From 6a351edb60c3356348e65cb6bceed21dcbebf5f2 Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 09:04:10 +0100
Subject: [PATCH 01/16] Define properties first and last track occurrence in
 TrackDataset

---
 OTAnalytics/domain/track_dataset.py                | 11 +++++++++++
 OTAnalytics/plugin_datastore/python_track_store.py |  8 ++++++++
 OTAnalytics/plugin_datastore/track_store.py        |  8 ++++++++
 3 files changed, 27 insertions(+)

diff --git a/OTAnalytics/domain/track_dataset.py b/OTAnalytics/domain/track_dataset.py
index 56d2d86f1..1b3e77831 100644
--- a/OTAnalytics/domain/track_dataset.py
+++ b/OTAnalytics/domain/track_dataset.py
@@ -1,5 +1,6 @@
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
+from datetime import datetime
 from typing import Callable, Iterable, Iterator, Optional, Sequence
 
 from OTAnalytics.domain.event import Event
@@ -17,6 +18,16 @@ class TrackDataset(ABC):
     def __iter__(self) -> Iterator[Track]:
         yield from self.as_list()
 
+    @property
+    @abstractmethod
+    def first_occurrence(self) -> datetime:
+        raise NotImplementedError
+
+    @property
+    @abstractmethod
+    def last_occurrence(self) -> datetime:
+        raise NotImplementedError
+
     @abstractmethod
     def add_all(self, other: Iterable[Track]) -> "TrackDataset":
         raise NotImplementedError
diff --git a/OTAnalytics/plugin_datastore/python_track_store.py b/OTAnalytics/plugin_datastore/python_track_store.py
index 66b3b0ec8..721bcb877 100644
--- a/OTAnalytics/plugin_datastore/python_track_store.py
+++ b/OTAnalytics/plugin_datastore/python_track_store.py
@@ -233,6 +233,14 @@ def calculate(self, detections: list[Detection]) -> str:
 class PythonTrackDataset(TrackDataset):
     """Pure Python implementation of a TrackDataset."""
 
+    @property
+    def first_occurrence(self) -> datetime:
+        raise NotImplementedError
+
+    @property
+    def last_occurrence(self) -> datetime:
+        raise NotImplementedError
+
     def __init__(
         self,
         values: Optional[dict[TrackId, Track]] = None,
diff --git a/OTAnalytics/plugin_datastore/track_store.py b/OTAnalytics/plugin_datastore/track_store.py
index a1b80c459..ce95b9d01 100644
--- a/OTAnalytics/plugin_datastore/track_store.py
+++ b/OTAnalytics/plugin_datastore/track_store.py
@@ -197,6 +197,14 @@ def extract_hostname(name: str) -> str:
 
 
 class PandasTrackDataset(TrackDataset):
+    @property
+    def first_occurrence(self) -> datetime:
+        raise NotImplementedError
+
+    @property
+    def last_occurrence(self) -> datetime:
+        raise NotImplementedError
+
     def __init__(
         self,
         track_geometry_factory: TRACK_GEOMETRY_FACTORY,

From 7ddd581138c8181b4490649c3a7fdaa9303d974c Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 09:39:03 +0100
Subject: [PATCH 02/16] Implement first and last occurrence properties for
 PythonTrackDataset

---
 OTAnalytics/plugin_datastore/python_track_store.py       | 6 ++++--
 .../plugin_datastore/test_python_track_storage.py        | 9 +++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/OTAnalytics/plugin_datastore/python_track_store.py b/OTAnalytics/plugin_datastore/python_track_store.py
index 721bcb877..eb2e22e58 100644
--- a/OTAnalytics/plugin_datastore/python_track_store.py
+++ b/OTAnalytics/plugin_datastore/python_track_store.py
@@ -235,11 +235,13 @@ class PythonTrackDataset(TrackDataset):
 
     @property
     def first_occurrence(self) -> datetime:
-        raise NotImplementedError
+        return min(
+            [track.first_detection.occurrence for track in self._tracks.values()]
+        )
 
     @property
     def last_occurrence(self) -> datetime:
-        raise NotImplementedError
+        return max([track.last_detection.occurrence for track in self._tracks.values()])
 
     def __init__(
         self,
diff --git a/tests/OTAnalytics/plugin_datastore/test_python_track_storage.py b/tests/OTAnalytics/plugin_datastore/test_python_track_storage.py
index e4a93f017..d02cd1f56 100644
--- a/tests/OTAnalytics/plugin_datastore/test_python_track_storage.py
+++ b/tests/OTAnalytics/plugin_datastore/test_python_track_storage.py
@@ -481,3 +481,12 @@ def __create_leave_scene_event(self, track: Track) -> Event:
             ),
             video_name=track.last_detection.video_name,
         )
+
+    def test_first_occurrence(self, first_track: Track, second_track: Track) -> None:
+        dataset = PythonTrackDataset.from_list([second_track, first_track])
+        assert dataset.first_occurrence == first_track.first_detection.occurrence
+        assert dataset.first_occurrence == second_track.first_detection.occurrence
+
+    def test_last_occurrence(self, first_track: Track, second_track: Track) -> None:
+        dataset = PythonTrackDataset.from_list([second_track, first_track])
+        assert dataset.last_occurrence == second_track.last_detection.occurrence

From 4b4dfaddc8319ca7ed73c399411116b492ee690a Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 10:01:06 +0100
Subject: [PATCH 03/16] Return None if TrackDataset is empty for first and last
 occurrence

---
 OTAnalytics/domain/track_dataset.py                       | 4 ++--
 OTAnalytics/plugin_datastore/python_track_store.py        | 8 ++++++--
 OTAnalytics/plugin_datastore/track_store.py               | 4 ++--
 .../plugin_datastore/test_python_track_storage.py         | 8 ++++++++
 4 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/OTAnalytics/domain/track_dataset.py b/OTAnalytics/domain/track_dataset.py
index 1b3e77831..55403f47c 100644
--- a/OTAnalytics/domain/track_dataset.py
+++ b/OTAnalytics/domain/track_dataset.py
@@ -20,12 +20,12 @@ def __iter__(self) -> Iterator[Track]:
 
     @property
     @abstractmethod
-    def first_occurrence(self) -> datetime:
+    def first_occurrence(self) -> datetime | None:
         raise NotImplementedError
 
     @property
     @abstractmethod
-    def last_occurrence(self) -> datetime:
+    def last_occurrence(self) -> datetime | None:
         raise NotImplementedError
 
     @abstractmethod
diff --git a/OTAnalytics/plugin_datastore/python_track_store.py b/OTAnalytics/plugin_datastore/python_track_store.py
index eb2e22e58..74474c86b 100644
--- a/OTAnalytics/plugin_datastore/python_track_store.py
+++ b/OTAnalytics/plugin_datastore/python_track_store.py
@@ -234,13 +234,17 @@ class PythonTrackDataset(TrackDataset):
     """Pure Python implementation of a TrackDataset."""
 
     @property
-    def first_occurrence(self) -> datetime:
+    def first_occurrence(self) -> datetime | None:
+        if not len(self):
+            return None
         return min(
             [track.first_detection.occurrence for track in self._tracks.values()]
         )
 
     @property
-    def last_occurrence(self) -> datetime:
+    def last_occurrence(self) -> datetime | None:
+        if not len(self):
+            return None
         return max([track.last_detection.occurrence for track in self._tracks.values()])
 
     def __init__(
diff --git a/OTAnalytics/plugin_datastore/track_store.py b/OTAnalytics/plugin_datastore/track_store.py
index ce95b9d01..d6bdcc3da 100644
--- a/OTAnalytics/plugin_datastore/track_store.py
+++ b/OTAnalytics/plugin_datastore/track_store.py
@@ -198,11 +198,11 @@ def extract_hostname(name: str) -> str:
 
 class PandasTrackDataset(TrackDataset):
     @property
-    def first_occurrence(self) -> datetime:
+    def first_occurrence(self) -> datetime | None:
         raise NotImplementedError
 
     @property
-    def last_occurrence(self) -> datetime:
+    def last_occurrence(self) -> datetime | None:
         raise NotImplementedError
 
     def __init__(
diff --git a/tests/OTAnalytics/plugin_datastore/test_python_track_storage.py b/tests/OTAnalytics/plugin_datastore/test_python_track_storage.py
index d02cd1f56..f6fd7ccdd 100644
--- a/tests/OTAnalytics/plugin_datastore/test_python_track_storage.py
+++ b/tests/OTAnalytics/plugin_datastore/test_python_track_storage.py
@@ -490,3 +490,11 @@ def test_first_occurrence(self, first_track: Track, second_track: Track) -> None
     def test_last_occurrence(self, first_track: Track, second_track: Track) -> None:
         dataset = PythonTrackDataset.from_list([second_track, first_track])
         assert dataset.last_occurrence == second_track.last_detection.occurrence
+
+    def test_first_occurrence_on_empty_dataset(self) -> None:
+        dataset = PythonTrackDataset()
+        assert dataset.first_occurrence is None
+
+    def test_last_occurrence_on_empty_dataset(self) -> None:
+        dataset = PythonTrackDataset()
+        assert dataset.last_occurrence is None

From 8f3557c6e79715fd20676e463def87229fa03cdb Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 10:24:35 +0100
Subject: [PATCH 04/16] Implement first and last occurrence for
 PandasTrackDataset

---
 OTAnalytics/plugin_datastore/track_store.py   | 20 ++++++-----
 .../plugin_datastore/test_track_store.py      | 35 +++++++++++++++++++
 2 files changed, 47 insertions(+), 8 deletions(-)

diff --git a/OTAnalytics/plugin_datastore/track_store.py b/OTAnalytics/plugin_datastore/track_store.py
index d6bdcc3da..6712e4f94 100644
--- a/OTAnalytics/plugin_datastore/track_store.py
+++ b/OTAnalytics/plugin_datastore/track_store.py
@@ -197,14 +197,6 @@ def extract_hostname(name: str) -> str:
 
 
 class PandasTrackDataset(TrackDataset):
-    @property
-    def first_occurrence(self) -> datetime | None:
-        raise NotImplementedError
-
-    @property
-    def last_occurrence(self) -> datetime | None:
-        raise NotImplementedError
-
     def __init__(
         self,
         track_geometry_factory: TRACK_GEOMETRY_FACTORY,
@@ -227,6 +219,18 @@ def __init__(
         else:
             self._geometry_datasets = geometry_datasets
 
+    @property
+    def first_occurrence(self) -> datetime | None:
+        if not len(self):
+            return None
+        return self._dataset.index.get_level_values(LEVEL_OCCURRENCE).min()
+
+    @property
+    def last_occurrence(self) -> datetime | None:
+        if not len(self):
+            return None
+        return self._dataset.index.get_level_values(LEVEL_OCCURRENCE).max()
+
     @staticmethod
     def from_list(
         tracks: list[Track],
diff --git a/tests/OTAnalytics/plugin_datastore/test_track_store.py b/tests/OTAnalytics/plugin_datastore/test_track_store.py
index 0a6bdc2ea..be1c5ecb6 100644
--- a/tests/OTAnalytics/plugin_datastore/test_track_store.py
+++ b/tests/OTAnalytics/plugin_datastore/test_track_store.py
@@ -460,3 +460,38 @@ def __create_leave_scene_event(self, track: Track) -> Event:
             ),
             video_name=track.last_detection.video_name,
         )
+
+    def test_first_occurrence(
+        self,
+        track_geometry_factory: TRACK_GEOMETRY_FACTORY,
+        first_track: Track,
+        second_track: Track,
+    ) -> None:
+        dataset = PandasTrackDataset.from_list(
+            [first_track, second_track], track_geometry_factory
+        )
+        assert dataset.first_occurrence == first_track.first_detection.occurrence
+        assert dataset.first_occurrence == second_track.first_detection.occurrence
+
+    def test_last_occurrence(
+        self,
+        track_geometry_factory: TRACK_GEOMETRY_FACTORY,
+        first_track: Track,
+        second_track: Track,
+    ) -> None:
+        dataset = PandasTrackDataset.from_list(
+            [first_track, second_track], track_geometry_factory
+        )
+        assert dataset.last_occurrence == second_track.last_detection.occurrence
+
+    def test_first_occurrence_on_empty_dataset(
+        self, track_geometry_factory: TRACK_GEOMETRY_FACTORY
+    ) -> None:
+        dataset = PandasTrackDataset(track_geometry_factory)
+        assert dataset.first_occurrence is None
+
+    def test_last_occurrence_on_empty_dataset(
+        self, track_geometry_factory: TRACK_GEOMETRY_FACTORY
+    ) -> None:
+        dataset = PandasTrackDataset(track_geometry_factory)
+        assert dataset.last_occurrence is None

From 44bd0e1894e0a9bf9d998f1cc7be7a6e080ef5ba Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 10:28:58 +0100
Subject: [PATCH 05/16] Reorder methods

---
 OTAnalytics/plugin_datastore/track_store.py | 24 ++++++++++-----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/OTAnalytics/plugin_datastore/track_store.py b/OTAnalytics/plugin_datastore/track_store.py
index 6712e4f94..84b1859b0 100644
--- a/OTAnalytics/plugin_datastore/track_store.py
+++ b/OTAnalytics/plugin_datastore/track_store.py
@@ -197,6 +197,18 @@ def extract_hostname(name: str) -> str:
 
 
 class PandasTrackDataset(TrackDataset):
+    @property
+    def first_occurrence(self) -> datetime | None:
+        if not len(self):
+            return None
+        return self._dataset.index.get_level_values(LEVEL_OCCURRENCE).min()
+
+    @property
+    def last_occurrence(self) -> datetime | None:
+        if not len(self):
+            return None
+        return self._dataset.index.get_level_values(LEVEL_OCCURRENCE).max()
+
     def __init__(
         self,
         track_geometry_factory: TRACK_GEOMETRY_FACTORY,
@@ -219,18 +231,6 @@ def __init__(
         else:
             self._geometry_datasets = geometry_datasets
 
-    @property
-    def first_occurrence(self) -> datetime | None:
-        if not len(self):
-            return None
-        return self._dataset.index.get_level_values(LEVEL_OCCURRENCE).min()
-
-    @property
-    def last_occurrence(self) -> datetime | None:
-        if not len(self):
-            return None
-        return self._dataset.index.get_level_values(LEVEL_OCCURRENCE).max()
-
     @staticmethod
     def from_list(
         tracks: list[Track],

From 759ffcab296e10df034d79ab51bfb3a9bb5d47bc Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 10:30:52 +0100
Subject: [PATCH 06/16] Define property classifications for TrackDataset

---
 OTAnalytics/domain/track_dataset.py                | 5 +++++
 OTAnalytics/plugin_datastore/python_track_store.py | 4 ++++
 OTAnalytics/plugin_datastore/track_store.py        | 4 ++++
 3 files changed, 13 insertions(+)

diff --git a/OTAnalytics/domain/track_dataset.py b/OTAnalytics/domain/track_dataset.py
index 55403f47c..40987c961 100644
--- a/OTAnalytics/domain/track_dataset.py
+++ b/OTAnalytics/domain/track_dataset.py
@@ -28,6 +28,11 @@ def first_occurrence(self) -> datetime | None:
     def last_occurrence(self) -> datetime | None:
         raise NotImplementedError
 
+    @property
+    @abstractmethod
+    def classifications(self) -> frozenset[str]:
+        raise NotImplementedError
+
     @abstractmethod
     def add_all(self, other: Iterable[Track]) -> "TrackDataset":
         raise NotImplementedError
diff --git a/OTAnalytics/plugin_datastore/python_track_store.py b/OTAnalytics/plugin_datastore/python_track_store.py
index 74474c86b..6b3e43942 100644
--- a/OTAnalytics/plugin_datastore/python_track_store.py
+++ b/OTAnalytics/plugin_datastore/python_track_store.py
@@ -247,6 +247,10 @@ def last_occurrence(self) -> datetime | None:
             return None
         return max([track.last_detection.occurrence for track in self._tracks.values()])
 
+    @property
+    def classifications(self) -> frozenset[str]:
+        raise NotImplementedError
+
     def __init__(
         self,
         values: Optional[dict[TrackId, Track]] = None,
diff --git a/OTAnalytics/plugin_datastore/track_store.py b/OTAnalytics/plugin_datastore/track_store.py
index 84b1859b0..654498666 100644
--- a/OTAnalytics/plugin_datastore/track_store.py
+++ b/OTAnalytics/plugin_datastore/track_store.py
@@ -209,6 +209,10 @@ def last_occurrence(self) -> datetime | None:
             return None
         return self._dataset.index.get_level_values(LEVEL_OCCURRENCE).max()
 
+    @property
+    def classifications(self) -> frozenset[str]:
+        raise NotImplementedError
+
     def __init__(
         self,
         track_geometry_factory: TRACK_GEOMETRY_FACTORY,

From 31e33d9e49a32856b09dae9931c5364877451cfa Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 10:39:56 +0100
Subject: [PATCH 07/16] Add unit tests for classifications property of
 TrackDataset

---
 .../test_python_track_storage.py              | 10 ++++++++++
 .../plugin_datastore/test_track_store.py      | 19 +++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/tests/OTAnalytics/plugin_datastore/test_python_track_storage.py b/tests/OTAnalytics/plugin_datastore/test_python_track_storage.py
index f6fd7ccdd..954654e0d 100644
--- a/tests/OTAnalytics/plugin_datastore/test_python_track_storage.py
+++ b/tests/OTAnalytics/plugin_datastore/test_python_track_storage.py
@@ -498,3 +498,13 @@ def test_first_occurrence_on_empty_dataset(self) -> None:
     def test_last_occurrence_on_empty_dataset(self) -> None:
         dataset = PythonTrackDataset()
         assert dataset.last_occurrence is None
+
+    def test_classifications(self, first_track: Track, second_track: Track) -> None:
+        dataset = PythonTrackDataset.from_list([first_track, second_track])
+        assert dataset.classifications == frozenset(
+            [first_track.classification, second_track.classification]
+        )
+
+    def test_classifications_on_empty_dataset(self) -> None:
+        dataset = PythonTrackDataset()
+        assert dataset.classifications == frozenset()
diff --git a/tests/OTAnalytics/plugin_datastore/test_track_store.py b/tests/OTAnalytics/plugin_datastore/test_track_store.py
index be1c5ecb6..aeae9f7d4 100644
--- a/tests/OTAnalytics/plugin_datastore/test_track_store.py
+++ b/tests/OTAnalytics/plugin_datastore/test_track_store.py
@@ -495,3 +495,22 @@ def test_last_occurrence_on_empty_dataset(
     ) -> None:
         dataset = PandasTrackDataset(track_geometry_factory)
         assert dataset.last_occurrence is None
+
+    def test_classifications(
+        self,
+        track_geometry_factory: TRACK_GEOMETRY_FACTORY,
+        first_track: Track,
+        second_track: Track,
+    ) -> None:
+        dataset = PandasTrackDataset.from_list(
+            [first_track, second_track], track_geometry_factory
+        )
+        assert dataset.classifications == frozenset(
+            [first_track.classification, second_track.classification]
+        )
+
+    def test_classifications_on_empty_dataset(
+        self, track_geometry_factory: TRACK_GEOMETRY_FACTORY
+    ) -> None:
+        dataset = PandasTrackDataset(track_geometry_factory)
+        assert dataset.classifications == frozenset()

From 2ca3ddecb602fe4a2253f785f12556d769121e81 Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 10:46:28 +0100
Subject: [PATCH 08/16] Implement property classifications for TrackDataset

---
 OTAnalytics/plugin_datastore/python_track_store.py | 2 +-
 OTAnalytics/plugin_datastore/track_store.py        | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/OTAnalytics/plugin_datastore/python_track_store.py b/OTAnalytics/plugin_datastore/python_track_store.py
index 6b3e43942..e97a58b74 100644
--- a/OTAnalytics/plugin_datastore/python_track_store.py
+++ b/OTAnalytics/plugin_datastore/python_track_store.py
@@ -249,7 +249,7 @@ def last_occurrence(self) -> datetime | None:
 
     @property
     def classifications(self) -> frozenset[str]:
-        raise NotImplementedError
+        return frozenset([track.classification for track in self._tracks.values()])
 
     def __init__(
         self,
diff --git a/OTAnalytics/plugin_datastore/track_store.py b/OTAnalytics/plugin_datastore/track_store.py
index 654498666..ce8c137dd 100644
--- a/OTAnalytics/plugin_datastore/track_store.py
+++ b/OTAnalytics/plugin_datastore/track_store.py
@@ -211,7 +211,9 @@ def last_occurrence(self) -> datetime | None:
 
     @property
     def classifications(self) -> frozenset[str]:
-        raise NotImplementedError
+        if not len(self):
+            return frozenset()
+        return frozenset(self._dataset[track.TRACK_CLASSIFICATION].unique())
 
     def __init__(
         self,

From 1ece2b0567eb9173fece7d62db25e1756439967f Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 11:13:33 +0100
Subject: [PATCH 09/16] Extend TrackRepository with new properties

---
 OTAnalytics/domain/track_repository.py | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/OTAnalytics/domain/track_repository.py b/OTAnalytics/domain/track_repository.py
index 0e9b74a59..4338f873e 100644
--- a/OTAnalytics/domain/track_repository.py
+++ b/OTAnalytics/domain/track_repository.py
@@ -1,5 +1,6 @@
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
+from datetime import datetime
 from pathlib import Path
 from typing import Iterable, Optional
 
@@ -99,6 +100,18 @@ def __init__(self, track_ids: list[TrackId], message: str):
 
 
 class TrackRepository:
+    @property
+    def first_occurrence(self) -> datetime | None:
+        return self._dataset.first_occurrence
+
+    @property
+    def last_occurrence(self) -> datetime | None:
+        return self._dataset.first_occurrence
+
+    @property
+    def classifications(self) -> frozenset[str]:
+        return self._dataset.classifications
+
     def __init__(self, dataset: TrackDataset) -> None:
         self._dataset = dataset
         self.observers = Subject[TrackRepositoryEvent]()

From 13ac5cceab7fce649611774f681eb26d01513666 Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 13:05:20 +0100
Subject: [PATCH 10/16] Use classification property of TrackRepository in
 TracksMetadata

---
 OTAnalytics/application/state.py              | 18 +++++++----------
 .../track_visualization/track_viz.py          |  2 +-
 tests/OTAnalytics/application/test_state.py   | 20 +++++--------------
 .../track_visualization/test_track_viz.py     |  2 +-
 4 files changed, 14 insertions(+), 28 deletions(-)

diff --git a/OTAnalytics/application/state.py b/OTAnalytics/application/state.py
index 5cdff1bde..8a93d2b6f 100644
--- a/OTAnalytics/application/state.py
+++ b/OTAnalytics/application/state.py
@@ -436,9 +436,9 @@ def __init__(self, track_repository: TrackRepository) -> None:
         self._last_detection_occurrence: ObservableOptionalProperty[
             datetime
         ] = ObservableOptionalProperty[datetime]()
-        self._classifications: ObservableProperty[set[str]] = ObservableProperty[set](
-            set()
-        )
+        self._classifications: ObservableProperty[frozenset[str]] = ObservableProperty[
+            frozenset
+        ](frozenset())
         self._detection_classifications: ObservableProperty[
             frozenset[str]
         ] = ObservableProperty[frozenset](frozenset([]))
@@ -464,7 +464,7 @@ def last_detection_occurrence(self) -> Optional[datetime]:
         return self._last_detection_occurrence.get()
 
     @property
-    def classifications(self) -> set[str]:
+    def classifications(self) -> frozenset[str]:
         """The current classifications in the track repository.
 
         Returns:
@@ -484,7 +484,7 @@ def detection_classifications(self) -> frozenset[str]:
     def notify_tracks(self, track_event: TrackRepositoryEvent) -> None:
         """Update tracks metadata on track repository changes"""
         self._update_detection_occurrences()
-        self._update_classifications(track_event.added)
+        self._update_classifications()
 
     def _update_detection_occurrences(self) -> None:
         """Update the first and last detection occurrences."""
@@ -495,13 +495,9 @@ def _update_detection_occurrences(self) -> None:
             self._first_detection_occurrence.set(sorted_detections[0].occurrence)
             self._last_detection_occurrence.set(sorted_detections[-1].occurrence)
 
-    def _update_classifications(self, new_tracks: list[TrackId]) -> None:
+    def _update_classifications(self) -> None:
         """Update current classifications."""
-        updated_classifications = self._classifications.get().copy()
-        for track_id in new_tracks:
-            if track := self._track_repository.get_for(track_id):
-                updated_classifications.add(track.classification)
-        self._classifications.set(updated_classifications)
+        self._classifications.set(self._track_repository.classifications)
 
     def _get_all_track_detections(self) -> Iterable[Detection]:
         """Get all track detections in the track repository.
diff --git a/OTAnalytics/plugin_prototypes/track_visualization/track_viz.py b/OTAnalytics/plugin_prototypes/track_visualization/track_viz.py
index 5b45b5dc7..4e9f82601 100644
--- a/OTAnalytics/plugin_prototypes/track_visualization/track_viz.py
+++ b/OTAnalytics/plugin_prototypes/track_visualization/track_viz.py
@@ -120,7 +120,7 @@ def __init__(self, default_palette: dict[str, str]) -> None:
         self._default_palette = default_palette
         self._palette: dict[str, str] = {}
 
-    def update(self, classifications: set[str]) -> None:
+    def update(self, classifications: frozenset[str]) -> None:
         for classification in classifications:
             if classification in self._default_palette.keys():
                 self._palette[classification] = self._default_palette[classification]
diff --git a/tests/OTAnalytics/application/test_state.py b/tests/OTAnalytics/application/test_state.py
index c3abfa4f0..1d2c2ccb9 100644
--- a/tests/OTAnalytics/application/test_state.py
+++ b/tests/OTAnalytics/application/test_state.py
@@ -382,26 +382,16 @@ def test_get_all_track_detections(
         assert detections == [first_detection, second_detection]
         track_repository.get_all.assert_called_once()
 
-    def test_update_classifications(self, track: Mock) -> None:
+    def test_update_classifications(self) -> None:
+        classifications = frozenset(["truck", "car", "pedestrian"])
         mock_track_repository = Mock(spec=TrackRepository)
-        mock_track_repository.get_for.return_value = track
+        mock_track_repository.classifications = classifications
 
         tracks_metadata = TracksMetadata(mock_track_repository)
-
         assert tracks_metadata.classifications == set()
 
-        tracks_metadata._update_classifications([track.id])
-
-        assert tracks_metadata.classifications == {"car"}
-        mock_track_repository.get_for.assert_any_call(track.id)
-        assert mock_track_repository.get_for.call_count == 1
-
-        track.detections[0].classification = "bicycle"
-        tracks_metadata._update_classifications([track.id])
-
-        assert tracks_metadata.classifications == {"car"}
-        mock_track_repository.get_for.assert_any_call(track.id)
-        assert mock_track_repository.get_for.call_count == 2
+        tracks_metadata._update_classifications()
+        assert tracks_metadata.classifications == classifications
 
     def test_update_detection_classes(self) -> None:
         tracks_metadata = TracksMetadata(Mock())
diff --git a/tests/OTAnalytics/plugin_prototypes/track_visualization/test_track_viz.py b/tests/OTAnalytics/plugin_prototypes/track_visualization/test_track_viz.py
index 605214efd..d179cdb55 100644
--- a/tests/OTAnalytics/plugin_prototypes/track_visualization/test_track_viz.py
+++ b/tests/OTAnalytics/plugin_prototypes/track_visualization/test_track_viz.py
@@ -306,7 +306,7 @@ class TestColorPaletteProvider:
     )
     def test_update_with_filled_default(
         self,
-        new_classifications: set[str],
+        new_classifications: frozenset[str],
         default_palette: dict[str, str],
         expected: dict[str, str],
     ) -> None:

From dc54d870f474db5b9b6ab551cf6d524a98feeb60 Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 13:16:53 +0100
Subject: [PATCH 11/16] Use first and last occurrence properties of
 TrackRepository in TracksMetadata

---
 OTAnalytics/application/state.py            | 25 ++----------
 tests/OTAnalytics/application/test_state.py | 44 +++++----------------
 2 files changed, 14 insertions(+), 55 deletions(-)

diff --git a/OTAnalytics/application/state.py b/OTAnalytics/application/state.py
index 8a93d2b6f..8d938895f 100644
--- a/OTAnalytics/application/state.py
+++ b/OTAnalytics/application/state.py
@@ -1,6 +1,6 @@
 from abc import ABC, abstractmethod
 from datetime import datetime
-from typing import Callable, Generic, Iterable, Optional
+from typing import Callable, Generic, Optional
 
 from OTAnalytics.application.config import DEFAULT_TRACK_OFFSET
 from OTAnalytics.application.datastore import Datastore, VideoMetadata
@@ -17,7 +17,7 @@
     SectionRepositoryEvent,
     SectionType,
 )
-from OTAnalytics.domain.track import Detection, TrackId, TrackImage
+from OTAnalytics.domain.track import TrackId, TrackImage
 from OTAnalytics.domain.track_repository import (
     TrackListObserver,
     TrackObserver,
@@ -488,30 +488,13 @@ def notify_tracks(self, track_event: TrackRepositoryEvent) -> None:
 
     def _update_detection_occurrences(self) -> None:
         """Update the first and last detection occurrences."""
-        sorted_detections = sorted(
-            self._get_all_track_detections(), key=lambda x: x.occurrence
-        )
-        if sorted_detections:
-            self._first_detection_occurrence.set(sorted_detections[0].occurrence)
-            self._last_detection_occurrence.set(sorted_detections[-1].occurrence)
+        self._first_detection_occurrence.set(self._track_repository.first_occurrence)
+        self._last_detection_occurrence.set(self._track_repository.last_occurrence)
 
     def _update_classifications(self) -> None:
         """Update current classifications."""
         self._classifications.set(self._track_repository.classifications)
 
-    def _get_all_track_detections(self) -> Iterable[Detection]:
-        """Get all track detections in the track repository.
-
-        Returns:
-            Iterable[Detection]: the track detections.
-        """
-        detections: list[Detection] = []
-
-        for track in self._track_repository.get_all():
-            detections.extend(track.detections)
-
-        return detections
-
     def update_detection_classes(self, new_classes: frozenset[str]) -> None:
         """Update the classifications used by the detection model."""
         updated_classes = self._detection_classifications.get().union(new_classes)
diff --git a/tests/OTAnalytics/application/test_state.py b/tests/OTAnalytics/application/test_state.py
index 1d2c2ccb9..7bf333c98 100644
--- a/tests/OTAnalytics/application/test_state.py
+++ b/tests/OTAnalytics/application/test_state.py
@@ -1,6 +1,6 @@
 from datetime import datetime, timedelta, timezone
 from typing import Callable, Optional
-from unittest.mock import Mock, call, patch
+from unittest.mock import Mock, call
 
 import pytest
 
@@ -342,45 +342,21 @@ def track(
         track.detections = [first_detection, second_detection, third_detection]
         return track
 
-    @patch("OTAnalytics.application.state.TracksMetadata._get_all_track_detections")
-    def test_update_detection_occurrences(
-        self,
-        mock_get_all_track_detections: Mock,
-        first_detection: Mock,
-        second_detection: Mock,
-        third_detection: Mock,
-    ) -> None:
-        mock_track_repository = Mock(spec=TrackRepository)
+    def test_update_detection_occurrences(self) -> None:
+        first_occurrence = datetime(2000, 1, 1, 12)
+        last_occurrence = datetime(2000, 1, 1, 15)
+        track_repository = Mock(spec=TrackRepository)
+        track_repository.first_occurrence = first_occurrence
+        track_repository.last_occurrence = last_occurrence
 
-        mock_get_all_track_detections.return_value = [
-            first_detection,
-            third_detection,
-            second_detection,
-        ]
-        tracks_metadata = TracksMetadata(mock_track_repository)
+        tracks_metadata = TracksMetadata(track_repository)
 
         assert tracks_metadata.first_detection_occurrence is None
         assert tracks_metadata.last_detection_occurrence is None
 
         tracks_metadata._update_detection_occurrences()
-        assert tracks_metadata.first_detection_occurrence == first_detection.occurrence
-        assert tracks_metadata.last_detection_occurrence == third_detection.occurrence
-
-        mock_get_all_track_detections.assert_called_once()
-
-    def test_get_all_track_detections(
-        self, first_detection: Mock, second_detection: Mock
-    ) -> None:
-        track = Mock(spec=Track).return_value
-        track.detections = [first_detection, second_detection]
-        track_repository = Mock(spec=TrackRepository)
-        track_repository.get_all.return_value = [track]
-
-        tracks_metadata = TracksMetadata(track_repository)
-        detections = tracks_metadata._get_all_track_detections()
-
-        assert detections == [first_detection, second_detection]
-        track_repository.get_all.assert_called_once()
+        assert tracks_metadata.first_detection_occurrence == first_occurrence
+        assert tracks_metadata.last_detection_occurrence == last_occurrence
 
     def test_update_classifications(self) -> None:
         classifications = frozenset(["truck", "car", "pedestrian"])

From d86610aa30e301d8a83c42b1345e0b5643064ca7 Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 13:28:21 +0100
Subject: [PATCH 12/16] Fix selecting wrong property for last occurrence in
 TrackRepository

---
 OTAnalytics/domain/track_repository.py            |  2 +-
 tests/OTAnalytics/domain/test_track_repository.py | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/OTAnalytics/domain/track_repository.py b/OTAnalytics/domain/track_repository.py
index 4338f873e..38b9091c5 100644
--- a/OTAnalytics/domain/track_repository.py
+++ b/OTAnalytics/domain/track_repository.py
@@ -106,7 +106,7 @@ def first_occurrence(self) -> datetime | None:
 
     @property
     def last_occurrence(self) -> datetime | None:
-        return self._dataset.first_occurrence
+        return self._dataset.last_occurrence
 
     @property
     def classifications(self) -> frozenset[str]:
diff --git a/tests/OTAnalytics/domain/test_track_repository.py b/tests/OTAnalytics/domain/test_track_repository.py
index 4a2a3daaa..71eeeee91 100644
--- a/tests/OTAnalytics/domain/test_track_repository.py
+++ b/tests/OTAnalytics/domain/test_track_repository.py
@@ -146,6 +146,20 @@ def test_len(self) -> None:
         assert result == expected_size
         dataset.__len__.assert_called_once()
 
+    def test_first_occurrence(self) -> None:
+        first_occurrence = Mock()
+        dataset = Mock()
+        dataset.first_occurrence = first_occurrence
+        repository = TrackRepository(dataset)
+        assert repository.first_occurrence == first_occurrence
+
+    def test_last_occurrence(self) -> None:
+        last_occurrence = Mock()
+        dataset = Mock()
+        dataset.last_occurrence = last_occurrence
+        repository = TrackRepository(dataset)
+        assert repository.last_occurrence == last_occurrence
+
 
 class TestTrackFileRepository:
     @pytest.fixture

From 32db5915f809c68d194df25a29b7e650ab509ba1 Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 13:29:17 +0100
Subject: [PATCH 13/16] Add unit test for classification property in
 TrackRepository

---
 tests/OTAnalytics/domain/test_track_repository.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tests/OTAnalytics/domain/test_track_repository.py b/tests/OTAnalytics/domain/test_track_repository.py
index 71eeeee91..37b68008b 100644
--- a/tests/OTAnalytics/domain/test_track_repository.py
+++ b/tests/OTAnalytics/domain/test_track_repository.py
@@ -160,6 +160,13 @@ def test_last_occurrence(self) -> None:
         repository = TrackRepository(dataset)
         assert repository.last_occurrence == last_occurrence
 
+    def test_classifications(self) -> None:
+        classifications = Mock()
+        dataset = Mock()
+        dataset.classifications = classifications
+        repository = TrackRepository(dataset)
+        assert repository.classifications == classifications
+
 
 class TestTrackFileRepository:
     @pytest.fixture

From 27ffe21108d0768bc5ec2e168fcb2b00d5de433f Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 13:38:43 +0100
Subject: [PATCH 14/16] Fix typo

---
 OTAnalytics/application/track_filter.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/OTAnalytics/application/track_filter.py b/OTAnalytics/application/track_filter.py
index 446665a68..f32b5c758 100644
--- a/OTAnalytics/application/track_filter.py
+++ b/OTAnalytics/application/track_filter.py
@@ -83,7 +83,7 @@ def test(self, to_test: Track) -> bool:
             to_test (Track): the track under test
 
         Returns:
-            bool: `True` if track has classification. Otherwise `False`.
+            bool: `True` if track has classification. Otherwise, `False`.
         """
         return to_test.classification in self._classifications
 

From f06e7412d6b13fbd009a4adcc91058ac217d248e Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 13:39:40 +0100
Subject: [PATCH 15/16] Clean up documentation

---
 OTAnalytics/application/track_filter.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/OTAnalytics/application/track_filter.py b/OTAnalytics/application/track_filter.py
index f32b5c758..d50505d1d 100644
--- a/OTAnalytics/application/track_filter.py
+++ b/OTAnalytics/application/track_filter.py
@@ -92,7 +92,6 @@ class TrackFilter(Filter[Track, bool]):
     """A `Track` filter.
 
     Args:
-        Filter (Filter[Track, bool]): extends the `Filter` interface
         predicate (Predicate[Track, bool]): the predicate to test against during
             filtering
     """

From f09af72cbfd28c44e9ac61dd611dabd7442935df Mon Sep 17 00:00:00 2001
From: Randy Seng <19281702+randy-seng@users.noreply.github.com>
Date: Thu, 11 Jan 2024 15:21:57 +0100
Subject: [PATCH 16/16] Use track properties

---
 OTAnalytics/application/track_filter.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/OTAnalytics/application/track_filter.py b/OTAnalytics/application/track_filter.py
index d50505d1d..28454bb44 100644
--- a/OTAnalytics/application/track_filter.py
+++ b/OTAnalytics/application/track_filter.py
@@ -46,7 +46,7 @@ def __init__(self, start_date: datetime) -> None:
         self._start_date = start_date
 
     def test(self, to_test: Track) -> bool:
-        return self._start_date <= to_test.detections[0].occurrence
+        return self._start_date <= to_test.first_detection.occurrence
 
 
 class TrackEndsBeforeOrAtDate(TrackPredicate):
@@ -60,7 +60,7 @@ def __init__(self, end_date: datetime) -> None:
         self._end_date = end_date
 
     def test(self, to_test: Track) -> bool:
-        return to_test.detections[0].occurrence <= self._end_date
+        return to_test.first_detection.occurrence <= self._end_date
 
 
 class TrackHasClassifications(TrackPredicate):