#include <chrono>
#include <coroutine>
#include <functional>
#include <iostream>
#include <queue>
#include <string>
#include <thread>

using task = std::function<void(const std::string&)>;

class executor {
private:
? ? std::thread work_thread_;
? ? std::queue<task> tasks_;

public:
? ? void add_task(task t) { tasks_.emplace(std::move(t)); }

? ? void run() {
? ? ? ? work_thread_ = std::thread([this]() {
? ? ? ? ? ? uint64_t times = 1;
? ? ? ? ? ? std::cout << "executor thread: " << std::this_thread::get_id() << "\n";
? ? ? ? ? ? while (true) {
? ? ? ? ? ? ? ? auto& task = tasks_.front();
? ? ? ? ? ? ? ? task(std::to_string(times));
? ? ? ? ? ? ? ? times++;
? ? ? ? ? ? ? ? tasks_.pop();

? ? ? ? ? ? ? ? using namespace std::chrono_literals;
? ? ? ? ? ? ? ? std::this_thread::sleep_for(1000ms);
? ? ? ? ? ? }
? ? ? ? ? ? });

? ? ? ? if (work_thread_.joinable()) {
? ? ? ? ? ? work_thread_.join();
? ? ? ? }
? ? }
};

class coroutine_task {
public:
? ? struct promise_type {
? ? ? ? std::suspend_never initial_suspend() noexcept { return {}; }

? ? ? ? std::suspend_always final_suspend() noexcept { return {}; }

? ? ? ? void unhandled_exception() noexcept {}

? ? ? ? coroutine_task get_return_object() noexcept {
? ? ? ? ? ? auto tk = coroutine_task{
? ? ? ? ? ? ? ? std::coroutine_handle<promise_type>::from_promise(*this) };
? ? ? ? ? ? return tk;
? ? ? ? }

? ? ? ? /*void return_value(int v) noexcept {}*/
? ? ? ? void return_void() noexcept {}

? ? ? ? std::suspend_always yield_value(std::string&& from) noexcept {
? ? ? ? ? ? value_ = std::move(from);
? ? ? ? ? ? return {};
? ? ? ? }

? ? ? ? std::string value_;
? ? };

private:
? ? std::coroutine_handle<promise_type> coro_;

public:
? ? coroutine_task(std::coroutine_handle<promise_type> h) : coro_(h) {}

? ? ~coroutine_task() {
? ? ? ? if (coro_) {
? ? ? ? ? ? coro_.destroy();
? ? ? ? }
? ? }

? ? std::string value() { return coro_.promise().value_; }
};

template <typename R, typename Executor = executor>
struct awaitable {
private:
? ? R buf_;
? ? Executor& e_;
? ? std::coroutine_handle<> coro_handle_;

public:
? ? awaitable(Executor& e) : e_(e) {}

? ? bool await_ready() noexcept { return false; }

? ? R await_resume() noexcept { return buf_; }

? ? void await_suspend(std::coroutine_handle<> p) noexcept {
? ? ? ? coro_handle_ = p;
? ? }

? ? void async_start() {
? ? ? ? e_.add_task([this](const R& times) {
? ? ? ? ? ? std::cout << "async resume thread: " << std::this_thread::get_id() << "\n";
? ? ? ? ? ? buf_ = times;
? ? ? ? ? ? coro_handle_.resume();
? ? ? ? ? ? });
? ? }
};

auto async_read(executor& e) {
? ? awaitable<std::string> aw{ e };
? ? aw.async_start();
? ? return aw;
}

coroutine_task coro_read1(executor& e) {
? ? std::cout << "coro_read1 begin thread: " << std::this_thread::get_id() << "\n";
? ? for (;;) {
? ? ? ? auto value = co_await async_read(e);
? ? ? ? std::cout << "1、coro_read1: " << value << " thread: " << std::this_thread::get_id() << "\n";
? ? ? ? value = co_await async_read(e);
? ? ? ? std::cout << "2、coro_read1: " << value << " thread: " << std::this_thread::get_id() << "\n";
? ? }
}

coroutine_task coro_read2(executor& e) {
? ? std::cout << "coro_read2 begin thread: " << std::this_thread::get_id() << "\n";
? ? for (;;) {
? ? ? ? auto value = co_await async_read(e);
? ? ? ? std::cout << "coro_read2: " << value << " thread: " << std::this_thread::get_id() << "\n";
? ? }
}

int main() {
? ? executor e;

? ? auto cr1 = coro_read1(e);
? ? auto cr2 = coro_read2(e);

? ? e.run();
? ? return 0;
}
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