adding persistence

.gitignore

@@ -15,7 +15,6 @@ dist/
 downloads/
 eggs/
 .eggs/
-lib/
 lib64/
 parts/
 sdist/

lib/DataStore.py

@@ -0,0 +1,29 @@
+from pathlib import Path
+from .TimeSlot import TimeSlot
+import json
+
+
+class DataStore:
+    def __init__(self, filename: Path, create=False):
+        self._filename = filename
+        if create:
+            self._time_slots = []
+            self._write_update()
+        else:
+            with open(self._filename, "r") as f:
+                self._time_slots = list(json.load(f))
+
+    def _write_update(self):
+        with open(self._filename, "w+") as f:
+            json.dump(self._time_slots, f, default=vars)
+
+    def add_time_slot(self, time_slot: TimeSlot):
+        self._time_slots.append(time_slot)
+        self._write_update()
+
+    def remove_time_slot(self, time_slot: TimeSlot):
+        self._time_slots.remove(time_slot)
+        self._write_update()
+
+    def get_all_time_slots(self):
+        return self._time_slots[:]

lib/TimeSlot.py

@@ -0,0 +1,37 @@
+from datetime import datetime
+
+
+class TimeSlot():
+
+    def __init__(self, name: str, start: datetime = datetime.now(), end: datetime = None):
+        self.name = name
+        self.start = start
+        if end:
+            self.end = end
+        self._creation_time = datetime.now().timestamp()
+
+    @property
+    def name(self):
+        return self._name
+
+    @name.setter
+    def name(self, n: str):
+        self._name = n
+
+    @property
+    def start(self):
+        return datetime.fromtimestamp(self._start)
+
+    @start.setter
+    def start(self, d: datetime):
+        self._start = d.timestamp()
+
+    @property
+    def end(self):
+        return datetime.fromtimestamp(self._end)
+
+    @end.setter
+    def end(self, d: datetime):
+        if d < self.start:
+            raise ValueError("End date must be after the start date.")
+        self._end = d.timestamp()