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

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

namespace Aurora::Console::ConsoleFIO
{
    static AuList<AuUInt8>                    gLogBuffer;
    static AuThreadPrimitives::RWLockUnique_t gLogMutex;
    static AuIOFS::OpenWriteUnique_t          gFileHandle;

    static const auto &gLogConfig = gRuntimeConfig.console.fio;

    AuString GetLogDirectory()
    {
        AuString path;
        AuString procName;

        if ((gLogConfig.writeLogsToUserDir) || (!IO::FS::GetProfileDomain(path)))
        {
            path = ".";
        }

        if (!Process::GetProcName(procName))
        {
            procName = "Unknown";
        }

        path += "/Logs/";
        path += procName;

        return path;
    }

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

        auto baseLogPath = GetLogDirectory();

        IO::FS::FilesInDirectory(baseLogPath, files);

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

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

    static void CompressLogs()
    {
        // TODO: write XZ's
    }

    void Flush()
    {
        /// It should be expected that the TLS teardown emergency flush to dispatch after deinit
        if (!gLogMutex)
        {
            return;
        }

        AU_LOCK_GUARD(gLogMutex->AsReadable());

        if (gFileHandle)
        {
            gFileHandle->Write(Aurora::Memory::MemoryViewStreamRead(gLogBuffer));
        }

        gLogBuffer.clear();
    }

    static bool OpenLogFile()
    {
        AuString path;

        auto tm = Time::ToCivilTime(Time::CurrentClockMS());

        path = fmt::format("{}/{:04}-{:02}-{:02}T{:02}-{:02}-{:02}Z.txt",
                           GetLogDirectory(),
                           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 static_cast<bool>(gFileHandle);
    }

    void FIOCleanup()
    {
        CleanupOldLogs();
        CompressLogs();
    }

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

        if (!OpenLogFile())
        {
            return;
        }

        gLogMutex = AuThreadPrimitives::RWLockUnique();
        if (!gLogMutex)
        {
            return;
        }

        Console::Hooks::AddFunctionalHook([&](const Console::ConsoleMessage &string) -> void
        {
            AU_LOCK_GUARD(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_IS_MODERNNT_DERIVED)
            gLogBuffer.insert(gLogBuffer.end(), AuUInt8('\r'));
        #endif
            gLogBuffer.insert(gLogBuffer.end(), AuUInt8('\n'));
        });
    }

    void Pump()
    {

    }

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