// AutocompleteBenchmark returns a configured autocomplete benchmarking function to be run by
// the benchmarker
func AutocompleteBenchmark(ac index.Autocompleter, fuzzy bool) func() error {
	counter := 0
	sz := len(prefixes)
	return func() error {
		_, err := ac.Suggest(prefixes[rand.Intn(sz)], 5, fuzzy)
		counter++
		return err
	}
}
// IngestDocuments ingests documents into an index using a DocumentReader
func IngestDocuments(fileName string, r DocumentReader, idx index.Index, ac index.Autocompleter, opts interface{}, chunk int) error {

	// open the file
	fp, err := os.Open(fileName)
	if err != nil {
		return err
	}
	defer fp.Close()

	// run the reader and let it spawn a goroutine
	ch, err := r.Read(fp)
	if err != nil {
		return err
	}

	docs := make([]index.Document, chunk)
	terms := make([]index.Suggestion, chunk)

	//freqs := map[string]int{}
	st := time.Now()

	nterms := 0
	i := 0
	n := 0
	dt := 0

	for doc := range ch {

		docs[i%chunk] = doc

		if doc.Score > 0 && ac != nil {

			//			words := strings.Fields(strings.ToLower(doc.Properties["body"].(string)))
			//			for _, w := range words {
			//				for i := 2; i < len(w) && i < 5; i++ {
			//					freqs[w[:i]] += 1
			//				}
			//			}

			terms[nterms] = index.Suggestion{
				strings.ToLower(doc.Properties["title"].(string)),
				float64(doc.Score),
			}
			nterms++

			if nterms == chunk {

				//				for k, v := range freqs {
				//					fmt.Printf("%d %s\n", v, k)
				//				}
				//				os.Exit(0)
				if err := ac.AddTerms(terms...); err != nil {
					return err
				}
				nterms = 0
			}

		}
		if doc.Score == 0 {
			doc.Score = 0.0000001
		}

		for k, v := range doc.Properties {
			switch s := v.(type) {
			case string:
				dt += len(s) + len(k)
			}
		}

		i++
		n++
		if i%chunk == 0 {
			if err := idx.Index(docs, opts); err != nil {
				return err
			}
		}

		// print report every CHUNK documents
		if i%chunk == 0 {
			rate := float32(n) / (float32(time.Since(st).Seconds()))
			dtrate := float32(dt) / (float32(time.Since(st).Seconds())) / float32(1024*1024)
			fmt.Println(i, "rate: ", rate, "d/s. data rate: ", dtrate, "MB/s")
			st = time.Now()
			n = 0
			dt = 0
		}
	}

	if i%chunk != 0 {
		return idx.Index(docs[:i%chunk], opts)
	}
	return nil
}