Update: Translations from eints

[openttd-github.git] / src / network / network_content.cpp

/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file network_content.cpp Content sending/receiving part of the network protocol. */

#include "../stdafx.h"
#include "../rev.h"
#include "../ai/ai.hpp"
#include "../game/game.hpp"
#include "../window_func.h"
#include "../error.h"
#include "../fileio_func.h"
#include "../base_media_base.h"
#include "../settings_type.h"
#include "network_content.h"

#include "table/strings.h"

#if defined(WITH_ZLIB)
#include <zlib.h>
#endif

#ifdef __EMSCRIPTEN__
#       include <emscripten.h>
#endif

#include "../safeguards.h"

extern bool HasScenario(const ContentInfo *ci, bool md5sum);

/** The client we use to connect to the server. */
ClientNetworkContentSocketHandler _network_content_client;

/** Wrapper function for the HasProc */
static bool HasGRFConfig(const ContentInfo *ci, bool md5sum)
{
        return FindGRFConfig(BSWAP32(ci->unique_id), md5sum ? FGCM_EXACT : FGCM_ANY, md5sum ? &ci->md5sum : nullptr) != nullptr;
}

/**
 * Check whether a function piece of content is locally known.
 * Matches on the unique ID and possibly the MD5 checksum.
 * @param ci     the content info to search for
 * @param md5sum also match the MD5 checksum?
 * @return true iff it's known
 */
typedef bool (*HasProc)(const ContentInfo *ci, bool md5sum);

bool ClientNetworkContentSocketHandler::Receive_SERVER_INFO(Packet &p)
{
        ContentInfo *ci = new ContentInfo();
        ci->type     = (ContentType)p.Recv_uint8();
        ci->id       = (ContentID)p.Recv_uint32();
        ci->filesize = p.Recv_uint32();

        ci->name        = p.Recv_string(NETWORK_CONTENT_NAME_LENGTH);
        ci->version     = p.Recv_string(NETWORK_CONTENT_VERSION_LENGTH);
        ci->url         = p.Recv_string(NETWORK_CONTENT_URL_LENGTH);
        ci->description = p.Recv_string(NETWORK_CONTENT_DESC_LENGTH, SVS_REPLACE_WITH_QUESTION_MARK | SVS_ALLOW_NEWLINE);

        ci->unique_id = p.Recv_uint32();
        p.Recv_bytes(ci->md5sum);

        uint dependency_count = p.Recv_uint8();
        ci->dependencies.reserve(dependency_count);
        for (uint i = 0; i < dependency_count; i++) {
                ContentID dependency_cid = (ContentID)p.Recv_uint32();
                ci->dependencies.push_back(dependency_cid);
                this->reverse_dependency_map.emplace(dependency_cid, ci->id);
        }

        uint tag_count = p.Recv_uint8();
        ci->tags.reserve(tag_count);
        for (uint i = 0; i < tag_count; i++) ci->tags.push_back(p.Recv_string(NETWORK_CONTENT_TAG_LENGTH));

        if (!ci->IsValid()) {
                delete ci;
                this->CloseConnection();
                return false;
        }

        /* Find the appropriate check function */
        HasProc proc = nullptr;
        switch (ci->type) {
                case CONTENT_TYPE_NEWGRF:
                        proc = HasGRFConfig;
                        break;

                case CONTENT_TYPE_BASE_GRAPHICS:
                        proc = BaseGraphics::HasSet;
                        break;

                case CONTENT_TYPE_BASE_MUSIC:
                        proc = BaseMusic::HasSet;
                        break;

                case CONTENT_TYPE_BASE_SOUNDS:
                        proc = BaseSounds::HasSet;
                        break;

                case CONTENT_TYPE_AI:
                        proc = AI::HasAI; break;
                        break;

                case CONTENT_TYPE_AI_LIBRARY:
                        proc = AI::HasAILibrary; break;
                        break;

                case CONTENT_TYPE_GAME:
                        proc = Game::HasGame; break;
                        break;

                case CONTENT_TYPE_GAME_LIBRARY:
                        proc = Game::HasGameLibrary; break;
                        break;

                case CONTENT_TYPE_SCENARIO:
                case CONTENT_TYPE_HEIGHTMAP:
                        proc = HasScenario;
                        break;

                default:
                        break;
        }

        if (proc != nullptr) {
                if (proc(ci, true)) {
                        ci->state = ContentInfo::ALREADY_HERE;
                } else {
                        ci->state = ContentInfo::UNSELECTED;
                        if (proc(ci, false)) ci->upgrade = true;
                }
        } else {
                ci->state = ContentInfo::UNSELECTED;
        }

        /* Something we don't have and has filesize 0 does not exist in the system */
        if (ci->state == ContentInfo::UNSELECTED && ci->filesize == 0) ci->state = ContentInfo::DOES_NOT_EXIST;

        /* Do we already have a stub for this? */
        for (ContentInfo *ici : this->infos) {
                if (ici->type == ci->type && ici->unique_id == ci->unique_id && ci->md5sum == ici->md5sum) {
                        /* Preserve the name if possible */
                        if (ci->name.empty()) ci->name = ici->name;
                        if (ici->IsSelected()) ci->state = ici->state;

                        /*
                         * As ici might be selected by the content window we cannot delete that.
                         * However, we want to keep most of the values of ci, except the values
                         * we (just) already preserved.
                         */
                        *ici = *ci;
                        delete ci;

                        this->OnReceiveContentInfo(ici);
                        return true;
                }
        }

        /* Missing content info? Don't list it */
        if (ci->filesize == 0) {
                delete ci;
                return true;
        }

        this->infos.push_back(ci);

        /* Incoming data means that we might need to reconsider dependencies */
        ConstContentVector parents;
        this->ReverseLookupTreeDependency(parents, ci);
        for (const ContentInfo *ici : parents) {
                this->CheckDependencyState(const_cast<ContentInfo *>(ici));
        }

        this->OnReceiveContentInfo(ci);

        return true;
}

/**
 * Request the content list for the given type.
 * @param type The content type to request the list for.
 */
void ClientNetworkContentSocketHandler::RequestContentList(ContentType type)
{
        if (type == CONTENT_TYPE_END) {
                this->RequestContentList(CONTENT_TYPE_BASE_GRAPHICS);
                this->RequestContentList(CONTENT_TYPE_BASE_MUSIC);
                this->RequestContentList(CONTENT_TYPE_BASE_SOUNDS);
                this->RequestContentList(CONTENT_TYPE_SCENARIO);
                this->RequestContentList(CONTENT_TYPE_HEIGHTMAP);
                this->RequestContentList(CONTENT_TYPE_AI);
                this->RequestContentList(CONTENT_TYPE_AI_LIBRARY);
                this->RequestContentList(CONTENT_TYPE_GAME);
                this->RequestContentList(CONTENT_TYPE_GAME_LIBRARY);
                this->RequestContentList(CONTENT_TYPE_NEWGRF);
                return;
        }

        this->Connect();

        auto p = std::make_unique<Packet>(this, PACKET_CONTENT_CLIENT_INFO_LIST);
        p->Send_uint8 ((uint8_t)type);
        p->Send_uint32(0xffffffff);
        p->Send_uint8 (1);
        p->Send_string("vanilla");
        p->Send_string(_openttd_content_version);

        /* Patchpacks can extend the list with one. In BaNaNaS metadata you can
         * add a branch in the 'compatibility' list, to filter on this. If you want
         * your patchpack to be mentioned in the BaNaNaS web-interface, create an
         * issue on https://github.com/OpenTTD/bananas-api asking for this.

        p->Send_string("patchpack"); // Or what-ever the name of your patchpack is.
        p->Send_string(_openttd_content_version_patchpack);

         */

        this->SendPacket(std::move(p));
}

/**
 * Request the content list for a given number of content IDs.
 * @param count The number of IDs to request.
 * @param content_ids The unique identifiers of the content to request information about.
 */
void ClientNetworkContentSocketHandler::RequestContentList(uint count, const ContentID *content_ids)
{
        this->Connect();

        while (count > 0) {
                /* We can "only" send a limited number of IDs in a single packet.
                 * A packet begins with the packet size and a byte for the type.
                 * Then this packet adds a uint16_t for the count in this packet.
                 * The rest of the packet can be used for the IDs. */
                uint p_count = std::min<uint>(count, (TCP_MTU - sizeof(PacketSize) - sizeof(uint8_t) - sizeof(uint16_t)) / sizeof(uint32_t));

                auto p = std::make_unique<Packet>(this, PACKET_CONTENT_CLIENT_INFO_ID, TCP_MTU);
                p->Send_uint16(p_count);

                for (uint i = 0; i < p_count; i++) {
                        p->Send_uint32(content_ids[i]);
                }

                this->SendPacket(std::move(p));
                count -= p_count;
                content_ids += p_count;
        }
}

/**
 * Request the content list for a list of content.
 * @param cv List with unique IDs and MD5 checksums.
 * @param send_md5sum Whether we want a MD5 checksum matched set of files or not.
 */
void ClientNetworkContentSocketHandler::RequestContentList(ContentVector *cv, bool send_md5sum)
{
        if (cv == nullptr) return;

        this->Connect();

        assert(cv->size() < 255);
        assert(cv->size() < (TCP_MTU - sizeof(PacketSize) - sizeof(uint8_t) - sizeof(uint8_t)) /
                        (sizeof(uint8_t) + sizeof(uint32_t) + (send_md5sum ? MD5_HASH_BYTES : 0)));

        auto p = std::make_unique<Packet>(this, send_md5sum ? PACKET_CONTENT_CLIENT_INFO_EXTID_MD5 : PACKET_CONTENT_CLIENT_INFO_EXTID, TCP_MTU);
        p->Send_uint8((uint8_t)cv->size());

        for (const ContentInfo *ci : *cv) {
                p->Send_uint8((uint8_t)ci->type);
                p->Send_uint32(ci->unique_id);
                if (!send_md5sum) continue;
                p->Send_bytes(ci->md5sum);
        }

        this->SendPacket(std::move(p));

        for (ContentInfo *ci : *cv) {
                bool found = false;
                for (ContentInfo *ci2 : this->infos) {
                        if (ci->type == ci2->type && ci->unique_id == ci2->unique_id &&
                                        (!send_md5sum || ci->md5sum == ci2->md5sum)) {
                                found = true;
                                break;
                        }
                }
                if (!found) {
                        this->infos.push_back(ci);
                } else {
                        delete ci;
                }
        }
}

/**
 * Actually begin downloading the content we selected.
 * @param[out] files The number of files we are going to download.
 * @param[out] bytes The number of bytes we are going to download.
 * @param fallback Whether to use the fallback or not.
 */
void ClientNetworkContentSocketHandler::DownloadSelectedContent(uint &files, uint &bytes, bool fallback)
{
        bytes = 0;

        ContentIDList content;
        for (const ContentInfo *ci : this->infos) {
                if (!ci->IsSelected() || ci->state == ContentInfo::ALREADY_HERE) continue;

                content.push_back(ci->id);
                bytes += ci->filesize;
        }

        files = (uint)content.size();

        /* If there's nothing to download, do nothing. */
        if (files == 0) return;

        this->isCancelled = false;

        if (fallback) {
                this->DownloadSelectedContentFallback(content);
        } else {
                this->DownloadSelectedContentHTTP(content);
        }
}

/**
 * Initiate downloading the content over HTTP.
 * @param content The content to download.
 */
void ClientNetworkContentSocketHandler::DownloadSelectedContentHTTP(const ContentIDList &content)
{
        std::string content_request;
        for (const ContentID &id : content) {
                content_request += std::to_string(id) + "\n";
        }

        this->http_response_index = -1;

        NetworkHTTPSocketHandler::Connect(NetworkContentMirrorUriString(), this, content_request);
}

/**
 * Initiate downloading the content over the fallback protocol.
 * @param content The content to download.
 */
void ClientNetworkContentSocketHandler::DownloadSelectedContentFallback(const ContentIDList &content)
{
        uint count = (uint)content.size();
        const ContentID *content_ids = content.data();
        this->Connect();

        while (count > 0) {
                /* We can "only" send a limited number of IDs in a single packet.
                 * A packet begins with the packet size and a byte for the type.
                 * Then this packet adds a uint16_t for the count in this packet.
                 * The rest of the packet can be used for the IDs. */
                uint p_count = std::min<uint>(count, (TCP_MTU - sizeof(PacketSize) - sizeof(uint8_t) - sizeof(uint16_t)) / sizeof(uint32_t));

                auto p = std::make_unique<Packet>(this, PACKET_CONTENT_CLIENT_CONTENT, TCP_MTU);
                p->Send_uint16(p_count);

                for (uint i = 0; i < p_count; i++) {
                        p->Send_uint32(content_ids[i]);
                }

                this->SendPacket(std::move(p));
                count -= p_count;
                content_ids += p_count;
        }
}

/**
 * Determine the full filename of a piece of content information
 * @param ci         the information to get the filename from
 * @param compressed should the filename end with .gz?
 * @return a statically allocated buffer with the filename or
 *         nullptr when no filename could be made.
 */
static std::string GetFullFilename(const ContentInfo *ci, bool compressed)
{
        Subdirectory dir = GetContentInfoSubDir(ci->type);
        if (dir == NO_DIRECTORY) return {};

        std::string buf = FioGetDirectory(SP_AUTODOWNLOAD_DIR, dir);
        buf += ci->filename;
        buf += compressed ? ".tar.gz" : ".tar";

        return buf;
}

/**
 * Gunzip a given file and remove the .gz if successful.
 * @param ci container with filename
 * @return true if the gunzip completed
 */
static bool GunzipFile(const ContentInfo *ci)
{
#if defined(WITH_ZLIB)
        bool ret = true;

        /* Need to open the file with fopen() to support non-ASCII on Windows. */
        auto ftmp = FileHandle::Open(GetFullFilename(ci, true), "rb");
        if (!ftmp.has_value()) return false;
        /* Duplicate the handle, and close the FILE*, to avoid double-closing the handle later. */
        int fdup = dup(fileno(*ftmp));
        gzFile fin = gzdopen(fdup, "rb");
        ftmp.reset();

        auto fout = FileHandle::Open(GetFullFilename(ci, false), "wb");

        if (fin == nullptr || !fout.has_value()) {
                ret = false;
        } else {
                uint8_t buff[8192];
                for (;;) {
                        int read = gzread(fin, buff, sizeof(buff));
                        if (read == 0) {
                                /* If gzread() returns 0, either the end-of-file has been
                                 * reached or an underlying read error has occurred.
                                 *
                                 * gzeof() can't be used, because:
                                 * 1.2.5 - it is safe, 1 means 'everything was OK'
                                 * 1.2.3.5, 1.2.4 - 0 or 1 is returned 'randomly'
                                 * 1.2.3.3 - 1 is returned for truncated archive
                                 *
                                 * So we use gzerror(). When proper end of archive
                                 * has been reached, then:
                                 * errnum == Z_STREAM_END in 1.2.3.3,
                                 * errnum == 0 in 1.2.4 and 1.2.5 */
                                int errnum;
                                gzerror(fin, &errnum);
                                if (errnum != 0 && errnum != Z_STREAM_END) ret = false;
                                break;
                        }
                        if (read < 0 || static_cast<size_t>(read) != fwrite(buff, 1, read, *fout)) {
                                /* If gzread() returns -1, there was an error in archive */
                                ret = false;
                                break;
                        }
                        /* DO NOT DO THIS! It will fail to detect broken archive with 1.2.3.3!
                         * if (read < sizeof(buff)) break; */
                }
        }

        if (fin != nullptr) {
                gzclose(fin);
        } else if (fdup != -1) {
                /* Failing gzdopen does not close the passed file descriptor. */
                close(fdup);
        }

        return ret;
#else
        NOT_REACHED();
#endif /* defined(WITH_ZLIB) */
}

/**
 * Simple wrapper around fwrite to be able to pass it to Packet's TransferOut.
 * @param file   The file to write data to.
 * @param buffer The buffer to write to the file.
 * @param amount The number of bytes to write.
 * @return The number of bytes that were written.
 */
static inline ssize_t TransferOutFWrite(std::optional<FileHandle> &file, const char *buffer, size_t amount)
{
        return fwrite(buffer, 1, amount, *file);
}

bool ClientNetworkContentSocketHandler::Receive_SERVER_CONTENT(Packet &p)
{
        if (!this->curFile.has_value()) {
                delete this->curInfo;
                /* When we haven't opened a file this must be our first packet with metadata. */
                this->curInfo = new ContentInfo;
                this->curInfo->type     = (ContentType)p.Recv_uint8();
                this->curInfo->id       = (ContentID)p.Recv_uint32();
                this->curInfo->filesize = p.Recv_uint32();
                this->curInfo->filename = p.Recv_string(NETWORK_CONTENT_FILENAME_LENGTH);

                if (!this->BeforeDownload()) {
                        this->CloseConnection();
                        return false;
                }
        } else {
                /* We have a file opened, thus are downloading internal content */
                size_t toRead = p.RemainingBytesToTransfer();
                if (toRead != 0 && static_cast<size_t>(p.TransferOut(TransferOutFWrite, std::ref(this->curFile))) != toRead) {
                        CloseWindowById(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_CONTENT_DOWNLOAD);
                        ShowErrorMessage(STR_CONTENT_ERROR_COULD_NOT_DOWNLOAD, STR_CONTENT_ERROR_COULD_NOT_DOWNLOAD_FILE_NOT_WRITABLE, WL_ERROR);
                        this->CloseConnection();
                        this->curFile.reset();

                        return false;
                }

                this->OnDownloadProgress(this->curInfo, (int)toRead);

                if (toRead == 0) this->AfterDownload();
        }

        return true;
}

/**
 * Handle the opening of the file before downloading.
 * @return false on any error.
 */
bool ClientNetworkContentSocketHandler::BeforeDownload()
{
        if (!this->curInfo->IsValid()) {
                delete this->curInfo;
                this->curInfo = nullptr;
                return false;
        }

        if (this->curInfo->filesize != 0) {
                /* The filesize is > 0, so we are going to download it */
                std::string filename = GetFullFilename(this->curInfo, true);
                if (filename.empty() || !(this->curFile = FileHandle::Open(filename, "wb")).has_value()) {
                        /* Unless that fails of course... */
                        CloseWindowById(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_CONTENT_DOWNLOAD);
                        ShowErrorMessage(STR_CONTENT_ERROR_COULD_NOT_DOWNLOAD, STR_CONTENT_ERROR_COULD_NOT_DOWNLOAD_FILE_NOT_WRITABLE, WL_ERROR);
                        return false;
                }
        }
        return true;
}

/**
 * Handle the closing and extracting of a file after
 * downloading it has been done.
 */
void ClientNetworkContentSocketHandler::AfterDownload()
{
        /* We read nothing; that's our marker for end-of-stream.
         * Now gunzip the tar and make it known. */
        this->curFile.reset();

        if (GunzipFile(this->curInfo)) {
                FioRemove(GetFullFilename(this->curInfo, true));

                Subdirectory sd = GetContentInfoSubDir(this->curInfo->type);
                if (sd == NO_DIRECTORY) NOT_REACHED();

                TarScanner ts;
                std::string fname = GetFullFilename(this->curInfo, false);
                ts.AddFile(sd, fname);

                if (this->curInfo->type == CONTENT_TYPE_BASE_MUSIC) {
                        /* Music can't be in a tar. So extract the tar! */
                        ExtractTar(fname, BASESET_DIR);
                        FioRemove(fname);
                }

#ifdef __EMSCRIPTEN__
                EM_ASM(if (window["openttd_syncfs"]) openttd_syncfs());
#endif

                this->OnDownloadComplete(this->curInfo->id);
        } else {
                ShowErrorMessage(STR_CONTENT_ERROR_COULD_NOT_EXTRACT, INVALID_STRING_ID, WL_ERROR);
        }
}

bool ClientNetworkContentSocketHandler::IsCancelled() const
{
        return this->isCancelled;
}

/* Also called to just clean up the mess. */
void ClientNetworkContentSocketHandler::OnFailure()
{
        this->http_response.clear();
        this->http_response.shrink_to_fit();
        this->http_response_index = -2;

        if (this->curFile.has_value()) {
                this->OnDownloadProgress(this->curInfo, -1);

                this->curFile.reset();
        }

        /* If we fail, download the rest via the 'old' system. */
        if (!this->isCancelled) {
                uint files, bytes;

                this->DownloadSelectedContent(files, bytes, true);
        }
}

void ClientNetworkContentSocketHandler::OnReceiveData(std::unique_ptr<char[]> data, size_t length)
{
        assert(data.get() == nullptr || length != 0);

        /* Ignore any latent data coming from a connection we closed. */
        if (this->http_response_index == -2) {
                return;
        }

        if (this->http_response_index == -1) {
                if (data != nullptr) {
                        /* Append the rest of the response. */
                        this->http_response.insert(this->http_response.end(), data.get(), data.get() + length);
                        return;
                } else {
                        /* Make sure the response is properly terminated. */
                        this->http_response.push_back('\0');

                        /* And prepare for receiving the rest of the data. */
                        this->http_response_index = 0;
                }
        }

        if (data != nullptr) {
                /* We have data, so write it to the file. */
                if (fwrite(data.get(), 1, length, *this->curFile) != length) {
                        /* Writing failed somehow, let try via the old method. */
                        this->OnFailure();
                } else {
                        /* Just received the data. */
                        this->OnDownloadProgress(this->curInfo, (int)length);
                }

                /* Nothing more to do now. */
                return;
        }

        if (this->curFile.has_value()) {
                /* We've finished downloading a file. */
                this->AfterDownload();
        }

        if ((uint)this->http_response_index >= this->http_response.size()) {
                /* It's not a real failure, but if there's
                 * nothing more to download it helps with
                 * cleaning up the stuff we allocated. */
                this->OnFailure();
                return;
        }

        delete this->curInfo;
        /* When we haven't opened a file this must be our first packet with metadata. */
        this->curInfo = new ContentInfo;

/** Check p for not being null and return calling OnFailure if that's not the case. */
#define check_not_null(p) { if ((p) == nullptr) { this->OnFailure(); return; } }
/** Check p for not being null and then terminate, or return calling OnFailure. */
#define check_and_terminate(p) { check_not_null(p); *(p) = '\0'; }

        for (;;) {
                char *str = this->http_response.data() + this->http_response_index;
                char *p = strchr(str, '\n');
                check_and_terminate(p);

                /* Update the index for the next one */
                this->http_response_index += (int)strlen(str) + 1;

                /* Read the ID */
                p = strchr(str, ',');
                check_and_terminate(p);
                this->curInfo->id = (ContentID)atoi(str);

                /* Read the type */
                str = p + 1;
                p = strchr(str, ',');
                check_and_terminate(p);
                this->curInfo->type = (ContentType)atoi(str);

                /* Read the file size */
                str = p + 1;
                p = strchr(str, ',');
                check_and_terminate(p);
                this->curInfo->filesize = atoi(str);

                /* Read the URL */
                str = p + 1;
                /* Is it a fallback URL? If so, just continue with the next one. */
                if (strncmp(str, "ottd", 4) == 0) {
                        if ((uint)this->http_response_index >= this->http_response.size()) {
                                /* Have we gone through all lines? */
                                this->OnFailure();
                                return;
                        }
                        continue;
                }

                p = strrchr(str, '/');
                check_not_null(p);
                p++; // Start after the '/'

                std::string filename = p;
                /* Remove the extension from the string. */
                for (uint i = 0; i < 2; i++) {
                        auto pos = filename.find_last_of('.');
                        if (pos == std::string::npos) {
                                this->OnFailure();
                                return;
                        }
                        filename.erase(pos);
                }

                /* Copy the string, without extension, to the filename. */
                this->curInfo->filename = std::move(filename);

                /* Request the next file. */
                if (!this->BeforeDownload()) {
                        this->OnFailure();
                        return;
                }

                NetworkHTTPSocketHandler::Connect(str, this);
                return;
        }

#undef check
#undef check_and_terminate
}

/**
 * Create a socket handler to handle the connection.
 */
ClientNetworkContentSocketHandler::ClientNetworkContentSocketHandler() :
        NetworkContentSocketHandler(),
        http_response_index(-2),
        curFile(std::nullopt),
        curInfo(nullptr),
        isConnecting(false),
        isCancelled(false)
{
        this->lastActivity = std::chrono::steady_clock::now();
}

/** Clear up the mess ;) */
ClientNetworkContentSocketHandler::~ClientNetworkContentSocketHandler()
{
        delete this->curInfo;

        for (ContentInfo *ci : this->infos) delete ci;
}

/** Connect to the content server. */
class NetworkContentConnecter : public TCPConnecter {
public:
        /**
         * Initiate the connecting.
         * @param address The address of the server.
         */
        NetworkContentConnecter(const std::string &connection_string) : TCPConnecter(connection_string, NETWORK_CONTENT_SERVER_PORT) {}

        void OnFailure() override
        {
                _network_content_client.isConnecting = false;
                _network_content_client.OnConnect(false);
        }

        void OnConnect(SOCKET s) override
        {
                assert(_network_content_client.sock == INVALID_SOCKET);
                _network_content_client.lastActivity = std::chrono::steady_clock::now();
                _network_content_client.isConnecting = false;
                _network_content_client.sock = s;
                _network_content_client.Reopen();
                _network_content_client.OnConnect(true);
        }
};

/**
 * Connect with the content server.
 */
void ClientNetworkContentSocketHandler::Connect()
{
        if (this->sock != INVALID_SOCKET || this->isConnecting) return;

        this->isCancelled = false;
        this->isConnecting = true;

        TCPConnecter::Create<NetworkContentConnecter>(NetworkContentServerConnectionString());
}

/**
 * Disconnect from the content server.
 */
NetworkRecvStatus ClientNetworkContentSocketHandler::CloseConnection(bool)
{
        NetworkContentSocketHandler::CloseConnection();

        if (this->sock == INVALID_SOCKET) return NETWORK_RECV_STATUS_OKAY;

        this->CloseSocket();
        this->OnDisconnect();

        return NETWORK_RECV_STATUS_OKAY;
}

/**
 * Cancel the current download.
 */
void ClientNetworkContentSocketHandler::Cancel(void)
{
        this->isCancelled = true;
        this->CloseConnection();
}

/**
 * Check whether we received/can send some data from/to the content server and
 * when that's the case handle it appropriately
 */
void ClientNetworkContentSocketHandler::SendReceive()
{
        if (this->sock == INVALID_SOCKET || this->isConnecting) return;

        /* Close the connection to the content server after inactivity; there can still be downloads pending via HTTP. */
        if (std::chrono::steady_clock::now() > this->lastActivity + IDLE_TIMEOUT) {
                this->CloseConnection();
                return;
        }

        if (this->CanSendReceive()) {
                if (this->ReceivePackets()) {
                        /* Only update activity once a packet is received, instead of every time we try it. */
                        this->lastActivity = std::chrono::steady_clock::now();
                }
        }

        this->SendPackets();
}

/**
 * Download information of a given Content ID if not already tried
 * @param cid the ID to try
 */
void ClientNetworkContentSocketHandler::DownloadContentInfo(ContentID cid)
{
        /* When we tried to download it already, don't try again */
        if (std::ranges::find(this->requested, cid) != this->requested.end()) return;

        this->requested.push_back(cid);
        this->RequestContentList(1, &cid);
}

/**
 * Get the content info based on a ContentID
 * @param cid the ContentID to search for
 * @return the ContentInfo or nullptr if not found
 */
ContentInfo *ClientNetworkContentSocketHandler::GetContent(ContentID cid) const
{
        for (ContentInfo *ci : this->infos) {
                if (ci->id == cid) return ci;
        }
        return nullptr;
}


/**
 * Select a specific content id.
 * @param cid the content ID to select
 */
void ClientNetworkContentSocketHandler::Select(ContentID cid)
{
        ContentInfo *ci = this->GetContent(cid);
        if (ci == nullptr || ci->state != ContentInfo::UNSELECTED) return;

        ci->state = ContentInfo::SELECTED;
        this->CheckDependencyState(ci);
}

/**
 * Unselect a specific content id.
 * @param cid the content ID to deselect
 */
void ClientNetworkContentSocketHandler::Unselect(ContentID cid)
{
        ContentInfo *ci = this->GetContent(cid);
        if (ci == nullptr || !ci->IsSelected()) return;

        ci->state = ContentInfo::UNSELECTED;
        this->CheckDependencyState(ci);
}

/** Select everything we can select */
void ClientNetworkContentSocketHandler::SelectAll()
{
        for (ContentInfo *ci : this->infos) {
                if (ci->state == ContentInfo::UNSELECTED) {
                        ci->state = ContentInfo::SELECTED;
                        this->CheckDependencyState(ci);
                }
        }
}

/** Select everything that's an update for something we've got */
void ClientNetworkContentSocketHandler::SelectUpgrade()
{
        for (ContentInfo *ci : this->infos) {
                if (ci->state == ContentInfo::UNSELECTED && ci->upgrade) {
                        ci->state = ContentInfo::SELECTED;
                        this->CheckDependencyState(ci);
                }
        }
}

/** Unselect everything that we've not downloaded so far. */
void ClientNetworkContentSocketHandler::UnselectAll()
{
        for (ContentInfo *ci : this->infos) {
                if (ci->IsSelected() && ci->state != ContentInfo::ALREADY_HERE) ci->state = ContentInfo::UNSELECTED;
        }
}

/** Toggle the state of a content info and check its dependencies */
void ClientNetworkContentSocketHandler::ToggleSelectedState(const ContentInfo *ci)
{
        switch (ci->state) {
                case ContentInfo::SELECTED:
                case ContentInfo::AUTOSELECTED:
                        this->Unselect(ci->id);
                        break;

                case ContentInfo::UNSELECTED:
                        this->Select(ci->id);
                        break;

                default:
                        break;
        }
}

/**
 * Reverse lookup the dependencies of (direct) parents over a given child.
 * @param parents list to store all parents in (is not cleared)
 * @param child   the child to search the parents' dependencies for
 */
void ClientNetworkContentSocketHandler::ReverseLookupDependency(ConstContentVector &parents, const ContentInfo *child) const
{
        auto range = this->reverse_dependency_map.equal_range(child->id);

        for (auto iter = range.first; iter != range.second; ++iter) {
                parents.push_back(GetContent(iter->second));
        }
}

/**
 * Reverse lookup the dependencies of all parents over a given child.
 * @param tree  list to store all parents in (is not cleared)
 * @param child the child to search the parents' dependencies for
 */
void ClientNetworkContentSocketHandler::ReverseLookupTreeDependency(ConstContentVector &tree, const ContentInfo *child) const
{
        tree.push_back(child);

        /* First find all direct parents. We can't use the "normal" iterator as
         * we are including stuff into the vector and as such the vector's data
         * store can be reallocated (and thus move), which means out iterating
         * pointer gets invalid. So fall back to the indices. */
        for (uint i = 0; i < tree.size(); i++) {
                ConstContentVector parents;
                this->ReverseLookupDependency(parents, tree[i]);

                for (const ContentInfo *ci : parents) {
                        include(tree, ci);
                }
        }
}

/**
 * Check the dependencies (recursively) of this content info
 * @param ci the content info to check the dependencies of
 */
void ClientNetworkContentSocketHandler::CheckDependencyState(ContentInfo *ci)
{
        if (ci->IsSelected() || ci->state == ContentInfo::ALREADY_HERE) {
                /* Selection is easy; just walk all children and set the
                 * autoselected state. That way we can see what we automatically
                 * selected and thus can unselect when a dependency is removed. */
                for (auto &dependency : ci->dependencies) {
                        ContentInfo *c = this->GetContent(dependency);
                        if (c == nullptr) {
                                this->DownloadContentInfo(dependency);
                        } else if (c->state == ContentInfo::UNSELECTED) {
                                c->state = ContentInfo::AUTOSELECTED;
                                this->CheckDependencyState(c);
                        }
                }
                return;
        }

        if (ci->state != ContentInfo::UNSELECTED) return;

        /* For unselection we need to find the parents of us. We need to
         * unselect them. After that we unselect all children that we
         * depend on and are not used as dependency for us, but only when
         * we automatically selected them. */
        ConstContentVector parents;
        this->ReverseLookupDependency(parents, ci);
        for (const ContentInfo *c : parents) {
                if (!c->IsSelected()) continue;

                this->Unselect(c->id);
        }

        for (auto &dependency : ci->dependencies) {
                const ContentInfo *c = this->GetContent(dependency);
                if (c == nullptr) {
                        DownloadContentInfo(dependency);
                        continue;
                }
                if (c->state != ContentInfo::AUTOSELECTED) continue;

                /* Only unselect when WE are the only parent. */
                parents.clear();
                this->ReverseLookupDependency(parents, c);

                /* First check whether anything depends on us */
                int sel_count = 0;
                bool force_selection = false;
                for (const ContentInfo *parent_ci : parents) {
                        if (parent_ci->IsSelected()) sel_count++;
                        if (parent_ci->state == ContentInfo::SELECTED) force_selection = true;
                }
                if (sel_count == 0) {
                        /* Nothing depends on us */
                        this->Unselect(c->id);
                        continue;
                }
                /* Something manually selected depends directly on us */
                if (force_selection) continue;

                /* "Flood" search to find all items in the dependency graph*/
                parents.clear();
                this->ReverseLookupTreeDependency(parents, c);

                /* Is there anything that is "force" selected?, if so... we're done. */
                for (const ContentInfo *parent_ci : parents) {
                        if (parent_ci->state != ContentInfo::SELECTED) continue;

                        force_selection = true;
                        break;
                }

                /* So something depended directly on us */
                if (force_selection) continue;

                /* Nothing depends on us, mark the whole graph as unselected.
                 * After that's done run over them once again to test their children
                 * to unselect. Don't do it immediately because it'll do exactly what
                 * we're doing now. */
                for (const ContentInfo *parent : parents) {
                        if (parent->state == ContentInfo::AUTOSELECTED) this->Unselect(parent->id);
                }
                for (const ContentInfo *parent : parents) {
                        this->CheckDependencyState(this->GetContent(parent->id));
                }
        }
}

/** Clear all downloaded content information. */
void ClientNetworkContentSocketHandler::Clear()
{
        for (ContentInfo *c : this->infos) delete c;

        this->infos.clear();
        this->requested.clear();
        this->reverse_dependency_map.clear();
}

/*** CALLBACK ***/

void ClientNetworkContentSocketHandler::OnConnect(bool success)
{
        for (size_t i = 0; i < this->callbacks.size(); /* nothing */) {
                ContentCallback *cb = this->callbacks[i];
                /* the callback may remove itself from this->callbacks */
                cb->OnConnect(success);
                if (i != this->callbacks.size() && this->callbacks[i] == cb) i++;
        }
}

void ClientNetworkContentSocketHandler::OnDisconnect()
{
        for (size_t i = 0; i < this->callbacks.size(); /* nothing */) {
                ContentCallback *cb = this->callbacks[i];
                cb->OnDisconnect();
                if (i != this->callbacks.size() && this->callbacks[i] == cb) i++;
        }
}

void ClientNetworkContentSocketHandler::OnReceiveContentInfo(const ContentInfo *ci)
{
        for (size_t i = 0; i < this->callbacks.size(); /* nothing */) {
                ContentCallback *cb = this->callbacks[i];
                /* the callback may add items and/or remove itself from this->callbacks */
                cb->OnReceiveContentInfo(ci);
                if (i != this->callbacks.size() && this->callbacks[i] == cb) i++;
        }
}

void ClientNetworkContentSocketHandler::OnDownloadProgress(const ContentInfo *ci, int bytes)
{
        for (size_t i = 0; i < this->callbacks.size(); /* nothing */) {
                ContentCallback *cb = this->callbacks[i];
                cb->OnDownloadProgress(ci, bytes);
                if (i != this->callbacks.size() && this->callbacks[i] == cb) i++;
        }
}

void ClientNetworkContentSocketHandler::OnDownloadComplete(ContentID cid)
{
        ContentInfo *ci = this->GetContent(cid);
        if (ci != nullptr) {
                ci->state = ContentInfo::ALREADY_HERE;
        }

        for (size_t i = 0; i < this->callbacks.size(); /* nothing */) {
                ContentCallback *cb = this->callbacks[i];
                /* the callback may remove itself from this->callbacks */
                cb->OnDownloadComplete(cid);
                if (i != this->callbacks.size() && this->callbacks[i] == cb) i++;
        }
}