Implement complete Android settings and recovery controls (#104)

android/platform/src/main/kotlin/de/rfc1437/ironstorage/platform/AndroidSettingsPlatform.kt

@@ -0,0 +1,138 @@
+package de.rfc1437.ironstorage.platform
+
+import android.content.ComponentName
+import android.content.Context
+import android.content.Intent
+import android.content.pm.PackageManager
+import android.credentials.CredentialManager
+import android.os.Build
+import android.provider.Settings
+import android.view.autofill.AutofillManager
+import androidx.activity.result.ActivityResultLauncher
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.core.net.toUri
+import androidx.fragment.app.FragmentActivity
+import de.rfc1437.ironstorage.core.ProviderStatus
+import de.rfc1437.ironstorage.core.SettingsPlatform
+
+class AndroidSettingsPlatform(
+    private val context: Context,
+    private val keystore: AndroidKeystoreAdapter
+) : SettingsPlatform {
+    private var picker: ActivityResultLauncher<String>? = null
+    private var host: java.lang.ref.WeakReference<FragmentActivity> = java.lang.ref.WeakReference(
+        null
+    )
+    fun attach(activity: FragmentActivity, selected: (List<String>) -> Unit) {
+        host = java.lang.ref.WeakReference(activity)
+        picker =
+            activity.activityResultRegistry.register(
+                "ironstorage.settings.qr-images",
+                activity,
+                ActivityResultContracts.GetMultipleContents()
+            ) { uris ->
+                if (uris.isNotEmpty()) selected(uris.map { it.toString() })
+            }
+    }
+    fun detach(activity: FragmentActivity) {
+        if (host.get() === activity) {
+            picker = null
+            host.clear()
+        }
+    }
+    override fun chooseQrImages(): Boolean {
+        val picker = picker ?: return false
+        return try {
+            picker.launch("image/*")
+            true
+        } catch (
+            _: android.content.ActivityNotFoundException
+        ) {
+            false
+        }
+    }
+
+    @Suppress("DEPRECATION")
+    private fun services(permission: String): List<ComponentName> =
+        context.packageManager.getPackageInfo(context.packageName, PackageManager.GET_SERVICES)
+            .services.orEmpty().filter { it.permission == permission }
+            .map { ComponentName(context.packageName, it.name) }
+    override fun autofill(): ProviderStatus {
+        val manager = context.getSystemService(AutofillManager::class.java)
+        return ProviderStatus(
+            manager?.isAutofillSupported == true,
+            services("android.permission.BIND_AUTOFILL_SERVICE").isNotEmpty(),
+            manager?.hasEnabledAutofillServices() == true
+        )
+    }
+    override fun credentials(): ProviderStatus {
+        val services = services("android.permission.BIND_CREDENTIAL_PROVIDER_SERVICE")
+        val enabled = if (Build.VERSION.SDK_INT >= 34) {
+            val manager = context.getSystemService(CredentialManager::class.java)
+            services.any { manager?.isEnabledCredentialProviderService(it) == true }
+        } else {
+            false
+        }
+        return ProviderStatus(Build.VERSION.SDK_INT >= 34, services.isNotEmpty(), enabled)
+    }
+    override fun biometricsAvailable() = keystore.deviceState().strongBiometric
+
+    @Suppress("DEPRECATION")
+    override fun version(): String = context.packageManager.getPackageInfo(context.packageName, 0)
+        .versionName.orEmpty()
+    private fun open(intent: Intent): Boolean = try {
+        context.startActivity(intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK))
+        true
+    } catch (
+        _: android.content.ActivityNotFoundException
+    ) {
+        false
+    } catch (_: SecurityException) {
+        false
+    }
+    override fun openAutofill(): Boolean {
+        if (!autofill().supported) return false
+        return open(
+            Intent(
+                Settings.ACTION_REQUEST_SET_AUTOFILL_SERVICE,
+                "package:${context.packageName}".toUri()
+            )
+        )
+    }
+    override fun openCredentials(): Boolean {
+        if (Build.VERSION.SDK_INT < 34) return false
+        val intent = if (Build.VERSION.SDK_INT >= 35) {
+            Intent(Settings.ACTION_CREDENTIAL_PROVIDER, "package:${context.packageName}".toUri())
+        } else {
+            Intent(
+                Settings.ACTION_REQUEST_SET_AUTOFILL_SERVICE,
+                "package:${context.packageName}".toUri()
+            )
+        }
+        return open(intent)
+    }
+    override suspend fun readQrImage(uri: String): ByteArray {
+        val selected = uri.toUri()
+        if (selected.scheme != "content") throw java.io.IOException("Not a content URI")
+        return context.contentResolver.openInputStream(selected)?.use { input ->
+            val output = java.io.ByteArrayOutputStream()
+            val buffer = ByteArray(16384)
+            while (true) {
+                val count = input.read(buffer)
+                if (count < 0) break
+                if (output.size() + count >
+                    32 * 1024 * 1024
+                ) {
+                    throw java.io.IOException("Image exceeds the supported size")
+                }
+                output.write(buffer, 0, count)
+            }
+            val bytes = output.toByteArray()
+            if (bytes.size > 32 * 1024 * 1024) {
+                bytes.fill(0)
+                throw java.io.IOException("Image exceeds the supported size")
+            }
+            bytes
+        } ?: throw java.io.IOException("Image unavailable")
+    }
+}