From 8eaa6904dd6965053a1b63a9a6cbb82ffc20e184 Mon Sep 17 00:00:00 2001
From: "Cameron (3539)" <theforgelover@gmail.com>
Date: Mon, 21 Oct 2024 10:37:00 -0400
Subject: [PATCH] Equal only by usb paths (#1481)

This bug would only appear when there are cameras with the same naming.
Old config matching would also match using the by-id this was
problematic. When one camera is disconnected it would assign the by-id
path to the other camera with the
same name. When the camera is replugged in it would not be reassigned
the by-id path and would fail the camerainfo equals check.
---
 .../vision/camera/CameraInfo.java             |  2 +-
 .../processes/VisionSourceManagerTest.java    | 53 +++++++++++++++++--
 2 files changed, 50 insertions(+), 5 deletions(-)

diff --git a/photon-core/src/main/java/org/photonvision/vision/camera/CameraInfo.java b/photon-core/src/main/java/org/photonvision/vision/camera/CameraInfo.java
index 2c702d33f..750679f77 100644
--- a/photon-core/src/main/java/org/photonvision/vision/camera/CameraInfo.java
+++ b/photon-core/src/main/java/org/photonvision/vision/camera/CameraInfo.java
@@ -95,7 +95,7 @@ public class CameraInfo extends UsbCameraInfo {
 
         if (!path.equals(other.path)) return false;
         if (!name.equals(other.name)) return false;
-        if (!Arrays.asList(this.otherPaths).containsAll(Arrays.asList(other.otherPaths))) return false;
+        if (!Arrays.asList(this.getUSBPath()).contains(other.getUSBPath())) return false;
         if (vendorId != other.vendorId) return false;
         if (productId != other.productId) return false;
 
diff --git a/photon-core/src/test/java/org/photonvision/vision/processes/VisionSourceManagerTest.java b/photon-core/src/test/java/org/photonvision/vision/processes/VisionSourceManagerTest.java
index 4b800d1dc..467501e2f 100644
--- a/photon-core/src/test/java/org/photonvision/vision/processes/VisionSourceManagerTest.java
+++ b/photon-core/src/test/java/org/photonvision/vision/processes/VisionSourceManagerTest.java
@@ -521,8 +521,11 @@ public class VisionSourceManagerTest {
                         "/dev/video0",
                         "Arducam OV2311 USB Camera",
                         new String[] {
-                            "/dev/v4l/by-id/usb-Arducam_Technology_Co.__Ltd._Arducam_OV2311_USB_Camera_UC621-video-index0",
-                            "/dev/v4l/by-path/platform-fc800000.usb-usb-0:1:1.0-video-index0"
+                            "/dev/v4l/by-path/platform-fc800000.usb-usb-0:1:1.0-video-index0" // V4l doesnt assign
+                            // by-id paths that
+                            // are identical to
+                            // two different
+                            // cameras
                         },
                         3141,
                         25446);
@@ -576,8 +579,11 @@ public class VisionSourceManagerTest {
                         "/dev/video0",
                         "Arducam OV2311 USB Camera",
                         new String[] {
-                            "/dev/v4l/by-id/usb-Arducam_Technology_Co.__Ltd._Arducam_OV2311_USB_Camera_UC621-video-index0",
-                            "/dev/v4l/by-path/platform-fc800000.usb-usb-0:1:1.0-video-index0"
+                            "/dev/v4l/by-path/platform-fc800000.usb-usb-0:1:1.0-video-index0" // V4l doesnt assign
+                            // by-id paths that
+                            // are identical to
+                            // two different
+                            // cameras
                         },
                         3141,
                         25446);
@@ -602,5 +608,44 @@ public class VisionSourceManagerTest {
         assertTrue(inst.knownCameras.contains(info1_dup));
         assertTrue(inst.knownCameras.contains(info2_dup));
         assertEquals(2, inst.knownCameras.size());
+
+        // duplciate cameras this simulates unplugging one and plugging the other in where v4l assigns
+        // the same by-id path to the other camera
+        var duplicateCameraInfos1 = new ArrayList<CameraInfo>();
+        CameraInfo info3_dup =
+                new CameraInfo(
+                        0,
+                        "/dev/video0",
+                        "Arducam OV2311 USB Camera",
+                        new String[] {
+                            "/dev/v4l/by-id/usb-Arducam_Technology_Co.__Ltd._Arducam_OV2311_USB_Camera_UC621-video-index0",
+                            "/dev/v4l/by-path/platform-fc800000.usb-usb-0:1:1.0-video-index0"
+                        },
+                        3141,
+                        25446);
+        CameraInfo info4_dup =
+                new CameraInfo(
+                        0,
+                        "/dev/video2",
+                        "Arducam OV2311 USB Camera",
+                        new String[] {
+                            "/dev/v4l/by-path/platform-fc880000.usb-usb-0:1:1.0-video-index0" // V4l doesnt assign
+                            // by-id paths that
+                            // are identical to
+                            // two different
+                            // cameras
+                        },
+                        3141,
+                        25446);
+
+        duplicateCameraInfos1.add(info3_dup);
+        duplicateCameraInfos1.add(info4_dup);
+
+        inst.tryMatchCamImpl(duplicateCameraInfos);
+
+        // Our cameras should be "known", and we should only "know" two cameras still
+        assertTrue(inst.knownCameras.contains(info3_dup));
+        assertTrue(inst.knownCameras.contains(info4_dup));
+        assertEquals(2, inst.knownCameras.size());
     }
 }