#include "thread_pool.hpp"

ThreadPool::ThreadPool(size_t num_threads) {
    states = new bool[num_threads]({ false });
    for (auto i = 0; i < num_threads; ++i) {
        threads.emplace_back([this, i] {
            while (true) {
                std::function<void()> task;

                std::unique_lock<std::mutex> lock(mutex);

                cv.wait(lock, [this] { return !tasks.empty() || stop; });

                if (tasks.empty() || stop) {
                    return;
                }

                states[i] = true;

                task = std::move(tasks.front());
                tasks.pop();

                lock.unlock();
                task();

                states[i] = false;
            }
        });
    }
}

ThreadPool::~ThreadPool() {
    std::unique_lock<std::mutex> lock(mutex);
    stop = true;
    lock.unlock();

    cv.notify_all();
    for (auto& thread : threads) {
        thread.join();
    }
}

void ThreadPool::add(std::function<void()> task) {
    std::unique_lock<std::mutex> lock(mutex);
    tasks.emplace(std::move(task));
    cv.notify_one();
    lock.unlock();
}

uint32_t ThreadPool::size() { return tasks.size(); }
bool ThreadPool::isWorking() { 
    for (auto i = 0; i < threads.size(); i++) {
        if (states[i]) {
            return true;
        }
    }
    return false;
}