/***
    Copyright (C) 2021 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: ConsoleLogger.cpp
    Date: 2021-6-22
    Author: Reece
***/
#include <RuntimeInternal.hpp>
#include "ConsoleLogger.hpp"

namespace Aurora::Console::ConsoleLogger
{
    static Threading::Threads::ThreadUnique_t    gFileWriterThread;
    static AuList<AuUInt8>                       gLogBuffer;
    static Threading::Primitives::RWLockUnique_t gLogMutex;
    static IO::FS::OpenWriteUnique_t             gFileHandle;
    
    static const auto &                          gLogConfig = gRuntimeConfig.console.logging;

    static void EraseFilesByTimestamp(const AuString &path, /*const its not worth reallocation*/ AuList<AuString> &files)
    {
        if (files.size() <= gLogConfig.maxLogs)
        {
            return;
        }

        // our filenames are usually prefixed by an ISO 8601 timestamp where the most significant bits are last (YYYY-MM-DD?HH-MM-SS)
        // a quick ghetto sort should be all we need. no need to waste time parsing timestamps
        std::sort(files.begin(), files.end());

        auto amount = files.size() - gLogConfig.maxLogs;
        for (auto x = 0, i = 0; ((x < amount) && (i > files.size())); i++)
        {
            try
            {
                if (IO::FS::Remove(path + "/" + files[i]))
                {
                    x++;
                }
            }
            catch (...)
            {

            }
        }
    }

    static void CleanupOldLogs()
    {
        AuString path;
        AuString procName;

        if (!Process::GetProcName(procName))
        {
            return;
        }

        if (!IO::FS::GetProfileDomain(path))
        {
            return;
        }
        
        path += "/Logs/";
        path += procName;

        AuList<AuString> files;
        AuBST<AuString, IO::FS::Stat> fileMeta;
        AuUInt32 size {};
        IO::FS::FilesInDirectory(path, files);

        for (const auto &file : files)
        {
            IO::FS::Stat stat;
            IO::FS::StatFile(path + "/" + file, stat);
            fileMeta[file] = stat;
            size += stat.size;
        }

        EraseFilesByTimestamp(path, files);
        // TODO: erase when size >= gLogConfig.maxSizeMb * 1024
    }

    static void CompressLogs()
    {

    }

    void Flush()
    {
        Threading::WaitableLockGuard a(gLogMutex->AsReadable());

        if (gFileHandle)
        {
            gFileHandle->Write(gLogBuffer.data(), gLogBuffer.size());
        }

        gLogBuffer.clear();
    }

    static bool OpenLogFile()
    {
        AuString path;
        AuString procName;

        if (!Process::GetProcName(procName))
        {
            return false;
        }

        if (!IO::FS::GetProfileDomain(path))
        {
            return false;
        }
        
        auto tm = Time::ToCivilTime(Time::CurrentClockMS());

        path += fmt::format("/Logs/{}/{:04}-{:02}-{:02}T{:02}-{:02}-{:02}Z.txt", 
                            procName,
                            tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
                            tm.tm_hour, tm.tm_min, tm.tm_sec);

        gFileHandle = IO::FS::OpenWriteUnique(path);
        return gFileHandle ? true : false;
    }

    static void LogThreadInit()
    {
        CleanupOldLogs();

        auto thread = Threading::Threads::GetThread();
        while (!thread->Exiting())
        {
            Sleep(500);
            Flush();
        }
    }

    void Init()
    {
        if (!gLogConfig.enableLogging)
        {
            return;
        }

        if (!OpenLogFile())
        {
            return;
        }
        
        gLogMutex = Threading::Primitives::RWLockUnique();
        if (!gLogMutex)
        {
            return;
        }

        Threading::Threads::AbstractThreadVectors handler;
        handler.DoRun = [](Threading::Threads::IAuroraThread *)
        {
            LogThreadInit();
        };

        gFileWriterThread = Threading::Threads::ThreadUnique(handler);
        if (!gFileWriterThread)
        {
            return;
        }
        
        gFileWriterThread->SetName("ConsoleFIO");
        gFileWriterThread->Run();
        
        Console::Hooks::AddHook([&](const Console::ConsoleMessage &string) -> void
        {
            Threading::WaitableLockGuard a(gLogMutex->AsWritable());
            auto str = string.ToSimplified();
            
            gLogBuffer.reserve(gLogBuffer.size() + str.size() + 2);

            gLogBuffer.insert(gLogBuffer.end(), reinterpret_cast<AuUInt8*>(str.data()), reinterpret_cast<AuUInt8*>(str.data()) + str.size());

        #if defined(AURORA_PLATFORM_WIN32)
            gLogBuffer.insert(gLogBuffer.end(), AuUInt8('\r'));
        #endif
            gLogBuffer.insert(gLogBuffer.end(), AuUInt8('\n'));
        });
    }

    void Pump()
    {

    }

    void Exit()
    {
        Flush();
        gFileWriterThread.reset();
        gLogMutex.reset();
        gFileHandle.reset();

        CompressLogs();
    }
}