Jungfraujoch/detector_control/DectrisSimplonClient.cpp

// SPDX-FileCopyrightText: 2025 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#include <base64/Base64.h>
#include <httplib.h>

#include "DectrisSimplonClient.h"

std::string to_string(SimplonState state) {
    switch (state) {
        case SimplonState::Na:        return "Na";
        case SimplonState::Ready:     return "Ready";
        case SimplonState::Initialize: return "Initialize";
        case SimplonState::Configure: return "Configure";
        case SimplonState::Acquire:   return "Acquire";
        case SimplonState::Idle:      return "Idle";
        case SimplonState::Test:      return "Test";
        case SimplonState::Error:     return "Error";
        default:                      return "Unknown";
    }
}

DectrisSimplonClient::DectrisSimplonClient(const std::string &addr, uint16_t in_port)
: hostname(addr), port(in_port),
  cmd_http(std::make_unique<httplib::Client>(addr, in_port)),
  status_http(std::make_unique<httplib::Client>(addr, in_port)) {
    cmd_http->set_keep_alive(true);
    cmd_http->set_connection_timeout(std::chrono::seconds(1));
    cmd_http->set_read_timeout(std::chrono::minutes(20)); // Initialize or disarm might take a lot of time
    cmd_http->set_write_timeout(std::chrono::minutes(20)); // Initialize or disarm might take a lot of time

    status_http->set_keep_alive(true);
    status_http->set_connection_timeout(std::chrono::milliseconds(500));
    status_http->set_read_timeout(std::chrono::seconds(1));
    status_http->set_write_timeout(std::chrono::seconds(1));
}

DectrisSimplonClient::~DectrisSimplonClient() = default;

void DectrisSimplonClient::SendDetectorCommand(SimplonDetectorCommand cmd) {
    std::string key;
    switch (cmd) {
        case SimplonDetectorCommand::Initialize:
            key = "initialize";
            break;
        case SimplonDetectorCommand::Arm:
            key =  "arm";
            break;
        case SimplonDetectorCommand::Disarm:
            key = "disarm";
            break;
        case SimplonDetectorCommand::Trigger:
            key = "trigger";
            break;
        case SimplonDetectorCommand::Cancel:
            key = "cancel";
            break;
    }
    auto addr = GenAddr(SimplonModule::Detector, SimplonTask::Command, key);

    std::lock_guard lg(cmd_mutex);
    auto res = cmd_http->Post(addr);

    if (!res || res->status != httplib::StatusCode::OK_200) {
        std::string err_msg = "Command failed " + key;
        if (!res)
            err_msg += "; " + to_string(res.error());
        else {
            err_msg += "; HTTP" + std::to_string(res->status);
            if (!res->body.empty())
                err_msg += "; " + res->body;
        }
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, err_msg);
    }
}

void DectrisSimplonClient::SetConfig(SimplonModule element, const std::string &key, const nlohmann::json &value) {
    std::string addr = GenAddr(element, SimplonTask::Config, key);

    nlohmann::json j;
    j["value"] = value;

    std::lock_guard lg(cmd_mutex);
    auto res = cmd_http->Post(addr, j.dump(), "application/json");

    if (!res || res->status != httplib::StatusCode::OK_200) {
        std::string err_msg = "Configure failed " + key;
        if (!res)
            err_msg += "; " + to_string(res.error());
        else {
            err_msg += "; HTTP" + std::to_string(res->status);
            if (!res->body.empty())
                err_msg += "; " + res->body;
        }
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, err_msg);
    }
}

void DectrisSimplonClient::SetConfigIfDifferent(SimplonModule element, const std::string &key, float value, float tolerance) {
    auto curr_val = GetConfig(element, key).val.get<float>();

    if (std::abs(curr_val - value) > tolerance)
        SetConfig(element, key, value);
}

void DectrisSimplonClient::SetConfigIfDifferent(SimplonModule element, const std::string &key, int64_t value) {
    auto curr_val = GetConfig(element, key).val.get<int64_t>();
    if (curr_val != value)
        SetConfig(element, key, value);
}

std::string DectrisSimplonClient::GenAddr(SimplonModule element, SimplonTask task, const std::string& key) {
    std::string addr;
    switch (element) {
        case SimplonModule::Detector:
            addr += "/detector/";
            break;
        case SimplonModule::Stream:
            addr += "/stream/";
            break;
        case SimplonModule::Filewriter:
            addr += "/filewriter/";
            break;
        case SimplonModule::Monitor:
            addr += "/monitor/";
            break;
    }
    addr += "api/";
    addr += api_version;
    switch (task) {
        case SimplonTask::Config:
            addr += "/config/";
            break;
        case SimplonTask::Command:
            addr += "/command/";
            break;
        case SimplonTask::Status:
            addr += "/status/";
            break;
    }
    addr += key;
    return addr;
}

SimplonConfig
DectrisSimplonClient::GetConfig(SimplonModule element, SimplonTask task, const std::string &key) {
    std::lock_guard lg(status_mutex);
    auto res = status_http->Get(GenAddr(element, task, key));

    if (!res) {
        throw JFJochException(JFJochExceptionCategory::SimplonError,
                              "Get key " + key + " timeout/error: " + to_string(res.error()));
    }
    if (res->status != httplib::StatusCode::OK_200) {
        throw JFJochException(JFJochExceptionCategory::SimplonError,
                              "Get key " + key + " failed: HTTP" + std::to_string(res->status)
                              + (res->body.empty() ? "" : "; " + res->body));
    }

    try {
        auto j = nlohmann::json::parse(res->body);
        SimplonConfig ret{};
        ret.val = j["value"];
        if (j.contains("unit"))
            ret.unit = j["unit"];
        if (j.contains("min"))
            ret.min = j["min"];
        if (j.contains("max"))
            ret.max = j["max"];
        return ret;
    } catch (const std::exception &e) {
        throw JFJochException(JFJochExceptionCategory::JSON, e.what());
    }
}

SimplonConfig DectrisSimplonClient::GetConfig(SimplonModule element, const std::string &key) {
    return GetConfig(element, SimplonTask::Config, key);
}

SimplonConfig DectrisSimplonClient::GetDetCfg(const std::string &key) {
    return GetConfig(SimplonModule::Detector, key);
}

nlohmann::json DectrisSimplonClient::GetStatus(SimplonModule element, const std::string &key) {
    return GetConfig(element, SimplonTask::Status, key).val;
}

template <class T>
T float2time(float time_in_seconds) {
    return std::chrono::duration_cast<T>(std::chrono::duration<float>(time_in_seconds));
}

void DectrisSimplonClient::ReadDetectorConfig(DetectorSetup &setup) {
    // Need to initialize to read configuration information

    if ((GetState() == SimplonState::Na)
        || (GetState() == SimplonState::Error))
        throw JFJochException(JFJochExceptionCategory::Detector,
                              "Detector state Na or Error - need to reinitialize before reading configuration");

    setup.Description(GetDetCfg( "description").val);
    setup.PixelSize_um(std::round(GetDetCfg( "x_pixel_size").val.get<float>() * 1e6f));
    setup.SerialNumber(GetDetCfg( "detector_number").val);
    setup.SensorMaterial(GetDetCfg( "sensor_material").val);
    setup.SensorThickness_um(std::round(GetDetCfg( "sensor_thickness").val.get<float>() * 1e6f));

    // Only the image depth is read: it sizes the image buffer before the first frame arrives, and
    // is replaced from the stream2 image_dtype when the detector arms. The electronic readout depth
    // is deliberately not read - nothing consumes it.
    setup.BitDepthImage(GetDetCfg("bit_depth_image").val.get<int64_t>());
    setup.MinFrameTime(float2time<std::chrono::nanoseconds>(GetDetCfg("frame_time").min.get<float>()));
    setup.MinCountTime(float2time<std::chrono::nanoseconds>(GetDetCfg("count_time").min.get<float>()));
    setup.ReadOutTime(float2time<std::chrono::nanoseconds>(GetDetCfg("detector_readout_time").val.get<float>()));

    nlohmann::json min_threshold_energy = GetDetCfg("threshold_energy").min;
    if (min_threshold_energy.is_number())
        setup.MinThreshold_keV(min_threshold_energy.get<float>() / 1000.0f);
    else
        setup.MinThreshold_keV(2.7f);

    int64_t width = GetDetCfg("x_pixels_in_detector").val.get<int64_t>();
    int64_t height = GetDetCfg( "y_pixels_in_detector").val.get<int64_t>();
    setup.Geometry(DetectorGeometryFixed(width, height));
}

void DectrisSimplonClient::InitializeDetector(DetectorSetup& setup) {
    auto state = GetState();

    if ((state == SimplonState::Na) || (state == SimplonState::Error))
        SendDetectorCommand(SimplonDetectorCommand::Initialize);

    if (GetState() != SimplonState::Idle)
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid,
                              "Initialize unsuccessful");

    SetConfig(SimplonModule::Detector, "roi_mode", setup.GetDECTRISROI());
    // Configure streaming, disable file writer and monitor
    SetConfig(SimplonModule::Stream, "format", "cbor");
    SetConfig(SimplonModule::Stream, "mode", "enabled");
    SetConfig(SimplonModule::Filewriter, "mode", "disabled");
    SetConfig(SimplonModule::Monitor, "mode", "disabled");
    ReadDetectorConfig(setup);
}

void DectrisSimplonClient::TriggerAcquisition() {
    SendDetectorCommand(SimplonDetectorCommand::Trigger);
}

void DectrisSimplonClient::CancelAcquisition() {
    SendDetectorCommand(SimplonDetectorCommand::Cancel);
}

void DectrisSimplonClient::EndAcquisitionFinished() {
    SendDetectorCommand(SimplonDetectorCommand::Disarm);
}

void DectrisSimplonClient::StartAcquisition(const DiffractionExperiment& experiment) {
    SetConfigIfDifferent(SimplonModule::Detector, "photon_energy", experiment.GetIncidentEnergy_keV() * 1e3f, 0.01f);
    auto thr = experiment.GetEigerThreshold_keV();
    SetConfigIfDifferent(SimplonModule::Detector, "threshold_energy", thr * 1e3f, 0.01);

    SetConfigIfDifferent(SimplonModule::Detector, "count_time", std::chrono::duration<float>(experiment.GetFrameCountTime()).count(), 1e-9);
    SetConfigIfDifferent(SimplonModule::Detector, "frame_time", std::chrono::duration<float>(experiment.GetFrameTime()).count(), 1e-9);
    SetConfigIfDifferent(SimplonModule::Detector, "nimages", experiment.GetFrameNumPerTrigger());
    SetConfigIfDifferent(SimplonModule::Detector, "ntrigger", experiment.GetNumTriggers());

    SendDetectorCommand(SimplonDetectorCommand::Arm);
}

void DectrisSimplonClient::ConfigureDetector(const DiffractionExperiment &experiment) {
    // TODO: Check if counting_mode retrigger is available
    if (experiment.GetDetectorMode() == DetectorMode::DarkMask)
        SetConfig(SimplonModule::Detector, "counting_mode", "normal");
    else
        SetConfig(SimplonModule::Detector, "counting_mode", "retrigger");

    SetConfigIfDifferent(SimplonModule::Detector, "photon_energy", experiment.GetIncidentEnergy_keV() * 1e3f, 0.01f);
    auto thr = experiment.GetEigerThreshold_keV();
    SetConfigIfDifferent(SimplonModule::Detector, "threshold_energy", thr * 1e3f, 0.01);

    switch (experiment.GetDetectorTiming()) {
        case DetectorTiming::Auto:
            SetConfig(SimplonModule::Detector, "trigger_mode", "ints");
            break;
        case DetectorTiming::Trigger:
            SetConfig(SimplonModule::Detector, "trigger_mode", "exts");
            break;
        case DetectorTiming::Gated:
            SetConfig(SimplonModule::Detector, "trigger_mode", "extg");
            break;
        case DetectorTiming::Burst:
            throw JFJochException(JFJochExceptionCategory::InputParameterInvalid,
                                  "Burst mode not supported with DECTRIS sytems");
    }

    SetConfig(SimplonModule::Detector, "trigger_start_delay", std::chrono::duration<float>(experiment.GetDetectorDelay()).count());
}

SimplonState DectrisSimplonClient::GetState() {
    auto c = GetStatus(SimplonModule::Detector,  "state");
    if (!c.is_string())
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid,
                              "value must be string");

    std::string res = c.get<std::string>();

    if (res == "na")
        return SimplonState::Na;
    else if (res == "ready")
        return SimplonState::Ready;
    else if (res == "idle")
        return SimplonState::Idle;
    else if (res == "acquire")
        return SimplonState::Acquire;
    else if (res == "error")
        return SimplonState::Error;
    else if (res == "initialize")
        return SimplonState::Initialize;
    else if (res == "configure")
        return SimplonState::Configure;
    else if (res == "test")
        return SimplonState::Test;

    throw JFJochException(JFJochExceptionCategory::InputParameterInvalid,
                          "State unknown " + res);
}

// List of error messages the detector reports (SIMPLON detector status "error"), as JSON text
std::string DectrisSimplonClient::GetErrorStatus() {
    return GetStatus(SimplonModule::Detector, "error").dump();
}

float DectrisSimplonClient::GetHumidity() {
    return GetStatus(SimplonModule::Detector, "humidity");
}

float DectrisSimplonClient::GetTemperature() {
    return GetStatus(SimplonModule::Detector, "temperature");
}


std::vector<uint32_t> DectrisSimplonClient::GetPixelMask() {
    auto mask = GetDetCfg("pixel_mask");
    if (!mask.val.is_object() || !mask.val.contains("shape") || !mask.val.contains("data"))
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, "No pixel mask");

    auto shape = mask.val["shape"];

    std::vector<uint32_t> pixel_mask(shape[0].get<int64_t>() * shape[1].get<int64_t>());
    macaron::Decode(mask.val["data"], pixel_mask);

    return pixel_mask;
}