Plugins: run inside the proot sandbox; Termux only with explicit 'termux' permission

app/src/main/java/io/github/abrarul/modularai/plugin/PluginHost.kt

@@ -2,13 +2,18 @@ package io.github.abrarul.modularai.plugin
 
 import android.content.Context
 import io.github.abrarul.modularai.bridge.TermuxBridge
+import io.github.abrarul.modularai.proot.Proot
 import org.json.JSONObject
 import java.io.File
 
 /**
  * Plugin layout: filesDir/plugins/<id>/plugin.json + entry script.
- * plugin.json: {"id","name","version","entry":"run.sh","permissions":["net","shell"],"hooks":["on_capture","on_model_loaded"]}
- * A plugin only runs hooks for permissions the user has explicitly granted.
+ * plugin.json: {"id","name","version","entry":"run.sh","permissions":["shell"],"hooks":["on_capture","on_model_loaded"]}
+ *
+ * Permissions (the user must grant them with `plugin grant <id>`):
+ *  - shell  : script runs inside the proot Linux sandbox. It sees only its own folder at /plugin.
+ *  - termux : script runs in Termux with Termux's rights (NOT sandboxed). Grant only to code you trust.
+ * Hook payloads never contain note text, only event names and short metadata.
  */
 data class Plugin(
     val id: String, val name: String, val version: String,
@@ -16,7 +21,7 @@ data class Plugin(
 )
 
 class PluginHost(private val ctx: Context) {
-    private val root = File(ctx.filesDir, "plugins").apply { mkdirs() }
+    val root = File(ctx.filesDir, "plugins").apply { mkdirs() }
     private val granted = ctx.getSharedPreferences("plugin_grants", Context.MODE_PRIVATE)
 
     fun installed(): List<Plugin> = root.listFiles()?.mapNotNull { load(it) } ?: emptyList()
@@ -24,22 +29,46 @@ class PluginHost(private val ctx: Context) {
     private fun load(d: File): Plugin? = try {
         val j = JSONObject(File(d, "plugin.json").readText())
         fun set(k: String) = j.optJSONArray(k)?.let { a -> (0 until a.length()).map { a.getString(it) }.toSet() } ?: emptySet()
-        Plugin(j.getString("id"), j.getString("name"), j.getString("version"),
-            j.getString("entry"), set("permissions"), set("hooks"), d)
+        val id = j.getString("id")
+        require(id.matches(Regex("[A-Za-z0-9._-]{1,64}")))
+        Plugin(id, j.getString("name"), j.getString("version"), j.getString("entry"), set("permissions"), set("hooks"), d)
     } catch (_: Exception) { null }
 
+    /** Creates a working example plugin the user can edit. */
+    fun createSample(id: String): Plugin {
+        require(id.matches(Regex("[A-Za-z0-9._-]{1,64}"))) { "Plugin id may contain letters, digits, . _ - only" }
+        val d = File(root, id).apply { mkdirs() }
+        File(d, "plugin.json").writeText(
+            JSONObject().put("id", id).put("name", "Sample $id").put("version", "1.0")
+                .put("entry", "run.sh").put("permissions", org.json.JSONArray().put("shell"))
+                .put("hooks", org.json.JSONArray().put("on_capture").put("on_model_loaded")).toString(2)
+        )
+        File(d, "run.sh").writeText("#!/bin/sh\necho \"\$(date) event=\$1 payload=\$2\" >> /plugin/events.log\n")
+        return load(d)!!
+    }
+
     fun grant(id: String, perms: Set<String>) = granted.edit().putStringSet(id, perms).apply()
     fun isGranted(p: Plugin) = granted.getStringSet(p.id, emptySet())!!.containsAll(p.permissions)
     fun remove(p: Plugin) { p.dir.deleteRecursively(); granted.edit().remove(p.id).apply() }
 
-    /** Fires [event]; payload is passed as the first script argument. */
+    private fun q(s: String) = "'" + s.replace("'", "'\\''") + "'"
+
+    /** Fires [event] for every granted plugin that subscribed to it. Never blocks the caller. */
     fun emit(event: String, payload: String = "") {
+        val proot = Proot(ctx)
         installed().filter { event in it.hooks && isGranted(it) }.forEach { p ->
-            // Entry paths must stay inside the plugin dir.
             val entry = File(p.dir, p.entry).canonicalFile
-            if (!entry.path.startsWith(p.dir.canonicalPath)) return@forEach
-            if ("shell" in p.permissions) {
-                TermuxBridge.run(ctx, "sh '${entry.path}' '$event' \"\$1\"", arrayOf("_", payload))
+            if (!entry.path.startsWith(p.dir.canonicalPath + File.separator) || !entry.isFile) return@forEach // must stay inside the plugin dir
+            val rel = entry.relativeTo(p.dir.canonicalFile).path
+            when {
+                "termux" in p.permissions && TermuxBridge.isInstalled(ctx) ->
+                    TermuxBridge.run(ctx, "sh ${q(entry.path)} ${q(event)} ${q(payload)}")
+                "shell" in p.permissions && proot.binaryAvailable && proot.installed ->
+                    Thread {
+                        runCatching {
+                            proot.exec("sh ${q("/plugin/$rel")} ${q(event)} ${q(payload)}", { }, listOf("${p.dir.canonicalPath}:/plugin"))
+                        }
+                    }.start()
             }
         }
     }