Feat/Add post processors + refactor project (#37)

* chg: feat: clean known patterns from title

* chg: refactor: remove duplicated code, and improve maintainability

* chg: feat: add audio tagging post-processor

* chg: refactor: add generic parallelMap function

* chg: refactor: move more function to common locations

* chg: docs: add func docs

api/post_processors.go

@@ -0,0 +1,61 @@
+package handler
+
+import (
+	"fmt"
+	"net/http"
+	"slices"
+	"strings"
+
+	"github.com/felipemarinho97/torrent-indexer/schema"
+	"github.com/felipemarinho97/torrent-indexer/utils"
+	"github.com/hbollon/go-edlib"
+)
+
+// CleanupTitleWebsites removes unwanted characters from the title
+func CleanupTitleWebsites(_ *Indexer, _ *http.Request, torrents []schema.IndexedTorrent) []schema.IndexedTorrent {
+	for i := range torrents {
+		torrents[i].Title = utils.RemoveKnownWebsites(torrents[i].Title)
+	}
+	return torrents
+}
+
+func AppendAudioTags(_ *Indexer, _ *http.Request, torrents []schema.IndexedTorrent) []schema.IndexedTorrent {
+	for i, it := range torrents {
+		torrents[i].Title = appendAudioISO639_2Code(torrents[i].Title, it.Audio)
+	}
+
+	return torrents
+}
+
+// SendToSearchIndexer sends the indexed torrents to the search indexer
+func SendToSearchIndexer(i *Indexer, _ *http.Request, torrents []schema.IndexedTorrent) []schema.IndexedTorrent {
+	go func() {
+		_ = i.search.IndexTorrents(torrents)
+	}()
+	return torrents
+}
+
+func AddSimilarityCheck(i *Indexer, r *http.Request, torrents []schema.IndexedTorrent) []schema.IndexedTorrent {
+	q := r.URL.Query().Get("q")
+
+	for i, it := range torrents {
+		jLower := strings.ReplaceAll(strings.ToLower(fmt.Sprintf("%s %s", it.Title, it.OriginalTitle)), ".", " ")
+		qLower := strings.ToLower(q)
+		splitLength := 2
+		torrents[i].Similarity = edlib.JaccardSimilarity(jLower, qLower, splitLength)
+	}
+
+	// remove the ones with zero similarity
+	if len(torrents) > 20 && r.URL.Query().Get("filter_results") != "" && r.URL.Query().Get("q") != "" {
+		torrents = utils.Filter(torrents, func(it schema.IndexedTorrent) bool {
+			return it.Similarity > 0
+		})
+	}
+
+	// sort by similarity
+	slices.SortFunc(torrents, func(i, j schema.IndexedTorrent) int {
+		return int((j.Similarity - i.Similarity) * 1000)
+	})
+
+	return torrents
+}