package storage

import (
	"fmt"
	"io/ioutil"
	"path"
	"regexp"
	"sort"
	"strconv"

	"github.com/chrislusf/seaweedfs/weed/storage/erasure_coding"
	"github.com/chrislusf/seaweedfs/weed/storage/needle"
)

var (
	re = regexp.MustCompile("\\.ec[0-9][0-9]")
)

func (l *DiskLocation) loadEcShards(baseName string, shards []string, collection string, vid needle.VolumeId) (err error){

	for _, shard := range shards{
		shardId, err := strconv.ParseInt(path.Ext(shard)[3:], 10, 64)
		if err != nil {
			return fmt.Errorf("failed to parse ec shard name %v: %v", shard, err)
		}
		ecVolumeShard, err := erasure_coding.NewEcVolumeShard(l.Directory, collection, vid, int(shardId))
		if err != nil {
			return fmt.Errorf("failed to create ec shard %v: %v", shard, err)
		}
		l.ecShardsLock.Lock()
		l.ecShards[vid] = append(l.ecShards[vid], ecVolumeShard)
		l.ecShardsLock.Unlock()
	}

	return nil
}

func (l *DiskLocation) loadAllEcShards() (err error){

	fileInfos, err := ioutil.ReadDir(l.Directory)
	if err != nil {
		return fmt.Errorf("load all ec shards in dir %s: %v", l.Directory, err)
	}

	sort.Slice(fileInfos, func(i, j int) bool {
		return fileInfos[i].Name() < fileInfos[j].Name()
	})

	var sameVolumeShards []string
	var prevVolumeId needle.VolumeId
	for _, fileInfo := range fileInfos{
		if fileInfo.IsDir(){
			continue
		}
		ext := path.Ext(fileInfo.Name())
		name := fileInfo.Name()
		baseName := name[:len(name)-len(ext)]

		collection, volumeId, err := parseCollectionVolumeId(baseName)
		if err != nil {
			continue
		}

		if re.MatchString(ext){
			if prevVolumeId == 0 || volumeId == prevVolumeId {
				sameVolumeShards = append(sameVolumeShards, fileInfo.Name())
			}else{
				sameVolumeShards = []string{fileInfo.Name()}
			}
			prevVolumeId = volumeId
			continue
		}

		if ext == ".ecx" && volumeId == prevVolumeId{
			if err = l.loadEcShards(baseName, sameVolumeShards, collection, volumeId);err!=nil{
				return fmt.Errorf("loadEcShards collection:%v volumeId:%d : %v", collection, volumeId, err)
			}
			prevVolumeId = volumeId
			continue
		}

	}
	return nil
}