/**
 * @file
 * @author  Caleb Fangmeier <caleb@fangmeier.tech>
 * @version 0.1
 *
 * @section LICENSE
 *
 *
 * MIT License
 *
 * Copyright (c) 2017 Caleb Fangmeier
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#ifndef dataset_hpp
#define dataset_hpp
#include <iostream>
#include <functional>

#include <sys/time.h>
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>

#include "value.hpp"
#include "container.hpp"
#include "memtrack.hpp"
#include "config.hpp"
#include "log.hpp"

#include "TFile.h"

namespace fv {

    void request_stop_callback(int);  // Forward Declaration
    class DataSet;  // Forward Declaration
    DataSet* the_dataset;

/*
 * A DataSet is a generic source of data that is used to populate
 * ObservedValues. For each ObservedValue, it is recommended that the DataSet
 * have a field whose value is updated when the load_next() method is called. A
 * pointer to this value is then passed during the creation of the
 * ObservedValue. It is important, therefore, that the location in memory of
 * the data not change from event to event.
 */
    class DataSet {
    private:
        void summary() {
            INFO(GenValue::summary());
        }

        timeval start_time;
        bool stop_requested;

        void print_status() {
            size_t m_used = fv_util::getCurrentRSS() / 1024 / 1024;
            timeval curr_time;
            gettimeofday(&curr_time, nullptr);
            float delta_secs = (curr_time.tv_sec - start_time.tv_sec) + (curr_time.tv_usec - start_time.tv_usec) / 1E6f;
            int current_event = get_current_event();
            float events_per_second = current_event / delta_secs;
            int secs_remaining = int((get_events() - current_event) / events_per_second);
            std::stringstream time_remaining;
            if (secs_remaining > 3600.) {
                int hours = secs_remaining / 3600;
                secs_remaining %= 3600;
                time_remaining << hours << "H ";
            }
            if (secs_remaining > 60) {
                int minutes = secs_remaining / 60;
                secs_remaining %= 60;
                time_remaining << minutes << "M ";

            }
            if (secs_remaining > 0) {
                time_remaining << secs_remaining << "S";
            }
            std::cout << "\rprocessing event: " << current_event + 1 << "/" << get_events()
                      << " of file: " << get_current_file().filename
                      << ", " << m_used <<  "MB used "
                      << ", " << time_remaining.str() << " est. time remaining"
                      << std::flush;
        }

    protected:
        std::map<std::string, GenContainer *> containers;
        long max_events;

        virtual int get_events() = 0;

        virtual int get_current_event() = 0;

        virtual fv_util::DataFileDescriptor &get_current_file() = 0;

        std::map<std::string, std::string> get_container_name_value_map() {
            std::map<std::string, std::string> value_map;
            for (auto container : containers)
                value_map[container.first] = container.second->get_value_name();
            return value_map;
        }

        virtual bool load_next() = 0;

        virtual void save_config() = 0;

    public:
        DataSet() : stop_requested(false){
            max_events = fv_util::the_config->get_max_events();
            the_dataset = this;

            signal(SIGINT, request_stop_callback);
            signal(SIGTERM, request_stop_callback);
        }

        bool next(bool verbose=true) {
            if (stop_requested) return false;
            int current_event = get_current_event();
            if (current_event == 0) gettimeofday(&start_time, nullptr);
            if (verbose and (((current_event + 1) % 500) == 0 or current_event+1 == get_events())) print_status();
            GenValue::reset();
            return load_next();
        }

        void set_max_events(const int &max_events) {
            this->max_events = max_events;
        }

        int get_max_events() {
            return this->max_events;
        }

        void request_stop() {
            stop_requested = true;
        }

        virtual void save_all() {
            for (auto container : containers)
                container.second->save();
            save_config();
        }

        template<typename C, typename... ArgTypes>
        C *register_container(ArgTypes... args) {
            C *container = new C(args...);
            if (containers[container->get_name()] != nullptr) {
                CRITICAL("Container with name \"" + container->get_name() + "\" already exists.");
            }
            containers[container->get_name()] = container;
            return container;
        }

        GenContainer *get_container(std::string container_name) {
            GenContainer *c = containers[container_name];
            if (c == nullptr) {
                CRITICAL("Request for container \"" << container_name << "\" failed. Doesn't exist.");
            }
            return c;
        }
    };

    void request_stop_callback(int) {
        std::cout << std::endl << "SIGINT/SIGTERM caught, stopping after current event" << std::endl;
        the_dataset->request_stop();
    }
}
#endif // dataset_hpp