MinimServerControl.kt

90 lines · 4.0 KB

Changed in: 0.5.0

1	package dev.stave.upnp
2
3	import kotlinx.coroutines.Dispatchers
4	import kotlinx.coroutines.withContext
5	import okhttp3.MediaType.Companion.toMediaType
6	import okhttp3.OkHttpClient
7	import okhttp3.Request
8	import okhttp3.RequestBody.Companion.toRequestBody
9	import java.util.concurrent.TimeUnit
10	import javax.inject.Inject
11	import javax.inject.Singleton
12
13	/**
14	* Client for MinimServer's [Web API](https://minimserver.com/ug-scripting.html#Web%20API).
15	*
16	* MinimServer exposes a tiny HTTP/POST control endpoint on its HTTP server port
17	* (default 9790, set by the `http.port` property). The body is a plain-text
18	* command script — for our purposes a single line: `rescan`. The receiver
19	* restarts the server and begins indexing; a 200 OK comes back when the rescan
20	* has started (not finished). MinimServer briefly disappears from the UPnP
21	* registry during the rescan, then reappears when indexing is complete —
22	* that's how [ServersViewModel] observes the cycle to know we're done.
23	*
24	* Port-discovery strategy: try the UPnP descriptor URL's port first (that's
25	* what `findDevice(udn).identity.descriptorURL` carries; for a stock MinimServer
26	* config it's usually 9791 — the ohnet.port — but custom setups sometimes
27	* collapse both onto 9790). Fall back to 9790 if the descriptor port refuses
28	* or 404s. We don't try other ports because there isn't a documented one.
29	*/
30	@Singleton
31	class MinimServerControl @Inject constructor(
32	private val holder: UpnpServiceHolder,
33	) {
34	sealed class Result {
35	object Success : Result()
36	data class Failure(val message: String) : Result()
37	}
38
39	private val http: OkHttpClient = OkHttpClient.Builder()
40	.connectTimeout(5, TimeUnit.SECONDS)
41	// Longer read timeout: the server takes the POST, restarts internally,
42	// and only then responds 200. That round-trip can be 5–15s on a busy
43	// server. 30s is a generous ceiling — most failures will surface as
44	// connection refusal much faster.
45	.readTimeout(30, TimeUnit.SECONDS)
46	.build()
47
48	/** POST `rescan` to the server identified by [udn]. Returns when the
49	* receiver acknowledges the command (which means the rescan has started,
50	* not that it has finished — wait for the server to disappear/reappear
51	* in the UPnP registry for that). */
52	suspend fun rescanLibrary(udn: String): Result = withContext(Dispatchers.IO) {
53	val device = holder.findDevice(udn)
54	?: return@withContext Result.Failure("Server no longer in registry")
55	val descriptor = device.identity.descriptorURL
56	?: return@withContext Result.Failure("Server has no descriptor URL")
57	val host = descriptor.host
58	?: return@withContext Result.Failure("Server descriptor URL has no host")
59
60	// Ports to try, in order. De-duped so we don't double-request when
61	// descriptor port already IS 9790.
62	val descriptorPort = descriptor.port.takeIf { it > 0 } ?: 80
63	val portsToTry = linkedSetOf(descriptorPort, MINIMSERVER_DEFAULT_HTTP_PORT)
64
65	var lastError: String? = null
66	for (port in portsToTry) {
67	val url = "http://$host:$port/"
68	val request = Request.Builder()
69	.url(url)
70	.post("rescan\n".toRequestBody(TEXT_PLAIN))
71	.build()
72	runCatching {
73	http.newCall(request).execute().use { response ->
74	if (response.isSuccessful) {
75	return@withContext Result.Success
76	}
77	lastError = "HTTP ${response.code} on $url"
78	}
79	}.onFailure { t ->
80	lastError = "${t.javaClass.simpleName}: ${t.message ?: "connection failed"} ($url)"
81	}
82	}
83	Result.Failure(lastError ?: "Rescan request failed")
84	}
85
86	companion object {
87	private const val MINIMSERVER_DEFAULT_HTTP_PORT = 9790
88	private val TEXT_PLAIN = "text/plain; charset=utf-8".toMediaType()
89	}
90	}