//
//  AssetResourceRequest.cpp
//  libraries/networking/src
//
//  Created by Ryan Huffman on 2015/07/23
//  Copyright 2015 High Fidelity, Inc.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

#include "AssetResourceRequest.h"

#include "AssetClient.h"
#include "AssetUtils.h"
#include "MappingRequest.h"
#include <QtCore/qloggingcategory.h>

AssetResourceRequest::~AssetResourceRequest() {
    if (_assetMappingRequest) {
        _assetMappingRequest->deleteLater();
    }
    
    if (_assetRequest) {
        _assetRequest->deleteLater();
    }

    if (_sendTimer) {
        cleanupTimer();
    }
}

bool AssetResourceRequest::urlIsAssetHash() const {
    static const QString ATP_HASH_REGEX_STRING { "^atp:([A-Fa-f0-9]{64})(\\.[\\w]+)?$" };

    QRegExp hashRegex { ATP_HASH_REGEX_STRING };
    return hashRegex.exactMatch(_url.toString());
}

void AssetResourceRequest::setupTimer() {
    Q_ASSERT(!_sendTimer);
    static const int TIMEOUT_MS = 2000;

    _sendTimer = new QTimer(this);
    connect(_sendTimer, &QTimer::timeout, this, &AssetResourceRequest::onTimeout);

    _sendTimer->setSingleShot(true);
    _sendTimer->start(TIMEOUT_MS);
}

void AssetResourceRequest::cleanupTimer() {
    Q_ASSERT(_sendTimer);
    disconnect(_sendTimer, 0, this, 0);
    _sendTimer->deleteLater();
    _sendTimer = nullptr;
}

void AssetResourceRequest::doSend() {
    // We'll either have a hash or an ATP path to a file (that maps to a hash)
    if (urlIsAssetHash()) {
        // We've detected that this is a hash - simply use AssetClient to request that asset
        auto parts = _url.path().split(".", QString::SkipEmptyParts);
        auto hash = parts.length() > 0 ? parts[0] : "";

        requestHash(hash);
    } else {
        // This is an ATP path, we'll need to figure out what the mapping is.
        // This may incur a roundtrip to the asset-server, or it may return immediately from the cache in AssetClient.

        auto path = _url.path();
        requestMappingForPath(path);
    }
}

void AssetResourceRequest::requestMappingForPath(const AssetPath& path) {
    auto assetClient = DependencyManager::get<AssetClient>();
    _assetMappingRequest = assetClient->createGetMappingRequest(path);

    // make sure we'll hear about the result of the get mapping request
    connect(_assetMappingRequest, &GetMappingRequest::finished, this, [this, path](GetMappingRequest* request){
        Q_ASSERT(_state == InProgress);
        Q_ASSERT(request == _assetMappingRequest);

        cleanupTimer();

        switch (request->getError()) {
            case MappingRequest::NoError:
                // we have no error, we should have a resulting hash - use that to send of a request for that asset
                qDebug() << "Got mapping for:" << path << "=>" << request->getHash();

                requestHash(request->getHash());

                break;
            default: {
                switch (request->getError()) {
                    case MappingRequest::NotFound:
                        // no result for the mapping request, set error to not found
                        _result = NotFound;
                        break;
                    case MappingRequest::NetworkError:
                        // didn't hear back from the server, mark it unavailable
                        _result = ServerUnavailable;
                        break;
                    default:
                        _result = Error;
                        break;
                }

                // since we've failed we know we are finished
                _state = Finished;
                emit finished();

                break;
            }
        }

        _assetMappingRequest->deleteLater();
        _assetMappingRequest = nullptr;
    });

    setupTimer();
    _assetMappingRequest->start();
}

void AssetResourceRequest::requestHash(const AssetHash& hash) {

    // Make request to atp
    auto assetClient = DependencyManager::get<AssetClient>();
    _assetRequest = assetClient->createRequest(hash);

    connect(_assetRequest, &AssetRequest::progress, this, &AssetResourceRequest::onDownloadProgress);
    connect(_assetRequest, &AssetRequest::finished, this, [this](AssetRequest* req) {
        Q_ASSERT(_state == InProgress);
        Q_ASSERT(req == _assetRequest);
        Q_ASSERT(req->getState() == AssetRequest::Finished);

        cleanupTimer();
        
        switch (req->getError()) {
            case AssetRequest::Error::NoError:
                _data = req->getData();
                _result = Success;
                break;
            case AssetRequest::InvalidHash:
                _result = InvalidURL;
                break;
            case AssetRequest::Error::NotFound:
                _result = NotFound;
                break;
            case AssetRequest::Error::NetworkError:
                _result = ServerUnavailable;
                break;
            default:
                _result = Error;
                break;
        }
        
        _state = Finished;
        emit finished();

        _assetRequest->deleteLater();
        _assetRequest = nullptr;
    });

    setupTimer();
    _assetRequest->start();
}

void AssetResourceRequest::onDownloadProgress(qint64 bytesReceived, qint64 bytesTotal) {
    Q_ASSERT(_state == InProgress);

    // We've received data, so reset the timer
    _sendTimer->start();

    emit progress(bytesReceived, bytesTotal);
}

void AssetResourceRequest::onTimeout() {
    if (_state == InProgress) {
        qWarning() << "Asset request timed out: " << _url;
        if (_assetRequest) {
            disconnect(_assetRequest, 0, this, 0);
            _assetRequest->deleteLater();
            _assetRequest = nullptr;
        }
        if (_assetMappingRequest) {
            disconnect(_assetMappingRequest, 0, this, 0);
            _assetMappingRequest->deleteLater();
            _assetMappingRequest = nullptr;
        }
        _result = Timeout;
        _state = Finished;
        emit finished();
    }
    cleanupTimer();
}