#include "TessesFramework/Filesystem/MountableFilesystem.hpp"
#include "TessesFramework/Filesystem/NullFilesystem.hpp"
#include <iostream>
namespace Tesses::Framework::Filesystem
{
    MountableFilesystem::MountableFilesystem() : MountableFilesystem(std::make_shared<NullFilesystem>())
    {

    }
    MountableFilesystem::MountableFilesystem(std::shared_ptr<VFS> root)
    {
        this->root = root;
    }
    MountableDirectory::~MountableDirectory()
    {
        for(auto dir : this->dirs) delete dir;
    }

    MountableFilesystem::~MountableFilesystem()
    {
        for(auto item : this->directories) delete item;
    }




    void MountableFilesystem::GetFS(VFSPath srcPath, VFSPath& destRoot, VFSPath& destPath, std::shared_ptr<VFS>& vfs)
    {
        if(srcPath.path.empty()) return;
        for(auto item : this->directories)
        {
            if(srcPath.path.front() == item->name)
            {
                if(item->vfs != nullptr)
                {
                    vfs = item->vfs;
                    VFSPath srcPath1(std::vector(srcPath.path.begin()+1,srcPath.path.end()));
                    srcPath1.relative=false;
                    destPath = srcPath1;
                    destRoot = VFSPath(VFSPath(),item->name);


                }
                VFSPath srcPath2(std::vector(srcPath.path.begin()+1,srcPath.path.end()));
                srcPath2.relative=false;
                item->GetFS(srcPath2,VFSPath(VFSPath(),item->name), destRoot,destPath,vfs);
                return;
            }
        }
    }



    void MountableDirectory::GetFS(VFSPath srcPath, VFSPath curDir, VFSPath& destRoot, VFSPath& destPath, std::shared_ptr<VFS>& vfs)
    {
        if(srcPath.path.empty()) return;
        for(auto item : this->dirs)
        {
            if(!srcPath.path.empty() && srcPath.path.front() == item->name)
            {
                if(item->vfs != nullptr)
                {
                    vfs = item->vfs;

                    VFSPath srcPath1(std::vector(srcPath.path.begin()+1,srcPath.path.end()));

                    srcPath1.relative=false;
                    destPath = srcPath1;
                    destRoot = curDir;

                }
                VFSPath srcPath2(std::vector(srcPath.path.begin()+1,srcPath.path.end()));
                srcPath2.relative=false;
                item->GetFS(srcPath2,VFSPath(curDir,item->name), destRoot,destPath,vfs);
                return;
            }
        }
    }

    VFSPath MountableFilesystem::ReadLink(VFSPath path)
    {
        path = path.CollapseRelativeParents();
        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);
        if(vfs != nullptr)
            return VFSPath(destRoot,vfs->ReadLink(destPath));
        return VFSPath();
    }

    bool MountableFilesystem::StatVFS(VFSPath path, StatVFSData& data)
    {
        path = path.CollapseRelativeParents();
        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);
        if(vfs != nullptr)
            return vfs->StatVFS(destPath,data);
        return false;
    }

    bool MountableFilesystem::Stat(VFSPath path, StatData& data)
    {
        path = path.CollapseRelativeParents();
        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);
        if(vfs != nullptr)
            return vfs->Stat(destPath,data);
        return false;
    }


    void MountableFilesystem::Chmod(VFSPath path, uint32_t mode)
    {
        path = path.CollapseRelativeParents();
        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);
        if(vfs != nullptr)
            vfs->Chmod(destPath,mode);
    }

    void MountableFilesystem::Chown(VFSPath path, uint32_t uid, uint32_t gid)
    {
        path = path.CollapseRelativeParents();
        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);
        if(vfs != nullptr)
            vfs->Chown(destPath,uid, gid);
    }


    FIFOCreationResult MountableFilesystem::CreateFIFO(VFSPath path, uint32_t mod)
    {
        path = path.CollapseRelativeParents();
        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);
        if(vfs != nullptr)
            return vfs->CreateFIFO(destPath,mod);
        return FIFOCreationResult::UnknownError;
    }


    std::shared_ptr<Tesses::Framework::Streams::Stream> MountableFilesystem::OpenFile(VFSPath path, std::string mode)
    {
        path = path.CollapseRelativeParents();
        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);

        if(vfs != nullptr)
            return vfs->OpenFile(destPath,mode);
        return nullptr;
    }
    void MountableFilesystem::CreateDirectory(VFSPath path)
    {
        path = path.CollapseRelativeParents();

        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);

        if(destPath.path.empty()) return;

        if(vfs != nullptr)
            vfs->CreateDirectory(destPath);

    }


    void MountableFilesystem::DeleteDirectory(VFSPath path)
    {
         path = path.CollapseRelativeParents();

        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);

        if(destPath.path.empty()) return;

        if(vfs != nullptr)
            vfs->DeleteDirectory(destPath);

    }




    void MountableFilesystem::DeleteFile(VFSPath path)
    {
        path = path.CollapseRelativeParents();

        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);

        if(vfs != nullptr)
            vfs->DeleteFile(destPath);

    }
     void MountableFilesystem::Lock(VFSPath path)
    {
        path = path.CollapseRelativeParents();

        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);

        if(vfs != nullptr)
            vfs->Lock(destPath);

    }
     void MountableFilesystem::Unlock(VFSPath path)
    {
        path = path.CollapseRelativeParents();

        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);

        if(vfs != nullptr)
            vfs->Unlock(destPath);

    }
    void MountableFilesystem::SetDate(VFSPath path, Date::DateTime lastWrite, Date::DateTime lastAccess)
    {

        path = path.CollapseRelativeParents();

        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);

        if(vfs != nullptr)
            vfs->SetDate(destPath,lastWrite,lastAccess);
    }
    void MountableFilesystem::CreateSymlink(VFSPath existingFile, VFSPath symlinkFile)
    {
        existingFile = existingFile.CollapseRelativeParents();
        symlinkFile = existingFile.CollapseRelativeParents();

        VFSPath existingDestRoot;
        VFSPath existingDestPath = existingFile;
        std::shared_ptr<VFS> existingVFS = root;
        VFSPath symlinkDestRoot;
        VFSPath symlinkDestPath = symlinkFile;
        std::shared_ptr<VFS> symlinkVFS = root;

        GetFS(existingFile, existingDestRoot, existingDestPath, existingVFS);
        GetFS(symlinkFile, symlinkDestRoot, symlinkDestPath, symlinkVFS);

        if(existingVFS != nullptr && existingVFS == symlinkVFS)
            existingVFS->CreateSymlink(existingDestPath, symlinkDestPath);
    }

    void MountableFilesystem::MoveDirectory(VFSPath src, VFSPath dest)
    {
        src = src.CollapseRelativeParents();
        dest = dest.CollapseRelativeParents();

        VFSPath srcDestRoot;
        VFSPath srcDestPath = src;
        std::shared_ptr<VFS> srcVFS = root;
        VFSPath destDestRoot;
        VFSPath destDestPath = dest;
        std::shared_ptr<VFS> destVFS = root;

        GetFS(src, srcDestRoot, srcDestPath, srcVFS);
        GetFS(dest, destDestRoot, destDestPath, destVFS);

        if(srcVFS != nullptr && srcVFS == destVFS)
            srcVFS->MoveDirectory(srcDestPath, destDestPath);
    }
    void MountableFilesystem::MoveFile(VFSPath src, VFSPath dest)
    {
        src = src.CollapseRelativeParents();
        dest = dest.CollapseRelativeParents();

        VFSPath srcDestRoot;
        VFSPath srcDestPath = src;
        std::shared_ptr<VFS> srcVFS = root;
        VFSPath destDestRoot;
        VFSPath destDestPath = dest;
        std::shared_ptr<VFS> destVFS = root;

        GetFS(src, srcDestRoot, srcDestPath, srcVFS);
        GetFS(dest, destDestRoot, destDestPath, destVFS);

        if(srcVFS != nullptr && srcVFS == destVFS)
            srcVFS->MoveFile(srcDestPath, destDestPath);
    }
    void MountableFilesystem::CreateHardlink(VFSPath existingFile, VFSPath newName)
    {
        existingFile = existingFile.CollapseRelativeParents();
        newName = existingFile.CollapseRelativeParents();

        VFSPath existingDestRoot;
        VFSPath existingDestPath = existingFile;
        std::shared_ptr<VFS> existingVFS = root;
        VFSPath newNameRoot;
        VFSPath newNamePath = newName;
        std::shared_ptr<VFS> newNameVFS = root;

        GetFS(existingFile, existingDestRoot, existingDestPath, existingVFS);
        GetFS(newName, newNameRoot, newNamePath, newNameVFS);

        if(existingVFS != nullptr && existingVFS == newNameVFS)
            existingVFS->CreateHardlink(existingDestPath, newNamePath);
    }
    class MountableEnumerationState {
        public:
            VFSPathEnumerator* enumerator;
            std::vector<MountableDirectory*> dirs;
            size_t index;
    };
    VFSPathEnumerator MountableFilesystem::EnumeratePaths(VFSPath path)
    {

        path = path.CollapseRelativeParents();
        bool mydirs = path.path.empty();
        std::vector<MountableDirectory*>* dirs = &this->directories;

        if(!path.path.empty())
        for(auto p : path.path)
        {
            mydirs=true;
            bool hasSet=false;

            for(auto itm : *dirs)
            {
                if(itm->name == p)
                {
                    hasSet=true;
                    dirs = &itm->dirs;
                    break;
                }
            }

            if(!hasSet)
            {
                mydirs=false;
                break;
            }
        }

        VFSPath destRoot;
        VFSPath destPath = path;
        std::shared_ptr<VFS> vfs = root;

        GetFS(path, destRoot, destPath, vfs);


        MountableEnumerationState* state = new MountableEnumerationState();
        state->dirs = *dirs;
        state->index = 0;
        if(vfs->DirectoryExists(destPath) || !mydirs)
        state->enumerator = vfs->EnumeratePaths(destPath).MakePointer();
        else
        state->enumerator = nullptr;

        return VFSPathEnumerator([state,path](VFSPath& path0)->bool{

            while(state->enumerator != nullptr && state->enumerator->MoveNext())
            {
                auto fname = state->enumerator->Current.GetFileName();

                bool mustContinue=false;
                for(auto item : state->dirs)
                {
                    if(item->name == fname)
                    {
                        mustContinue=true;
                        break;
                    }
                }
                if(mustContinue) continue;
                path0 = path / fname;
                return true;
            }
            if(state->enumerator != nullptr)
            {
                delete state->enumerator;
                state->enumerator = nullptr;
            }
            if(state->index < state->dirs.size())
            {
                path0 =  path / state->dirs[state->index++]->name;
                return true;
            }
            return false;
        },[state]()->void{
            if(state->enumerator) delete state->enumerator;
            delete state;
        });
    }

    void MountableFilesystem::Mount(VFSPath path, std::shared_ptr<VFS> fs)
    {
         path = path.CollapseRelativeParents();

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

        auto* fsLs = &this->directories;
        bool needToCreate=true;
        for(auto index = path.path.begin(); index < path.path.end()-1; index++)
        {
            needToCreate=true;
            for(auto item : *fsLs)
            {
                if(item->name == *index)
                {
                    needToCreate=false;
                    fsLs = &(item->dirs);
                    break;
                }
            }
            if(needToCreate)
            {
                MountableDirectory* dir = new MountableDirectory();
                dir->name = *index;
                dir->owns=false;
                dir->vfs=NULL;

                fsLs->push_back(dir);
                fsLs = &(dir->dirs);
            }
        }

        needToCreate=true;
        std::string lastDir = path.GetFileName();

        for(auto item : *fsLs)
        {
            if(item->name == lastDir)
            {
                needToCreate=false;

                item->vfs = fs;
                break;
            }
        }

        if(needToCreate)
        {
             MountableDirectory* dir = new MountableDirectory();
                dir->name = lastDir;

                dir->vfs=fs;
                fsLs->push_back(dir);
        }

    }

    static bool myumount(MountableDirectory* dir,VFSPath path)
    {
        if(path.path.empty())
        {
            dir->vfs = nullptr;
        }

        if(dir->dirs.empty())
        {
            delete dir;
            return true;
        }

        for(auto index = dir->dirs.begin(); index < dir->dirs.end(); index++)
        {
            auto item = *index;
            if(!path.path.empty() && path.path.front() == item->name)
            {
                VFSPath srcPath2(std::vector(path.path.begin()+1,path.path.end()));



                if(myumount(item,srcPath2))
                {
                    dir->dirs.erase(index);
                }

                if(dir->dirs.empty())
                {
                    delete dir;
                    return true;
                }
                return false;
            }
        }
        return false;
    }

    void MountableFilesystem::Unmount(VFSPath path)
    {
        path = path.CollapseRelativeParents();

        for(auto index = this->directories.begin(); index < this->directories.end(); index++)
        {
            auto item = *index;
            if(!path.path.empty() && path.path.front() == item->name)
            {
                 VFSPath srcPath2(std::vector(path.path.begin()+1,path.path.end()));

                if(myumount(item,srcPath2))
                {
                    this->directories.erase(index);
                }
                return;
            }
        }
    }

    std::string MountableFilesystem::VFSPathToSystem(VFSPath path)
    {
        return path.ToString();
    }
    VFSPath MountableFilesystem::SystemToVFSPath(std::string path)
    {
        return VFSPath(path);
    }
}