#include "cuda_search.h"

#include <utility>

// Build this translation unit only in the CPU-only target. CUDA-enabled
// targets compile cuda_search.cu instead; both files intentionally implement
// the same public ABI.

namespace cuda_search {

namespace {

constexpr const char* kUnavailableMessage =
    "CUDA search backend is not compiled into this executable.";

}  // namespace

struct BatchSession::Impl {
    bool is_initialized = false;
};

BackendInfo query_backend(int device_index) {
    BackendInfo result;
    result.selected_device = device_index;
    result.error = kUnavailableMessage;
    return result;
}

BatchSession::BatchSession() : impl_(std::make_unique<Impl>()) {}

BatchSession::~BatchSession() = default;

BatchSession::BatchSession(BatchSession&& other) noexcept = default;

BatchSession& BatchSession::operator=(BatchSession&& other) noexcept = default;

bool BatchSession::initialize(
    const Topology&,
    const SearchConfig&,
    const std::vector<PlaneState>&,
    std::string& error) {
    if (!impl_) {
        impl_ = std::make_unique<Impl>();
    }
    impl_->is_initialized = false;
    error = kUnavailableMessage;
    return false;
}

BatchResult BatchSession::run(const BatchRunConfig&) {
    BatchResult result;
    result.error = kUnavailableMessage;
    return result;
}

void BatchSession::reset() {
    if (impl_) {
        impl_->is_initialized = false;
    }
}

bool BatchSession::initialized() const noexcept {
    return impl_ != nullptr && impl_->is_initialized;
}

BatchResult run_batch(
    const Topology&,
    const SearchConfig& config,
    const std::vector<PlaneState>&) {
    BatchResult result;
    result.device_index = config.device_index;
    result.error = kUnavailableMessage;
    return result;
}

}  // namespace cuda_search