package amntfs

import (
	"git.swzry.com/ProjectNagae/FsUtils/mountree"
	"github.com/GUAIK-ORG/go-snowflake/snowflake"
	"github.com/spf13/afero"
)

var _ afero.Fs = (*AMNTFS)(nil)

type AMNTFS struct {
	mountTree  *mountree.SimpleUnixLikePathTree[*MountNode]
	snowflaker *snowflake.Snowflake
}

func NewAMNTFS() *AMNTFS {
	sn, err := snowflake.NewSnowflake(0, 0)
	if err != nil {
		panic(err)
	}
	fs := &AMNTFS{
		mountTree:  mountree.NewSimpleUnixLikePathTree[*MountNode](),
		snowflaker: sn,
	}
	return fs
}

func (fs *AMNTFS) Mount(path string, childFs afero.Fs, forceRemountExists bool) error {
	node := &MountNode{
		mountId:        fs.snowflaker.NextVal(),
		mountPoint:     path,
		filesystemType: childFs.Name(),
		filesystem:     childFs,
	}
	err := fs.mountTree.Mount(path, node, forceRemountExists)
	if err != nil {
		if mountree.CheckErrorType(err, mountree.ErrMountPointAlreadyExists) {
			return NewAMNTFSError(ErrMountPointAlreadyMounted, nil)
		} else {
			return NewAMNTFSError(ErrUnknownInternalError, err)
		}
	}
	return nil
}

func (fs *AMNTFS) Umount(path string) error {
	err := fs.mountTree.Umount(path)
	if err != nil {
		if mountree.CheckErrorType(err, mountree.ErrMountPointNotExists) {
			return NewAMNTFSError(ErrMountPointAlreadyMounted, nil)
		} else {
			return NewAMNTFSError(ErrUnknownInternalError, err)
		}
	}
	return nil
}

func (fs *AMNTFS) ListAllMount() []MountInfoEntity {
	mil := make([]MountInfoEntity, 0)
	fs.mountTree.ListAllMount(func(path string, payload *MountNode) {
		mil = append(mil, MountInfoEntity{
			MountId:    payload.MountId(),
			MountPoint: payload.MountPoint(),
			FsType:     payload.FsType(),
		})
	})
	return mil
}

func (fs *AMNTFS) getMountEntity(path string) (*MountNode, string) {
	p, remain, err := fs.mountTree.GetPayload(path)
	if err != nil {
		return nil, ""
	}
	return *p, remain
}