/**
 * @file utils/Trace.hpp
 * @author See the AUTHORS file
 */

/*
 * Copyright (C) 2012-2019 ULCO http://www.univ-littoral.fr
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef ARTIS_UTILS_TRACE
#define ARTIS_UTILS_TRACE

#include <algorithm>
#include <iterator>
#include <memory>
#include <mutex>
#include <sstream>
#include <string>
#include <vector>
#include <map>

#include <artis/utils/DateTime.hpp>
#include <artis/kernel/Any.hpp>

#if WIN32
#include <iso646.h>
#endif

//fwd decl for friend classes in TraceElement
namespace artis {
    namespace kernel {
        template<typename T, typename U, typename V, typename W>
        class AbstractCoupledModel;

        template<typename T, typename U, typename V>
        class AbstractAtomicModel;

        template<typename Time, typename Parameters>
        class AbstractModel;

        template<typename T, typename U, typename V>
        class Internals;

        template<typename T, typename U, typename V>
        class Externals;
    }
}

namespace artis {
    namespace utils {

        enum TraceType {
            NONE = 0, CHECK = 1, CONSTRUCT, SUBMODEL_ADD, INTERNAL_DECL,
            EXTERNAL_DECL, INTERNAL_LINK, INIT, START, BEFORE_COMPUTE,
            COMPUTE, PUT, AFTER_COMPUTE, DESTRUCT, KERNEL
        };
        static const std::vector<std::string> TraceTypesStr = {
                "none", "check", "construct", "submodel_add", "internal_decl",
                "external_decl", "internal_link", "init", "start", "before_compute",
                "compute", "put", "after_compute", "destruct", "kernel"};

        class KernelInfo {
        public:
            static std::map<std::string, int> elt_dictionary;
            static std::vector<std::string> elt_names;

            static unsigned int term(const std::string& v)
            {
                if (elt_dictionary.find(v) == elt_dictionary.end()) {
                    elt_dictionary[v] = elt_names.size();
                    elt_names.push_back(v);
                }
                return elt_dictionary[v];
            }

            static const std::string& term(unsigned int i) { return elt_names[i]; }

            KernelInfo()
                    :
                    _internal_var(false), _empty(true)
            {
                set_var("");
                set_value("");
                set_tgt_model("");
                set_tgt_internal_var("");
            }

            KernelInfo(const std::string& var, bool internal_var,
                    const std::string& value)
                    :
                    _internal_var(internal_var), _empty(false)
            {
                set_var(var);
                set_value(value);
                set_tgt_model("");
                set_tgt_internal_var("");
            }

            KernelInfo(const std::string& var, const std::string& tgt_model,
                    const std::string& tgt_internal_var)
                    :
                    _internal_var(true), _empty(false)
            {
                set_var(var);
                set_value("");
                set_tgt_model(tgt_model);
                set_tgt_internal_var(tgt_internal_var);
            }

            KernelInfo(const std::string& var, bool internal_var)
                    :
                    _internal_var(internal_var), _empty(false)
            {
                set_var(var);
                set_value("");
                set_tgt_model("");
                set_tgt_internal_var("");
            }

            KernelInfo(const std::string& tgt_model)
                    :
                    _internal_var(false), _empty(false)
            {
                set_var("");
                set_value("");
                set_tgt_model(tgt_model);
                set_tgt_internal_var("");
            }

            void set_var(const std::string& v) { _var = KernelInfo::term(v); }

            void set_value(const std::string& v) { _value = KernelInfo::term(v); }

            void set_tgt_model(const std::string& v) { _tgt_model = KernelInfo::term(v); }

            void set_tgt_internal_var(const std::string& v) { _tgt_internal_var = KernelInfo::term(v); }

            const std::string& var() const { return KernelInfo::term(_var); }

            const std::string& value() const { return KernelInfo::term(_value); }

            const std::string& tgt_model() const { return KernelInfo::term(_tgt_model); }

            const std::string& tgt_internal_var() const { return KernelInfo::term(_tgt_internal_var); }

            unsigned int var_idx() const { return _var; }

            unsigned int tgt_internal_var_idx() const { return _tgt_internal_var; }

            unsigned int tgt_model_idx() const { return _tgt_model; }

            bool is_internal_var() const { return _internal_var; }

            bool empty() const { return _empty; }

            std::string to_string() const
            {
                std::ostringstream ss;
                if (not KernelInfo::term(_var).empty()) {
                    ss << ":";
                    if (not _internal_var)
                        ss << "*";
                    ss << KernelInfo::term(_var);
                }
                if (not KernelInfo::term(_value).empty()) {
                    ss << "=" << KernelInfo::term(_value);
                }
                if (not KernelInfo::term(_tgt_model).empty()) {
                    ss << " -> " << KernelInfo::term(_tgt_model);
                    if (not KernelInfo::term(_tgt_internal_var).empty()) {
                        ss << ":" << KernelInfo::term(_tgt_internal_var);
                    }
                }
                return ss.str();
            }

        private:
            unsigned int _var;
            unsigned int _value;
            unsigned int _tgt_model;
            unsigned int _tgt_internal_var;
            bool _internal_var;
            bool _empty;
        };

        template<class Time>
        class TraceElement {
            template<typename T, typename U, typename V, typename W>
            friend
            class artis::kernel::AbstractCoupledModel;

            template<typename T, typename U, typename V>
            friend
            class artis::kernel::AbstractAtomicModel;

            template<typename T, typename P>
            friend
            class artis::kernel::AbstractModel;

            template<typename T, typename U, typename V>
            friend
            class artis::kernel::Internals;

            template<typename T, typename U, typename V>
            friend
            class artis::kernel::Externals;

        private:
            TraceElement(bool from_kernel, const std::string& model_name,
                    typename Time::type time, TraceType type)
                    :
                    _time(time), _type(type),
                    _from_kernel(from_kernel)
            {
                _model_name = KernelInfo::term(model_name);
            }

        public:
            TraceElement()
                    :_time(Time::null), _type(NONE),
                     _from_kernel(false) { }

            TraceElement(const std::string& model_name, typename Time::type time,
                    TraceType type)
                    :
                    _time(time), _type(type),
                    _from_kernel(false)
            {
                _model_name = KernelInfo::term(model_name);
            }

            virtual ~TraceElement() { }

            const std::string& get_comment() const { return _comment; }

            const std::string& get_model_name() const { return KernelInfo::term(_model_name); }

            unsigned int get_model_name_idx() const { return _model_name; }

            typename Time::type get_time() const { return _time; }

            TraceType get_type() const { return _type; }

            const KernelInfo& get_kernel_info() const { return _kernel_info; }

            void set_comment(const std::string& comment) { _comment = comment; }

            bool from_kernel() const { return _from_kernel; }

            void set_kernel_info(const KernelInfo& info) { _kernel_info = info; }

            std::string to_string(artis::utils::DateFormat date_format =
            artis::utils::DATE_FORMAT_EXTENDED) const
            {
                std::ostringstream ss;
                ss << (from_kernel() ? "KERNEL" : "TRACE ");
                if (get_time() != Time::null) {
                    ss << "(" << utils::DateTime::toJulianDayFmt(get_time(),
                            date_format)
                       << ")";
                }
                ss << ": ";
                ss << "<" + TraceTypesStr[get_type()] + ">";
                ss << " " << get_model_name();
                if (not get_kernel_info().empty()) {
                    ss << get_kernel_info().to_string();
                }
                if (not get_comment().empty()) {
                    ss << " => " << get_comment();
                }
                return ss.str();

            }

        private:
            unsigned int _model_name;
            typename Time::type _time;
            TraceType _type;
            std::string _comment;
            KernelInfo _kernel_info;
            bool _from_kernel;
        };

        template<class Time>
        class TraceElements : public std::vector<TraceElement<Time> > {
        public:
            TraceElements() { }

            virtual ~TraceElements() { }

            TraceElements filter_model_name(
                    const std::string& model_name) const
            {
                TraceElements<Time> result;

                std::copy_if(
                        TraceElements<Time>::begin(),
                        TraceElements<Time>::end(), std::back_inserter(result),
                        [model_name](TraceElement<Time> const& x) {
                            if (not x.get_kernel_info().empty()) {
                                if (x.get_kernel_info().tgt_model() == model_name) {
                                    return true;
                                }
                            }
                            return x.get_model_name() == model_name;
                        });
                return result;
            }

            TraceElements filter_time(typename Time::type time) const
            {
                TraceElements result;

                std::copy_if(TraceElements<Time>::begin(),
                        TraceElements<Time>::end(), std::back_inserter(result),
                        [time](TraceElement<Time> const& x) { return x.get_time() == time; });
                return result;
            }

            TraceElements filter_type(TraceType type) const
            {
                TraceElements result;

                std::copy_if(TraceElements<Time>::begin(),
                        TraceElements<Time>::end(), std::back_inserter(result),
                        [type](TraceElement<Time> const& x) { return x.get_type() == type; });
                return result;
            }

            TraceElements filter_variable(const std::string& var_name) const
            {
                TraceElements result;

                std::copy_if(TraceElements<Time>::begin(),
                        TraceElements<Time>::end(), std::back_inserter(result),
                        [var_name](TraceElement<Time> const& x) {
                            if (x.get_kernel_info().empty())
                                return false;
                            return ((x.get_kernel_info().var() == var_name)
                                    or (x.get_kernel_info().tgt_internal_var() == var_name));
                        });
                return result;
            }

            std::string to_string(artis::utils::DateFormat date_format =
            artis::utils::DATE_FORMAT_EXTENDED) const
            {
                std::ostringstream ss;

                for (typename TraceElements<Time>::const_iterator it =
                        TraceElements<Time>::begin();
                     it != TraceElements<Time>::end(); ++it) {
                    ss << it->to_string(date_format) << std::endl;
                }
                return ss.str();
            }
        };

        template<class Time>
        class Trace {
        public:
            virtual ~Trace() { }

            static Trace& trace()
            {
                std::call_once(_flag, []() { _instance.reset(new Trace()); }
                );
                return *_instance;
            }

            void clear() { _trace.clear(); }

            const TraceElements<Time>& elements() const { return _trace; }

            void flush()
            {
                if (_sstream) {
                    _element.set_comment(_sstream->str());
                    delete _sstream;
                    _sstream = 0;
                }
                _trace.push_back(_element);
            }

            std::mutex& mutex() { return _mutex; }

            void set_element(const TraceElement<Time>& element) { _element = element; }

            void set_kernel_info(const KernelInfo& info) { _element.set_kernel_info(info); }

            std::ostringstream& sstream()
            {
                if (_sstream == 0) {
                    _sstream = new std::ostringstream();
                }
                return *_sstream;
            }

        private:
            Trace() { _sstream = 0; }

            static std::shared_ptr<Trace<Time> > _instance;
            static std::once_flag _flag;

            TraceElements<Time> _trace;
            TraceElement<Time> _element;
            std::ostringstream* _sstream;
            std::mutex _mutex;
        };

    }
}

template<class Time>
artis::utils::Trace<Time>& operator<<(
        artis::utils::Trace<Time>& trace,
        const artis::utils::TraceElement<Time>& e)
{
    std::lock_guard<std::mutex> lock(trace.mutex());

    trace.set_element(e);
    return trace;
}

template<class Time>
artis::utils::Trace<Time>& operator<<(
        artis::utils::Trace<Time>& trace,
        const artis::utils::KernelInfo& info)
{
    std::lock_guard<std::mutex> lock(trace.mutex());

    trace.set_kernel_info(info);
    return trace;
}

template<class Time>
artis::utils::Trace<Time>& operator<<(
        artis::utils::Trace<Time>& trace,
        const std::string& str)
{
    std::lock_guard<std::mutex> lock(trace.mutex());

    trace.sstream() << str;
    return trace;
}

template<class Time>
artis::utils::Trace<Time>& operator<<(
        artis::utils::Trace<Time>& trace,
        typename Time::type t)
{
    std::lock_guard<std::mutex> lock(trace.mutex());

    trace.sstream() << t;
    return trace;
}

template<class Time>
std::shared_ptr<artis::utils::Trace<Time> >
        artis::utils::Trace<Time>::_instance;

template<class Time>
std::once_flag artis::utils::Trace<Time>::_flag;

#endif