GenreParser.kt

34 lines · 1.5 KB

Changed in: 0.5.0

1	package dev.stave.domain.model
2
3	/**
4	* Parse a genre string into individual genre tokens.
5	*
6	* UPnP/DIDL servers emit multi-genre tags with inconsistent separators across
7	* implementations and across the source files' own metadata conventions:
8	* MinimServer "Rock; Pop"
9	* iTunes / ID3v2.4 "Rock/Pop" or "Rock\Pop"
10	* Foobar2000 "Rock // Pop"
11	* Plex / BubbleUPnP "Rock, Pop"
12	* Doubled variants "Rock\\Pop" (escaped-backslash or literal double-backslash)
13	*
14	* We collapse `//` and `\\` to single delimiters first, then split on any of
15	* `,`, `;`, `/`, `\`. Tokens are trimmed; blanks are discarded. Order preserved.
16	*
17	* Returns an empty list for null/blank input. Doesn't lowercase — callers that need
18	* case-insensitive comparison should do that themselves.
19	*/
20	fun parseGenres(raw: String?): List<String> {
21	if (raw.isNullOrBlank()) return emptyList()
22	// Collapse doubled separators first. Without this, "Rock // Pop" split on `/` would
23	// yield ["Rock ", " ", " Pop"], and the middle empty token would pass through trim()
24	// as "" and get filtered out — slow but correct. Doing this first is cheaper and
25	// also handles the literal-double-backslash case "Rock\\Pop" which would otherwise
26	// split to ["Rock", "", "Pop"].
27	val normalized = raw
28	.replace("//", "/")
29	.replace("\\\\", "\\")
30	return normalized
31	.split(',', ';', '/', '\\')
32	.map { it.trim() }
33	.filter { it.isNotEmpty() }
34	}