package filer_pb

import (
	"fmt"
	"sync"
	"time"

	"github.com/chrislusf/seaweedfs/weed/util"
)

func TraverseBfs(filerClient FilerClient, parentPath util.FullPath, fn func(parentPath util.FullPath, entry *Entry)) (err error) {

	K := 5

	var jobQueueWg sync.WaitGroup
	queue := util.NewQueue()
	jobQueueWg.Add(1)
	queue.Enqueue(parentPath)
	var isTerminating bool

	for i := 0; i < K; i++ {
		go func() {
			for {
				if isTerminating {
					break
				}
				t := queue.Dequeue()
				if t == nil {
					time.Sleep(329 * time.Millisecond)
					continue
				}
				dir := t.(util.FullPath)
				processErr := processOneDirectory(filerClient, dir, queue, &jobQueueWg, fn)
				if processErr != nil {
					err = processErr
				}
				jobQueueWg.Done()
			}
		}()
	}
	jobQueueWg.Wait()
	isTerminating = true
	return
}

func processOneDirectory(filerClient FilerClient, parentPath util.FullPath, queue *util.Queue, jobQueueWg *sync.WaitGroup, fn func(parentPath util.FullPath, entry *Entry)) (err error) {

	return ReadDirAllEntries(filerClient, parentPath, "", func(entry *Entry, isLast bool) error {

		fn(parentPath, entry)

		if entry.IsDirectory {
			subDir := fmt.Sprintf("%s/%s", parentPath, entry.Name)
			if parentPath == "/" {
				subDir = "/" + entry.Name
			}
			jobQueueWg.Add(1)
			queue.Enqueue(util.FullPath(subDir))
		}
		return nil
	})

}