#pragma once
#include "camera_pipeline.hpp"
#include <atomic>
#include <csignal>
#include <pthread.h>
#include <stdexcept>
#include <thread>

namespace cms {
// Construct before starting workers so all threads inherit the signal mask.
// Stop requests run in an ordinary thread, never an asynchronous signal handler.
class StopSignals {
public:
    explicit StopSignals(CameraPipeline& pipeline):pipeline_(pipeline) {
        sigemptyset(&signals_);sigaddset(&signals_,SIGINT);sigaddset(&signals_,SIGTERM);
        if(pthread_sigmask(SIG_BLOCK,&signals_,&old_)!=0)throw std::runtime_error("Cannot block termination signals");
        try {
            thread_=std::thread([this]{
                while(!done_) {
                    timespec timeout{0,100000000};
                    int signal=sigtimedwait(&signals_,nullptr,&timeout);
                    if(signal==SIGINT||signal==SIGTERM){pipeline_.requestStop();break;}
                }
            });
        }catch(...){pthread_sigmask(SIG_SETMASK,&old_,nullptr);throw;}
    }
    ~StopSignals(){done_=true;if(thread_.joinable())thread_.join();pthread_sigmask(SIG_SETMASK,&old_,nullptr);}
    StopSignals(StopSignals const&)=delete;
    StopSignals& operator=(StopSignals const&)=delete;
private:
    CameraPipeline& pipeline_;
    sigset_t signals_{},old_{};
    std::atomic<bool> done_{false};
    std::thread thread_;
};
}