// SPDX-License-Identifier: MIT
// SPDX-FileCopyrightText: 2026 Martino Ferrari

#include "source/probe_source.hpp"

#include "source/registry.hpp"

#include <adwaita.h>

#include <algorithm>
#include <chrono>
#include <cmath>
#include <functional>
#include <memory>
#include <thread>

namespace udpscope {

ProbeSource::ProbeSource(const SourceConfig& cfg)
    : rate_hz_(std::max(1.0, cfg.get_double("rate", 1000.0))), batch_(kBatch, 0.0) {
  SignalInfo s;
  s.name = "probe";
  s.unit = "V";
  s.type_code = 9;  // float64
  s.rows = 1;
  s.cols = 1;
  s.range_min = -1.0;
  s.range_max = 1.0;
  s.time_mode = kTimePacket;
  s.sampling_rate = rate_hz_;
  signals_.push_back(s);
}

void ProbeSource::open(SourceSink& sink) {
  sink_ = &sink;
  configured_ = false;
  open_.store(true, std::memory_order_relaxed);
}

void ProbeSource::close() { open_.store(false, std::memory_order_relaxed); }

SourceStats ProbeSource::stats() const {
  SourceStats s;
  s.packets = frames_;
  s.frames = frames_;
  s.connected = open_.load(std::memory_order_relaxed);
  return s;
}

void ProbeSource::poll(int timeout_ms) {
  drain_commands();
  if (!open_.load(std::memory_order_relaxed) || sink_ == nullptr) return;
  if (!configured_) {
    configured_ = true;
    sink_->on_config(signals_, /*publish_mode=*/1);
    sink_->on_event(SourceEvent::Connected, "");
  }
  // One batch takes kBatch / rate seconds to "arrive".
  const int period_ms = std::max(1, static_cast<int>(1000.0 * kBatch / rate_hz_));
  std::this_thread::sleep_for(std::chrono::milliseconds(std::min(period_ms, timeout_ms)));
  const double step = 2.0 * M_PI * 5.0 / rate_hz_;  // a 5 Hz sine
  for (std::uint32_t k = 0; k < kBatch; ++k) {
    batch_[k] = std::sin(phase_);
    phase_ += step;
  }
  values_.values = batch_.data();
  values_.count = kBatch;
  Frame f;
  f.counter = counter_++;
  f.lost = 0;
  f.late = false;
  f.recv_time = std::chrono::duration<double>(std::chrono::system_clock::now().time_since_epoch())
                    .count();
  f.publish_mode = 1;
  f.num_samples = kBatch;
  f.num_signals = 1;
  f.signals = signals_.data();
  f.values = &values_;
  ++frames_;
  sink_->on_data(f);
}

namespace {

void on_rate_changed(GObject*, GParamSpec*, gpointer user) {
  const auto& cb = *static_cast<std::shared_ptr<std::function<void()>>*>(user);
  if (cb && *cb) (*cb)();
}

class ProbeKind final : public SourceKind {
 public:
  std::string id() const override { return "probe"; }
  std::string display_name() const override { return "Probe (test)"; }
  std::string identity(const SourceConfig& cfg) const override {
    return "rate" + std::to_string(cfg.get_int("rate", 1000));
  }
  std::unique_ptr<DataSource> make(const SourceConfig& cfg) const override {
    return std::make_unique<ProbeSource>(cfg);
  }

  ConfigForm make_config_form() const override {
    GtkWidget* rate = GTK_WIDGET(adw_spin_row_new_with_range(1, 100000, 1));
    adw_preferences_row_set_title(ADW_PREFERENCES_ROW(rate), "_Rate (Hz)");
    adw_preferences_row_set_use_underline(ADW_PREFERENCES_ROW(rate), TRUE);
    adw_spin_row_set_value(ADW_SPIN_ROW(rate), 1000);

    auto cb = std::make_shared<std::function<void()>>();
    g_signal_connect_data(rate, "notify::value", G_CALLBACK(on_rate_changed),
                          new std::shared_ptr<std::function<void()>>(cb),
                          +[](gpointer d, GClosure*) {
                            delete static_cast<std::shared_ptr<std::function<void()>>*>(d);
                          },
                          static_cast<GConnectFlags>(0));

    ConfigForm f;
    f.rows = {rate};
    f.description = "A synthetic 5 Hz sine, for the self-check";
    f.focus = rate;
    f.write = [=](const SourceConfig& c) {
      adw_spin_row_set_value(ADW_SPIN_ROW(rate), static_cast<double>(c.get_int("rate", 1000)));
    };
    f.read = [=]() {
      SourceConfig c;
      c.set("rate", std::to_string(static_cast<long>(adw_spin_row_get_value(ADW_SPIN_ROW(rate)))));
      return c;
    };
    f.valid = []() { return true; };
    f.on_change = [cb](std::function<void()> fn) { *cb = std::move(fn); };
    return f;
  }

  std::vector<SourcePanel> make_panels(DataSource& source) const override {
    GtkWidget* box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 6);
    gtk_widget_set_margin_top(box, 12);
    gtk_widget_set_margin_bottom(box, 12);
    gtk_widget_set_margin_start(box, 12);
    gtk_widget_set_margin_end(box, 12);
    GtkWidget* label = gtk_label_new("Test panel");
    gtk_widget_set_halign(label, GTK_ALIGN_START);
    gtk_box_append(GTK_BOX(box), label);
    // The probe finds the button as the box's last child. It reaches the source only through
    // `post()`: the command runs inside the next `poll()`, on the producer thread.
    GtkWidget* poke = gtk_button_new_with_label("Poke");
    gtk_box_append(GTK_BOX(box), poke);
    DataSource* src = &source;
    g_signal_connect_data(
        poke, "clicked",
        G_CALLBACK(+[](GtkButton*, gpointer user) {
          DataSource* s = static_cast<DataSource*>(user);
          s->post([s] { static_cast<ProbeSource*>(s)->note_applied(); });
        }),
        src, nullptr, static_cast<GConnectFlags>(0));
    SourcePanel p;
    p.id = "poke";
    p.title = "Probe";
    p.widget = box;
    return {p};
  }
};

}  // namespace

std::unique_ptr<SourceKind> make_probe_kind() { return std::make_unique<ProbeKind>(); }

}  // namespace udpscope