// SPDX-License-Identifier: MPL-2.0
#include "sequa/3d/null_adapter.hpp"

#include <utility>

namespace sequa::three_d {

NullEngineAdapter::NullEngineAdapter()
    : NullEngineAdapter(EngineCapabilities{"null", "0", BufferSet::all(), false, true, 0, 0})
{
}

NullEngineAdapter::NullEngineAdapter(EngineCapabilities capabilities)
    : capabilities_(std::move(capabilities))
{
}

std::optional<Error> NullEngineAdapter::start(const EngineConfig& config)
{
    if (running_) {
        return Error{Error::Code::already_started, "adaptateur déjà démarré"};
    }
    if (config.headless ? !capabilities_.headless : !capabilities_.windowed) {
        return Error{Error::Code::unsupported, config.headless ? "rendu hors écran non pris en charge"
                                                               : "fenêtre non prise en charge"};
    }
    scene_.clear();
    running_ = true;
    return std::nullopt;
}

void NullEngineAdapter::stop() noexcept
{
    running_ = false;
}

std::optional<Error> NullEngineAdapter::apply(const SceneDelta& delta)
{
    if (!running_) {
        return Error{Error::Code::not_started, "adaptateur arrêté"};
    }
    return scene_.apply(delta);
}

FrameOutcome NullEngineAdapter::render_frame(const FrameRequest& request)
{
    if (!running_) {
        return Error{Error::Code::not_started, "adaptateur arrêté"};
    }
    if (std::optional<Error> error = validate_request(request, capabilities_)) {
        return *std::move(error);
    }
    return FrameResult{request.frame_index, scene_.world_version(), request.buffers, {}};
}

std::optional<PlayerInput> NullEngineAdapter::poll_input()
{
    if (!running_ || !capabilities_.player_input) {
        return std::nullopt;
    }
    return input_;
}

} // namespace sequa::three_d