package filer

import (
	"context"
	"errors"
	"github.com/chrislusf/seaweedfs/weed/util"
	"io"
)

const CountEntryChunksForGzip = 50

var (
	ErrUnsupportedListDirectoryPrefixed      = errors.New("unsupported directory prefix listing")
	ErrUnsupportedSuperLargeDirectoryListing = errors.New("unsupported super large directory listing")
	ErrKvNotImplemented                      = errors.New("kv not implemented yet")
	ErrKvNotFound                            = errors.New("kv: not found")
)

type ListEachEntryFunc func(entry *Entry) bool

type FilerStore interface {
	// GetName gets the name to locate the configuration in filer.toml file
	GetName() string
	// Initialize initializes the file store
	Initialize(configuration util.Configuration, prefix string) error
	InsertEntry(context.Context, *Entry) error
	UpdateEntry(context.Context, *Entry) (err error)
	// err == filer_pb.ErrNotFound if not found
	FindEntry(context.Context, util.FullPath) (entry *Entry, err error)
	DeleteEntry(context.Context, util.FullPath) (err error)
	DeleteFolderChildren(context.Context, util.FullPath) (err error)
	ListDirectoryEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, eachEntryFunc ListEachEntryFunc) (lastFileName string, err error)
	ListDirectoryPrefixedEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, prefix string, eachEntryFunc ListEachEntryFunc) (lastFileName string, err error)

	BeginTransaction(ctx context.Context) (context.Context, error)
	CommitTransaction(ctx context.Context) error
	RollbackTransaction(ctx context.Context) error

	KvPut(ctx context.Context, key []byte, value []byte) (err error)
	KvGet(ctx context.Context, key []byte) (value []byte, err error)
	KvDelete(ctx context.Context, key []byte) (err error)

	Shutdown()
}

type BucketAware interface {
	OnBucketCreation(bucket string)
	OnBucketDeletion(bucket string)
	CanDropWholeBucket() bool
}

type Debuggable interface {
	Debug(writer io.Writer)
}
