// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.

#include "messagetypepolicy.h"
#include <vespa/documentapi/messagebus/documentprotocol.h>
#include <vespa/messagebus/message.h>
#include <vespa/vespalib/stllike/hash_map.hpp>
#include <vespa/config/helper/configfetcher.hpp>
#include <vespa/config/subscription/configuri.h>


using vespa::config::content::MessagetyperouteselectorpolicyConfig;

namespace documentapi {

namespace policy {

using MessageTypeMapT = vespalib::hash_map<int, mbus::Route>;

class MessageTypeMap : public MessageTypeMapT {
public:
    using MessageTypeMapT::MessageTypeMapT;
};

}

MessageTypePolicy::MessageTypePolicy(const config::ConfigUri & configUri) :
    mbus::IRoutingPolicy(),
    config::IFetcherCallback<MessagetyperouteselectorpolicyConfig>(),
    _map(),
    _defaultRoute(),
    _fetcher(std::make_unique<config::ConfigFetcher>(configUri.getContext()))
{
    _fetcher->subscribe<MessagetyperouteselectorpolicyConfig>(configUri.getConfigId(), this);
    _fetcher->start();
}

MessageTypePolicy::~MessageTypePolicy() {}

void
MessageTypePolicy::configure(std::unique_ptr<MessagetyperouteselectorpolicyConfig> cfg)
{
    auto map = std::make_unique<policy::MessageTypeMap>();
    for (size_t i(0), m(cfg->route.size()); i < m; i++) {
        const MessagetyperouteselectorpolicyConfig::Route & r = cfg->route[i];
        (*map)[r.messagetype] = mbus::Route::parse(r.name);
    }
    _map.set(map.release());
    _defaultRoute.set(new mbus::Route(mbus::Route::parse(cfg->defaultroute)));
    _map.latch();
    _defaultRoute.latch();
}

void
MessageTypePolicy::select(mbus::RoutingContext & context)
{
    int messageType = context.getMessage().getType();
    std::shared_ptr<policy::MessageTypeMap> map = _map.get();
    policy::MessageTypeMap::const_iterator found = map->find(messageType);
    if (found != map->end()) {
         context.addChild(found->second);
    } else {
        context.addChild(*_defaultRoute.get());
    }
}

void
MessageTypePolicy::merge(mbus::RoutingContext &context)
{
    DocumentProtocol::merge(context);
}
}  // namespace documentapi