchWriteRequest *>(req)->Clear();
    }

    CEloqStoreStatus CEloqStore_ExecBatchWrite(CEloqStoreHandle store,
                                               CBatchWriteHandle req)
    {
        clear_last_error();
        if (!store || !req)
        {
            return CEloqStoreStatus_InvalidArgs;
        }

        auto *cpp_store = reinterpret_cast<EloqStore *>(store);
        auto *cpp_req = reinterpret_cast<BatchWriteRequest *>(req);

        try
        {
            cpp_store->ExecSync(cpp_req);
            return kv_error_to_c(cpp_req->Error());
        }
        catch (const std::exception &e)
        {
            set_last_error(e.what());
            return CEloqStoreStatus_InvalidArgs;
        }
    }

    // ============================================================
    // Error message query
    // ============================================================

    const char *CEloqStore_GetLastError(CEloqStoreHandle store)
    {
        return g_last_error_message.empty() ? nullptr
                                            : g_last_error_message.c_str();
    }

    // ============================================================
    // Memory free functions (for Get/Floor results)
    // ============================================================

    void CEloqStore_FreeGetResult(CGetResult *result)
    {
        if (result)
        {
            if (result->value && result->owns_value)
            {
                delete[] result->value;
                result->value = nullptr;
            }
            result->value_len = 0;
            result->owns_value = false;
            result->found = false;
        }
    }

    void CEloqStore_FreeFloorResult(CFloorResult *result)
    {
        if (result)
        {
            if (result->key)
            {
                delete[] result->key;
                result->key = nullptr;
            }
            if (result->value)
            {
                delete[] result->value;
                result->value = nullptr;
            }
            result->key_len = 0;
            result->value_len = 0;
            result->found = false;
        }
    }
}  // extern "C"