Link preview (#286)

* link preview

* link previews

app/src/main/java/com/bitchat/android/ui/LinkPreviewPill.kt

@@ -0,0 +1,180 @@
+package com.bitchat.android.ui
+
+import android.content.Intent
+import android.net.Uri
+import androidx.compose.foundation.background
+import androidx.compose.foundation.border
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.Link
+import androidx.compose.material3.*
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import java.net.URL
+
+/**
+ * LinkPreviewPill - A compact link preview component that matches the iOS design
+ * 
+ * This component replicates the iOS link preview pill functionality:
+ * - Shows a clickable pill with link icon, title, and host
+ * - No preview image fetching - just styled link display
+ * - Opens link in external browser when clicked
+ * - Uses iOS-style green colors and monospaced fonts
+ */
+
+@Composable
+fun LinkPreviewPill(
+    url: String,
+    title: String? = null,
+    modifier: Modifier = Modifier
+) {
+    val context = LocalContext.current
+    val colorScheme = MaterialTheme.colorScheme
+    val isDark = colorScheme.background.red + colorScheme.background.green + colorScheme.background.blue < 1.5f
+    
+    // iOS-style colors
+    val textColor = if (isDark) Color.Green else Color(red = 0f, green = 0.5f, blue = 0f)
+    val backgroundColor = if (isDark) Color.Gray.copy(alpha = 0.15f) else Color.Gray.copy(alpha = 0.08f)
+    val borderColor = textColor.copy(alpha = 0.3f)
+    
+    // Parse URL for host extraction
+    val parsedUrl = try {
+        URL(url)
+    } catch (e: Exception) {
+        null
+    }
+    
+    val displayTitle = title ?: parsedUrl?.host ?: "Link"
+    val displayHost = parsedUrl?.host ?: url
+    
+    Surface(
+        modifier = modifier
+            .fillMaxWidth()
+            .clip(RoundedCornerShape(10.dp))
+            .background(backgroundColor)
+            .border(1.dp, borderColor, RoundedCornerShape(10.dp))
+            .clickable {
+                try {
+                    val intent = Intent(Intent.ACTION_VIEW, Uri.parse(url))
+                    context.startActivity(intent)
+                } catch (e: Exception) {
+                    // Silently fail if URL can't be opened
+                }
+            },
+        color = Color.Transparent
+    ) {
+        Row(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(10.dp),
+            horizontalArrangement = Arrangement.spacedBy(12.dp),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            // Link icon (matches iOS placeholder)
+            Surface(
+                modifier = Modifier.size(60.dp),
+                shape = RoundedCornerShape(8.dp),
+                color = Color.Blue.copy(alpha = 0.1f)
+            ) {
+                Box(
+                    modifier = Modifier.fillMaxSize(),
+                    contentAlignment = Alignment.Center
+                ) {
+                    Icon(
+                        imageVector = Icons.Outlined.Link,
+                        contentDescription = "Link",
+                        modifier = Modifier.size(24.dp),
+                        tint = Color.Blue
+                    )
+                }
+            }
+            
+            // Text content
+            Column(
+                modifier = Modifier.weight(1f),
+                verticalArrangement = Arrangement.spacedBy(4.dp)
+            ) {
+                // Title - matches iOS styling
+                Text(
+                    text = displayTitle,
+                    fontFamily = FontFamily.Monospace,
+                    fontSize = 14.sp,
+                    fontWeight = FontWeight.SemiBold,
+                    color = textColor,
+                    maxLines = 2,
+                    overflow = TextOverflow.Ellipsis
+                )
+                
+                // Host - matches iOS styling
+                Text(
+                    text = displayHost,
+                    fontFamily = FontFamily.Monospace,
+                    fontSize = 11.sp,
+                    color = textColor.copy(alpha = 0.6f),
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis
+                )
+            }
+        }
+    }
+}
+
+/**
+ * URL detection utility that extracts URLs from text content
+ * Matches the iOS extractURLs() extension functionality
+ */
+object URLDetector {
+    
+    // Regex pattern for URL detection (matches common URL patterns)
+    private val urlRegex = Regex(
+        """(?i)\b(?:https?://|www\d{0,3}[.]|[a-z0-9.\-]+[.][a-z]{2,4}/)(?:[^\s()<>]+|\([^\s()<>]+\))+(?:\([^\s()<>]+\)|[^\s`!()\[\]{};:'".,<>?«»""''])""",
+        RegexOption.IGNORE_CASE
+    )
+    
+    data class UrlMatch(
+        val url: String,
+        val range: IntRange
+    )
+    
+    /**
+     * Extract URLs from text content
+     * Returns list of URL matches with their positions in the text
+     */
+    fun extractUrls(text: String): List<UrlMatch> {
+        val urls = mutableListOf<UrlMatch>()
+        val matches = urlRegex.findAll(text)
+        
+        for (match in matches) {
+            var url = match.value
+            val start = match.range.first
+            val end = match.range.last
+            
+            // Add protocol if missing
+            if (!url.startsWith("http://") && !url.startsWith("https://")) {
+                url = "https://$url"
+            }
+            
+            urls.add(UrlMatch(url, start..end))
+        }
+        
+        return urls
+    }
+    
+    /**
+     * Check if a string contains any URLs
+     */
+    fun containsUrls(text: String): Boolean {
+        return urlRegex.containsMatchIn(text)
+    }
+}

app/src/main/java/com/bitchat/android/ui/MessageComponents.kt

@@ -102,27 +102,54 @@ fun MessageItem(
     val colorScheme = MaterialTheme.colorScheme
     val timeFormatter = remember { SimpleDateFormat("HH:mm:ss", Locale.getDefault()) }
     
-    Row(
+    Column(
         modifier = Modifier.fillMaxWidth(),
-        horizontalArrangement = Arrangement.SpaceBetween,
+        verticalArrangement = Arrangement.spacedBy(0.dp)
-        verticalAlignment = Alignment.Top
     ) {
-        // Create a custom layout that combines selectable text with clickable nickname areas
+        Row(
-        MessageTextWithClickableNicknames(
+            modifier = Modifier.fillMaxWidth(),
-            message = message,
+            horizontalArrangement = Arrangement.SpaceBetween,
-            currentUserNickname = currentUserNickname,
+            verticalAlignment = Alignment.Top
-            meshService = meshService,
+        ) {
-            colorScheme = colorScheme,
+            // Create a custom layout that combines selectable text with clickable nickname areas
-            timeFormatter = timeFormatter,
+            MessageTextWithClickableNicknames(
-            onNicknameClick = onNicknameClick,
+                message = message,
-            onNicknameLongPress = onNicknameLongPress,
+                currentUserNickname = currentUserNickname,
-            modifier = Modifier.weight(1f)
+                meshService = meshService,
-        )
+                colorScheme = colorScheme,
+                timeFormatter = timeFormatter,
+                onNicknameClick = onNicknameClick,
+                onNicknameLongPress = onNicknameLongPress,
+                modifier = Modifier.weight(1f)
+            )
+            
+            // Delivery status for private messages
+            if (message.isPrivate && message.sender == currentUserNickname) {
+                message.deliveryStatus?.let { status ->
+                    DeliveryStatusIcon(status = status)
+                }
+            }
+        }
         
-        // Delivery status for private messages
+        // Link preview pills for URLs in message content
-        if (message.isPrivate && message.sender == currentUserNickname) {
+        if (message.sender != "system") {
-            message.deliveryStatus?.let { status ->
+            val urls = URLDetector.extractUrls(message.content)
-                DeliveryStatusIcon(status = status)
+            if (urls.isNotEmpty()) {
+                Column(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .padding(top = 3.dp, start = 1.dp, end = 1.dp),
+                    verticalArrangement = Arrangement.spacedBy(3.dp)
+                ) {
+                    // Show up to 3 URL previews (matches iOS behavior)
+                    urls.take(3).forEach { urlMatch ->
+                        LinkPreviewPill(
+                            url = urlMatch.url,
+                            title = null,
+                            modifier = Modifier.fillMaxWidth()
+                        )
+                    }
+                }
             }
         }
     }