#include "MainLoop.h"

#include "Timer.h"
#include "config.h"
#include "log.h"

#include <chrono>
#include <cmath>
#include <cstdint>
#include <exception>
#include <iostream>
#include <limits>
#include <memory>
#include <stdexcept>

#include <stdio.h>
#include <sys/types.h>
#include <sys/time.h>
#include <time.h>
#include <signal.h>

using namespace std::chrono_literals;
using namespace std::string_literals;

namespace bp = boost::process;

MainLoop::MainLoop(int argc, char** argv):
  m_status{},
  m_config{argc, argv},
  m_note_click{m_config},
  m_clock_click{},
  m_internal_click{m_config},
  m_midi{},
  m_pcm{m_config},
  m_ui{m_config}
{
  m_status.add(LED{"/sys/class/leds/ACT", "/sys/class/leds/PWR"});
  m_status.add(LED{"/sys/class/leds/thingm1:green:led1", "/sys/class/leds/thingm1:red:led1"});

  start_fcgi();
}

MainLoop::~MainLoop()
{
  stop_fcgi();
}

void MainLoop::start_fcgi()
{
  m_child_fcgi = bp::child("spawn-fcgi -a 127.0.0.1 -p 9090 -n -- ./click-fcgi");
  if (!m_child_fcgi.valid() || !m_child_fcgi.running()) {
    throw std::runtime_error("click-fcgi not started");
  }
}

void MainLoop::stop_fcgi()
{
  if (m_child_fcgi.valid()) {
    m_child_fcgi.terminate();
  }
}

bool run_flag = true;

void signal_handler(int) {
  run_flag = false;
  std::cout << "Signal received. Terminating." << std::endl;
}

void MainLoop::reconfigure_mode() {
  debug_cout << "reconfiguring mode" << std::endl;

  m_click_connection.disconnect();

  int mode = m_config.get_mode();

  if (mode == 0) {
    m_click_connection = m_note_click.signal_click.connect([&](){m_pcm.click({});});
  } else if (mode == 1) {
    m_click_connection = m_clock_click.signal_click.connect([&](){m_pcm.click({});});
  } else if (mode == 2) {
    m_click_connection = m_internal_click.signal_click.connect([&](std::chrono::duration<double> offset){m_pcm.click(offset);});
  } else {
    log_cout << fmt::format("Error: Unknown mode: {}", mode) << std::endl;
  }
}

int MainLoop::run()
{
  try {
    signal(SIGTERM, signal_handler);
    signal(SIGINT, signal_handler);

    //debug_cout.activate();
    log_cout.activate();
    log_cout.log_lines(log_lines);

    m_pcm.write();

    Timer timer_50ms(50ms, true);
    timer_50ms.start();

    Timer timer_500ms(500ms, true);
    timer_500ms.start();

    Timer timer_10min(10min, true);
    timer_10min.start();

    // Main signals
    boost::signals2::signal<void()> signal_count_loops;

    //
    // Signal-Slot Connections:
    //
    m_midi.signal_note.connect([&](int channel, int note, uint64_t timestamp){m_note_click.receive_note(channel, note, timestamp);});
    //m_click_connection = m_note_click.signal_click.connect([&](){m_pcm.click(0);});
    reconfigure_mode();
    m_note_click.signal_bpm.connect([&](int bpm){m_ui.slot_note_bpm(bpm);});
    m_clock_click.signal_bpm.connect([&](int bpm){m_ui.slot_clock_bpm(bpm);});
    m_midi.signal_active_sensing.connect([&](){m_ui.slot_active_sensing();});
    timer_500ms.elapsed.connect([&](){m_ui.draw();});
    signal_count_loops.connect([&](){m_ui.count_main_loops();});
    m_midi.signal_count_events.connect([&](size_t size){m_ui.count_midi_events(size);});
    timer_10min.elapsed.connect([&](){m_config.persist();});
    m_midi.signal_note.connect([&](int channel, int note, uint64_t timestamp){m_ui.slot_midi_note(channel, note, timestamp);});
    m_midi.signal_clock.connect([&](){m_clock_click.receive_clock();});
    m_config.signal_mode.connect([&](int mode){reconfigure_mode();});
    timer_50ms.elapsed.connect([&](){m_internal_click.run_cyclic_50ms();});

    m_midi.flush();

    while (run_flag) {
      debug_cout << "Main loop entered." << std::endl;
      signal_count_loops();

      fd_set read_set;
      FD_ZERO(&read_set);
      FD_SET(m_midi.fd(), &read_set);
      FD_SET(0, &read_set);

      if constexpr (0) {
        // PCM fd almost always writeable: for single frames at high speed
        fd_set write_set;
        FD_ZERO(&write_set);
        FD_SET(m_pcm.fd(), &write_set);
      }

      struct timeval timeout;
      timeout.tv_sec = 0;
      timeout.tv_usec = 20000;

      int result = select(FD_SETSIZE, &read_set, nullptr/*&write_set*/, nullptr, &timeout);
      if (result < 0) {
        throw std::runtime_error("select() failed");
      } else if (result == 0) {
        debug_cout << "select() timeout" << std::endl;
      }

      while (m_midi.event_ready())
      {
        //std::cout << "read..." << std::endl;
        auto event = m_midi.read();
        //std::cout << "process..." << std::endl;
        m_midi.process(event);
      }

      if (m_pcm.write_available()) {
        //std::cout << "DEBUG: WRITE" << std::endl;
        m_pcm.write();
      }

      while (m_ui.key_available()) {
        m_ui.handle_input();
      }

      // handle timers, TODO: make updates more efficient at scale
      timer_50ms.update();
      timer_500ms.update();
      timer_10min.update();
    }

    return 0;
  } catch (const std::exception& ex) {
    std::cerr << "Error: " << ex.what() << std::endl;
    m_status.setMode(StatusLED::Mode::Error);
    return 1;
  }
}