package vfs

import (
	"context"
	"os"
	"time"

	db2 "gitlink.org.cn/cloudream/storage2/client/internal/db"
	"gitlink.org.cn/cloudream/storage2/client/internal/mount/fuse"
	"gitlink.org.cn/cloudream/storage2/client/internal/mount/vfs/cache"
	clitypes "gitlink.org.cn/cloudream/storage2/client/types"
	"gorm.io/gorm"
)

type FuseDir struct {
	vfs       *Vfs
	pathComps []string
	modTime   time.Time
	mode      os.FileMode
}

func newDirFromCache(ch cache.CacheEntryInfo, vfs *Vfs) *FuseDir {
	return &FuseDir{
		vfs:       vfs,
		pathComps: ch.PathComps,
		modTime:   ch.ModTime,
		mode:      ch.Mode,
	}
}

func (r *FuseDir) PathComps() []string {
	return r.pathComps
}

func (r *FuseDir) Name() string {
	return r.pathComps[len(r.pathComps)-1]
}

func (r *FuseDir) Size() int64 {
	return 0
}

func (r *FuseDir) Mode() os.FileMode {
	return os.ModeDir | r.mode
}

func (r *FuseDir) ModTime() time.Time {
	return r.modTime
}

func (r *FuseDir) IsDir() bool {
	return true
}

func (r *FuseDir) SetModTime(time time.Time) error {
	dir := r.loadCacheDir()
	if dir == nil {
		return fuse.ErrNotExists
	}

	return dir.SetModTime(time)
}

// 如果不存在，应该返回ErrNotExists
func (r *FuseDir) Child(ctx context.Context, name string) (fuse.FsEntry, error) {
	return child(r.vfs, ctx, r, name)
}

func (r *FuseDir) Children(ctx context.Context) ([]fuse.FsEntry, error) {
	return listChildren(r.vfs, ctx, r)
}

func (r *FuseDir) ReadChildren() (fuse.DirReader, error) {
	ens, err := listChildren(r.vfs, context.Background(), r)
	if err != nil {
		return nil, err
	}

	return newFuseDirReader(ens), nil
}

func (r *FuseDir) NewDir(ctx context.Context, name string) (fuse.FsDir, error) {
	return newDir(r.vfs, ctx, name, r)
}

func (r *FuseDir) NewFile(ctx context.Context, name string, flags uint32) (fuse.FileHandle, uint32, error) {
	return newFile(r.vfs, ctx, name, r, flags)
}

func (r *FuseDir) RemoveChild(ctx context.Context, name string) error {
	return removeChild(r.vfs, ctx, name, r)
}

func (r *FuseDir) MoveChild(ctx context.Context, oldName string, newName string, newParent fuse.FsDir) error {
	return moveChild(r.vfs, ctx, oldName, r, newName, newParent.(FuseNode))
}

func (r *FuseDir) loadCacheDir() *cache.CacheDir {
	var createOpt *cache.CreateDirOption

	err := r.vfs.db.DoTx(func(tx db2.SQLContext) error {
		pkg, err := r.vfs.db.Package().GetByFullName(tx, r.pathComps[0], r.pathComps[1])
		if err != nil {
			return err
		}

		err = r.vfs.db.Object().HasObjectWithPrefix(tx, pkg.PackageID, clitypes.JoinObjectPath(r.pathComps[2:]...))
		if err == nil {
			createOpt = &cache.CreateDirOption{
				ModTime: time.Now(),
			}
			return nil
		}

		if err == gorm.ErrRecordNotFound {
			return nil
		}

		return err
	})
	if err != nil {
		return nil
	}

	return r.vfs.cache.LoadDir(r.pathComps, createOpt)
}

var _ fuse.FsDir = (*FuseDir)(nil)
var _ FuseNode = (*FuseDir)(nil)