package redis_lua

import (
	"context"
	"fmt"

	"github.com/redis/go-redis/v9"

	"robotfs/pb"
	"robotfs/store"
	"robotfs/store/redis_lua/stored_procedure"
	"robotfs/utils"
)

const (
	DIR_LIST_MARKER = "\x00"
)

type UniversalRedisLuaStore struct {
	Client                  redis.UniversalClient
	superLargeDirectoryHash map[string]bool
}

func (store *UniversalRedisLuaStore) isSuperLargeDirectory(dir string) (isSuperLargeDirectory bool) {
	_, isSuperLargeDirectory = store.superLargeDirectoryHash[dir]
	return
}

func (store *UniversalRedisLuaStore) loadSuperLargeDirectories(superLargeDirectories []string) {
	store.superLargeDirectoryHash = make(map[string]bool)
	for _, dir := range superLargeDirectories {
		store.superLargeDirectoryHash[dir] = true
	}
}

func (store *UniversalRedisLuaStore) BeginTransaction(ctx context.Context) (context.Context, error) {
	return ctx, nil
}
func (store *UniversalRedisLuaStore) CommitTransaction(ctx context.Context) error {
	return nil
}
func (store *UniversalRedisLuaStore) RollbackTransaction(ctx context.Context) error {
	return nil
}

func (store *UniversalRedisLuaStore) InsertEntry(ctx context.Context, entry *pb.FileEntry) (err error) {

	// value, err := entry.EncodeAttributesAndChunks()
	// if err != nil {
	// 	return fmt.Errorf("encoding %s %+v: %v", entry.FullPath, entry.Attr, err)
	// }

	// if len(entry.GetChunks()) > CountEntryChunksForGzip {
	// 	value = util.MaybeGzipData(value)
	// }

	// dir, name := entry.FullPath.DirAndName()

	// err = stored_procedure.InsertEntryScript.Run(ctx, store.Client,
	// 	[]string{string(entry.FullPath), genDirectoryListKey(dir)},
	// 	value, entry.TtlSec,
	// 	store.isSuperLargeDirectory(dir), 0, name).Err()

	// if err != nil {
	// 	return fmt.Errorf("persisting %s : %v", entry.FullPath, err)
	// }

	return nil
}

func (store *UniversalRedisLuaStore) UpdateEntry(ctx context.Context, entry *pb.FileEntry) (err error) {

	return store.InsertEntry(ctx, entry)
}

func (store *UniversalRedisLuaStore) FindEntry(ctx context.Context, fullpath utils.FullPath) (entry *pb.FileEntry, err error) {

	// data, err := store.Client.Get(ctx, string(fullpath)).Result()
	// if err == redis.Nil {
	// 	return nil, pb.ErrNotFound
	// }

	// if err != nil {
	// 	return nil, fmt.Errorf("get %s : %v", fullpath, err)
	// }

	// entry = &pb.FileEntry{
	// 	FullPath: fullpath.Name(),
	// }
	// err = entry.DecodeAttributesAndChunks(util.MaybeDecompressData([]byte(data)))
	// if err != nil {
	// 	return entry, fmt.Errorf("decode %s : %v", entry.FullPath, err)
	// }

	return entry, nil
}

func (store *UniversalRedisLuaStore) DeleteEntry(ctx context.Context, fullpath utils.FullPath) (err error) {

	dir, name := fullpath.DirAndName()

	err = stored_procedure.DeleteEntryScript.Run(ctx, store.Client,
		[]string{string(fullpath), genDirectoryListKey(string(fullpath)), genDirectoryListKey(dir)},
		store.isSuperLargeDirectory(dir), name).Err()

	if err != nil {
		return fmt.Errorf("DeleteEntry %s : %v", fullpath, err)
	}

	return nil
}

func (store *UniversalRedisLuaStore) DeleteFolderChildren(ctx context.Context, fullpath utils.FullPath) (err error) {

	if store.isSuperLargeDirectory(string(fullpath)) {
		return nil
	}

	err = stored_procedure.DeleteFolderChildrenScript.Run(ctx, store.Client,
		[]string{string(fullpath)}).Err()

	if err != nil {
		return fmt.Errorf("DeleteFolderChildren %s : %v", fullpath, err)
	}

	return nil
}

func (store *UniversalRedisLuaStore) ListDirectoryPrefixedEntries(ctx context.Context, dirPath utils.FullPath, startFileName string, includeStartFile bool, limit int64, prefix string, eachEntryFunc store.ListEachEntryFunc) (lastFileName string, err error) {
	// return lastFileName, engine.ErrUnsupportedListDirectoryPrefixed
	return lastFileName, err
}

func (store *UniversalRedisLuaStore) ListDirectoryEntries(ctx context.Context, dirPath utils.FullPath, startFileName string, includeStartFile bool, limit int64, eachEntryFunc store.ListEachEntryFunc) (lastFileName string, err error) {

	// dirListKey := genDirectoryListKey(string(dirPath))

	// min := "-"
	// if startFileName != "" {
	// 	if includeStartFile {
	// 		min = "[" + startFileName
	// 	} else {
	// 		min = "(" + startFileName
	// 	}
	// }

	// members, err := store.Client.ZRangeByLex(ctx, dirListKey, &redis.ZRangeBy{
	// 	Min:    min,
	// 	Max:    "+",
	// 	Offset: 0,
	// 	Count:  limit,
	// }).Result()
	// if err != nil {
	// 	return lastFileName, fmt.Errorf("list %s : %v", dirPath, err)
	// }

	// // fetch entry meta
	// for _, fileName := range members {
	// 	path := utils.NewFullPath(string(dirPath), fileName)
	// 	entry, err := store.FindEntry(ctx, path)
	// 	lastFileName = fileName
	// 	if err != nil {

	// 		if err == pb.ErrNotFound {
	// 			continue
	// 		}
	// 	} else {
	// 		if entry.TtlSec > 0 {
	// 			if entry.Attr.Crtime.Add(time.Duration(entry.TtlSec) * time.Second).Before(time.Now()) {
	// 				store.DeleteEntry(ctx, path)
	// 				continue
	// 			}
	// 		}
	// 		if !eachEntryFunc(entry) {
	// 			break
	// 		}
	// 	}
	// }

	return lastFileName, err
}

func genDirectoryListKey(dir string) (dirList string) {
	return dir + DIR_LIST_MARKER
}

func (store *UniversalRedisLuaStore) Shutdown() {
	store.Client.Close()
}