package filesys

import (
	"context"
	"fmt"

	"bazil.org/fuse"
	"bazil.org/fuse/fs"
	"github.com/chrislusf/seaweedfs/weed/glog"
	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
	"path/filepath"
	"os"
	"time"
	"github.com/chrislusf/seaweedfs/weed/filer2"
)

var _ = fs.Node(&File{})
var _ = fs.NodeOpener(&File{})
var _ = fs.NodeFsyncer(&File{})
var _ = fs.NodeSetattrer(&File{})

type File struct {
	Chunks     []*filer_pb.FileChunk
	Name       string
	dir        *Dir
	wfs        *WFS
	attributes *filer_pb.FuseAttributes
}

func (file *File) Attr(context context.Context, attr *fuse.Attr) error {

	fullPath := filepath.Join(file.dir.Path, file.Name)
	item := file.wfs.listDirectoryEntriesCache.Get(fullPath)
	if item != nil {
		entry := item.Value().(*filer_pb.Entry)
		file.Chunks = entry.Chunks
		file.attributes = entry.Attributes
		glog.V(1).Infof("file attr read cached %v attributes", file.Name)
	} else {
		err := file.wfs.withFilerClient(func(client filer_pb.SeaweedFilerClient) error {

			request := &filer_pb.GetEntryAttributesRequest{
				Name:      file.Name,
				ParentDir: file.dir.Path,
			}

			resp, err := client.GetEntryAttributes(context, request)
			if err != nil {
				glog.V(0).Infof("file attr read file %v: %v", request, err)
				return err
			}

			file.attributes = resp.Attributes
			file.Chunks = resp.Chunks

			glog.V(1).Infof("file attr %v %+v: %d", fullPath, file.attributes, filer2.TotalSize(file.Chunks))

			return nil
		})

		if err != nil {
			return err
		}
	}

	attr.Mode = os.FileMode(file.attributes.FileMode)
	attr.Size = filer2.TotalSize(file.Chunks)
	attr.Mtime = time.Unix(file.attributes.Mtime, 0)
	attr.Gid = file.attributes.Gid
	attr.Uid = file.attributes.Uid

	return nil

}

func (file *File) Open(ctx context.Context, req *fuse.OpenRequest, resp *fuse.OpenResponse) (fs.Handle, error) {

	fullPath := filepath.Join(file.dir.Path, file.Name)

	glog.V(3).Infof("%v file open %+v", fullPath, req)

	return &FileHandle{
		wfs:        file.wfs,
		dirPath:    file.dir.Path,
		name:       file.Name,
		RequestId:  req.Header.ID,
		NodeId:     req.Header.Node,
		Uid:        req.Uid,
		Gid:        req.Gid,
		attributes: file.attributes,
		Chunks:     file.Chunks,
	}, nil

}

func (file *File) Setattr(ctx context.Context, req *fuse.SetattrRequest, resp *fuse.SetattrResponse) error {
	fullPath := filepath.Join(file.dir.Path, file.Name)

	glog.V(3).Infof("%v file setattr %+v", fullPath, req)
	if req.Valid.Size() {

		if req.Size == 0 {
			fmt.Printf("truncate %v \n", fullPath)
			file.Chunks = nil
		}
		file.attributes.FileSize = req.Size
	}
	if req.Valid.Mode() {
		file.attributes.FileMode = uint32(req.Mode)
	}

	if req.Valid.Uid() {
		file.attributes.Uid = req.Uid
	}

	if req.Valid.Gid() {
		file.attributes.Gid = req.Gid
	}

	if req.Valid.Mtime() {
		file.attributes.Mtime = req.Mtime.Unix()
	}

	return nil

}

func (file *File) Fsync(ctx context.Context, req *fuse.FsyncRequest) error {
	// fsync works at OS level
	// write the file chunks to the filer
	glog.V(3).Infof("%s/%s fsync file %+v", file.dir.Path, file.Name, req)

	return nil
}