feat: open deep links, mailto: URLs and share-sheet payloads in the app

android/app/src/main/java/com/anonymous/bulwarkmobile/BulwarkFcmModule.kt

@@ -91,6 +91,12 @@ class BulwarkFcmModule(reactContext: ReactApplicationContext)
         promise.resolve(payload?.toMap())
     }
 
+    @ReactMethod
+    fun getInitialShare(promise: Promise) {
+        val payload = ShareIntentStore.consume()
+        promise.resolve(payload?.toMap())
+    }
+
     private fun postNotification(
         notificationId: String,
         title: String,

android/app/src/main/java/com/anonymous/bulwarkmobile/MainActivity.kt

@@ -19,11 +19,15 @@ class MainActivity : ReactActivity() {
     setTheme(R.style.AppTheme);
     super.onCreate(null)
     NotificationTapStore.captureFromIntent(intent)
+    ShareIntentStore.captureFromIntent(intent)
   }
 
   override fun onNewIntent(intent: Intent) {
     super.onNewIntent(intent)
     setIntent(intent)
+    ShareIntentStore.captureFromIntent(intent)?.let { share ->
+      BulwarkFcmModule.emit("app:share", share.toMap())
+    }
     val payload = NotificationTapStore.captureFromIntent(intent) ?: return
     BulwarkFcmModule.emit("fcm:notificationTap", payload.toMap())
   }

android/app/src/main/java/com/anonymous/bulwarkmobile/ShareIntentStore.kt

@@ -0,0 +1,85 @@
+package com.anonymous.bulwarkmobile
+
+import android.content.Intent
+import android.net.Uri
+import android.os.Build
+import com.facebook.react.bridge.Arguments
+import com.facebook.react.bridge.WritableMap
+
+// Process-wide holder for the most recent ACTION_SEND / ACTION_SEND_MULTIPLE
+// intent (the system share sheet). MainActivity fills this on onCreate /
+// onNewIntent; JS drains it via BulwarkFcm.getInitialShare or reacts to the
+// live "app:share" event and opens the composer.
+object ShareIntentStore {
+    @Volatile
+    private var pending: SharePayload? = null
+
+    fun consume(): SharePayload? {
+        val value = pending
+        pending = null
+        return value
+    }
+
+    fun captureFromIntent(intent: Intent?): SharePayload? {
+        val action = intent?.action ?: return null
+        if (action != Intent.ACTION_SEND && action != Intent.ACTION_SEND_MULTIPLE) return null
+
+        val text = intent.getStringExtra(Intent.EXTRA_TEXT)?.take(MAX_TEXT)
+        val subject = intent.getStringExtra(Intent.EXTRA_SUBJECT)?.take(512)
+        val uris = mutableListOf<Uri>()
+        if (action == Intent.ACTION_SEND) {
+            streamExtra(intent)?.let { uris.add(it) }
+        } else {
+            streamExtras(intent)?.let { uris.addAll(it) }
+        }
+        val type = intent.type
+
+        if (text.isNullOrBlank() && uris.isEmpty()) return null
+        val payload = SharePayload(
+            text = text,
+            subject = subject,
+            uris = uris.map { it.toString() },
+            mimeTypes = uris.map { type ?: "" },
+        )
+        pending = payload
+        // Clear so a later lifecycle event doesn't replay this share.
+        intent.removeExtra(Intent.EXTRA_TEXT)
+        intent.removeExtra(Intent.EXTRA_SUBJECT)
+        intent.removeExtra(Intent.EXTRA_STREAM)
+        intent.action = Intent.ACTION_MAIN
+        return payload
+    }
+
+    @Suppress("DEPRECATION")
+    private fun streamExtra(intent: Intent): Uri? =
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            intent.getParcelableExtra(Intent.EXTRA_STREAM, Uri::class.java)
+        } else {
+            intent.getParcelableExtra(Intent.EXTRA_STREAM)
+        }
+
+    @Suppress("DEPRECATION")
+    private fun streamExtras(intent: Intent): List<Uri>? =
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            intent.getParcelableArrayListExtra(Intent.EXTRA_STREAM, Uri::class.java)
+        } else {
+            intent.getParcelableArrayListExtra(Intent.EXTRA_STREAM)
+        }
+
+    data class SharePayload(
+        val text: String?,
+        val subject: String?,
+        val uris: List<String>,
+        val mimeTypes: List<String>,
+    ) {
+        fun toMap(): WritableMap = Arguments.createMap().apply {
+            if (text != null) putString("text", text)
+            if (subject != null) putString("subject", subject)
+            putArray("uris", Arguments.fromList(uris))
+            putArray("mimeTypes", Arguments.fromList(mimeTypes))
+        }
+    }
+
+    // 1 MiB of shared text is plenty; anything bigger is an attachment.
+    private const val MAX_TEXT = 1 * 1024 * 1024
+}