#include "td-client.h"
#include "config.h"

class UpdateHandler {
public:
    UpdateHandler(PurpleTdClient *owner) : m_owner(owner) {}

    void operator()(td::td_api::updateAuthorizationState &update_authorization_state) const {
        purple_debug_misc(config::pluginId, "Incoming update: authorization state\n");
        m_owner->m_lastAuthState = update_authorization_state.authorization_state_->get_id();
        td::td_api::downcast_call(*update_authorization_state.authorization_state_, *m_owner->m_authUpdateHandler);
    }

    void operator()(td::td_api::updateConnectionState &connectionUpdate) {
        purple_debug_misc(config::pluginId, "Incoming update: connection state\n");
        if (connectionUpdate.state_ && (connectionUpdate.state_->get_id() == td::td_api::connectionStateReady::ID)) {
            g_idle_add(PurpleTdClient::connectionReady, m_owner);
        }
    }

    void operator()(auto &update) const {
        purple_debug_misc(config::pluginId, "Incoming update: ignorig ID=%d\n", update.get_id());
    }
private:
    PurpleTdClient *m_owner;
};

class AuthUpdateHandler {
public:
    AuthUpdateHandler(PurpleTdClient *owner) : m_owner(owner) {}

    void operator()(td::td_api::authorizationStateWaitEncryptionKey &) const {
        purple_debug_misc(config::pluginId, "Authorization state update: encriytion key requested\n");
        m_owner->sendQuery(td::td_api::make_object<td::td_api::checkDatabaseEncryptionKey>(""), &PurpleTdClient::authResponse);
    }

    void operator()(td::td_api::authorizationStateWaitTdlibParameters &) const {
        purple_debug_misc(config::pluginId, "Authorization state update: TDLib parameters requested\n");
        m_owner->sendTdlibParameters();
    }

    void operator()(td::td_api::authorizationStateWaitPhoneNumber &) const {
        purple_debug_misc(config::pluginId, "Authorization state update: phone number requested\n");
        m_owner->sendPhoneNumber();
    }

    void operator()(td::td_api::authorizationStateWaitCode &codeState) const {
        purple_debug_misc(config::pluginId, "Authorization state update: authentication code requested\n");
        m_owner->m_authCodeInfo = std::move(codeState.code_info_);
        g_idle_add(PurpleTdClient::requestAuthCode, m_owner);
    }

    void operator()(td::td_api::authorizationStateReady &) const {
        purple_debug_misc(config::pluginId, "Authorization state update: ready\n");
    }

    void operator()(auto &update) const {
        purple_debug_misc(config::pluginId, "Authorization state update: ignorig ID=%d\n", update.get_id());
    }
private:
    PurpleTdClient *m_owner;
};

PurpleTdClient::PurpleTdClient(PurpleAccount *acct)
{
    m_account           = acct;
    m_updateHandler     = std::make_unique<UpdateHandler>(this);
    m_authUpdateHandler = std::make_unique<AuthUpdateHandler>(this);
}

PurpleTdClient::~PurpleTdClient()
{
    m_stopThread = true;
    m_client->send({UINT64_MAX, td::td_api::make_object<td::td_api::close>()});
    m_pollThread.join();
}

void PurpleTdClient::setLogLevel(int level)
{
    // Why not just call setLogVerbosityLevel? No idea!
    td::Client::execute({0, td::td_api::make_object<td::td_api::setLogVerbosityLevel>(level)});
}

void PurpleTdClient::startLogin()
{
#if !GLIB_CHECK_VERSION(2, 32, 0)
    // GLib threading system is automaticaly initialized since 2.32.
    // For earlier versions, it have to be initialized before calling any
    // Glib or GTK+ functions.
    if (!g_thread_supported())
        g_thread_init(NULL);
#endif

    m_client = std::make_unique<td::Client>();
    if (!m_pollThread.joinable()) {
        m_lastQueryId = 0;
        m_stopThread = false;
        m_pollThread = std::thread([this]() { pollThreadLoop(); });
    }
}

void PurpleTdClient::pollThreadLoop()
{
    while (!m_stopThread)
        processResponse(m_client->receive(1));
}

void PurpleTdClient::processResponse(td::Client::Response response)
{
    if (response.object) {
        if (response.id == 0) {
            purple_debug_misc(config::pluginId, "Incoming update\n");
            td::td_api::downcast_call(*response.object, *m_updateHandler);
        } else {
            ResponseCb callback = nullptr;
            {
                std::unique_lock<std::mutex> dataLock(m_dataMutex);
                auto it = m_responseHandlers.find(response.id);
                if (it != m_responseHandlers.end()) {
                    callback = it->second;
                    m_responseHandlers.erase(it);
                }
            }
            if (callback)
                (this->*callback)(response.id, std::move(response.object));
        }
    } else
        purple_debug_misc(config::pluginId, "Response id %lu timed out or something\n", response.id);
}

void PurpleTdClient::sendTdlibParameters()
{
    auto parameters = td::td_api::make_object<td::td_api::tdlibParameters>();
    const char *username = purple_account_get_username(m_account);
    parameters->database_directory_ = std::string(purple_user_dir()) + G_DIR_SEPARATOR_S +
                                      config::configSubdir + G_DIR_SEPARATOR_S + username;
    purple_debug_misc(config::pluginId, "Account %s using database directory %s\n",
                      username, parameters->database_directory_.c_str());
    parameters->use_message_database_ = true;
    parameters->use_secret_chats_ = true;
    parameters->api_id_ = 94575;
    parameters->api_hash_ = "a3406de8d171bb422bb6ddf3bbd800e2";
    parameters->system_language_code_ = "en";
    parameters->device_model_ = "Desktop";
    parameters->system_version_ = "Unknown";
    parameters->application_version_ = "1.0";
    parameters->enable_storage_optimizer_ = true;
    sendQuery(td::td_api::make_object<td::td_api::setTdlibParameters>(std::move(parameters)),
              &PurpleTdClient::authResponse);
}

void PurpleTdClient::sendPhoneNumber()
{
    const char *number = purple_account_get_username(m_account);
    sendQuery(td::td_api::make_object<td::td_api::setAuthenticationPhoneNumber>(number, nullptr),
              &PurpleTdClient::authResponse);
}

static std::string getAuthCodeDesc(const td::td_api::AuthenticationCodeType &codeType)
{
    switch (codeType.get_id()) {
    case td::td_api::authenticationCodeTypeTelegramMessage::ID:
        return "Telegram message (length: " +
               std::to_string(static_cast<const td::td_api::authenticationCodeTypeTelegramMessage &>(codeType).length_) +
               ")";
    case td::td_api::authenticationCodeTypeSms::ID:
        return "SMS (length: " +
               std::to_string(static_cast<const td::td_api::authenticationCodeTypeSms &>(codeType).length_) +
               ")";
    case td::td_api::authenticationCodeTypeCall::ID:
        return "Phone call (length: " +
               std::to_string(static_cast<const td::td_api::authenticationCodeTypeCall &>(codeType).length_) +
               ")";
    case td::td_api::authenticationCodeTypeFlashCall::ID:
        return "Poor man's phone call (pattern: " +
               static_cast<const td::td_api::authenticationCodeTypeFlashCall &>(codeType).pattern_ +
               ")";
    default:
        return "Pigeon post";
    }
}

int PurpleTdClient::requestAuthCode(gpointer user_data)
{
    PurpleTdClient *self = static_cast<PurpleTdClient *>(user_data);
    std::string message = "Enter authentication code\n";

    if (self->m_authCodeInfo) {
        if (self->m_authCodeInfo->type_)
            message += "Code sent via: " + getAuthCodeDesc(*self->m_authCodeInfo->type_) + "\n";
        if (self->m_authCodeInfo->next_type_)
            message += "Next code will be: " + getAuthCodeDesc(*self->m_authCodeInfo->next_type_) + "\n";
    }

    if (!purple_request_input (purple_account_get_connection(self->m_account),
                               (char *)"Login code",
                               message.c_str(),
                               NULL, // secondary message
                               NULL, // default value
                               FALSE, // multiline input
                               FALSE, // masked input
                               (char *)"the code",
                               (char *)"OK", G_CALLBACK(requestCodeEntered),
                               (char *)"Cancel", G_CALLBACK(requestCodeCancelled),
                               self->m_account,
                               NULL, // buddy
                               NULL, // conversation
                               self))
    {
        purple_connection_set_state (purple_account_get_connection(self->m_account), PURPLE_CONNECTED);
        PurpleConversation *conv = purple_conversation_new (PURPLE_CONV_TYPE_IM, self->m_account, "Telegram");
        purple_conversation_write (conv, "Telegram",
            "Authentication code needs to be entered but this libpurple won't cooperate",
            (PurpleMessageFlags)(PURPLE_MESSAGE_RECV | PURPLE_MESSAGE_SYSTEM), 0);
    }

    return FALSE; // This idle handler will not be called again
}

void PurpleTdClient::requestCodeEntered(PurpleTdClient *self, const gchar *code)
{
    purple_debug_misc(config::pluginId, "Authentication code entered: '%s'\n", code);
    self->sendQuery(td::td_api::make_object<td::td_api::checkAuthenticationCode>(code),
                    &PurpleTdClient::authResponse);
}

void PurpleTdClient::requestCodeCancelled(PurpleTdClient *self)
{
    purple_connection_error(purple_account_get_connection(self->m_account),
                            "Authentication code required");
}

void PurpleTdClient::sendQuery(td::td_api::object_ptr<td::td_api::Function> f, ResponseCb handler)
{
    uint64_t queryId = ++m_lastQueryId;
    purple_debug_misc(config::pluginId, "Sending query id %lu\n", (unsigned long)queryId);
    if (handler) {
        std::unique_lock<std::mutex> dataLock(m_dataMutex);
        m_responseHandlers.emplace(queryId, std::move(handler));
    }
    m_client->send({queryId, std::move(f)});
}

void PurpleTdClient::authResponse(uint64_t requestId, td::td_api::object_ptr<td::td_api::Object> object)
{
    if (object->get_id() == td::td_api::error::ID) {
        td::td_api::object_ptr<td::td_api::error> error = td::move_tl_object_as<td::td_api::error>(object);
        purple_debug_misc(config::pluginId, "Authentication error on query %lu (auth step %d): code %d (%s)\n",
                          (unsigned long)requestId, (int)m_lastAuthState, (int)error->code_,
                          error->message_.c_str());
        m_authError     = std::move(error);
        g_idle_add(notifyAuthError, this);
    } else
        purple_debug_misc(config::pluginId, "Authentication success on query %lu\n", (unsigned long)requestId);
}

int PurpleTdClient::notifyAuthError(gpointer user_data)
{
    PurpleTdClient *self = static_cast<PurpleTdClient *>(user_data);

    std::string message;
    switch (self->m_lastAuthState) {
    case td::td_api::authorizationStateWaitEncryptionKey::ID:
        message = "Error applying database encryption key";
        break;
    case td::td_api::authorizationStateWaitPhoneNumber::ID:
        message = "Authentication error after sending phone number";
        break;
    default:
        message = "Authentication error";
    }

    if (self->m_authError) {
        message += ": code " + std::to_string(self->m_authError->code_) + " (" +
                self->m_authError->message_ + ")";
        self->m_authError.reset();
    }

    purple_connection_error(purple_account_get_connection(self->m_account), message.c_str());
    return FALSE; // This idle handler will not be called again
}

int PurpleTdClient::connectionReady(gpointer user_data)
{
    PurpleTdClient *self = static_cast<PurpleTdClient *>(user_data);

    purple_connection_set_state (purple_account_get_connection(self->m_account), PURPLE_CONNECTED);
    purple_blist_add_account(self->m_account);

    return FALSE; // This idle handler will not be called again
}