feat: initial commit — unarr CLI

Search, inspect, stream, and download torrents from the terminal.
Replaces the entire *arr stack with a single binary.

internal/parser/torrent.go

@@ -0,0 +1,114 @@
+package parser
+
+import (
+	"net/url"
+	"regexp"
+	"strings"
+)
+
+// ParsedTorrent contains information extracted from a magnet URI, hash, or torrent name.
+type ParsedTorrent struct {
+	InfoHash string
+	Name     string
+	Quality  string
+	Codec    string
+	Year     string
+	IsMagnet bool
+}
+
+var (
+	hashRegex       = regexp.MustCompile(`^[a-fA-F0-9]{40}$`)
+	qualityRegex    = regexp.MustCompile(`(?i)(2160p|1080p|720p|480p|4K|UHD)`)
+	codecRegex      = regexp.MustCompile(`(?i)(x264|x265|h\.?264|h\.?265|HEVC|AVC|AV1|VP9|XviD|DivX)`)
+	yearRegex       = regexp.MustCompile(`(?:^|[\s.(])((?:19|20)\d{2})(?:[\s.)]|$)`)
+	artifactsRegex  = regexp.MustCompile(`(?i)(BluRay|BDRip|HDRip|WEBRip|WEB-DL|HDTV|DVDRip|BRRip|CAM|TS|TC|PROPER|REPACK|REMASTERED|REMUX|EXTENDED|UNRATED|IMAX|DUAL|MULTi|AAC|DTS|DD5\.1|AC3|Atmos|FLAC|EAC3|10bit|HDR10?\+?|DV|DoVi|SDR|YTS|YIFY|RARBG|NTG|SPARKS|AMIABLE|FGT|\[.*?\]|\(.*?\))`)
+	whitespaceRegex = regexp.MustCompile(`\s+`)
+)
+
+// Parse parses a magnet URI, info hash, or torrent name.
+func Parse(input string) ParsedTorrent {
+	input = strings.TrimSpace(input)
+
+	if strings.HasPrefix(input, "magnet:") {
+		return parseMagnet(input)
+	}
+
+	if hashRegex.MatchString(input) {
+		return ParsedTorrent{
+			InfoHash: strings.ToLower(input),
+		}
+	}
+
+	// Treat as a torrent name/filename
+	return parseName(input)
+}
+
+func parseMagnet(uri string) ParsedTorrent {
+	result := ParsedTorrent{IsMagnet: true}
+
+	u, err := url.Parse(uri)
+	if err != nil {
+		return result
+	}
+
+	xt := u.Query().Get("xt")
+	if strings.HasPrefix(xt, "urn:btih:") {
+		result.InfoHash = strings.ToLower(strings.TrimPrefix(xt, "urn:btih:"))
+	}
+
+	dn := u.Query().Get("dn")
+	if dn != "" {
+		result.Name = dn
+		parsed := parseName(dn)
+		result.Quality = parsed.Quality
+		result.Codec = parsed.Codec
+		result.Year = parsed.Year
+	}
+
+	return result
+}
+
+func parseName(name string) ParsedTorrent {
+	result := ParsedTorrent{Name: name}
+
+	if m := qualityRegex.FindString(name); m != "" {
+		result.Quality = strings.ToLower(m)
+		if result.Quality == "4k" || result.Quality == "uhd" {
+			result.Quality = "2160p"
+		}
+	}
+
+	if m := codecRegex.FindString(name); m != "" {
+		result.Codec = m
+	}
+
+	if m := yearRegex.FindStringSubmatch(name); len(m) > 1 {
+		result.Year = m[1]
+	}
+
+	return result
+}
+
+// ExtractSearchQuery cleans a torrent name to use as a search query.
+func ExtractSearchQuery(name string) string {
+	q := name
+
+	// Remove common release artifacts
+	for _, re := range []*regexp.Regexp{qualityRegex, codecRegex} {
+		q = re.ReplaceAllString(q, "")
+	}
+
+	q = artifactsRegex.ReplaceAllString(q, "")
+
+	// Replace dots and underscores with spaces
+	q = strings.NewReplacer(".", " ", "_", " ", "-", " ").Replace(q)
+
+	// Remove year
+	q = yearRegex.ReplaceAllString(q, " ")
+
+	// Collapse whitespace
+	q = whitespaceRegex.ReplaceAllString(q, " ")
+	q = strings.TrimSpace(q)
+
+	return q
+}