refactor: Create MainWindow class for main application windows

This commit refactors the main application window into a `MainWindow`
class.  This improves code organization and facilitates unit testing
of the UI.

- Created `MainWindow` class inheriting from `ctk.CTk`.
- Moved UI elements and logic into the `MainWindow` class.
- Modified methods to use the Database and PDFExporter classes.
- Implemented load_log_entries to refresh log entries

ui/main_window.py

@@ -0,0 +1,295 @@
+# timelogix/ui/main_window.py
+import customtkinter as ctk
+import tkinter as tk
+from tkinter import ttk
+import time
+import csv
+import datetime
+from .components import create_label, create_entry, create_button, create_combo, create_text_box
+
+
+class MainWindow(ctk.CTk):
+    def __init__(self, db, pdf_exporter):
+        super().__init__()
+        self.db = db
+        self.pdf_exporter = pdf_exporter
+        self.title("TimeLogix")
+
+        # Theme Configuration
+        ctk.set_appearance_mode("Dark")  # Or "Light", "System"
+        ctk.set_default_color_theme("blue")
+
+        # Styling
+        self.font_family = "Segoe UI"
+        self.font_size = 12
+
+        # App Data
+        self.is_running = False
+        self.start_time = None
+        self.elapsed_time = 0
+        self.timer_id = None
+
+        # Load settings from the database
+        settings = self.db.load_settings()
+        if settings:
+            self.company_name = settings["company_name"]
+            self.company_address = settings["company_address"]
+            self.client_name = settings["client_name"]
+            self.client_address = settings["client_address"]
+            self.hourly_rate = settings["hourly_rate"]
+            self.invoice_number = settings["invoice_number"]
+        else:
+            # Provide default values if settings are not found
+            self.company_name = "Your Company Name"
+            self.company_address = "123 Main St, Anytown, USA"
+            self.client_name = "Client Name"
+            self.client_address = "Client Address"
+            self.hourly_rate = 60.00
+            self.invoice_number = 1
+
+
+        # UI Components
+        self.scrollable_frame = ctk.CTkScrollableFrame(self, width=450, height=600)
+        self.scrollable_frame.pack(fill="both", expand=True, padx=10, pady=10)
+
+        self.task_label = create_label(self.scrollable_frame, "Task Description:", self.font_family, self.font_size)
+        self.task_label.pack(pady=(10, 2))
+        self.task_entry = create_entry(self.scrollable_frame, width=250)
+        self.task_entry.pack(pady=(2, 10))
+
+        self.project_label = create_label(self.scrollable_frame, "Project:", self.font_family, self.font_size)
+        self.project_label.pack(pady=(10, 2))
+        self.projects = self.db.load_projects()
+        self.project_combo = create_combo(self.scrollable_frame, values=self.projects, width=250)
+        self.project_combo.pack(pady=(2, 10))
+        if self.projects:
+            self.project_combo.set(self.projects[0])
+
+        self.time_label = create_label(self.scrollable_frame, "00:00:00", self.font_family, 36)
+        self.time_label.pack(pady=(15, 20))
+        self.start_stop_button = create_button(self.scrollable_frame, "Start", self.toggle_timer)
+        self.start_stop_button.pack(pady=(5, 20))
+
+        self.log_label = create_label(self.scrollable_frame, "Log Entries:", self.font_family, self.font_size)
+        self.log_label.pack(pady=(10, 2))
+        self.log_text = create_text_box(self.scrollable_frame, width=400, height=100, font=(self.font_family, self.font_size))
+        self.log_text.pack(pady=5, padx=10, fill="both", expand=True)
+
+        self.new_project_label = create_label(self.scrollable_frame, "New Project:", self.font_family, self.font_size)
+        self.new_project_label.pack(pady=(10, 2))
+        self.new_project_entry = create_entry(self.scrollable_frame, width=250)
+        self.new_project_entry.pack(pady=(2, 10))
+        self.add_project_button = create_button(self.scrollable_frame, "Add Project", self.add_project)
+        self.add_project_button.pack(pady=(5, 15))
+
+        button_frame = ctk.CTkFrame(self.scrollable_frame)
+        button_frame.pack(pady=(10, 15))
+        self.export_csv_button = create_button(button_frame, "Export to CSV", self.export_to_csv)
+        self.export_csv_button.pack(side="left", padx=5, pady=5)
+        self.export_pdf_button = create_button(button_frame, "Export to PDF", self.export_to_pdf)
+        self.export_pdf_button.pack(side="left", padx=5, pady=5)
+        self.exit_button = create_button(button_frame, "Exit", self.exit_app)
+        self.exit_button.pack(side="left", padx=5, pady=5)
+
+        self.total_time_button = create_button(self.scrollable_frame, "Calculate Total Time", self.calculate_total_time)
+        self.total_time_button.pack(pady=(5, 15))
+        self.total_time_label = create_label(self.scrollable_frame, "Total Time: 00:00:00", self.font_family, self.font_size)
+        self.total_time_label.pack(pady=(5, 15))
+
+        # Settings UI
+        self.company_name_label = create_label(self.scrollable_frame, "Company Name:", self.font_family, self.font_size)
+        self.company_name_label.pack(pady=(10, 2))
+        self.company_name_entry = create_entry(self.scrollable_frame, width=250)
+        self.company_name_entry.pack(pady=(2, 10))
+        self.company_name_entry.insert(0, self.company_name)  # Initial value
+
+        self.company_address_label = create_label(self.scrollable_frame, "Company Address:", self.font_family, self.font_size)
+        self.company_address_label.pack(pady=(10, 2))
+        self.company_address_entry = create_entry(self.scrollable_frame, width=250)
+        self.company_address_entry.pack(pady=(2, 10))
+        self.company_address_entry.insert(0, self.company_address)  # Initial value
+
+        self.client_name_label = create_label(self.scrollable_frame, "Client Name:", self.font_family, self.font_size)
+        self.client_name_label.pack(pady=(10, 2))
+        self.client_name_entry = create_entry(self.scrollable_frame, width=250)
+        self.client_name_entry.pack(pady=(2, 10))
+        self.client_name_entry.insert(0, self.client_name)  # Initial value
+
+        self.client_address_label = create_label(self.scrollable_frame, "Client Address:", self.font_family, self.font_size)
+        self.client_address_label.pack(pady=(10, 2))
+        self.client_address_entry = create_entry(self.scrollable_frame, width=250)
+        self.client_address_entry.pack(pady=(2, 10))
+        self.client_address_entry.insert(0, self.client_address)  # Initial value
+
+        self.hourly_rate_label = create_label(self.scrollable_frame, "Hourly Rate:", self.font_family, self.font_size)
+        self.hourly_rate_label.pack(pady=(10, 2))
+        self.hourly_rate_entry = create_entry(self.scrollable_frame, width=100)
+        self.hourly_rate_entry.pack(pady=(2, 10))
+        self.hourly_rate_entry.insert(0, str(self.hourly_rate))  # Initial value
+
+        self.update_settings_button = create_button(self.scrollable_frame, "Update Settings", self.update_settings)
+        self.update_settings_button.pack(pady=(15, 20))
+
+
+        self.load_log_entries()  # Load log entries after UI is set up
+
+    def toggle_timer(self):
+        if self.is_running:
+            self.stop_timer()
+        else:
+            self.start_timer()
+
+    def start_timer(self):
+        self.is_running = True
+        self.start_stop_button.configure(text="Stop")
+        self.start_time = time.time()
+        self.update_timer()
+
+    def stop_timer(self):
+        self.is_running = False
+        self.start_stop_button.configure(text="Start")
+        self.after_cancel(self.timer_id)
+        self.log_time_entry()
+
+    def update_timer(self):
+        if self.is_running:
+            self.elapsed_time = time.time() - self.start_time
+            minutes, seconds = divmod(self.elapsed_time, 60)
+            hours, minutes = divmod(minutes, 60)
+            time_str = "{:02d}:{:02d}:{:02d}".format(
+                int(hours), int(minutes), int(seconds)
+            )
+            self.time_label.configure(text=time_str)
+            self.timer_id = self.after(100, self.update_timer)
+
+    def log_time_entry(self):
+        end_time = datetime.datetime.now()
+        task_description = self.task_entry.get()
+        project = self.project_combo.get()
+        duration = self.elapsed_time
+        start_time_str = end_time - datetime.timedelta(seconds=duration)
+
+        # Get project ID from the database
+        project_id = self.db.get_project_id(project)
+        if not project_id:
+            print("Project not found in the database.")
+            return
+
+        self.db.insert_log_entry(
+            task_description,
+            project_id,
+            start_time_str.strftime("%Y-%m-%d %H:%M:%S"),
+            end_time.strftime("%Y-%m-%d %H:%M:%S"),
+            duration,
+        )
+
+        self.load_log_entries()  # Refresh log entries
+        self.elapsed_time = 0
+        self.time_label.configure(text="00:00:00")
+
+    def update_log_display(self):
+        self.log_text.delete("1.0", tk.END)
+        for entry in self.log_entries:
+            self.log_text.insert(tk.END, f"Task: {entry['task']}\n")
+            self.log_text.insert(tk.END, f"Project: {entry['project']}\n")
+            self.log_text.insert(tk.END, f"Start: {entry['start_time']}\n")
+            self.log_text.insert(tk.END, f"End: {entry['end_time']}\n")
+            self.log_text.insert(
+                tk.END, f"Duration: {entry['duration']} seconds\n"
+            )
+            self.log_text.insert(tk.END, "-" * 20 + "\n")
+
+    def load_log_entries(self):
+        self.log_entries = self.db.load_log_entries()
+        self.update_log_display()
+
+    def add_project(self):
+        new_project = self.new_project_entry.get().strip()
+        if new_project and new_project not in self.projects:
+            if self.db.add_project(new_project):
+                self.projects.append(new_project)
+                self.project_combo.configure(values=self.projects)
+                self.project_combo.set(new_project)
+                self.new_project_entry.delete(0, tk.END)
+            else:
+                print("Project already exists in the database.")
+        elif new_project in self.projects:
+            print("Project already exists.")
+        else:
+            print("Project name cannot be empty.")
+
+    def update_settings(self):
+        company_name = self.company_name_entry.get()
+        company_address = self.company_address_entry.get()
+        client_name = self.client_name_entry.get()
+        client_address = self.client_address_entry.get()
+        try:
+            hourly_rate = float(self.hourly_rate_entry.get())
+        except ValueError:
+            print("Invalid hourly rate. Using default.")
+            hourly_rate = 50.00
+
+        self.db.update_settings(
+            company_name, company_address, client_name, client_address, hourly_rate
+        )
+
+        # Update local settings
+        self.company_name = company_name
+        self.company_address = company_address
+        self.client_name = client_name
+        self.client_address = client_address
+        self.hourly_rate = hourly_rate
+
+    def export_to_csv(self):
+        try:
+            with open("working_sessions.csv", "w", newline="", encoding='utf-8') as csvfile:
+                fieldnames = ["task", "project", "start_time", "end_time", "duration"]
+                writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
+                writer.writeheader()
+                for entry in self.log_entries:
+                    writer.writerow(entry)
+            print("Exported to CSV successfully!")
+        except Exception as e:
+            print(f"Error exporting to CSV: {e}")
+
+    def export_to_pdf(self):
+        try:
+            # Load settings and increment invoice number
+            settings = self.db.load_settings()
+            if settings:
+                self.company_name = settings["company_name"]
+                self.company_address = settings["company_address"]
+                self.client_name = settings["client_name"]
+                self.client_address = settings["client_address"]
+                self.hourly_rate = settings["hourly_rate"]
+                self.invoice_number = settings["invoice_number"]
+
+            self.pdf_exporter.company_name = self.company_name
+            self.pdf_exporter.company_address = self.company_address
+            self.pdf_exporter.client_name = self.client_name
+            self.pdf_exporter.client_address = self.client_address
+            self.pdf_exporter.hourly_rate = self.hourly_rate
+            self.pdf_exporter.invoice_number = self.invoice_number
+
+            self.pdf_exporter.export_to_pdf(self.log_entries)
+
+            # Increment and save the invoice number
+            self.invoice_number += 1
+            self.db.save_invoice_number(self.invoice_number)
+            self.db.conn.commit()
+        except Exception as e:
+            print(f"Error exporting to PDF: {e}")
+
+    def calculate_total_time(self):
+        total_seconds = sum(entry["duration"] for entry in self.log_entries)
+        minutes, seconds = divmod(total_seconds, 60)
+        hours, minutes = divmod(minutes, 60)
+        time_str = "{:02d}:{:02d}:{:02d}".format(
+            int(hours), int(minutes), int(seconds)
+        )
+        self.total_time_label.configure(text=f"Total Time: {time_str}")
+
+    def exit_app(self):
+        self.destroy()  # Correctly destroy the main window and all children
+
+