// Copyright (c) Microsoft. All rights reserved.
#include <string.h>

#include "LogSessionData.hpp"
#include "pal/PAL.hpp"
#include "Logger.hpp"
#include "DebugEvents.hpp"

#include "utils/Utils.hpp"
#include "utils/StringUtils.hpp"
#include "utils/FileUtils.hpp"

#include <memory>

using namespace std;

namespace ARIASDK_NS_BEGIN {

    inline void remove_eol(string& result)
    {
        if (!result.empty() && result[result.length() - 1] == '\n')
        {
            result.erase(result.length() - 1);
        }
    }

    LogSessionData::LogSessionData(string const& cacheFilePath)
    {
        m_sessionFirstTimeLaunch = PAL::getUtcSystemTimeMs();
        string sessionPath = cacheFilePath.empty() ? "" : (cacheFilePath + ".ses").c_str();
        if (!sessionPath.empty())
        {
            open(sessionPath);
        }
    }

    void LogSessionData::open(const string& path)
    {
        bool recreate = true;

        if (MAT::FileExists(path.c_str()))
        {
            auto contents = MAT::FileGetContents(path.c_str());
            recreate = !parse(contents);
        }

        if (recreate)
        {
            m_sessionFirstTimeLaunch = PAL::getUtcSystemTimeMs();
            m_sessionSDKUid = PAL::generateUuidString();
            string contents;
            contents += std::to_string(m_sessionFirstTimeLaunch);
            contents += '\n';
            contents += m_sessionSDKUid;
            contents += '\n';
            if (!MAT::FileWrite(path.c_str(), contents.c_str()))
            {
                LOG_WARN("Unable to save session analytics to %s", path.c_str());
            }
        }

    }

    bool LogSessionData::parse(const string& cacheContents)
    {
       if (cacheContents.empty())
       {
          return false;
       }

       vector<string> v;
       StringUtils::SplitString(cacheContents, '\n', v);
       if (v.size() != 2)
       {
          return false;
       }

       remove_eol(v[0]);
       remove_eol(v[1]);
       try
       {
          // First launch time
          m_sessionFirstTimeLaunch = std::stoull(v[0]);
          // SDK UUID
          m_sessionSDKUid = v[1];
          return true;
       }
       catch (const std::invalid_argument&)
       {
          LOG_ERROR("Non-integer data passed to std::stoull");
       }
       catch (const std::out_of_range&)
       {
          LOG_ERROR("Value passed to std::stoull was larger than unsigned long long could represent");
       }

       return false;
    }

} ARIASDK_NS_END