Archive

todo_cli/todo.py

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+"""Todo item data model and manager module.
+
+This module defines the TodoItem dataclass and the TodoManager class
+that provides CRUD operations for todo items, backed by a Storage instance.
+"""
+
+import datetime
+from dataclasses import dataclass, field, asdict
+from typing import List, Optional, Dict, Any
+
+from storage import Storage
+
+
+@dataclass
+class TodoItem:
+    """Represents a single todo item.
+
+    Attributes:
+        id: Unique identifier for the item.
+        title: Short title of the task.
+        description: Optional detailed description.
+        due_date: Optional due date string (e.g., '2025-01-01').
+        completed: Whether the task is completed.
+        created_at: ISO-formatted creation timestamp.
+    """
+    id: int
+    title: str
+    description: str = ""
+    due_date: str = ""
+    completed: bool = False
+    created_at: str = field(default_factory=lambda: datetime.datetime.now().isoformat())
+
+    def to_dict(self) -> Dict[str, Any]:
+        """Convert the TodoItem to a dictionary for JSON serialization.
+
+        Returns:
+            A dictionary with all fields.
+        """
+        return asdict(self)
+
+    @classmethod
+    def from_dict(cls, data: Dict[str, Any]) -> "TodoItem":
+        """Create a TodoItem from a dictionary (e.g., loaded from JSON).
+
+        Args:
+            data: Dictionary containing todo item fields.
+
+        Returns:
+            A new TodoItem instance.
+        """
+        return cls(
+            id=data["id"],
+            title=data["title"],
+            description=data.get("description", ""),
+            due_date=data.get("due_date", ""),
+            completed=data.get("completed", False),
+            created_at=data.get("created_at", ""),
+        )
+
+
+class TodoManager:
+    """Manages a collection of TodoItems with persistent storage.
+
+    Attributes:
+        items: List of current TodoItem objects.
+        storage: Storage instance for data persistence.
+        next_id: The next available ID for new items.
+    """
+
+    def __init__(self, storage: Storage) -> None:
+        """Initialize the manager with a Storage instance and load existing data.
+
+        Args:
+            storage: A Storage object for reading/writing JSON data.
+        """
+        self.storage = storage
+        self.items: List[TodoItem] = []
+        self.next_id: int = 1
+        self._load()
+
+    def add(self, title: str, description: str = "", due_date: str = "") -> TodoItem:
+        """Add a new todo item.
+
+        Args:
+            title: The title of the task.
+            description: Optional description.
+            due_date: Optional due date string.
+
+        Returns:
+            The newly created TodoItem.
+        """
+        item = TodoItem(
+            id=self.next_id,
+            title=title,
+            description=description,
+            due_date=due_date,
+        )
+        self.items.append(item)
+        self.next_id += 1
+        self._save()
+        return item
+
+    def list_all(self) -> List[TodoItem]:
+        """Return all todo items.
+
+        Returns:
+            A list of all TodoItem objects.
+        """
+        return self.items
+
+    def list_by_status(self, completed: bool) -> List[TodoItem]:
+        """Return todo items filtered by completion status.
+
+        Args:
+            completed: True for completed items, False for pending.
+
+        Returns:
+            A list of matching TodoItem objects.
+        """
+        return [item for item in self.items if item.completed == completed]
+
+    def mark_done(self, item_id: int) -> bool:
+        """Mark a todo item as completed.
+
+        Args:
+            item_id: The ID of the item to mark.
+
+        Returns:
+            True if the item was found and updated, False otherwise.
+        """
+        item = self._find_by_id(item_id)
+        if item is None:
+            return False
+        item.completed = True
+        self._save()
+        return True
+
+    def mark_undone(self, item_id: int) -> bool:
+        """Mark a todo item as not completed.
+
+        Args:
+            item_id: The ID of the item to mark.
+
+        Returns:
+            True if the item was found and updated, False otherwise.
+        """
+        item = self._find_by_id(item_id)
+        if item is None:
+            return False
+        item.completed = False
+        self._save()
+        return True
+
+    def delete(self, item_id: int) -> bool:
+        """Delete a todo item by its ID.
+
+        Args:
+            item_id: The ID of the item to delete.
+
+        Returns:
+            True if the item was found and removed, False otherwise.
+        """
+        item = self._find_by_id(item_id)
+        if item is None:
+            return False
+        self.items.remove(item)
+        self._save()
+        return True
+
+    def edit(
+        self,
+        item_id: int,
+        title: Optional[str] = None,
+        description: Optional[str] = None,
+        due_date: Optional[str] = None,
+        completed: Optional[bool] = None,
+    ) -> bool:
+        """Edit fields of an existing todo item.
+
+        Only fields that are not None will be updated.
+
+        Args:
+            item_id: The ID of the item to edit.
+            title: New title (or None to keep unchanged).
+            description: New description (or None to keep unchanged).
+            due_date: New due date (or None to keep unchanged).
+            completed: New completion status (or None to keep unchanged).
+
+        Returns:
+            True if the item was found and updated, False otherwise.
+        """
+        item = self._find_by_id(item_id)
+        if item is None:
+            return False
+        if title is not None:
+            item.title = title
+        if description is not None:
+            item.description = description
+        if due_date is not None:
+            item.due_date = due_date
+        if completed is not None:
+            item.completed = completed
+        self._save()
+        return True
+
+    def _load(self) -> None:
+        """Load todo items from storage and initialize next_id."""
+        raw_data = self.storage.load()
+        self.items = [TodoItem.from_dict(d) for d in raw_data]
+        if self.items:
+            max_id = max(item.id for item in self.items)
+            self.next_id = max_id + 1
+        else:
+            self.next_id = 1
+
+    def _save(self) -> None:
+        """Save current todo items to storage."""
+        data = [item.to_dict() for item in self.items]
+        self.storage.save(data)
+
+    def _find_by_id(self, item_id: int) -> Optional[TodoItem]:
+        """Find a todo item by its ID.
+
+        Args:
+            item_id: The ID to search for.
+
+        Returns:
+            The TodoItem if found, None otherwise.
+        """
+        for item in self.items:
+            if item.id == item_id:
+                return item
+        return None