ApiManager.cpp

#include "ApiManager.h"
#include <QNetworkRequest>
#include <QNetworkAccessManager>
#include <QEventLoop>
#include <QThread>
#include <future>

using namespace ThingSpeak;

const QUrl ApiManager::apiUrlDefault = QUrl("https://api.thingspeak.com");

ApiManager::ApiManager(const QUrl &apiUrl) : apiUrl(apiUrl)
{
}

qint64 ApiManager::getTimeSinceLastRequestSec()
{
    QDateTime currentDateTime(QDateTime::currentDateTime());
    return currentDateTime.toTime_t() - lastRequest.toTime_t();
}

quint64 ApiManager::getWaitTimeSec()
{
    qint64 timeDiffSec = getTimeSinceLastRequestSec();

    if (timeDiffSec < timeBetweenRequestsSec)
        return timeBetweenRequestsSec - timeDiffSec + 2;

    return 0;
}

void ApiManager::waitForTimeout()
{
    quint64 waitTime = getWaitTimeSec();
    if (waitTime == 0)
        return;

    QThread::sleep(waitTime);
}


QUrl ApiManager::buildRequestUrl(const QString &path)
{
    QUrl url = apiUrl;
    url.setPath(path);
    return url;
}

QNetworkReply* ApiManager::sendPostRequestSync(const QString &path, const QUrlQuery &query)
{
    // Build the url.
    QUrl url = buildRequestUrl(path);

    // Create request
    QNetworkRequest request(url);
    request.setHeader(QNetworkRequest::ContentTypeHeader, "application/x-www-form-urlencoded");

    // Wait until we can issue the next request
    waitForTimeout();
    lastRequest = QDateTime(QDateTime::currentDateTime());

    // Perform request and wait for completion
    // Create an event loop to synchronize http request
    QEventLoop syncEventLoop;
    QObject::connect(&manager, SIGNAL(finished(QNetworkReply*)), &syncEventLoop, SLOT(quit()));
    QNetworkReply *reply = manager.post(request, query.toString(QUrl::FullyEncoded).toUtf8());

    // Wait for completion
    syncEventLoop.exec();
    return reply;
}

QNetworkReply* ApiManager::sendGetRequestSync(const QString &path, const QUrlQuery &query)
{
    // Build the url.
    QUrl url = buildRequestUrl(path);
    url.setQuery(query);

    // Create request
    QNetworkRequest request(url);
    request.setHeader(QNetworkRequest::ContentTypeHeader, "application/x-www-form-urlencoded");

    // Wait until we can issue the next request
    waitForTimeout();
    lastRequest = QDateTime(QDateTime::currentDateTime());

    // Perform request and wait for completion
    // Connect the network manager's finish() signal in order to synchronize http requests
    QEventLoop syncEventLoop;
    QObject::connect(&manager, SIGNAL(finished(QNetworkReply*)), &syncEventLoop, SLOT(quit()));

    QNetworkReply *reply = manager.get(request);

    // Wait for completion
    syncEventLoop.exec();

    return reply;
}

void ApiManager::sendGetRequestAsync(const QString &path, const QUrlQuery &query, const std::function <void (QNetworkReply*)> &callback)
{
    std::async(std::launch::async, [&](){
        // Build the url.
        QUrl url = buildRequestUrl(path);
        url.setQuery(query);

        // Create request
        QNetworkRequest request(url);
        request.setHeader(QNetworkRequest::ContentTypeHeader, "application/x-www-form-urlencoded");

        // Wait until we can issue the next request
        waitForTimeout();
        lastRequest = QDateTime(QDateTime::currentDateTime());

        qDebug() << "Here";

        // Perform request and wait for completion
        // Connect the network manager's finish() signal in order to synchronize http requests
        QObject::connect(&manager, &QNetworkAccessManager::finished, callback);
        manager.get(request);
    });
}

unsigned int ApiManager::getTimeBetweenRequestsSec() const
{
    return timeBetweenRequestsSec;
}

void ApiManager::setTimeBetweenRequestsSec(unsigned int value)
{
    timeBetweenRequestsSec = value;
}