/*
* Copyright (c) 2013-2020, The PurpleI2P Project
*
* This file is part of Purple i2pd project and licensed under BSD3
*
* See full license text in LICENSE file at top of project tree
*/

#include <sys/stat.h>
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/ini_parser.hpp>
#include "Base.h"
#include "FS.h"
#include "Log.h"
#include "Profiling.h"

namespace i2p {
    namespace data {
        i2p::fs::HashedStorage m_ProfilesStorage("peerProfiles", "p", "profile-", "txt");

        RouterProfile::RouterProfile() :
                m_LastUpdateTime(boost::posix_time::second_clock::local_time()),
                m_NumTunnelsAgreed(0), m_NumTunnelsDeclined(0), m_NumTunnelsNonReplied(0),
                m_NumTimesTaken(0), m_NumTimesRejected(0) {
        }

        boost::posix_time::ptime RouterProfile::GetTime() const {
            return boost::posix_time::second_clock::local_time();
        }

        void RouterProfile::UpdateTime() {
            m_LastUpdateTime = GetTime();
        }

        void RouterProfile::Save(const IdentHash &identHash) {
            // fill sections
            boost::property_tree::ptree participation;
            participation.put(PEER_PROFILE_PARTICIPATION_AGREED, m_NumTunnelsAgreed);
            participation.put(PEER_PROFILE_PARTICIPATION_DECLINED, m_NumTunnelsDeclined);
            participation.put(PEER_PROFILE_PARTICIPATION_NON_REPLIED, m_NumTunnelsNonReplied);
            boost::property_tree::ptree usage;
            usage.put(PEER_PROFILE_USAGE_TAKEN, m_NumTimesTaken);
            usage.put(PEER_PROFILE_USAGE_REJECTED, m_NumTimesRejected);
            // fill property tree
            boost::property_tree::ptree pt;
            pt.put(PEER_PROFILE_LAST_UPDATE_TIME, boost::posix_time::to_simple_string(m_LastUpdateTime));
            pt.put_child(PEER_PROFILE_SECTION_PARTICIPATION, participation);
            pt.put_child(PEER_PROFILE_SECTION_USAGE, usage);

            // save to file
            std::string ident = identHash.ToBase64();
            std::string path = m_ProfilesStorage.Path(ident);

            try {
                boost::property_tree::write_ini(path, pt);
            } catch (std::exception &ex) {
                /* boost exception verbose enough */
                LogPrint(eLogError, "Profiling: ", ex.what());
            }
        }

        void RouterProfile::Load(const IdentHash &identHash) {
            std::string ident = identHash.ToBase64();
            std::string path = m_ProfilesStorage.Path(ident);
            boost::property_tree::ptree pt;

            if (!i2p::fs::Exists(path)) {
                LogPrint(eLogWarning, "Profiling: No profile yet for ", ident);
                return;
            }

            try {
                boost::property_tree::read_ini(path, pt);
            } catch (std::exception &ex) {
                /* boost exception verbose enough */
                LogPrint(eLogError, "Profiling: ", ex.what());
                return;
            }

            try {
                auto t = pt.get(PEER_PROFILE_LAST_UPDATE_TIME, "");
                if (t.length() > 0)
                    m_LastUpdateTime = boost::posix_time::time_from_string(t);
                if ((GetTime() - m_LastUpdateTime).hours() < PEER_PROFILE_EXPIRATION_TIMEOUT) {
                    try {
                        // read participations
                        auto participations = pt.get_child(PEER_PROFILE_SECTION_PARTICIPATION);
                        m_NumTunnelsAgreed = participations.get(PEER_PROFILE_PARTICIPATION_AGREED, 0);
                        m_NumTunnelsDeclined = participations.get(PEER_PROFILE_PARTICIPATION_DECLINED, 0);
                        m_NumTunnelsNonReplied = participations.get(PEER_PROFILE_PARTICIPATION_NON_REPLIED, 0);
                    }
                    catch (boost::property_tree::ptree_bad_path &ex) {
                        LogPrint(eLogWarning, "Profiling: Missing section ", PEER_PROFILE_SECTION_PARTICIPATION,
                                 " in profile for ", ident);
                    }
                    try {
                        // read usage
                        auto usage = pt.get_child(PEER_PROFILE_SECTION_USAGE);
                        m_NumTimesTaken = usage.get(PEER_PROFILE_USAGE_TAKEN, 0);
                        m_NumTimesRejected = usage.get(PEER_PROFILE_USAGE_REJECTED, 0);
                    }
                    catch (boost::property_tree::ptree_bad_path &ex) {
                        LogPrint(eLogWarning, "Profiling: Missing section ", PEER_PROFILE_SECTION_USAGE,
                                 " in profile for ", ident);
                    }
                } else
                    *this = RouterProfile();
            }
            catch (std::exception &ex) {
                LogPrint(eLogError, "Profiling: Can't read profile ", ident, " :", ex.what());
            }
        }

        void RouterProfile::TunnelBuildResponse(uint8_t ret) {
            UpdateTime();
            if (ret > 0)
                m_NumTunnelsDeclined++;
            else
                m_NumTunnelsAgreed++;
        }

        void RouterProfile::TunnelNonReplied() {
            m_NumTunnelsNonReplied++;
            UpdateTime();
        }

        bool RouterProfile::IsLowPartcipationRate() const {
            return 4 * m_NumTunnelsAgreed < m_NumTunnelsDeclined; // < 20% rate
        }

        bool RouterProfile::IsLowReplyRate() const {
            auto total = m_NumTunnelsAgreed + m_NumTunnelsDeclined;
            return m_NumTunnelsNonReplied > 10 * (total + 1);
        }

        bool RouterProfile::IsBad() {
            auto isBad = IsAlwaysDeclining() || IsLowPartcipationRate() /*|| IsLowReplyRate ()*/;
            if (isBad && m_NumTimesRejected > 10 * (m_NumTimesTaken + 1)) {
                // reset profile
                m_NumTunnelsAgreed = 0;
                m_NumTunnelsDeclined = 0;
                m_NumTunnelsNonReplied = 0;
                isBad = false;
            }
            if (isBad) m_NumTimesRejected++; else m_NumTimesTaken++;
            return isBad;
        }

        std::shared_ptr<RouterProfile> GetRouterProfile(const IdentHash &identHash) {
            auto profile = std::make_shared<RouterProfile>();
            profile->Load(identHash); // if possible
            return profile;
        }

        void InitProfilesStorage() {
            m_ProfilesStorage.SetPlace(i2p::fs::GetDataDir());
            m_ProfilesStorage.Init(i2p::data::GetBase64SubstitutionTable(), 64);
        }

        void DeleteObsoleteProfiles() {
            struct stat st;
            std::time_t now = std::time(nullptr);

            std::vector<std::string> files;
            m_ProfilesStorage.Traverse(files);
            for (const auto &path: files) {
                if (stat(path.c_str(), &st) != 0) {
                    LogPrint(eLogWarning, "Profiling: Can't stat(): ", path);
                    continue;
                }
                if (((now - st.st_mtime) / 3600) >= PEER_PROFILE_EXPIRATION_TIMEOUT) {
                    LogPrint(eLogDebug, "Profiling: Removing expired peer profile: ", path);
                    i2p::fs::Remove(path);
                }
            }
        }
    }
}