/**
 * @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 config_hpp
#define config_hpp

#include <cstdlib>
#include <cstdio>
#include <string>
#include <fstream>
#include <sstream>

#include <regex>

#include "yaml-cpp/yaml.h"

namespace fv_util {
    struct DataFileDescriptor {
        std::string filename;
        std::string label;
        std::string category;
        int file_number;
        int n_events;

        DataFileDescriptor() : filename(""), label(""), category(""), file_number(-1), n_events(-1) {}

        DataFileDescriptor(const std::string filename, const std::string label, const std::string category,
                           const int n_events)
                : filename(filename), label(label), category(category), file_number(-1), n_events(n_events) {}

        DataFileDescriptor(const std::string filename, const std::string label, const std::string category,
                           const int file_number, const int n_events)
                : filename(filename), label(label), category(category), file_number(file_number), n_events(n_events) {}
    };
}

namespace YAML {
    template<>
    struct convert<fv_util::DataFileDescriptor> {
        static Node encode(const fv_util::DataFileDescriptor &rhs) {
            Node node;
            node["filename"] = rhs.filename;
            node["label"] = rhs.label;
            node["category"] = rhs.category;
            node["n_events"] = rhs.n_events;
            return node;
        }

        static bool decode(const Node &node, fv_util::DataFileDescriptor &rhs) {
            if (!node.IsMap()) {
                return false;
            }

            if (!node["filename"]) return false;
            rhs.filename = node["filename"].as<std::string>();
            if (node["label"]) rhs.label = node["label"].as<std::string>();
            if (node["category"]) rhs.category = node["category"].as<std::string>();
            if (node["n_events"]) rhs.n_events = node["n_events"].as<int>();
            return true;
        }
    };
}

namespace fv_util {


    std::vector<std::string> glob(const std::string& base) {
        std::stringstream ss;
        ss << "ls -1 " << base << " > __tmp__";
        system(ss.str().c_str());

        std::vector<std::string> filenames;
        std::ifstream f("__tmp__");
        std::string line;
        while (std::getline(f, line)) {
            filenames.push_back(line);
        }
        std::remove("__tmp__");
        return filenames;
    }

    class Config {
    private:
        std::string input_filename;
        YAML::Node root;
    public:
        Config()
                : root(), input_filename("") {}

        Config(const Config &c)
                : root(c.root), input_filename(c.input_filename) {}

        Config(const std::string &input_filename)
                : root(YAML::LoadFile(input_filename)),
                  input_filename(input_filename) {}

        template<typename KEY_TYPE>
        YAML::Node get(const KEY_TYPE &key) {
            auto val = root[key];
            return val;
        }

        template<typename T>
        void update_key(const std::string &key, const T &val) {
            root[key] = val;
        }

        std::string as_string() {
            std::stringstream config;
            std::ifstream s(input_filename);
            for (std::string line; std::getline(s, line);) {
                config << line << std::endl;
            }
            return config.str();
        }

        size_t get_max_events() {
            YAML::Node max_events = root["max-events"];
            if (!max_events) {
                return 0;
            }
            return max_events.as<size_t>();
        }

        bool get_debug() {
            YAML::Node debug_node = root["debug"];
            if (!debug_node) {
                return false;
            }
            return debug_node.as<bool>();
        }

        std::string get_output_filename() {
            YAML::Node output_file = root["output-file"];
            if (output_file) {
                return output_file.as<std::string>();
            } else {
                YAML::Node key = root["source-file-key"];
                if (key) {
                    return "../hists/" + key.as<std::string>() + ".root";
                } else {
                    return "../hists/output.root";
                }
            }
        }

        std::vector<DataFileDescriptor> get_source_files() {
            std::vector<DataFileDescriptor> source_files;
            std::string source_file_key = "source-files";
            if (root["source-file-key"]) {
                source_file_key = root["source-file-key"].as<std::string>();
            }
            YAML::Node source_files_nd = root[source_file_key];
            if (source_files_nd.IsMap()) {
                auto filenames = glob(source_files_nd["files"].as<std::string>());
                DataFileDescriptor dfd;
                for (const auto& filename : filenames) {
                    dfd.filename = filename;
                    source_files.push_back(dfd);
                }
            } else if (source_files_nd.IsSequence()) {
                for (const auto &f : source_files_nd) {
                    source_files.push_back(f.as<DataFileDescriptor>());
                }
            } else {
                std::cout << "source-files missing or not a sequence" << std::endl;
            }
            return source_files;
        }
    };

    Config *the_config = nullptr;
    bool debug_on = false;

    void init_config(const std::string &input_filename) {
        if (the_config) delete the_config;
        the_config = new Config(input_filename);
        debug_on = the_config->get_debug();
    }

}
#endif // config_hpp