/***
    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 AuROString &physicalDevicePath)
    {
        InitPlatformFSCacheAtLoad();

        AU_LOCK_GLOBAL_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 AuROString &path)
    {
        AuPair<AuUInt, const FSDevice *> lastDev =
            AuMakePair<AuUInt, const FSDevice *>(0, nullptr);

        InitPlatformFSCacheAtLoad();

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

        AU_LOCK_GLOBAL_GUARD(gFSDirMutex);

        for (const auto &refFSDevice : gCachedDevices)
        {
            for (const auto &refPart : refFSDevice.partitions)
            {
                for (const auto &refMnt : refPart.filesystemMountPoints)
                {
                    if (AuStartsWith(path, refMnt))
                    {
                        if (AuGet<0>(lastDev) < refMnt.size())
                        {
                            lastDev = AuMakePair(refMnt.size(), &refFSDevice);
                        }
                    }
                }
            }
        }

        if (AuGet<0>(lastDev) == 0)
        {
            return {};
        }

        auto copy = *AuGet<1>(lastDev);
        return AuMove(copy);
    }

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

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

        AU_LOCK_GLOBAL_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_GLOBAL_GUARD(gFSDirMutex);
        gCachedDevices = AuMove(SysGetFSDevices());
    }
}