/*
 *  IXDNSLookup.h
 *  Author: Benjamin Sergeant
 *  Copyright (c) 2018 Machine Zone, Inc. All rights reserved.
 *
 *  Resolve a hostname+port to a struct addrinfo obtained with getaddrinfo
 *  Does this in a background thread so that it can be cancelled, since
 *  getaddrinfo is a blocking call, and we don't want to block the main thread
 * on Mobile.
 */

#pragma once

#include "IXCancellationRequest.h"
#include <atomic>
#include <memory>
#include <mutex>
#include <set>
#include <string>

struct addrinfo;

namespace ix
{
class DNSLookup : public std::enable_shared_from_this<DNSLookup>
{
public:
    DNSLookup(const std::string &hostname,
              int port,
              int64_t wait = DNSLookup::kDefaultWait);
    ~DNSLookup() = default;

    struct addrinfo *resolve(std::string &errMsg,
                             const CancellationRequest &isCancellationRequested,
                             bool cancellable = true);

    void release(struct addrinfo *addr);

private:
    struct addrinfo *
        resolveCancellable(std::string &errMsg,
                           const CancellationRequest &isCancellationRequested);
    struct addrinfo *resolveUnCancellable(
        std::string &errMsg,
        const CancellationRequest &isCancellationRequested);

    static struct addrinfo *
        getAddrInfo(const std::string &hostname, int port, std::string &errMsg);

    void run(std::weak_ptr<DNSLookup> self,
             std::string hostname,
             int port); // thread runner

    void setErrMsg(const std::string &errMsg);
    const std::string &getErrMsg();

    void setRes(struct addrinfo *addr);
    struct addrinfo *getRes();

    std::string _hostname;
    int _port;
    int64_t _wait;
    const static int64_t kDefaultWait;

    struct addrinfo *_res;
    std::mutex _resMutex;

    std::string _errMsg;
    std::mutex _errMsgMutex;

    std::atomic<bool> _done;
};
} // namespace ix