#include "cassandra_support.h"
#include "mosquittopp.h"
#include "trygvis/sensor/io.h"
#include <thread>
#include <boost/lexical_cast.hpp>
#include <boost/program_options.hpp>

using namespace std;
using namespace std::chrono;
using namespace trygvis::sensor;
using namespace trygvis::sensor::io;
using namespace trygvis::cassandra_support;
using namespace boost;
namespace po = boost::program_options;

static bool should_run;
static string mqtt_broker_host;
static auto mqtt_broker_port = 1883;
static auto queue_name = "/trygvis";
static string keyspace_name = "soil_moisture";

static unique_ptr<cassandra_session> current_cassandra_session;

struct sensor_measurement {
    int sensor;
    int value;

    sensor_measurement(int sensor, int value) : sensor(sensor), value(value) {
    }

    ~sensor_measurement() = default;
};

struct device_measurement {
    string device;
    long timestamp;
    vector<sensor_measurement> sensors;

    device_measurement(string &device, long timestamp, vector<sensor_measurement> &&sensors) :
            device(device), timestamp(timestamp), sensors(std::move(sensors)) {
    };

    ~device_measurement() = default;

    string str() {
        stringstream buf;
        buf << "device=" << device;
        buf << ", timestamp=" << timestamp;
        std::for_each(sensors.begin(), sensors.end(), [&](auto &sensor) {
            buf << ", #" << sensor.sensor << "=" + sensor.value;
        });
        return buf.str();
    }
};

string &&to_string(CassFuture *f) {
    const char *message;
    size_t message_length;
    cass_future_error_message(f, &message, &message_length);

    return std::move(string(message, message_length));
}

class mqtt_lib {
public:
    mqtt_lib() {
        mosquitto_lib_init();
    }

    ~mqtt_lib() {
        mosquitto_lib_cleanup();
    }
};

class mqtt_client : private mosqpp::mosquittopp {
public:
    mqtt_client(std::function<void(const struct mosquitto_message *)> on_message_) : mosquittopp(),
                                                                                     on_message_(on_message_) {
        cout << "Connecting to " << mqtt_broker_host << ":" << mqtt_broker_port << endl;
        loop_start();
        connect_async(mqtt_broker_host.c_str(), mqtt_broker_port, 10);
    }

    ~mqtt_client() {
        loop_stop(true);
        disconnect();
    }

private:
    std::function<void(const struct mosquitto_message *)> on_message_;
    bool subscribed = false;

    void on_connect(int rc) override {
        cout << "Connected to MQTT broker, rc=" << rc << endl;
//        should_run = false;
        int qos = 0;
        if (!subscribed) {
            subscribed = true;
            cout << "Subscribing..." << endl;
            subscribe(nullptr, queue_name, qos);
        }
    }

    void on_disconnect(int rc) override {
        subscribed = false;

        cout << "Oops, disconnected, rc=" << rc << endl;
    }

    void on_publish(int mid) override {
    }

    void on_message(const struct mosquitto_message *message) override {
        string payload((const char *) message->payload, (size_t) message->payloadlen);
        on_message_(message);
    }

    void on_subscribe(int mid, int qos_count, const int *granted_qos) override {
        cout << "Subscribed" << endl;
    }

    void on_unsubscribe(int mid) override {
        cout << "Oops, unsubscribed" << endl;
    }

    void on_log(int level, const char *str) override {
        cout << "MQTT: " << level << ":" << str << endl;
    }

    void on_error() override {
        cout << "Oops, error" << endl;
    }
};

void print_error(CassFuture *future) {
    cout << "Cassandra error: " << error_message(future) << endl;
}

auto insert_into_sm_by_day(CassSession *session, device_measurement &&measurement) {
    cassandra_statement q("INSERT INTO sm_by_day(device, day, timestamp, sensors) VALUES (?, ?, ?, ?);", 4);

    q.bind(0, measurement.device);

    std::time_t t = measurement.timestamp;
    char day[100];
    std::strftime(day, sizeof(day), "%Y-%m-%d", std::localtime(&t));
    q.bind(1, day);

    q.bind(2, measurement.timestamp * 1000);

    cassandra_collection sensors(CASS_COLLECTION_TYPE_LIST, measurement.sensors.size());
    for_each(measurement.sensors.cbegin(), measurement.sensors.cend(), [&](auto sensor) {
        cassandra_tuple tuple(2);
        tuple.set(0, sensor.sensor);
        tuple.set(1, sensor.value);
        sensors.append(std::move(tuple));
    });

    q.bind(3, sensors);

    return cass_session_execute(session, q.statement);
}

template<typename Target, typename Source>
boost::optional<Target> map(boost::optional<Source> &a, std::function<Target(Source)> f) {
    if (!a.is_initialized()) {
        return boost::none;
    }

    return make_optional(f(a));
}

template<typename Target, typename Source>
boost::optional<Target> flat_map(boost::optional<Source> &a, boost::optional<Target> (&f)(Source)) {
    if (!a.is_initialized()) {
        return boost::none;
    }

    return f(a.get());
}

template<typename Target, typename Source = string>
boost::optional<Target> l_c(const Source source) {
    try {
        return boost::lexical_cast<Target>(source);
    } catch (bad_lexical_cast &e) {
        return boost::none;
    }
};

void on_message(const struct mosquitto_message *message) {
    string payload((const char *) message->payload, (size_t) message->payloadlen);
    cout << "storing message: " << endl;
    cout << payload << endl;
    cout << "----------------------------------------" << endl;

    KeyDictionary dict;
    auto sample_buffer = make_shared<VectorSampleOutputStream>();
    auto input = make_shared<KeyValueSampleStreamParser>(sample_buffer, dict);

    mutable_buffers_1 buffer = boost::asio::buffer(message->payload, (std::size_t) message->payloadlen);

    input->process(buffer);
    input->finish();

    cout << "sample_buffer->samples: " << sample_buffer->samples.size() << endl;

    auto device_key = dict.indexOf("device");
    auto timestamp_key = dict.indexOf("timestamp");

    std::for_each(sample_buffer->samples.cbegin(), sample_buffer->samples.cend(), [&](auto &sample) {
        cout << "Sample: " << sample.to_string() << endl;

        auto deviceO = sample.at(device_key);
        auto timestampS = sample.at(timestamp_key);

        if (!deviceO) {
            cout << "Missing required key 'device'" << endl;
        }

        if (!timestampS) {
            cout << "Missing required key 'timestamp'" << endl;
        }

        auto device = deviceO.get();

        auto timestamp = flat_map(timestampS, l_c<long>);
        if (!timestamp) {
            cout << "Invalid value for 'timestamp'" << endl;
        }

        vector<sensor_measurement> sensors;

        for (int i = 0; i < 10; i++) {
            auto valueS = sample.at(dict.indexOf("sensor" + to_string(i)));

            auto value = flat_map(valueS, l_c<int>);

            if (!value) {
                continue;
            }

            sensors.emplace_back(i, value.get());
        }

        if (sensors.size() == 0) {
            return;
        }

        device_measurement measurement(device, timestamp.get(), std::move(sensors));

        cout << "Measurement: " << measurement.str() << endl;

        if (current_cassandra_session) {
            handle_future(insert_into_sm_by_day(current_cassandra_session->session, std::move(measurement)), [&](auto future) {
                cout << "Success!" << endl;
            }, [&](auto future, auto err) {
                cout << "Failure: " << error_message(future) << endl;
            });
        } else {
            cout << "Not connected to Cassandra" << endl;
        }
    });
}

int main(int argc, const char **argv) {
    mqtt_lib mqtt_lib();

    string cassandra_cluster;
    po::options_description all("Options");
    all.add_options()("cassandra-cluster", po::value<string>(&cassandra_cluster)->default_value("127.0.0.1"));
    all.add_options()("mqtt-broker-host", po::value<string>(&mqtt_broker_host)->default_value("trygvis.io"));

    po::variables_map vm;
    try {
        auto parsed = po::parse_command_line(argc, argv, all);
        po::store(parsed, vm);
        po::notify(vm);
        auto unrecognized = po::collect_unrecognized(parsed.options, po::include_positional);

        if (vm.count("help")) {
            cerr << all << "\n";
            return EXIT_FAILURE;
        }

        if (unrecognized.size()) {
            cerr << "Unrecognized option: " << unrecognized.at(0) << "\n";
            return EXIT_FAILURE;
        }

    } catch (po::required_option &e) {
        cerr << "Missing required option: " << e.get_option_name() << endl;
        cerr << all << endl;
    } catch (po::unknown_option &e) {
        cerr << e.what() << endl;
        return EXIT_FAILURE;
    }

    mqtt_client mqtt_client(on_message);
    CassFuture *connect_future = nullptr;
    CassCluster *cluster = cass_cluster_new();
    auto session = make_unique<cassandra_session>();

    cass_cluster_set_contact_points(cluster, cassandra_cluster.c_str());

    connect_future = cass_session_connect(session->session, cluster);

    if (cass_future_error_code(connect_future) != CASS_OK) {
        string s = to_string(connect_future);
        cerr << "Could not connect to Cassandra:" << s << endl;
        return EXIT_FAILURE;
    }

    cout << "Connected to Cassandra" << endl;
    current_cassandra_session = std::move(session);

    execute_query(current_cassandra_session->session, "USE " + keyspace_name);

    should_run = true;
    while (should_run) {
        cout << "sleeping.." << endl;
        std::this_thread::sleep_for(60s);
    }

    current_cassandra_session.release();

    return 0;
}