PDF imposer 4123

import tkinter as tk
from tkinter import ttk, filedialog, messagebox
from PyPDF2 import PdfReader, PdfWriter
import os
import traceback
import sys

class PDFImposerApp:
    PAGES_PER_SHEET = 4  # Constant for pages per sheet

    def __init__(self, root):
        self.root = root
        self.root.title("PDF Imposer")
        self.root.geometry("600x450")  # Adjusted height for LabelFrames

        main_frame = ttk.Frame(root, padding="10")  # Reduced padding
        main_frame.grid(row=0, column=0, sticky=(tk.W, tk.E, tk.N, tk.S))
        root.columnconfigure(0, weight=1)
        root.rowconfigure(0, weight=1)

        # Input File Section
        input_frame = ttk.LabelFrame(main_frame, text="Input PDF", padding=10)
        input_frame.grid(row=0, column=0, columnspan=3, sticky=(tk.W, tk.E), pady=5, padx=5)
        input_frame.columnconfigure(1, weight=1)

        ttk.Label(input_frame, text="Input PDF:").grid(row=0, column=0, sticky=tk.W, pady=5, padx=5)
        self.input_path = tk.StringVar()
        ttk.Entry(input_frame, textvariable=self.input_path, width=50).grid(row=0, column=1, padx=5, sticky=(tk.W, tk.E))
        ttk.Button(input_frame, text="Browse", command=self.browse_input).grid(row=0, column=2, padx=5)

        # Output File Section
        output_frame = ttk.LabelFrame(main_frame, text="Output PDF", padding=10)
        output_frame.grid(row=1, column=0, columnspan=3, sticky=(tk.W, tk.E), pady=5, padx=5)
        output_frame.columnconfigure(1, weight=1)

        ttk.Label(output_frame, text="Output PDF:").grid(row=0, column=0, sticky=tk.W, pady=5, padx=5)
        self.output_path = tk.StringVar()
        ttk.Entry(output_frame, textvariable=self.output_path, width=50).grid(row=0, column=1, padx=5, sticky=(tk.W, tk.E))
        ttk.Button(output_frame, text="Browse", command=self.browse_output).grid(row=0, column=2, padx=5)

        # Blank Pages Control
        blank_frame = ttk.LabelFrame(main_frame, text="Blank Pages", padding=10)
        blank_frame.grid(row=2, column=0, columnspan=3, sticky=(tk.W, tk.E), pady=10, padx=5)
        blank_frame.columnconfigure(1, weight=1)

        ttk.Label(blank_frame, text="Additional Blank Pages:").grid(row=0, column=0, sticky=tk.W, pady=5, padx=5)
        self.blank_pages = tk.IntVar(value=0)
        blank_controls_frame = ttk.Frame(blank_frame)
        blank_controls_frame.grid(row=0, column=1, sticky=tk.E, padx=5)

        ttk.Button(blank_controls_frame, text="-", width=3, command=self.decrease_blank).pack(side=tk.LEFT, padx=2)
        ttk.Label(blank_controls_frame, textvariable=self.blank_pages, width=5, anchor="center").pack(side=tk.LEFT, padx=2)
        ttk.Button(blank_controls_frame, text="+", width=3, command=self.increase_blank).pack(side=tk.LEFT, padx=2)

        # Impose button
        ttk.Button(main_frame, text="Rearrange that SHEET!", command=self.impose_pdf).grid(row=3, column=0, columnspan=3, pady=15)

        # Status message
        self.status_var = tk.StringVar()
        ttk.Label(main_frame, textvariable=self.status_var, wraplength=580).grid(row=4, column=0, columnspan=3, sticky=(tk.W, tk.E), padx=5)

    def browse_input(self):
        filename = filedialog.askopenfilename(filetypes=[("PDF files", "*.pdf")])
        if filename:
            self.input_path.set(filename)
            output_dir = os.path.dirname(filename)
            input_name = os.path.splitext(os.path.basename(filename))[0]  # Get name without extension
            output_name = f"imposed_{input_name}.pdf"
            self.output_path.set(os.path.join(output_dir, output_name))

    def browse_output(self):
        filename = filedialog.asksaveasfilename(
            defaultextension=".pdf",
            filetypes=[("PDF files", "*.pdf")]
        )
        if filename:
            self.output_path.set(filename)

    def decrease_blank(self):
        if self.blank_pages.get() > 0:
            self.blank_pages.set(self.blank_pages.get() - 1)

    def increase_blank(self):
        self.blank_pages.set(self.blank_pages.get() + 1)

    def create_blank_page(self, template_page):
        """Creates a blank page with the same size as the template page."""
        try:
            media_box = template_page.mediabox
            writer = PdfWriter()
            writer.add_blank_page(width=float(media_box.width), height=float(media_box.height))
            return writer.pages[0]
        except Exception as e:
            raise Exception(f"Error creating blank page: {str(e)}")

    def impose_pdf(self):
        try:
            input_path = self.input_path.get()
            output_path = self.output_path.get()

            if not input_path or not output_path:
                messagebox.showerror("Error", "Please select both input and output files.")
                return

            if not os.path.exists(input_path):
                messagebox.showerror("Error", "Input file not found.")
                return

            self.status_var.set("Processing PDF...")
            self.root.update()

            pdf_reader = PdfReader(input_path)
            pdf_writer = PdfWriter()

            num_pages = len(pdf_reader.pages)
            if not pdf_reader.pages:
                messagebox.showerror("Error", "Input PDF has no pages.")
                return

            template_page = pdf_reader.pages[0]

            # Calculate required blank pages directly
            blanks_needed = (self.PAGES_PER_SHEET - (num_pages % self.PAGES_PER_SHEET)) % self.PAGES_PER_SHEET
            total_pages = num_pages + blanks_needed

            all_pages = list(pdf_reader.pages)  # Create a copy
            for _ in range(blanks_needed):
                all_pages.append(self.create_blank_page(template_page))

            for i in range(0, total_pages, self.PAGES_PER_SHEET):
                page_indices = [i + 3, i, i + 1, i + 2]
                for idx in page_indices:
                    if idx < total_pages:
                        pdf_writer.add_page(all_pages[idx])

            with open(output_path, "wb") as output_file:
                pdf_writer.write(output_file)

            self.status_var.set(f"Success! Imposed PDF saved to: {output_path}")
            messagebox.showinfo("Success", "PDF imposition completed successfully!")

        except FileNotFoundError:
            self.status_var.set("Error: Input file not found.")
            messagebox.showerror("Error", "Input file not found.")
        except Exception as e:
            error_msg = f"Error: {str(e)}\n\nFull traceback:\n{traceback.format_exc()}"
            self.status_var.set(error_msg)
            messagebox.showerror("Error", error_msg)

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