#ifndef root_container_hpp
#define root_container_hpp
#include <iostream>
#include <utility>
#include <map>

#include "TROOT.h"
#include "TFile.h"
#include "TCanvas.h"
#include "TGraph.h"
#include "TH1.h"
#include "TH2.h"

#include "TMVA/Factory.h"
#include "TMVA/DataLoader.h"
#include "TMVA/DataSetInfo.h"

#include "filval/container.hpp"

namespace fv::root::util{
    /**
     * Save a TObject. The TObject will typically be a Histogram or Graph object,
     * but can really be any TObject. The SaveOption can be used to specify how to
     * save the file.
     */
    void save_as(TObject* container, const std::string& fname, const SaveOption& option = SaveOption::PNG) {

        auto save_img = [](TObject* container, const std::string& fname){
            TCanvas* c1 = new TCanvas("c1");
            container->Draw();
            c1->Draw();
            c1->SaveAs(fname.c_str());
            delete c1;
        };

        auto save_bin = [](TObject* container){
            INFO("Saving object: " << container->GetName() << " into file " << gDirectory->GetName());
            container->Write(container->GetName(), TObject::kOverwrite);
        };

        switch(option){
            case PNG:
                save_img(container, fname+".png"); break;
            case PDF:
                save_img(container, fname+".pdf"); break;
            case ROOT:
                save_bin(container); break;
            default:
                break;
        }
    }


    /**
     * Saves an STL container into a ROOT file. ROOT knows how to serialize STL
     * containers, but it needs the *name* of the type of the container, eg.
     * std::map<int,int> to be able to do this. In order to generate this name at
     * run-time, the fv::util::get_type_name function uses RTTI to get type info
     * and use it to look up the proper name.
     *
     * For nexted containers, it is necessary to generate the CLING dictionaries
     * for each type at compile time to enable serialization. To do this, add the
     * type definition into the LinkDef.hpp header file.
     */
    void save_as_stl(void* container, const std::string& type_name,
                      const std::string& obj_name,
                      const SaveOption& option = SaveOption::PNG) {
        switch(option){
            case PNG:
                INFO("Cannot save STL container " << type_name <<" as png");
                break;
            case PDF:
                INFO("Cannot save STL container " << type_name <<" as pdf");
                break;
            case ROOT:
                /* DEBUG("Writing object \"" << obj_name << "\" of type \"" << type_name << "\"\n"); */
                gDirectory->WriteObjectAny(container, type_name.c_str(), obj_name.c_str());
                break;
            default:
                break;
        }
    }
}

namespace fv::root {

struct TH1Params{
    std::string label_x;
    int nbins;
    double low;
    double high;
    std::string label_y;

    static TH1Params lookup(const std::string&& param_key){
        auto hist_params = fv::util::the_config->get("hist-params");
        if(!hist_params[param_key]){
            CRITICAL("Key \"" << param_key << "\" does not exist under hist-params in supplied config file. Add it!", true);
        }
        else{
            auto params = hist_params[param_key];
            return TH1Params({params["label_x"].as<std::string>(),
                              params["nbins"].as<int>(),
                              params["low"].as<double>(),
                              params["high"].as<double>(),
                              params["label_y"].as<std::string>()
                              });

        }
    }
};

template <typename V>
class _ContainerTH1 : public Container<TH1,V>{
    private:
        void _fill(){
            if (this->container == nullptr){
                if (this->value == nullptr){
                    CRITICAL("Container: \"" << this->get_name() << "\" has a null Value object. "
                             << "Probably built with imcompatible type",-1);
                }
                this->container = new TH1D(this->get_name().c_str(), this->title.c_str(),
                                           params.nbins, params.low, params.high);
                this->container->SetXTitle(params.label_x.c_str());
                this->container->SetYTitle(params.label_y.c_str());
            }
            _do_fill();
        }

    protected:
        std::string title;
        TH1Params params;

        virtual void _do_fill() = 0;

    public:
        explicit _ContainerTH1(const std::string& name, Value<V>* value,
                               const std::string& title,
                               const TH1Params& params)
          :Container<TH1,V>(name, value),
           title(title),
           params(params) { }

        void save_as(const std::string& fname, const SaveOption& option = SaveOption::PNG) {
            util::save_as(this->get_container(), fname, option);
        }
};

template <typename V>
class ContainerTH1 : public _ContainerTH1<V>{
    using _ContainerTH1<V>::_ContainerTH1;
    void _do_fill(){
        this->container->Fill(this->value->get_value());
    }
    public:
        GenContainer* clone_as(const std::string& new_name){
            return new ContainerTH1<V>(new_name, this->value, this->title, this->params);
        }
};

template <typename V>
class ContainerTH1Many : public _ContainerTH1<std::vector<V>>{
    using _ContainerTH1<std::vector<V>>::_ContainerTH1;
    void _do_fill(){
        for(const V &x : this->value->get_value())
            this->container->Fill(x);
    }
    public:
        GenContainer* clone_as(const std::string& new_name){
            return new ContainerTH1Many<V>(new_name, this->value, this->title, this->params);
        }
};

struct TH2Params{
    std::string label_x;
    int nbins_x;
    double low_x;
    double high_x;
    std::string label_y;
    int nbins_y;
    double low_y;
    double high_y;

    static TH2Params lookup(const std::string&& param_key){
        auto hist_params = fv::util::the_config->get("hist-params");
        if(!hist_params[param_key]){
            CRITICAL("Key \"" << param_key << "\" does not exist under hist-params in supplied config file. Add it!", true);
        }
        else{
            auto params = hist_params[param_key];
            return TH2Params({params["label_x"].as<std::string>(),
                              params["nbins_x"].as<int>(),
                              params["low_x"].as<double>(),
                              params["high_x"].as<double>(),
                              params["label_y"].as<std::string>(),
                              params["nbins_y"].as<int>(),
                              params["low_y"].as<double>(),
                              params["high_y"].as<double>()
                              });

        }
    }
};

template <typename V>
class _ContainerTH2 : public Container<TH2,std::pair<V,V>>{
    private:
        void _fill(){
            if (this->container == nullptr){
                if (this->value == nullptr){
                    CRITICAL("Container: \"" << this->get_name() << "\" has a null Value object. "
                             << "Probably built with imcompatible type",-1);
                }
                this->container = new TH2D(this->get_name().c_str(), this->title.c_str(),
                                           params.nbins_x, params.low_x, params.high_x,
                                           params.nbins_y, params.low_y, params.high_y);
                this->container->SetXTitle(params.label_x.c_str());
                this->container->SetYTitle(params.label_y.c_str());
            }
            _do_fill(this->value->get_value());
        }

    protected:
        std::string title;
        TH2Params params;

        virtual void _do_fill(const std::pair<V,V>& val) = 0;

    public:
        explicit _ContainerTH2(const std::string& name, Value<std::pair<V, V>>* value,
                               const std::string& title,
                               TH2Params params)
          :Container<TH2,std::pair<V,V>>(name, value),
           title(title),
           params(params) { }

        void save_as(const std::string& fname, const SaveOption& option = SaveOption::PNG) {
            util::save_as(this->get_container(), fname, option);
        }

};

template <typename V>
class ContainerTH2 : public _ContainerTH2<V>{
    using _ContainerTH2<V>::_ContainerTH2;
    void _do_fill(const std::pair<V,V>& val){
        this->container->Fill(val.first,val.second);
    }
    public:
        GenContainer* clone_as(const std::string& new_name){
            return new ContainerTH2<V>(new_name, this->value, this->title, this->params);
        }
};

template <typename V>
class ContainerTH2Many : public _ContainerTH2<std::vector<V>>{
    using _ContainerTH2<std::vector<V>>::_ContainerTH2;
    void _do_fill(const std::pair<std::vector<V>,std::vector<V>>& val){
        int min_size = std::min(val.first.size(), val.second.size());
        for(int i=0; i<min_size; i++)
            this->container->Fill(val.first[i],val.second[i]);
    }
    public:
        GenContainer* clone_as(const std::string& new_name){
            return new ContainerTH2Many<V>(new_name, this->value, this->title, this->params);
        }
};

template <typename V>
class ContainerTGraph : public Container<TGraph,std::pair<V,V>>{
    private:
        std::vector<V> x_data;
        std::vector<V> y_data;
        std::string title;
        bool data_modified;
        void _fill(){
            auto val = this->value->get_value();
            x_data.push_back(val.first);
            y_data.push_back(val.second);
            data_modified = true;
        }
    public:
        ContainerTGraph(const std::string& name, const std::string& title, Value<std::pair<V, V>>* value)
          :Container<TGraph,std::pair<V,V>>(name, value),
           data_modified(false){
            this->container = new TGraph();
           }

        TGraph* get_container(){
            if (data_modified){
                delete this->container;
                this->container = new TGraph(x_data.size(), x_data.data(), y_data.data());
                this->container->SetName(this->get_name().c_str());
                this->container->SetTitle(title.c_str());
                data_modified = false;
            }
            return this->container;
        }

        GenContainer* clone_as(const std::string& new_name){
            return new ContainerTGraph<V>(new_name, this->title, this->value);
        }

        void save_as(const std::string& fname, const SaveOption& option = SaveOption::PNG) {
            util::save_as(get_container(), fname, option);
        }
};

template <typename V>
class Vector : public Container<std::vector<V>,V>{
    private:

        void _fill(){
            this->container->push_back(this->value->get_value());
        }
    public:
        Vector(const std::string& name, Value<V>* value)
          :Container<std::vector<V>,V>(name, value){
            this->container = new std::vector<V>;
        }

        GenContainer* clone_as(const std::string& new_name){
            return new Vector<V>(new_name, this->value);
        }

        void save_as(const std::string& fname, const SaveOption& option = SaveOption::PNG) {
            std::string type_name = "std::vector<"+fv::util::get_type_name(typeid(V))+">";
            util::save_as_stl(this->get_container(), type_name, this->get_name(), option);
        }
};

template <typename V>
class VectorMany : public Container<std::vector<V>,std::vector<V>>{
    private:

        void _fill(){
            for(const V& val: this->value->get_value())
                this->container->push_back(val);
        }
    public:
        VectorMany(const std::string& name, Value<std::vector<V>>* value)
          :Container<std::vector<V>,std::vector<V>>(name, value){
            this->container = new std::vector<V>;
        }

        GenContainer* clone_as(const std::string& new_name){
            return new VectorMany<V>(new_name, this->value);
        }

        void save_as(const std::string& fname, const SaveOption& option = SaveOption::PNG) {
            std::string type_name = "std::vector<"+fv::util::get_type_name(typeid(V))+">";
            util::save_as_stl(this->get_container(), type_name, this->get_name(), option);
        }
};

template <typename V, typename D>
class _Counter : public Container<std::map<D,int>,V>{
    public:
        explicit _Counter(const std::string& name, Value<V>* value)
          :Container<std::map<D,int>,V>(name, value) {
            this->container = new std::map<D,int>;
        }

        void save_as(const std::string& fname, const SaveOption& option = SaveOption::PNG) {
            std::string type_name = "std::map<"+fv::util::get_type_name(typeid(D))+",int>";
            util::save_as_stl(this->get_container(), type_name, this->get_name(), option);
        }
};


/**
 * A Counter that keeps a mapping of the number of occurances of each input
 * value.
 */
template <typename V>
class Counter : public _Counter<V,V>{
    using _Counter<V,V>::_Counter;
        void _fill(){
            (*this->container)[this->value->get_value()]++;
        }
    public:
        GenContainer* clone_as(const std::string& new_name){
            return new Counter<V>(new_name, this->value);
        }
};

/**
 * Same as Counter but accepts multiple values per fill.
 */
template <typename V>
class CounterMany : public _Counter<std::vector<V>,V>{
    using _Counter<std::vector<V>,V>::_Counter;
        void _fill(){
            for(V& val : this->value->get_value())
                (*this->container)[val]++;
        }
    public:
        GenContainer* clone_as(const std::string& new_name){
            return new CounterMany<V>(new_name, this->value);
        }
};

class PassCount : public Container<int,bool>{
    private:
        void _fill() {
            if(this->value->get_value()) (*this->container)++;
        }
    public:
        PassCount(const std::string& name, Value<bool>* value)
          :Container<int,bool>(name, value){
            this->container = new int(0);
        }

        GenContainer* clone_as(const std::string& new_name){
            return new PassCount(new_name, this->value);
        }

        void save_as(const std::string& fname, const SaveOption& option = SaveOption::PNG) {
            //ROOT(hilariously) cannot serialize basic data types, we wrap this
            //in a vector.
            std::vector<int> v({*this->get_container()});
            util::save_as_stl(&v, "std::vector<int>", this->get_name(), option);
        }
};


template <typename T>
class EfficiencyContainer : public Container<TH1F, std::vector<T>>{
    private:
        std::function<bool(T)>* selector;  // Selects whether object is up for consideration
        std::function<bool(T)>* predicate; // Says whether the object passes the efficiency criteria
        std::function<float(T)>* get_val;  // Returns a floating point value from the object that is actually
                                           // used in the histogram
        bool write_num_den;
        TH1F num;
        TH1F den;
        TH1F eff;

        TH1Params params;

        void _fill(){
            for (auto& obj : this->value->get_value()) {
                if (selector == nullptr or (*selector)(obj)) {
                    float val = (*get_val)(obj);
                    den.Fill(val);
                    if ((*predicate)(obj)) {
                        num.Fill(val);
                    }
                }
            }
        }

    public:
        EfficiencyContainer(const std::string& name, Value<std::vector<T>>* value, TH1Params params,
                            std::function<bool(T)>* selector, std::function<bool(T)>* predicate,
                            std::function<float(T)>* get_val, bool write_num_den=false)
          :Container<TH1F, std::vector<T>>(name, value),
           num{(name+"_num").c_str(), (name+"_num").c_str(), params.nbins, params.low, params.high},
           den{(name+"_den").c_str(), (name+"_den").c_str(), params.nbins, params.low, params.high},
           eff{name.c_str(), name.c_str(), params.nbins, params.low, params.high},
           selector(selector), predicate(predicate), get_val(get_val), params(params), write_num_den(write_num_den) {
            num.SetXTitle(params.label_x.c_str()); num.SetYTitle(params.label_y.c_str());
            den.SetXTitle(params.label_x.c_str()); den.SetYTitle(params.label_y.c_str());
            eff.SetXTitle(params.label_x.c_str()); eff.SetYTitle(params.label_y.c_str());
            this->container = &eff;
           }

        TH1F* get_container() {
            eff.Sumw2();
            eff.Divide(&num, &den, 1, 1, "B");
            return this->container;
        }

        GenContainer* clone_as(const std::string& new_name){
            return new EfficiencyContainer<T>(new_name, this->value, this->params, selector, predicate, get_val);
        }

        void save_as(const std::string& fname, const SaveOption& option = SaveOption::PNG) {
            util::save_as(this->get_container(), fname, option);
            if (write_num_den) {
                util::save_as(&num, fname, option);
                util::save_as(&den, fname, option);
            }
        }
};

template <typename... ArgTypes>
class MVA : public Container<TMVA::DataLoader,typename MVAData<ArgTypes...>::type>{
    private:
        std::vector<std::pair<std::string,std::string>> methods;

        std::string cut;
        std::string opt;

        void _fill(){
            std::tuple<ArgTypes...> t;
            typename MVAData<ArgTypes...>::type& event = this->value->get_value();
            bool is_training, is_signal;
            double weight;
            std::tie(is_training, is_signal, weight, t) = event;
            std::vector<double> v = t2v<double>(t);
            if (is_signal){
                if (is_training){
                    this->container->AddSignalTrainingEvent(v, weight);
                } else {
                    this->container->AddSignalTestEvent(v, weight);
                }
            } else {
                if (is_training){
                    this->container->AddBackgroundTrainingEvent(v, weight);
                } else {
                    this->container->AddBackgroundTestEvent(v, weight);
                }
            }
        }
    public:
        MVA(const std::string& name, MVAData<ArgTypes...>* value, const std::string& cut = "", const std::string& opt = "")
          :Container<TMVA::DataLoader,typename MVAData<ArgTypes...>::type>(name, value),
           cut(cut), opt(opt) {
            this->container = new TMVA::DataLoader(name);
            for (std::pair<std::string,char>& p : value->get_label_types()){
                this->container->AddVariable(p.first, p.second);
            }
        }

        void add_method(const std::string& method_name, const std::string& method_params) {
            methods.push_back(std::make_pair(method_name, method_params));
        }

        GenContainer* clone_as(const std::string& new_name){
            auto mva = new MVA<ArgTypes...>(new_name, (MVAData<ArgTypes...>*)this->value, this->cut, this->opt);
            mva->methods = methods;
            return mva;
        }

        void save_as(const std::string& fname, const SaveOption& option = SaveOption::PNG) {
            TFile* outputFile = gDirectory->GetFile();

            this->container->PrepareTrainingAndTestTree(cut.c_str(), opt.c_str());
            TMVA::Factory *factory = new TMVA::Factory("TMVAClassification", outputFile,
                                                       "!V:!Silent:Color:DrawProgressBar:Transformations=I;D;P;G,D:AnalysisType=Classification");

            TMVA::Types& types = TMVA::Types::Instance();
            for(auto& p : methods){
                std::string method_name, method_params;
                std::tie(method_name, method_params)  = p;
                TMVA::Types::EMVA method_type = types.GetMethodType(method_name);
                factory->BookMethod(this->container, method_type, method_name, method_params);
            }

            // Train MVAs using the set of training events
            factory->TrainAllMethods();
            // Evaluate all MVAs using the set of test events
            factory->TestAllMethods();
            // Evaluate and compare performance of all configured MVAs
            factory->EvaluateAllMethods();

            delete factory;
        }
};
}
#endif // root_container_hpp