feat: Implement CLI and TUI for Fountain Pen Tracker

- Added CLI functionality for adding, editing, viewing, and deleting fountain pens.
- Introduced TUI using Textual for a more interactive experience.
- Created Pen and PenTracker classes to manage pen data and CSV storage.
- Implemented input validation for date fields.
- Added export functionality to JSON format.
- Updated project version to 0.2.0.
- Added unit tests for PenTracker functionality.

build/lib/pen_tracker/engine.py

@@ -0,0 +1,85 @@
+import csv
+import os
+import logging
+from dataclasses import dataclass, asdict
+from typing import List
+
+logger = logging.getLogger(__name__)
+
+@dataclass
+class Pen:
+    Make: str = "N/A"
+    Model: str = "N/A"
+    Date_Purchased: str = "N/A"
+    Vendor: str = "N/A"
+    Nib: str = "N/A"
+    Nib_Material: str = "N/A"
+    Body: str = "N/A"
+    Cap: str = "N/A"
+    Post: str = "N/A"
+    Current_Ink: str = "N/A"
+    Inked_date: str = "N/A"
+    Notes: str = "N/A"
+
+class PenTracker:
+    def __init__(self, storage_file: str = None):
+        if storage_file is None:
+            storage_file = os.getenv('PEN_TRACKER_CSV', 'Pens.csv')
+        self.storage_file = storage_file
+        self.headers = [
+            'Make', 'Model', 'Date-Purchased', 'Vendor', 'Nib',
+            'Nib-Material', 'Body', 'Cap', 'Post',
+            'Current-Ink', 'Inked-date', 'Notes'
+        ]
+        self.key_map = {
+            'Date-Purchased': 'Date_Purchased',
+            'Inked-date': 'Inked_date',
+            'Nib-Material': 'Nib_Material',
+            'Current-Ink': 'Current_Ink'
+        }
+        self.reverse_key_map = {v: k for k, v in self.key_map.items()}
+        self.pens: List[Pen] = self.load_data()
+
+    def _sort_pens(self):
+        """Sorts the pens list by Make, then by Model alphabetically."""
+        self.pens.sort(key=lambda x: (x.Make.lower(), x.Model.lower()))
+
+    def load_data(self) -> List[Pen]:
+        """Loads data from the CSV file."""
+        if not os.path.exists(self.storage_file):
+            self._create_empty_csv()
+            return []
+        
+        pens = []
+        try:
+            # Standard, clean way to open the file
+            with open(self.storage_file, mode='r', encoding='utf-8-sig') as f:
+                reader = csv.DictReader(f)
+                for row in reader:
+                    # Strip whitespace from keys and values, handle empty values
+                    clean_row = {k.strip(): (v.strip() if v else "N/A") for k, v in row.items()}
+                    # Map keys to dataclass field names
+                    mapped_row = {self.key_map.get(k, k): v for k, v in clean_row.items()}
+                    pens.append(Pen(**mapped_row))
+            pens.sort(key=lambda x: (x.Make.lower(), x.Model.lower()))
+        except Exception as e:
+            logger.error(f"Error loading CSV: {e}")
+        return pens
+
+    def _create_empty_csv(self):
+        """Creates the CSV file with headers if it is missing."""
+        with open(self.storage_file, mode='w', newline='', encoding='utf-8') as f:
+            writer = csv.DictWriter(f, fieldnames=self.headers)
+            writer.writeheader()
+
+    def save_data(self):
+        """Sorts the data before writing to ensure persistent alphabetical order."""
+        self._sort_pens()
+        with open(self.storage_file, mode='w', newline='', encoding='utf-8') as f:
+            writer = csv.DictWriter(f, fieldnames=self.headers)
+            writer.writeheader()
+            for pen in self.pens:
+                row = asdict(pen)
+                # Map back to CSV keys
+                csv_row = {k.replace('_', '-'): v for k, v in row.items()}
+                writer.writerow(csv_row)