package local

import (
	"crypto/sha256"
	"io"
	"os"
	"path/filepath"

	"gitlink.org.cn/cloudream/common/pkgs/logger"
	"gitlink.org.cn/cloudream/common/utils/io2"
	stgtypes "gitlink.org.cn/cloudream/jcs-pub/common/pkgs/storage/types"
	jcstypes "gitlink.org.cn/cloudream/jcs-pub/common/types"
)

type BaseStore struct {
	root   string
	detail *jcstypes.UserSpaceDetail
}

func NewBaseStore(root string, detail *jcstypes.UserSpaceDetail) (*BaseStore, error) {
	return &BaseStore{
		root:   root,
		detail: detail,
	}, nil
}

func (s *BaseStore) Write(pat jcstypes.JPath, stream io.Reader, opt stgtypes.WriteOption) (stgtypes.FileInfo, error) {
	log := s.getLogger()

	absObjPath := filepath.Join(s.root, pat.String())

	err := os.MkdirAll(filepath.Dir(absObjPath), 0755)
	if err != nil {
		return stgtypes.FileInfo{}, err
	}

	f, err := os.Create(absObjPath)
	if err != nil {
		return stgtypes.FileInfo{}, err
	}
	defer f.Close()

	counter := io2.Counter(stream)
	hasher := io2.NewReadHasher(sha256.New(), counter)

	_, err = io.Copy(f, hasher)
	if err != nil {
		return stgtypes.FileInfo{}, err
	}

	if !opt.ModTime.IsZero() {
		err := os.Chtimes(absObjPath, opt.ModTime, opt.ModTime)
		if err != nil {
			log.Warnf("change file %v mod time: %v", absObjPath, err)
		}
	}

	return stgtypes.FileInfo{
		Path: pat,
		Size: counter.Count(),
		Hash: jcstypes.NewFullHash(hasher.Sum()),
	}, nil
}

func (s *BaseStore) Read(objPath jcstypes.JPath, opt stgtypes.OpenOption) (io.ReadCloser, error) {
	absObjPath := filepath.Join(s.root, objPath.JoinOSPath())
	file, err := os.Open(absObjPath)
	if err != nil {
		return nil, err
	}

	if opt.Offset > 0 {
		_, err = file.Seek(opt.Offset, io.SeekStart)
		if err != nil {
			file.Close()
			return nil, err
		}
	}

	var ret io.ReadCloser = file

	if opt.Length >= 0 {
		ret = io2.Length(ret, opt.Length)
	}

	return ret, nil
}

func (s *BaseStore) Mkdir(path jcstypes.JPath) error {
	absObjPath := filepath.Join(s.root, path.JoinOSPath())
	err := os.MkdirAll(absObjPath, 0755)
	if err != nil {
		return err
	}

	return nil
}

func (s *BaseStore) ReadDir(pat jcstypes.JPath) stgtypes.DirReader {
	return &DirReader{
		absRootPath: filepath.Join(s.root, pat.JoinOSPath()),
		rootJPath:   pat.Clone(),
	}
}

func (s *BaseStore) CleanTemps() {
	log := s.getLogger()

	tempDir := filepath.Join(s.root, s.detail.UserSpace.WorkingDir.JoinOSPath(), stgtypes.TempWorkingDir)
	entries, err := os.ReadDir(tempDir)
	if err != nil {
		log.Warnf("read temp dir: %v", err)
		return
	}

	for _, entry := range entries {
		if entry.IsDir() {
			continue
		}

		info, err := entry.Info()
		if err != nil {
			log.Warnf("get temp file %v info: %v", entry.Name(), err)
			continue
		}

		path := filepath.Join(tempDir, entry.Name())
		err = os.Remove(path)
		if err != nil {
			log.Warnf("remove temp file %v: %v", path, err)
		} else {
			log.Infof("remove unused temp file %v, size: %v, last mod time: %v", path, info.Size(), info.ModTime())
		}
	}
}

func (s *BaseStore) Test() error {
	_, err := os.Stat(s.root)
	return err
}

func (s *BaseStore) getLogger() logger.Logger {
	return logger.WithField("BaseStore", "Local").WithField("UserSpace", s.detail.UserSpace)
}