Initial open-source release

Claude-Session: https://claude.ai/code/session_01B65qLEKnkeYTGdbwhLpjCu

fixtures/python-app/src/tasks/models.py

@@ -0,0 +1,57 @@
+from __future__ import annotations
+
+import os
+import sys
+from dataclasses import dataclass, field
+from datetime import date
+from enum import IntEnum
+
+
+class Priority(IntEnum):
+    LOW = 1
+    NORMAL = 2
+    HIGH = 3
+
+
+@dataclass
+class Task:
+    title: str
+    priority: Priority = Priority.NORMAL
+    due: date | None = None
+    done: bool = False
+    tags: set[str] = field(default_factory=set)
+
+    def is_overdue(self, today: date) -> bool:
+        return not self.done and self.due is not None and self.due < today
+
+
+class TaskList:
+    def __init__(self) -> None:
+        self._tasks: list[Task] = []
+
+    def add(self, title: str, priority: Priority = Priority.NORMAL, due: date | None = None, *tags: str) -> Task:
+        if not title.strip():
+            raise ValueError("title must not be empty")
+        task = Task(title.strip(), priority, due, tags=set(tags))
+        self._tasks.append(task)
+        return task
+
+    def complete(self, title: str) -> Task:
+        for task in self._tasks:
+            if task.title == title:
+                task.done = True
+                return task
+        raise KeyError(title)
+
+    def pending(self) -> list[Task]:
+        # TODO: stable ordering for equal priorities (by due date)
+        return sorted((t for t in self._tasks if not t.done), key=lambda t: -t.priority)
+
+    def overdue(self, today: date) -> list[Task]:
+        return [t for t in self._tasks if t.is_overdue(today)]
+
+    def by_tag(self, tag: str) -> list[Task]:
+        return [t for t in self._tasks if tag in t.tags]
+
+    def __len__(self) -> int:
+        return len(self._tasks)