Why do i need the Class Tableapp. What i mean is why do i have to do it in a class? Python code: import ctypes
import csv
import json
from pathlib import Path
import tkinter as tk
from tkinter import filedialog, messagebox, simpledialog
from tkinter import ttk
from tksheet import Sheet

def set_dpi_awareness():
    """Enable DPI awareness for high DPI settings."""
    try:
        ctypes.windll.shcore.SetProcessDpiAwareness(1)
    except Exception as e:
        print(f"Error setting DPI awareness: {e}")

class TableApp:
    """Table Editor application with a sidebar and table management."""

    def __init__(self, root: tk.Tk):
        """Initialize the TableApp."""
        self.root = root
        self.config_dimensions()
        self.config_fonts()
        self.config_colors()
        self.initialize_data()
        self.setup_ui()
        self.load_tables()
    
    def config_dimensions(self):
        """Configure application dimensions."""
        self.root.title("Database")
        self.root.geometry("1920x1080")
        self.root.minsize(1200, 560)

        self.sidebar_width = 400
        self.static_frame_width = 100
        self.header_height = 190

    def config_fonts(self):
        """Configure application fonts."""
        font_name, font_size, font_style = "Literata", 12, "normal"
        self.default_font = (font_name, font_size, font_style)
        self.root.option_add("*Font", f"{font_name} {font_size}")
    
    def config_colors(self):
        """Configure application colors."""
        self.text_color = "#333333"
        self.background_color = "#FFFFFF"
        self.sidebar_color = "#F7F8FC"
        self.button_color = "#F7F8FC"
        self.button_color_selected = "#EAEDEF"

    def setup_ui(self):
        """Set up the user interface components."""
        self.create_sidebar()
        self.create_main_frame()
        self.create_header_frame()
        self.create_table_frame()

    def create_sidebar(self):
        """Create the sidebar with navigation and actions."""
        sidebar = self._create_frame(
            parent=self.root,
            width=self.sidebar_width,
            bg=self.sidebar_color,
            side='left',
            anchor='nw',
            fill='y'
        )
        
        self._create_frame(
            parent=self.root,
            width=self.static_frame_width,
            bg=self.background_color,
            side='left',
            anchor='nw',
            fill='y'
        )
        sidebar.pack_propagate(False)

        self._add_normal_buttons(sidebar)
        self._add_scrollable_canvas(sidebar)
        self._add_delete_table_section(sidebar)

    def _create_frame(
        self,
        parent: tk.Widget,
        width: int | None,
        bg: str,
        side: str,
        anchor: str,
        fill: str,
        expand: bool = False
    ) -> tk.Frame:
        """Create and pack a frame with specified properties."""
        frame = tk.Frame(parent, width=width, bg=bg, bd=0, relief='flat')
        frame.pack(side=side, anchor=anchor, fill=fill, expand=expand)
        return frame

    def _add_normal_buttons(self, sidebar: tk.Frame):
        """Add navigation buttons to the sidebar."""
        normal_buttons_frame = self._create_frame(
            parent=sidebar,
            width=None,
            bg=self.sidebar_color,
            side='top',
            anchor='nw',
            fill='x',
        )

        create_table_label = self._create_clickable_label(
            parent=normal_buttons_frame,
            text="Create New Table",
            command=self.create_new_table
        )
        create_table_label.pack(fill='x')
        self.add_custom_hover(create_table_label)

        self._add_separator(normal_buttons_frame)

    def _add_scrollable_canvas(self, sidebar: tk.Frame):
        """Add a scrollable canvas to display table labels."""
        scrollbar_frame = self._create_frame(
            parent=sidebar,
            width=None,
            bg=self.sidebar_color,
            side='top',
            anchor='nw',
            fill='both',
            expand=True
        )
    
        canvas = tk.Canvas(scrollbar_frame, bg=self.sidebar_color, highlightthickness=0, width=self.sidebar_width - 15)
        canvas.pack(side="left", fill="both", expand=True)
    
        scrollbar = ttk.Scrollbar(scrollbar_frame, orient="vertical", command=canvas.yview)
        scrollbar.pack(side="right", fill="y")
    
        canvas.configure(yscrollcommand=scrollbar.set)
    
        self.table_labels_frame = tk.Frame(canvas, bg=self.sidebar_color)
        canvas.create_window((0, 0), window=self.table_labels_frame, anchor="nw")
    
        self._bind_scrollbar_events(canvas, scrollbar, scrollbar_frame)

    def _bind_scrollbar_events(self, canvas: tk.Canvas, scrollbar: ttk.Scrollbar, scrollbar_frame: tk.Frame):
        """Manage scrollbar visibility based on content size."""
        def configure_scrollbar(event: tk.Event | None = None):
            canvas.update_idletasks()
            canvas_height = scrollbar_frame.winfo_height()
            content_height = self.table_labels_frame.winfo_reqheight()

            if content_height > canvas_height:
                scrollbar.pack(side="right", fill="y")
            else:
                scrollbar.pack_forget()

            canvas.configure(scrollregion=canvas.bbox("all"))

        self.table_labels_frame.bind("<Configure>", configure_scrollbar)
        scrollbar_frame.bind("<Configure>", configure_scrollbar)

    def _add_delete_table_section(self, sidebar: tk.Frame):
        """Add the delete table option to the sidebar."""
        self._add_separator(sidebar)

        delete_table_label = self._create_clickable_label(
            parent=sidebar,
            text="🗑 Delete Selected Table",
            command=self.delete_table
        )
        delete_table_label.pack(fill='x', side='bottom')
        self.add_custom_hover(delete_table_label)

    def _add_separator(self, parent: tk.Widget):
        """Add a horizontal separator to the parent widget."""
        separator = ttk.Separator(parent, orient='horizontal')
        separator.pack(fill='x')

    def _create_clickable_label(self, parent: tk.Widget, text: str, command, allow_rename: bool = False) -> tk.Label:
        """Create a clickable label with optional rename capability."""
        label = tk.Label(
            parent,
            text=text,
            bg=self.button_color,
            fg=self.text_color,
            cursor="hand2" if not allow_rename else "arrow",
            anchor='w',
        )
        label.bind("<Button-1>", lambda _: command())
        if allow_rename:
            label.bind("<Double-1>", lambda _: self.begin_rename(text))
        return label

    def create_main_frame(self):
        """Create the main frame for displaying tables."""
        self.main_frame = tk.Frame(self.root)
        self.main_frame.pack(expand=True, fill='both', side='right')

    def create_header_frame(self):
        """Create the header with filter and action buttons."""
        header_frame = tk.Frame(self.main_frame, height=self.header_height, bg=self.background_color)
        header_frame.pack(fill='x')
        header_frame.pack_propagate(False) 

        tk.Label(header_frame, text="Filter:", bg=self.background_color, fg=self.text_color).pack(
            side='left')
        
        self.filter_entry = tk.Entry(header_frame, fg=self.text_color)
        self.filter_entry.pack(side='left')
        self.filter_entry.bind("<KeyRelease>", lambda _: self.apply_filter())

        rename_headers = self._create_clickable_label(
            parent=header_frame,
            text="Rename Headers",
            command=self.rename_headers,
            allow_rename=False
        )
        rename_headers.pack(side='left', fill='x')

        import_table = self._create_clickable_label(
            parent=header_frame,
            text="Import Table",
            command=self.import_file,
            allow_rename=False
        )
        import_table.pack(side='right', fill='x')

        export_table = self._create_clickable_label(
            parent=header_frame,
            text="Export Table",
            command=self.export_table,
            allow_rename=False
        )
        export_table.pack(side='right', fill='x')

    def create_table_frame(self):
        """Create the frame to hold the active table."""
        self.table_frame = tk.Frame(self.main_frame, bg=self.background_color)
        self.table_frame.pack(expand=True, fill='both')

    def initialize_data(self):
        """Initialize data structures and directories."""
        self.save_file_dir = Path("tables")
        self.save_file_dir.mkdir(exist_ok=True)

        self.tables: dict[str, Sheet] = {}
        self.table_labels: dict[str, tk.Label] = {}
        self.original_data: dict[str, list[list[str]]] = {}
        self.headers: dict[str, list[str]] = {}
        self.current_table_name: str | None = None
        self.rename_entry: tk.Entry | None = None
        self.selected_table_label: tk.Label | None = None

    def create_new_table(self):
        """Create a new table and select it."""
        table_name = f"Table {len(self.tables) + 1}"
        self.add_table(table_name)
        self.load_selected_table(table_name)

    def import_file(self):
        """Import a table from a CSV or JSON file."""
        file_path = filedialog.askopenfilename(
            title="Open File",
            filetypes=[("JSON files", "*.json"), ("CSV files", "*.csv")]
        )
        if not file_path:
            return

        try:
            if file_path.endswith('.csv'):
                with open(file_path, newline='', encoding='utf-8') as csvfile:
                    data = list(csv.reader(csvfile))
            elif file_path.endswith('.json'):
                with open(file_path, 'r', encoding='utf-8') as jsonfile:
                    data = json.load(jsonfile)
            else:
                raise ValueError("Unsupported file format.")

            headers, table_data = data[0], data[1:]
            self.add_table_from_data(file_path, headers, table_data)
        except Exception as e:
            messagebox.showerror("File Import Error", str(e))

    def add_table_from_data(self, file_path: str, headers: list[str], table_data: list[list[str]]):
        """Add a table using existing data from a file."""
        table_name = Path(file_path).stem
        table_name = self.ensure_unique_table_name(table_name)

        self.add_table(table_name, table_data)
        self.headers[table_name] = headers
        self.load_selected_table(table_name)
        self.save_data(table_name)

    def ensure_unique_table_name(self, table_name: str) -> str:
        """Ensure the table name is unique by appending suffixes if necessary."""
        original_name = table_name
        counter = 1
        while table_name in self.tables:
            table_name = f"{original_name} (New {counter})"
            counter += 1
        return table_name

    def save_table_data(self, file_path: str, data: list[list[str]], format: str):
        """Save table data in the specified format (CSV or JSON)."""
        match format:
            case 'csv':
                with open(file_path, 'w', newline='', encoding='utf-8') as file:
                    csv.writer(file).writerows(data)
            case 'json':
                with open(file_path, 'w', encoding='utf-8') as file:
                    json.dump(data, file, indent=4)
            case _:
                raise ValueError("Unsupported file format.")
            
    def export_table(self):
        """Export the current table to a CSV or JSON file."""
        if not self.current_table_name:
            messagebox.showwarning("No Table Selected", "Please select a table to export.")
            return

        file_path = filedialog.asksaveasfilename(
            title="Save As",
            defaultextension=".json",
            filetypes=[("JSON files", "*.json"), ("CSV files", "*.csv")],
            initialfile=self.current_table_name
        )
        if not file_path:
            return

        try:
            data = [self.headers[self.current_table_name]] + self.tables[self.current_table_name].get_sheet_data()
            if file_path.endswith('.csv'):
                self.save_table_data(file_path, data, 'csv')
            elif file_path.endswith('.json'):
                self.save_table_data(file_path, data, 'json')
            else:
                raise ValueError("Unsupported file format.")

            messagebox.showinfo("Export Successful", f"Table '{self.current_table_name}' has been exported successfully.")
        except Exception as e:
            messagebox.showerror("Export Failed", f"An error occurred during export: {e}")

    def add_table(self, table_name: str, data: list[list[str]] | None = None):
        """Add a new table to the application."""
        default_data = [["" for _ in range(5)] for _ in range(10)]
        sheet = Sheet(
            self.table_frame,
            data=data or default_data,
            show_table=True,
            headers=None,
            font=self.default_font,
            header_font=self.default_font,
            auto_resize_columns=True
        )
        sheet.set_options(table_fg=self.text_color, header_fg=self.text_color)
        sheet.enable_bindings()
        sheet.extra_bindings([("end_edit_cell", lambda _: self.save_data(table_name))])
        sheet.pack_forget()

        self.tables[table_name] = sheet
        self.original_data[table_name] = sheet.get_sheet_data()
        self.headers.setdefault(table_name, sheet.headers())

        self.create_table_label(table_name)

    def create_table_label(self, table_name: str):
        """Create a label for the table in the sidebar."""
        label = self._create_clickable_label(
            parent=self.table_labels_frame,
            text=table_name,
            command=lambda: self.load_selected_table(table_name),
            allow_rename=True
        )
        label.pack(fill='x')
        self.table_labels[table_name] = label
        self.add_custom_hover(label)

    def delete_table(self):
        """Delete the currently selected table."""
        if not self.current_table_name:
            messagebox.showwarning("No Table Selected", "Please select a table to delete.")
            return

        if messagebox.askyesno("Delete Table", f"Are you sure you want to delete the table '{self.current_table_name}'?"):
            self.remove_table(self.current_table_name)

    def remove_table(self, table_name: str):
        """Remove a table from the application."""
        self.tables[table_name].destroy()
        self.table_labels[table_name].destroy()
        del self.tables[table_name]
        del self.original_data[table_name]
        del self.headers[table_name]
        del self.table_labels[table_name]
        (self.save_file_dir / f"{table_name}.json").unlink(missing_ok=True)
        self.current_table_name = None
        self.selected_table_label = None

    def load_tables(self):
        """Load existing tables from the save directory."""
        for file_path in self.save_file_dir.glob("*.json"):
            table_name = file_path.stem
            with file_path.open('r', encoding='utf-8') as file:
                data = json.load(file)

            headers, table_data = data.pop(0), data
            self.add_table(table_name, table_data)
            self.headers[table_name] = headers

    def load_selected_table(self, table_name: str):
        """Display the selected table and hide others."""
        for name, sheet in self.tables.items():
            if name == table_name:
                sheet.pack(expand=True, fill='both')
                self.current_table_name = name
                sheet.headers(self.headers[name])
                self.apply_filter()
                self.selected_table_label = self.table_labels[name]
                self.selected_table_label.config(bg=self.button_color_selected)
            else:
                sheet.pack_forget()
                self.table_labels[name].config(bg=self.button_color)

    def save_data(self, table_name: str):
        """Save the current data of a table."""
        data = [self.headers[table_name]] + self.tables[table_name].get_sheet_data()
        file_path = self.save_file_dir / f"{table_name}.json"
        with file_path.open('w', encoding='utf-8') as file:
            json.dump(data, file)
        print(f"Data for {table_name} saved successfully.")

    def apply_filter(self):
        """Filter table data based on the filter entry."""
        if not self.current_table_name:
            return

        term = self.filter_entry.get().lower()
        original_data = self.original_data[self.current_table_name]
        filtered_data = [
            row for row in original_data
            if any(term in str(cell).lower() for cell in row)
        ]
        self.tables[self.current_table_name].set_sheet_data(filtered_data)

    def rename_headers(self):
        """Rename the headers of the selected table."""
        if not self.current_table_name:
            messagebox.showwarning("No Table Selected", "Please select a table to rename headers.")
            return

        current_headers = self.headers[self.current_table_name]
        new_headers = simpledialog.askstring(
            "Rename Headers",
            "Enter new headers (comma-separated):",
            initialvalue=", ".join(current_headers)
        )
        if new_headers:
            header_list = [header.strip() for header in new_headers.split(',')]
            self.headers[self.current_table_name] = header_list
            self.tables[self.current_table_name].headers(header_list)
            self.save_data(self.current_table_name)

    def begin_rename(self, table_name: str):
        """Start renaming a table by replacing its label with an entry."""
        if table_name not in self.table_labels:
            messagebox.showerror("Error", f"Table '{table_name}' not found.")
            return

        label = self.table_labels[table_name]
        self.cancel_rename()

        self.rename_entry = tk.Entry(
            self.table_labels_frame,
            bg=label.cget("bg"),
            fg=self.text_color,
            relief='flat'
        )
        self.rename_entry.insert(0, table_name)
        self.rename_entry.place(
            x=label.winfo_x(),
            y=label.winfo_y(),
            width=label.winfo_width(),
            height=label.winfo_height()
        )
        self.rename_entry.focus()
        self.rename_entry.select_range(0, tk.END)
        self.rename_entry.bind('<Return>', lambda _: self.end_rename(table_name))
        self.rename_entry.bind('<FocusOut>', lambda _: self.cancel_rename())

    def end_rename(self, old_name: str):
        """Finalize the renaming of a table."""
        new_name = self.rename_entry.get().strip()

        if not new_name:
            messagebox.showerror("Invalid Name", "Table name cannot be empty.")
            self.rename_entry.focus_set()
            return

        if new_name in self.tables and new_name != old_name:
            messagebox.showerror("Duplicate Name", f"A table named '{new_name}' already exists.")
            self.rename_entry.focus_set()
            return

        if new_name != old_name:
            self.update_table_name(old_name, new_name)
            self.load_selected_table(new_name)

        self.cancel_rename()

    def update_table_name(self, old_name: str, new_name: str):
        """Update the table's name and associated resources."""
        self.tables[new_name] = self.tables.pop(old_name)
        self.original_data[new_name] = self.original_data.pop(old_name)
        self.headers[new_name] = self.headers.pop(old_name)

        label = self.table_labels.pop(old_name)
        label.config(text=new_name)
        label.bind("<Button-1>", lambda _: self.load_selected_table(new_name))
        label.bind("<Double-1>", lambda _: self.begin_rename(new_name))

        self.table_labels[new_name] = label

        if self.selected_table_label == label:
            label.config(bg=self.button_color_selected)

        current_file = self.save_file_dir / f"{old_name}.json"
        new_file = self.save_file_dir / f"{new_name}.json"
        current_file.rename(new_file)

    def cancel_rename(self):
        """Cancel the ongoing rename operation."""
        if self.rename_entry:
            self.rename_entry.destroy()
            self.rename_entry = None

    def add_custom_hover(self, label: tk.Label):
        """Add hover effects to a label."""
        def on_enter(_: tk.Event):
            if label != self.selected_table_label:
                label.config(bg=self.button_color_selected)

        def on_leave(_: tk.Event):
            if label != self.selected_table_label:
                label.config(bg=self.button_color)

        label.bind("<Enter>", on_enter)
        label.bind("<Leave>", on_leave)

if __name__ == "__main__":
    set_dpi_awareness()
    root = tk.Tk()
    app = TableApp(root)
    root.mainloop()