Merge pull request #2971 from vitorpamplona/claude/add-nowhere-links-LPMnM

Add Nowhere link detection and branded card rendering

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/components/NowhereLinkCard.kt

@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.components
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalUriHandler
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.richtext.NowhereLinkSegment
+import com.vitorpamplona.amethyst.ui.stringRes
+import com.vitorpamplona.amethyst.ui.theme.innerPostModifier
+
+// Maps the first path segment of a nowhere URL to a localized label. The nowhere project ships
+// eight tools (event, fundraiser, store, petition, message, drop, art, forum) and the URL path
+// uses the first letter as a discriminator (e.g. nowhr.xyz/s#... is a store). Unknown codes
+// fall through to the generic "Nowhere site" label.
+private val nowhereToolLabels =
+    mapOf(
+        "e" to R.string.nowhere_link_card_event,
+        "f" to R.string.nowhere_link_card_fundraiser,
+        "s" to R.string.nowhere_link_card_store,
+        "p" to R.string.nowhere_link_card_petition,
+        "m" to R.string.nowhere_link_card_message,
+        "d" to R.string.nowhere_link_card_drop,
+        "a" to R.string.nowhere_link_card_art,
+        "fo" to R.string.nowhere_link_card_forum,
+    )
+
+@Composable
+fun NowhereLinkCard(segment: NowhereLinkSegment) {
+    val uri = LocalUriHandler.current
+    val titleRes = segment.tool?.lowercase()?.let { nowhereToolLabels[it] } ?: R.string.nowhere_link_card_generic
+
+    Column(
+        modifier =
+            MaterialTheme.colorScheme.innerPostModifier
+                .clickable {
+                    runCatching {
+                        val target = if (segment.segmentText.contains("://")) segment.segmentText else "https://${segment.segmentText}"
+                        uri.openUri(target)
+                    }
+                }.padding(12.dp),
+    ) {
+        Text(
+            text = stringRes(titleRes),
+            style = MaterialTheme.typography.bodyMedium,
+            fontWeight = FontWeight.Bold,
+        )
+
+        Spacer(modifier = Modifier.padding(top = 2.dp))
+
+        Text(
+            text = segment.host,
+            style = MaterialTheme.typography.bodySmall,
+            color = Color.Gray,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+        )
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/components/RichTextViewer.kt

@@ -80,6 +80,7 @@ import com.vitorpamplona.amethyst.commons.richtext.ImageGalleryParagraph
 import com.vitorpamplona.amethyst.commons.richtext.ImageSegment
 import com.vitorpamplona.amethyst.commons.richtext.InvoiceSegment
 import com.vitorpamplona.amethyst.commons.richtext.LinkSegment
+import com.vitorpamplona.amethyst.commons.richtext.NowhereLinkSegment
 import com.vitorpamplona.amethyst.commons.richtext.ParagraphState
 import com.vitorpamplona.amethyst.commons.richtext.PdfSegment
 import com.vitorpamplona.amethyst.commons.richtext.PhoneSegment
@@ -481,6 +482,8 @@ private fun RenderWordWithoutPreview(
 
         is LinkSegment -> ClickableUrl(word.segmentText, word.segmentText)
 
+        is NowhereLinkSegment -> ClickableUrl(word.segmentText, word.segmentText)
+
         is EmojiSegment -> RenderCustomEmoji(word.segmentText, state)
 
         // Don't offer to pay invoices
@@ -530,6 +533,7 @@ private fun RenderWordWithPreview(
         is VideoSegment -> ZoomableContentView(word.segmentText, state, accountViewModel)
         is PdfSegment -> ZoomableContentView(word.segmentText, state, accountViewModel)
         is LinkSegment -> LoadUrlPreview(word.segmentText, word.segmentText, callbackUri, accountViewModel)
+        is NowhereLinkSegment -> NowhereLinkCard(word)
         is EmojiSegment -> RenderCustomEmoji(word.segmentText, state)
         is InvoiceSegment -> MayBeInvoicePreview(word.segmentText, accountViewModel)
         is WithdrawSegment -> MayBeWithdrawal(word.segmentText, accountViewModel)

amethyst/src/main/res/values/strings.xml

@@ -2893,4 +2893,15 @@
     <string name="community_rules_violation_quota_exceeded">You have already posted %1$d events of this kind today (limit %2$d).</string>
     <string name="community_rules_violation_wot_gate_failed">You don\'t pass this community\'s web-of-trust requirements.</string>
     <string name="community_rules_violation_stale_rules">The latest community rules document was rejected as stale.</string>
+
+    <!-- Nowhere links (hostednowhere.com / nowhr.xyz). The site name "Nowhere" is a proper noun, do not translate. -->
+    <string name="nowhere_link_card_generic">Nowhere site</string>
+    <string name="nowhere_link_card_event">Nowhere Event</string>
+    <string name="nowhere_link_card_fundraiser">Nowhere Fundraiser</string>
+    <string name="nowhere_link_card_store">Nowhere Store</string>
+    <string name="nowhere_link_card_petition">Nowhere Petition</string>
+    <string name="nowhere_link_card_message">Nowhere Message</string>
+    <string name="nowhere_link_card_drop">Nowhere Drop</string>
+    <string name="nowhere_link_card_art">Nowhere Art</string>
+    <string name="nowhere_link_card_forum">Nowhere Forum</string>
 </resources>

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/richtext/RichTextParser.kt

@@ -332,9 +332,15 @@ class RichTextParser {
             }
         }
 
-        if (urls.withoutScheme.contains(word)) return SchemelessUrlSegment(word)
+        if (urls.withoutScheme.contains(word)) {
+            parseNowhereLink(word)?.let { return it }
+            return SchemelessUrlSegment(word)
+        }
 
-        if (urls.withScheme.contains(word)) return LinkSegment(word)
+        if (urls.withScheme.contains(word)) {
+            parseNowhereLink(word)?.let { return it }
+            return LinkSegment(word)
+        }
 
         if (urls.emails.contains(word)) return EmailSegment(word)
 
@@ -529,6 +535,29 @@ class RichTextParser {
         }
 
         fun isUrlWithoutScheme(url: String) = noProtocolUrlValidator.matches(url)
+
+        // Nowhere links (https://github.com/5t34k/nowhere) encode an entire mini-site in the URL
+        // fragment. Servers never see the fragment, so OpenGraph previews return nothing useful
+        // (and hostednowhere.com 403s scrapers). Detect them by host + presence of a fragment
+        // so the renderer can show a branded card instead of falling through to LoadUrlPreview.
+        private val nowhereHosts = listOf("nowhr.xyz", "hostednowhere.com")
+
+        fun parseNowhereLink(word: String): NowhereLinkSegment? {
+            val afterScheme =
+                when {
+                    word.startsWith("https://", ignoreCase = true) -> word.substring(8)
+                    word.startsWith("http://", ignoreCase = true) -> word.substring(7)
+                    else -> word
+                }
+            val slash = afterScheme.indexOf('/')
+            if (slash < 0) return null
+            val host = afterScheme.substring(0, slash).lowercase()
+            if (host !in nowhereHosts) return null
+            val hash = afterScheme.indexOf('#', slash)
+            if (hash < 0) return null
+            val pathSegment = afterScheme.substring(slash + 1, hash).substringBefore('/').takeIf { it.isNotEmpty() }
+            return NowhereLinkSegment(word, host, pathSegment)
+        }
     }
 }
 

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/richtext/RichTextParserSegments.kt

@@ -158,6 +158,13 @@ class SchemelessUrlSegment(
     segment: String,
 ) : Segment(segment)
 
+@Immutable
+class NowhereLinkSegment(
+    segment: String,
+    val host: String,
+    val tool: String?,
+) : Segment(segment)
+
 @Immutable
 class RegularTextSegment(
     segment: String,

commons/src/commonTest/kotlin/com/vitorpamplona/amethyst/commons/richtext/RichTextParserTest.kt

@@ -4400,6 +4400,52 @@ class RichTextParserTest {
             }
     }
 
+    @Test
+    fun testNowhereLinkInTheMiddleOfAPost() {
+        val text = "Check out my store https://nowhr.xyz/s#bYxNC4JAEEDRX7LbpcsirR9F1MW0jRDLPsEOMZaHinJTCzOl right now"
+        val state = RichTextParser().parseText(text, EmptyTagList, null)
+        val nowhere = state.paragraphs.flatMap { it.words }.firstOrNull { it is NowhereLinkSegment } as? NowhereLinkSegment
+        assertEquals("https://nowhr.xyz/s#bYxNC4JAEEDRX7LbpcsirR9F1MW0jRDLPsEOMZaHinJTCzOl", nowhere?.segmentText)
+        assertEquals("nowhr.xyz", nowhere?.host)
+        assertEquals("s", nowhere?.tool)
+    }
+
+    @Test
+    fun testHostedNowhereSchemelessLink() {
+        val text = "see hostednowhere.com/m#bYxNAB end"
+        val state = RichTextParser().parseText(text, EmptyTagList, null)
+        val nowhere = state.paragraphs.flatMap { it.words }.firstOrNull { it is NowhereLinkSegment } as? NowhereLinkSegment
+        assertEquals("hostednowhere.com/m#bYxNAB", nowhere?.segmentText)
+        assertEquals("hostednowhere.com", nowhere?.host)
+        assertEquals("m", nowhere?.tool)
+    }
+
+    @Test
+    fun testNowhereLinkWithLargeBase64UrlFragment() {
+        // Real nowhere links can be kilobytes long (a full store catalogue or forum thread
+        // base64url-encoded). Verify both UrlDetector capture and our classifier survive a
+        // ~5KB fragment containing every base64url-legal character (A-Z, a-z, 0-9, -, _).
+        val alphabet = ('A'..'Z').joinToString("") + ('a'..'z').joinToString("") + ('0'..'9').joinToString("") + "-_"
+        val payload = (0 until 80).joinToString("") { alphabet }
+        val url = "https://nowhr.xyz/s#$payload"
+        val text = "look at this big store $url and reply"
+        val state = RichTextParser().parseText(text, EmptyTagList, null)
+        val nowhere = state.paragraphs.flatMap { it.words }.firstOrNull { it is NowhereLinkSegment } as? NowhereLinkSegment
+        assertEquals(url, nowhere?.segmentText)
+        assertEquals(payload.length, nowhere?.segmentText?.substringAfter('#')?.length)
+        assertEquals("nowhr.xyz", nowhere?.host)
+        assertEquals("s", nowhere?.tool)
+    }
+
+    @Test
+    fun testPlainNowhereHostWithoutFragmentStaysAsLink() {
+        // No fragment => not a nowhere site, fall through to LinkSegment.
+        val text = "Visit https://hostednowhere.com/manage to manage"
+        val state = RichTextParser().parseText(text, EmptyTagList, null)
+        val nowhere = state.paragraphs.flatMap { it.words }.firstOrNull { it is NowhereLinkSegment }
+        assertEquals(null, nowhere)
+    }
+
     private fun printStateForDebug(state: RichTextViewerState) {
         state.paragraphs.forEach { paragraph ->
             paragraph.words.forEach { seg ->

commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/richtext/RichTextParserNowhereJvmTest.kt

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.commons.richtext
+
+import com.vitorpamplona.amethyst.commons.model.EmptyTagList
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+class RichTextParserNowhereJvmTest {
+    @Test
+    fun realWorldNowhereStoreLinkRoundtripsThroughTheParser() {
+        // Verbatim from a real Nostr note ("Works, thanks!\n\nhttps://nowhr.xyz/s#..."): a
+        // published nowhr.xyz store catalogue with a ~5KB base64url fragment. Kept as a
+        // resource so the URL isn't subject to source-editor truncation.
+        val url =
+            this::class.java
+                .classLoader!!
+                .getResourceAsStream("richtext/realNowhereStoreUrl.txt")!!
+                .bufferedReader()
+                .readText()
+                .trim()
+
+        assertTrue(url.startsWith("https://nowhr.xyz/s#"), "resource lost its prefix")
+        assertTrue(url.length > 5000, "resource shorter than expected: ${url.length}")
+
+        val text = "Works, thanks!\n\n$url"
+
+        val state = RichTextParser().parseText(text, EmptyTagList, null)
+        val nowhere = state.paragraphs.flatMap { it.words }.firstOrNull { it is NowhereLinkSegment } as? NowhereLinkSegment
+
+        assertEquals(url, nowhere?.segmentText)
+        assertEquals("nowhr.xyz", nowhere?.host)
+        assertEquals("s", nowhere?.tool)
+        assertTrue(state.urlSet.withScheme.contains(url), "url not in detected withScheme set")
+    }
+}