/***
    Copyright (C) 2023 Jamie Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: FSPlatformDevices.cpp
    Date: 2023-08-11
    Date: 2023-12-05
    Author: Reece
***/
#include <Source/RuntimeInternal.hpp>
#include "FS.hpp"
#include "FSPlatformDevices.hpp"

namespace Aurora::IO::FS
{
    void InitPlatformFSCacheAtLoad()
    {
        static AuInitOnce gInitOnce;

        gInitOnce.Call([]()
        {
            ResetDeviceCache();
        });
    }

    AUKN_SYM AuResult<AuString> GetDeviceModel(const AuString &physicalDevicePath)
    {
        InitPlatformFSCacheAtLoad();

        AU_LOCK_GUARD(gFSDirMutex);
        for (const auto &refFSDevice : gCachedDevices)
        {
            if (refFSDevice.devicePath == physicalDevicePath)
            {
                auto copy = refFSDevice.productModel;
                return AuMove(copy);
            }
        }

        return {};
    }

    AUKN_SYM AuResult<FSDevice>      GetFSDeviceByFilePath(const AuString &path)
    {
        AuList<AuPair<AuUInt, const FSDevice *>> devs;

        InitPlatformFSCacheAtLoad();

        auto normalized = AuFS::NormalizePathRet(path);
        if (normalized.empty())
        {
            return {};
        }

        {
            AU_LOCK_GUARD(gFSDirMutex);

            for (const auto &refFSDevice : gCachedDevices)
            {
                for (const auto &refPart : refFSDevice.partitions) // todo sort
                {
                    for (const auto &refMnt : refPart.filesystemMountPoints) // todo sort
                    {
                        if (AuStartsWith(path, refMnt))
                        {
                            devs.push_back(AuMakePair(refMnt.size(), &refFSDevice));
                        }
                    }
                }
            }
        }

        if (devs.empty())
        {
            return {};
        }

        std::sort(devs.begin(),
                  devs.end(),
                  [](AuPair<AuUInt, const FSDevice *> a, AuPair<AuUInt, const FSDevice *> b)
        {
            return AuGet<0>(a) > AuGet<0>(b);
        });

        auto copy = AuGet<1>(devs[0]);
        return AuMove(copy);
    }

    AUKN_SYM AuList<FSDevice>        GetFSDevices()
    {
        InitPlatformFSCacheAtLoad();
        AU_LOCK_GUARD(gFSDirMutex);
        return gCachedDevices;
    } 

    AUKN_SYM AuResult<FSDevice>      GetFSDeviceByDevice(const AuString &physicalDevicePath)
    {
        InitPlatformFSCacheAtLoad();

        AU_LOCK_GUARD(gFSDirMutex);
        for (const auto &refFSDevice : gCachedDevices)
        {
            if (refFSDevice.devicePath == physicalDevicePath)
            {
                auto copy = refFSDevice;
                return AuMove(copy);
            }
        }

        return {};
    }

    AUKN_SYM const AuList<FSDevice> &GetFSDevicesCachedUnsafe()
    {
        InitPlatformFSCacheAtLoad();
        return gCachedDevices;
    }

    AuList<FSDevice> SysGetFSDevices();

    AUKN_SYM void ResetDeviceCache()
    {
        AU_LOCK_GUARD(gFSDirMutex);
        gCachedDevices = AuMove(SysGetFSDevices());
    }
}