/*
 * Copyright (c) 2015-2016 Isode Limited.
 * All rights reserved.
 * See the COPYING file for more information.
 */

#include <Swiften/Disco/FeatureOracle.h>

#include <algorithm>
#include <iterator>
#include <vector>

#include <Swiften/Base/foreach.h>
#include <Swiften/Disco/EntityCapsProvider.h>
#include <Swiften/Elements/Presence.h>
#include <Swiften/FileTransfer/FileTransferManager.h>
#include <Swiften/JID/JID.h>
#include <Swiften/Presence/PresenceOracle.h>

namespace Swift {

FeatureOracle::FeatureOracle(EntityCapsProvider* capsProvider, PresenceOracle* presenceOracle) : capsProvider_(capsProvider), presenceOracle_(presenceOracle) {

}

Tristate FeatureOracle::isFileTransferSupported(const JID& jid) {
    DiscoInfo::ref discoInfo = getDiscoResultForJID(jid);
    if (discoInfo) {
        return FileTransferManager::isSupportedBy(discoInfo) ? Yes : No;
    }
    else {
        return Maybe;
    }
}

Tristate FeatureOracle::isMessageReceiptsSupported(const JID& jid) {
    return isFeatureSupported(jid, DiscoInfo::MessageDeliveryReceiptsFeature);
}

Tristate FeatureOracle::isMessageCorrectionSupported(const JID& jid) {
    return isFeatureSupported(jid, DiscoInfo::MessageCorrectionFeature);
}

DiscoInfo::ref FeatureOracle::getDiscoResultForJID(const JID& jid) {
    DiscoInfo::ref discoInfo;
    if (jid.isBare()) {
        // Calculate the common subset of disco features of all available results and return that.
        std::vector<Presence::ref> availablePresences =  presenceOracle_->getAllPresence(jid);

        bool commonFeaturesInitialized = false;
        std::vector<std::string> commonFeatures;
        foreach(Presence::ref presence, availablePresences) {
            DiscoInfo::ref presenceDiscoInfo = capsProvider_->getCaps(presence->getFrom());
            if (presenceDiscoInfo) {
                std::vector<std::string> features = presenceDiscoInfo->getFeatures();
                if (!commonFeaturesInitialized) {
                    commonFeatures = features;
                    commonFeaturesInitialized = true;
                }
                else {
                    std::vector<std::string> featuresToRemove;
                    foreach(const std::string& feature, commonFeatures) {
                        if (std::find(features.begin(), features.end(), feature) == features.end()) {
                            featuresToRemove.push_back(feature);
                        }
                    }
                    foreach(const std::string& featureToRemove, featuresToRemove) {
                        commonFeatures.erase(std::remove(commonFeatures.begin(), commonFeatures.end(), featureToRemove), commonFeatures.end());
                    }
                }
            }
        }
        discoInfo = std::make_shared<DiscoInfo>();

        foreach(const std::string& commonFeature, commonFeatures) {
            discoInfo->addFeature(commonFeature);
        }
    }
    else {
        // Return the disco result of the full JID.
        discoInfo = capsProvider_->getCaps(jid);
    }

    return discoInfo;
}

Tristate FeatureOracle::isFeatureSupported(const JID& jid, const std::string& feature) {
    DiscoInfo::ref discoInfo = getDiscoResultForJID(jid);
    if (discoInfo) {
        return discoInfo->hasFeature(feature) ? Yes : No;
    }
    else {
        return Maybe;
    }
}

}