#include "data/cassandra/impl/Cluster.hpp"

#include "data/cassandra/impl/ManagedObject.hpp"
#include "data/cassandra/impl/SslContext.hpp"
#include "util/OverloadSet.hpp"
#include "util/log/Logger.hpp"

#include <cassandra.h>
#include <fmt/format.h>

#include <stdexcept>
#include <string>
#include <variant>

namespace {

constexpr auto kCLUSTER_DELETER = [](CassCluster* ptr) { cass_cluster_free(ptr); };

};  // namespace

namespace data::cassandra::impl {

Cluster::Cluster(Settings const& settings) : ManagedObject{cass_cluster_new(), kCLUSTER_DELETER}
{
    using std::to_string;

    cass_cluster_set_token_aware_routing(*this, cass_true);
    if (auto const rc = cass_cluster_set_protocol_version(*this, CASS_PROTOCOL_VERSION_V4);
        rc != CASS_OK) {
        throw std::runtime_error(
            fmt::format("Error setting cassandra protocol version to v4: {}", cass_error_desc(rc))
        );
    }

    if (auto const rc = cass_cluster_set_num_threads_io(*this, settings.threads); rc != CASS_OK) {
        throw std::runtime_error(
            fmt::format(
                "Error setting cassandra io threads to {}: {}",
                settings.threads,
                cass_error_desc(rc)
            )
        );
    }

    cass_log_set_level(settings.enableLog ? CASS_LOG_TRACE : CASS_LOG_DISABLED);
    cass_cluster_set_connect_timeout(*this, settings.connectionTimeout.count());
    cass_cluster_set_request_timeout(*this, settings.requestTimeout.count());

    // TODO: AWS keyspace reads should be local_one to save cost
    if (settings.provider == cassandra::impl::Provider::Keyspace) {
        if (auto const rc = cass_cluster_set_consistency(*this, CASS_CONSISTENCY_LOCAL_QUORUM);
            rc != CASS_OK) {
            throw std::runtime_error(
                fmt::format("Error setting keyspace consistency: {}", cass_error_desc(rc))
            );
        }
    } else {
        if (auto const rc = cass_cluster_set_consistency(*this, CASS_CONSISTENCY_QUORUM);
            rc != CASS_OK) {
            throw std::runtime_error(
                fmt::format("Error setting cassandra consistency: {}", cass_error_desc(rc))
            );
        }
    }

    if (auto const rc =
            cass_cluster_set_core_connections_per_host(*this, settings.coreConnectionsPerHost);
        rc != CASS_OK) {
        throw std::runtime_error(
            fmt::format("Could not set core connections per host: {}", cass_error_desc(rc))
        );
    }

    auto const queueSize = settings.queueSizeIO.value_or(
        settings.maxWriteRequestsOutstanding + settings.maxReadRequestsOutstanding
    );
    if (auto const rc = cass_cluster_set_queue_size_io(*this, queueSize); rc != CASS_OK) {
        throw std::runtime_error(
            fmt::format("Could not set queue size for IO per host: {}", cass_error_desc(rc))
        );
    }

    setupConnection(settings);
    setupCertificate(settings);
    setupCredentials(settings);

    LOG(log_.info()) << "Threads: " << settings.threads;
    LOG(log_.info()) << "Core connections per host: " << settings.coreConnectionsPerHost;
    LOG(log_.info()) << "IO queue size: " << queueSize;
    LOG(log_.info()) << "Batched writes auto-chunk size: " << settings.writeBatchSize;
}

void
Cluster::setupConnection(Settings const& settings)
{
    std::visit(
        util::OverloadSet{
            [this](Settings::ContactPoints const& points) { setupContactPoints(points); },
            [this](Settings::SecureConnectionBundle const& bundle) { setupSecureBundle(bundle); }
        },
        settings.connectionInfo
    );
}

void
Cluster::setupContactPoints(Settings::ContactPoints const& points)
{
    using std::to_string;
    auto throwErrorIfNeeded = [](CassError rc, std::string const& label, std::string const& value) {
        if (rc != CASS_OK) {
            throw std::runtime_error(
                fmt::format(
                    "Cassandra: Error setting {} [{}]: {}", label, value, cass_error_desc(rc)
                )
            );
        }
    };

    {
        LOG(log_.debug()) << "Attempt connection using contact points: " << points.contactPoints;
        auto const rc = cass_cluster_set_contact_points(*this, points.contactPoints.data());
        throwErrorIfNeeded(rc, "contact_points", points.contactPoints);
    }

    if (points.port) {
        auto const rc = cass_cluster_set_port(*this, *points.port);
        throwErrorIfNeeded(rc, "port", to_string(*points.port));
    }
}

void
Cluster::setupSecureBundle(Settings::SecureConnectionBundle const& bundle)
{
    LOG(log_.debug()) << "Attempt connection using secure bundle";
    if (auto const rc =
            cass_cluster_set_cloud_secure_connection_bundle(*this, bundle.bundle.data());
        rc != CASS_OK) {
        throw std::runtime_error(
            "Failed to connect using secure connection bundle " + bundle.bundle
        );
    }
}

void
Cluster::setupCertificate(Settings const& settings)
{
    if (not settings.certificate)
        return;

    LOG(log_.debug()) << "Configure SSL context";
    SslContext const context = SslContext(*settings.certificate);
    cass_cluster_set_ssl(*this, context);
}

void
Cluster::setupCredentials(Settings const& settings)
{
    if (not settings.username || not settings.password)
        return;

    LOG(log_.debug()) << "Set credentials; username: " << *settings.username;
    cass_cluster_set_credentials(*this, settings.username->c_str(), settings.password->c_str());
}

}  // namespace data::cassandra::impl