/****************************************************************************
 Copyright (c) 2017-2022 Xiamen Yaji Software Co., Ltd.

 http://www.cocos.com

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated engine source code (the "Software"), a limited,
 worldwide, royalty-free, non-assignable, revocable and non-exclusive license
 to use Cocos Creator solely to develop games on your target platforms. You shall
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 used for developing games. You are not granted to publish, distribute,
 sublicense, and/or sell copies of Cocos Creator.

 The software or tools in this License Agreement are licensed, not sold.
 Xiamen Yaji Software Co., Ltd. reserves all rights not expressly granted to you.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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****************************************************************************/

#include "Reachability.h"
#include "base/Macros.h"

#include <SystemConfiguration/SystemConfiguration.h>
#include <arpa/inet.h>
#include <ifaddrs.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/socket.h>

namespace {

#define ShouldPrintReachabilityFlags 0

static void PrintReachabilityFlags(SCNetworkReachabilityFlags flags, const char *comment) {
#if ShouldPrintReachabilityFlags

    printf("Reachability Flag Status: %c%c %c%c%c%c%c%c%c %s\n",
    #if CC_PLATFORM == CC_PLATFORM_MAC_IOS
           (flags & kSCNetworkReachabilityFlagsIsWWAN) ? 'W' : '-',
    #else
           '-',
    #endif
           (flags & kSCNetworkReachabilityFlagsReachable) ? 'R' : '-',

           (flags & kSCNetworkReachabilityFlagsTransientConnection) ? 't' : '-',
           (flags & kSCNetworkReachabilityFlagsConnectionRequired) ? 'c' : '-',
           (flags & kSCNetworkReachabilityFlagsConnectionOnTraffic) ? 'C' : '-',
           (flags & kSCNetworkReachabilityFlagsInterventionRequired) ? 'i' : '-',
           (flags & kSCNetworkReachabilityFlagsConnectionOnDemand) ? 'D' : '-',
           (flags & kSCNetworkReachabilityFlagsIsLocalAddress) ? 'l' : '-',
           (flags & kSCNetworkReachabilityFlagsIsDirect) ? 'd' : '-',
           comment);
#endif
}

cc::Reachability::NetworkStatus getNetworkStatusForFlags(SCNetworkReachabilityFlags flags) {
    PrintReachabilityFlags(flags, "networkStatusForFlags");
    if ((flags & kSCNetworkReachabilityFlagsReachable) == 0) {
        // The target host is not reachable.
        return cc::Reachability::NetworkStatus::NOT_REACHABLE;
    }

    cc::Reachability::NetworkStatus returnValue = cc::Reachability::NetworkStatus::NOT_REACHABLE;

    if ((flags & kSCNetworkReachabilityFlagsConnectionRequired) == 0) {
        /*
             If the target host is reachable and no connection is required then we'll assume (for now) that you're on Wi-Fi...
             */
        returnValue = cc::Reachability::NetworkStatus::REACHABLE_VIA_WIFI;
    }

    if ((((flags & kSCNetworkReachabilityFlagsConnectionOnDemand) != 0) ||
         (flags & kSCNetworkReachabilityFlagsConnectionOnTraffic) != 0)) {
        /*
             ... and the connection is on-demand (or on-traffic) if the calling application is using the CFSocketStream or higher APIs...
             */

        if ((flags & kSCNetworkReachabilityFlagsInterventionRequired) == 0) {
            /*
                 ... and no [user] intervention is needed...
                 */
            returnValue = cc::Reachability::NetworkStatus::REACHABLE_VIA_WIFI;
        }
    }

#if CC_PLATFORM == CC_PLATFORM_MAC_IOS
    if ((flags & kSCNetworkReachabilityFlagsIsWWAN) == kSCNetworkReachabilityFlagsIsWWAN) {
        /*
             ... but WWAN connections are OK if the calling application is using the CFNetwork APIs.
             */
        returnValue = cc::Reachability::NetworkStatus::REACHABLE_VIA_WWAN;
    }
#endif

    return returnValue;
}
} // namespace

namespace cc {

Reachability *Reachability::createWithHostName(const std::string &hostName) {
    Reachability *           returnValue  = nullptr;
    SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithName(nullptr, hostName.c_str());
    if (reachability != nullptr) {
        returnValue = new (std::nothrow) Reachability();
        if (returnValue != nullptr) {
            returnValue->autorelease();
            returnValue->_reachabilityRef = reachability;
        } else {
            CFRelease(reachability);
        }
    }
    return returnValue;
}

Reachability *Reachability::createWithAddress(const struct sockaddr *hostAddress) {
    SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, hostAddress);

    Reachability *returnValue = nullptr;

    if (reachability != nullptr) {
        returnValue = new (std::nothrow) Reachability();
        if (returnValue != nullptr) {
            returnValue->autorelease();
            returnValue->_reachabilityRef = reachability;
        } else {
            CFRelease(reachability);
        }
    }
    return returnValue;
}

Reachability *Reachability::createForInternetConnection() {
    struct sockaddr_in zeroAddress;
    bzero(&zeroAddress, sizeof(zeroAddress));
    zeroAddress.sin_len    = sizeof(zeroAddress);
    zeroAddress.sin_family = AF_INET;

    return createWithAddress((const struct sockaddr *)&zeroAddress);
}

Reachability::Reachability()
: _callback(nullptr),
  _userData(nullptr),
  _reachabilityRef(nullptr) {
}

Reachability::~Reachability() {
    stopNotifier();
    if (_reachabilityRef != nullptr) {
        CFRelease(_reachabilityRef);
    }
}

void Reachability::onReachabilityCallback(SCNetworkReachabilityRef target, SCNetworkReachabilityFlags flags, void *info) {
    CCASSERT(info != nullptr, "info was nullptr in onReachabilityCallback");

    cc::Reachability *thiz = reinterpret_cast<cc::Reachability *>(info);
    if (thiz->_callback != nullptr) {
        NetworkStatus status = getNetworkStatusForFlags(flags);
        thiz->_callback(thiz, status, thiz->_userData);
    }
}

bool Reachability::startNotifier(const ReachabilityCallback &cb, void *userData) {
    _callback = cb;
    _userData = userData;

    bool                         returnValue = false;
    SCNetworkReachabilityContext context     = {0, this, nullptr, nullptr, nullptr};

    if (SCNetworkReachabilitySetCallback(_reachabilityRef, onReachabilityCallback, &context)) {
        if (SCNetworkReachabilityScheduleWithRunLoop(_reachabilityRef, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode)) {
            returnValue = true;
        }
    }

    return returnValue;
}

void Reachability::stopNotifier() {
    if (_reachabilityRef != nullptr) {
        SCNetworkReachabilityUnscheduleFromRunLoop(_reachabilityRef, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
    }
}

bool Reachability::isConnectionRequired() const {
    CCASSERT(_reachabilityRef != nullptr, "connectionRequired called with nullptr reachabilityRef");
    SCNetworkReachabilityFlags flags;

    if (SCNetworkReachabilityGetFlags(_reachabilityRef, &flags)) {
        return (flags & kSCNetworkReachabilityFlagsConnectionRequired);
    }

    return false;
}

Reachability::NetworkStatus Reachability::getCurrentReachabilityStatus() const {
    CCASSERT(_reachabilityRef != nullptr, "currentNetworkStatus called with nullptr SCNetworkReachabilityRef");
    NetworkStatus              returnValue = NetworkStatus::NOT_REACHABLE;
    SCNetworkReachabilityFlags flags;

    if (SCNetworkReachabilityGetFlags(_reachabilityRef, &flags)) {
        returnValue = getNetworkStatusForFlags(flags);
    }

    return returnValue;
}

} // namespace cc