[dahuadoor] Restore snapshots and enforce retention (#20692)

* [dahuadoor] add door image persistence on startup

Signed-off-by: Sven Schad <svnsssd@gmail.com>

Author: svnsssd

bundles/org.openhab.binding.dahuadoor/README.md

@@ -30,6 +30,7 @@ VTO2202 is a single-button outdoor station; VTO3211 is a dual-button outdoor sta
 | username      | text    | Yes      |                         | Username to access the device                                                                                                                                                                |
 | password      | text    | Yes      |                         | Password to access the device                                                                                                                                                                |
 | snapshotPath  | text    | Yes      |                         | Linux path where image files are stored (e.g., /var/lib/openhab/door-images)                                                                                                                 |
+| maxImages     | integer | No       | 20                      | Maximum number of timestamped snapshots to keep (0 disables cleanup). For VTO3211 this applies per button.                                                                                   |
 | useHttps      | boolean | No       | false                   | Use HTTPS (port 443) for snapshot and door-open requests. Enable if the device has HTTPS turned on in its network settings. When disabled, plain HTTP (port 80) is used.                     |
 | enableWebRTC  | boolean | No       | false                   | Enables local go2rtc sidecar management and publishes a `webrtc-url` channel.                                                                                                                |
 | go2rtcPath    | text    | No       |                         | Absolute path to the go2rtc binary (required when `enableWebRTC=true`).                                                                                                                      |
@@ -44,6 +45,12 @@ VTO2202 is a single-button outdoor station; VTO3211 is a dual-button outdoor sta
 | localSipPort  | integer | No       | 5060                    | Local UDP SIP listening port.                                                                                                                                                                |
 | sipRealm      | text    | No       | VDP                     | SIP authentication realm (default for Dahua VTO devices).                                                                                                                                    |
 
+**Snapshot persistence:**
+The binding stores snapshots in `snapshotPath` and reloads the latest snapshot on startup to restore the `door-image` channels.
+For VTO2202, the latest file is `Doorbell.jpg` and timestamped files are named `Doorbell_YYYY-MM-DD_HH-mm-ss.jpg`.
+For VTO3211, the latest files are `Doorbell-1.jpg` and `Doorbell-2.jpg`, with timestamped files named `Doorbell-1_YYYY-MM-DD_HH-mm-ss.jpg` and `Doorbell-2_YYYY-MM-DD_HH-mm-ss.jpg`.
+Timestamped files are capped by `maxImages` (0 disables cleanup).
+
 **Note on SIP configuration:**
 To enable SIP call signaling, set `enableSip=true` and configure at least one value in `sipExtension`.
 If your VTO requires a dedicated SIP password, set `sipPassword`; otherwise the binding uses `password`.
@@ -104,6 +111,7 @@ Thing dahuadoor:vto2202:frontdoor "Front Door Station" @ "Entrance" [
     username="admin",
     password="password123",
     snapshotPath="/var/lib/openhab/door-images",
+    maxImages=20,
     useHttps=false
 ]
 ```
@@ -141,6 +149,7 @@ Thing dahuadoor:vto3211:entrance "Entrance Station" @ "Entrance" [
     username="admin",
     password="password123",
     snapshotPath="/var/lib/openhab/door-images",
+    maxImages=20,
     useHttps=false
 ]
 ```
@@ -185,7 +194,7 @@ end
 Intercom operation is implemented with WebRTC via the `go2rtc` binary.
 It converts the Dahua RTP audio/video stream into browser-compatible WebRTC. The audio stream is transcoded using `ffmpeg`. Hence both tools are needed.
 When `enableWebRTC=true`, the binding starts everything automatically when a call is received.
-The binding registers itself at the VTO. Define one or more terminals (for example `9901#2` or `9901#2,9901#3`, type `public`) and list those accounts in `sipExtension` as a comma-separated list. Use the matching `sipPassword` (single password for all accounts).
+The binding registers itself at the VTO similar to a VTH device. Create one or more SIP terminals in the VTO menu (type `public`) for the number of parallel connections you expect (for example `9901#2`, `9901#3`, `9901#4`), then list those accounts in `sipExtension` as a comma-separated list. Use the matching `sipPassword` (single password for all accounts).
 You can try Dahua's default password for initial testing, but do not use it in production. Consult your VTO manual for setup details.
 
 ### Tool installation
@@ -236,6 +245,7 @@ Thing dahuadoor:vto2202:frontdoor "Front Door Station" @ "Entrance" [
   username="admin",
   password="password123",
   snapshotPath="/var/lib/openhab/door-images",
+  maxImages=20,
   enableWebRTC=true,
   go2rtcPath="/usr/local/bin/go2rtc",
   go2rtcApiPort=1984,

bundles/org.openhab.binding.dahuadoor/src/main/java/org/openhab/binding/dahuadoor/internal/DahuaDoorBaseHandler.java

@@ -21,6 +21,8 @@
 import java.net.InetAddress;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -192,6 +194,8 @@ public void initialize() {
             updateState(CHANNEL_SIP_CALL_STATE, new StringType(SipClient.SipCallState.IDLE.name()));
         }
 
+        restoreLastSnapshots();
+
         // Set status to UNKNOWN - will be set to ONLINE when first DHIP event is received
         updateStatus(ThingStatus.UNKNOWN);
     }
@@ -333,6 +337,14 @@ private void stopWebRtc() {
     }
 
     public void saveSnapshot(byte @Nullable [] buffer) {
+        saveSnapshot(buffer, null);
+    }
+
+    public void saveSnapshot(byte @Nullable [] buffer, int lockNumber) {
+        saveSnapshot(buffer, Integer.valueOf(lockNumber));
+    }
+
+    private void saveSnapshot(byte @Nullable [] buffer, @Nullable Integer lockNumber) {
         final DahuaDoorConfiguration localConfig = config;
         if (localConfig == null) {
             logger.warn("Configuration not initialized");
@@ -354,8 +366,9 @@ public void saveSnapshot(byte @Nullable [] buffer) {
             return;
         }
 
+        String suffix = lockNumber == null ? "" : "-" + lockNumber;
         String timestamp = new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss", Locale.ROOT).format(new Date());
-        String filename = localConfig.snapshotPath + "/DoorBell_" + timestamp + ".jpg";
+        String filename = localConfig.snapshotPath + "/Doorbell" + suffix + "_" + timestamp + ".jpg";
 
         try (FileOutputStream fos = new FileOutputStream(new File(filename))) {
             fos.write(buffer);
@@ -364,22 +377,106 @@ public void saveSnapshot(byte @Nullable [] buffer) {
         }
 
         // Write buffer directly to latest snapshot file (avoids copy-from-source failures)
-        String latestSnapshotFilename = localConfig.snapshotPath + "/Doorbell.jpg";
+        String latestSnapshotFilename = localConfig.snapshotPath + "/Doorbell" + suffix + ".jpg";
         try (FileOutputStream fos = new FileOutputStream(new File(latestSnapshotFilename))) {
             fos.write(buffer);
         } catch (IOException e) {
             logger.warn("Could not write latest snapshot to '{}', check permissions and path", latestSnapshotFilename,
                     e);
         }
+
+        cleanupOldSnapshots(lockNumber);
+    }
+
+    private void cleanupOldSnapshots(@Nullable Integer lockNumber) {
+        final DahuaDoorConfiguration localConfig = config;
+        if (localConfig == null || localConfig.snapshotPath.isEmpty() || localConfig.maxImages <= 0) {
+            return;
+        }
+
+        Path snapshotDir = Path.of(localConfig.snapshotPath);
+        if (!Files.isDirectory(snapshotDir)) {
+            return;
+        }
+
+        String suffix = lockNumber == null ? "" : "-" + lockNumber;
+        String prefix = "Doorbell" + suffix + "_";
+        List<Path> candidates = new ArrayList<>();
+
+        try (var stream = Files.list(snapshotDir)) {
+            stream.filter(path -> {
+                String name = path.getFileName().toString();
+                return name.startsWith(prefix) && name.endsWith(".jpg");
+            }).forEach(candidates::add);
+        } catch (IOException e) {
+            logger.warn("Could not list snapshot directory '{}', check permissions and path", localConfig.snapshotPath,
+                    e);
+            return;
+        }
+
+        int maxImages = localConfig.maxImages;
+        if (candidates.size() <= maxImages) {
+            return;
+        }
+
+        candidates.sort((left, right) -> left.getFileName().toString().compareTo(right.getFileName().toString()));
+        int deleteCount = candidates.size() - maxImages;
+        for (int i = 0; i < deleteCount; i++) {
+            Path candidate = candidates.get(i);
+            try {
+                Files.deleteIfExists(candidate);
+            } catch (IOException e) {
+                logger.warn("Could not delete snapshot '{}', check permissions and path", candidate, e);
+            }
+        }
     }
 
     private void updateChannelImage(byte @Nullable [] buffer) {
+        updateImageChannel(CHANNEL_DOOR_IMAGE, buffer);
+    }
+
+    protected void updateImageChannel(String channelId, byte @Nullable [] buffer) {
         if (buffer == null || buffer.length == 0) {
-            updateState(CHANNEL_DOOR_IMAGE, UnDefType.UNDEF);
+            updateState(channelId, UnDefType.UNDEF);
             return;
         }
         RawType image = new RawType(buffer, "image/jpeg");
-        updateState(CHANNEL_DOOR_IMAGE, image);
+        updateState(channelId, image);
+    }
+
+    protected byte @Nullable [] readLatestSnapshot() {
+        return readLatestSnapshotInternal(null);
+    }
+
+    protected byte @Nullable [] readLatestSnapshot(int lockNumber) {
+        return readLatestSnapshotInternal(Integer.valueOf(lockNumber));
+    }
+
+    private byte @Nullable [] readLatestSnapshotInternal(@Nullable Integer lockNumber) {
+        final DahuaDoorConfiguration localConfig = config;
+        if (localConfig == null || localConfig.snapshotPath.isEmpty()) {
+            return null;
+        }
+
+        String suffix = lockNumber == null ? "" : "-" + lockNumber;
+        String latestSnapshotFilename = localConfig.snapshotPath + "/Doorbell" + suffix + ".jpg";
+        return readSnapshotFile(latestSnapshotFilename);
+    }
+
+    private byte @Nullable [] readSnapshotFile(String filename) {
+        Path path = Path.of(filename);
+        if (!Files.isRegularFile(path)) {
+            return null;
+        }
+        try {
+            return Files.readAllBytes(path);
+        } catch (IOException e) {
+            logger.warn("Could not read snapshot from '{}', check permissions and path", filename, e);
+            return null;
+        }
+    }
+
+    protected void restoreLastSnapshots() {
     }
 
     protected void handleButtonPressed() {

bundles/org.openhab.binding.dahuadoor/src/main/java/org/openhab/binding/dahuadoor/internal/DahuaDoorConfiguration.java

@@ -30,6 +30,7 @@ public class DahuaDoorConfiguration {
     public String username = "";
     public String password = "";
     public String snapshotPath = "";
+    public int maxImages = 20;
     public boolean useHttps = false;
 
     // WebRTC / go2rtc settings

bundles/org.openhab.binding.dahuadoor/src/main/java/org/openhab/binding/dahuadoor/internal/DahuaVto2202Handler.java

@@ -15,7 +15,6 @@
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.openhab.binding.dahuadoor.internal.dahuaeventhandler.DahuaEventClient;
 import org.openhab.binding.dahuadoor.internal.media.PlayStreamServlet;
-import org.openhab.core.library.types.RawType;
 import org.openhab.core.thing.Channel;
 import org.openhab.core.thing.Thing;
 
@@ -40,6 +39,12 @@ protected void handleInvite(JsonObject eventList, JsonObject eventData) {
         handleResolvedDoorbellEvent("DHIP", 1);
     }
 
+    @Override
+    protected void restoreLastSnapshots() {
+        byte[] buffer = readLatestSnapshot();
+        updateImageChannel(DahuaDoorBindingConstants.CHANNEL_DOOR_IMAGE, buffer);
+    }
+
     @Override
     protected void onButtonPressed(int lockNumber) {
         logger.debug("Button pressed on VTO2202 (lockNumber ignored, single button)");
@@ -63,8 +68,7 @@ protected void onButtonPressed(int lockNumber) {
             byte[] buffer = localClient.requestImage();
             if (buffer != null && buffer.length > 0) {
                 // Update image channel
-                RawType image = new RawType(buffer, "image/jpeg");
-                updateState(DahuaDoorBindingConstants.CHANNEL_DOOR_IMAGE, image);
+                updateImageChannel(DahuaDoorBindingConstants.CHANNEL_DOOR_IMAGE, buffer);
 
                 // Save snapshot
                 saveSnapshot(buffer);

bundles/org.openhab.binding.dahuadoor/src/main/java/org/openhab/binding/dahuadoor/internal/DahuaVto3211Handler.java

@@ -15,7 +15,6 @@
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.openhab.binding.dahuadoor.internal.dahuaeventhandler.DahuaEventClient;
 import org.openhab.binding.dahuadoor.internal.media.PlayStreamServlet;
-import org.openhab.core.library.types.RawType;
 import org.openhab.core.thing.Channel;
 import org.openhab.core.thing.Thing;
 
@@ -51,15 +50,25 @@ protected void handleInvite(JsonObject eventList, JsonObject eventData) {
         handleResolvedDoorbellEvent("DHIP", lockNumber);
     }
 
+    @Override
+    protected void restoreLastSnapshots() {
+        byte[] buffer1 = readLatestSnapshot(1);
+        updateImageChannel(DahuaDoorBindingConstants.CHANNEL_DOOR_IMAGE_1, buffer1);
+
+        byte[] buffer2 = readLatestSnapshot(2);
+        updateImageChannel(DahuaDoorBindingConstants.CHANNEL_DOOR_IMAGE_2, buffer2);
+    }
+
     @Override
     protected void onButtonPressed(int lockNumber) {
-        logger.debug("Button {} pressed on VTO3211", lockNumber);
+        int resolvedLockNumber = lockNumber == 2 ? 2 : 1;
+        logger.debug("Button {} pressed on VTO3211", resolvedLockNumber);
 
         // Determine channel IDs based on lock number
         String bellButtonChannelId;
         String doorImageChannelId;
 
-        if (lockNumber == 2) {
+        if (resolvedLockNumber == 2) {
             bellButtonChannelId = DahuaDoorBindingConstants.CHANNEL_BELL_BUTTON_2;
             doorImageChannelId = DahuaDoorBindingConstants.CHANNEL_DOOR_IMAGE_2;
         } else {
@@ -88,13 +97,12 @@ protected void onButtonPressed(int lockNumber) {
             byte[] buffer = localClient.requestImage();
             if (buffer != null && buffer.length > 0) {
                 // Update image channel for the specific button
-                RawType image = new RawType(buffer, "image/jpeg");
-                updateState(doorImageChannelIdFinal, image);
+                updateImageChannel(doorImageChannelIdFinal, buffer);
 
                 // Save snapshot image
-                saveSnapshot(buffer);
+                saveSnapshot(buffer, resolvedLockNumber);
             } else {
-                logger.warn("Received empty or null image buffer from VTO3211 button {}", lockNumber);
+                logger.warn("Received empty or null image buffer from VTO3211 button {}", resolvedLockNumber);
             }
         });
     }

bundles/org.openhab.binding.dahuadoor/src/main/resources/OH-INF/i18n/dahuadoor.properties

@@ -40,6 +40,8 @@ thing-type.config.dahuadoor.vto2202.hostname.label = Hostname
 thing-type.config.dahuadoor.vto2202.hostname.description = Hostname or IP address of the device
 thing-type.config.dahuadoor.vto2202.localSipPort.label = Local SIP Port
 thing-type.config.dahuadoor.vto2202.localSipPort.description = Local UDP port for SIP client (default 5060). Must be unique per thing if multiple SIP clients are used.
+thing-type.config.dahuadoor.vto2202.maxImages.label = Max Images
+thing-type.config.dahuadoor.vto2202.maxImages.description = Maximum number of timestamped snapshots to keep (0 disables cleanup)
 thing-type.config.dahuadoor.vto2202.password.label = Password
 thing-type.config.dahuadoor.vto2202.password.description = Password to access the device
 thing-type.config.dahuadoor.vto2202.rtspChannel.label = RTSP Channel
@@ -74,6 +76,8 @@ thing-type.config.dahuadoor.vto3211.hostname.label = Hostname
 thing-type.config.dahuadoor.vto3211.hostname.description = Hostname or IP address of the device
 thing-type.config.dahuadoor.vto3211.localSipPort.label = Local SIP Port
 thing-type.config.dahuadoor.vto3211.localSipPort.description = Local UDP port for SIP client (default 5060). Must be unique per thing if multiple SIP clients are used.
+thing-type.config.dahuadoor.vto3211.maxImages.label = Max Images
+thing-type.config.dahuadoor.vto3211.maxImages.description = Maximum number of timestamped snapshots to keep per button (0 disables cleanup)
 thing-type.config.dahuadoor.vto3211.password.label = Password
 thing-type.config.dahuadoor.vto3211.password.description = Password to access the device
 thing-type.config.dahuadoor.vto3211.rtspChannel.label = RTSP Channel

bundles/org.openhab.binding.dahuadoor/src/main/resources/OH-INF/thing/vto2202.xml

@@ -49,6 +49,11 @@
 				<label>Snapshot Path</label>
 				<description>Path where snapshots will be saved (e.g., /var/lib/openhab/door-images)</description>
 			</parameter>
+			<parameter name="maxImages" type="integer">
+				<label>Max Images</label>
+				<description>Maximum number of timestamped snapshots to keep (0 disables cleanup)</description>
+				<default>20</default>
+			</parameter>
 			<parameter name="useHttps" type="boolean">
 				<label>Use HTTPS</label>
 				<description>Use HTTPS (port 443) for snapshot and door-open requests. Enable if the device has HTTPS turned on.

bundles/org.openhab.binding.dahuadoor/src/main/resources/OH-INF/thing/vto3211.xml

@@ -63,6 +63,11 @@
 				<label>Snapshot Path</label>
 				<description>Path where snapshots will be saved (e.g., /var/lib/openhab/door-images)</description>
 			</parameter>
+			<parameter name="maxImages" type="integer">
+				<label>Max Images</label>
+				<description>Maximum number of timestamped snapshots to keep per button (0 disables cleanup)</description>
+				<default>20</default>
+			</parameter>
 			<parameter name="useHttps" type="boolean">
 				<label>Use HTTPS</label>
 				<description>Use HTTPS (port 443) for snapshot and door-open requests. Enable if the device has HTTPS turned on.