using selector_callback_t = std::function<void (WFSelectorTask *)>;

class WFTaskFactory
{
public:
    static WFSelectorTask *create_selector_task(size_t candidates,
                                                selector_callback_t callback);
};

class WFSelectorTask : public WFGenericTask
{
public:
    virtual int submit(void *msg);

    void *get_message() const;
};

#include <stdlib.h>
#include <stdio.h>
#include "workflow/WFTaskFactory.h"
#include "workflow/WFFacilities.h"

WFSelectorTask *selector;
WFFacilities::WaitGroup wait_group(2);

void http_callback(WFHttpTask *t)
{
    if (t->get_state() == WFT_STATE_SUCCESS)
        selector->submit(t->user_data);
    else
        selector->submit(NULL);

    wait_group.done();
}

int main(int argc, char *argv[])
{
    if (argc != 4)
    {
        fprintf(stderr, "USAGE: %s <http URL1> <http URL2> <timeout>\n", argv[0]);
        exit(1); 
    }

    selector = WFTaskFactory::create_selector_task(3, [](WFSelectorTask *selector) {
        void *msg = selector->get_message();
        if (msg)
            printf("%s\n", (char *)msg);
        else
            printf("failed\n");
    });

    auto *t = WFTaskFactory::create_http_task(argv[1], 0, 0, http_callback);
    t->user_data = argv[1];
    t->start();

    t = WFTaskFactory::create_http_task(argv[2], 0, 0, http_callback);
    t->user_data = argv[2];
    t->start();

    auto *timer = WFTaskFactory::create_timer_task(atoi(argv[3]), 0, [](WFTimerTask *timer){
        if (timer->get_state() == WFT_STATE_SUCCESS)
            selector->submit((void *)"timeout");
        else
            selector->submit(NULL);
    });
    timer->start();

    selector->start();

    wait_group.wait();
    return 0;
}