"""
Progress dialog with progress bar, ETA, and cancel button.
"""
import tkinter as tk
from tkinter import ttk
import time
import threading


class ProgressDialog:
    """
    A modal progress dialog with progress bar, status text, ETA, and cancel button.
    Thread-safe for updating from background threads.
    """
    
    def __init__(self, parent, title="Progress"):
        self.parent = parent
        self.cancelled = False
        self._start_time = time.time()
        
        # Create dialog
        self.dialog = tk.Toplevel(parent)
        self.dialog.title(title)
        self.dialog.geometry("500x150")
        self.dialog.resizable(False, False)
        
        # Make it modal
        self.dialog.transient(parent)
        self.dialog.grab_set()
        
        # Center on parent
        self.dialog.update_idletasks()
        x = parent.winfo_x() + (parent.winfo_width() - 500) // 2
        y = parent.winfo_y() + (parent.winfo_height() - 150) // 2
        self.dialog.geometry(f"+{x}+{y}")
        
        # Status label
        self.status_var = tk.StringVar(value="Starting...")
        ttk.Label(self.dialog, textvariable=self.status_var, font=("Segoe UI", 10)).pack(pady=(15, 5))
        
        # Progress bar
        self.progress = ttk.Progressbar(self.dialog, length=450, mode='determinate')
        self.progress.pack(pady=(5, 5), padx=25)
        
        # ETA label
        self.eta_var = tk.StringVar(value="Calculating...")
        ttk.Label(self.dialog, textvariable=self.eta_var, font=("Segoe UI", 9), foreground="#666").pack(pady=(0, 10))
        
        # Cancel button
        self.cancel_btn = ttk.Button(self.dialog, text="Cancel", command=self.cancel)
        self.cancel_btn.pack(pady=(0, 15))
        
        # Handle window close
        self.dialog.protocol("WM_DELETE_WINDOW", self.cancel)
    
    def update(self, current, total, status_text=None):
        """
        Update progress bar and ETA.
        Thread-safe - can be called from background threads.
        
        Args:
            current: Current item number (0-based or 1-based)
            total: Total number of items
            status_text: Optional status text to display
        """
        def _update():
            if self.cancelled:
                return
            
            # Update progress bar
            if total > 0:
                percentage = (current / total) * 100
                self.progress['value'] = percentage
            
            # Update status text
            if status_text:
                self.status_var.set(status_text)
            
            # Calculate and update ETA
            if current > 0 and total > 0:
                elapsed = time.time() - self._start_time
                avg_time_per_item = elapsed / current
                remaining_items = total - current
                eta_seconds = remaining_items * avg_time_per_item
                
                if eta_seconds < 60:
                    eta_text = f"ETA: {int(eta_seconds)}s"
                elif eta_seconds < 3600:
                    eta_text = f"ETA: {int(eta_seconds / 60)}m {int(eta_seconds % 60)}s"
                else:
                    hours = int(eta_seconds / 3600)
                    minutes = int((eta_seconds % 3600) / 60)
                    eta_text = f"ETA: {hours}h {minutes}m"
                
                self.eta_var.set(f"{current}/{total} items - {eta_text}")
            else:
                self.eta_var.set(f"{current}/{total} items")
        
        # Schedule update on main thread
        if threading.current_thread() == threading.main_thread():
            _update()
        else:
            self.dialog.after(0, _update)
    
    def cancel(self):
        """Mark as cancelled and close dialog."""
        self.cancelled = True
        self.close()
    
    def close(self):
        """Close the dialog."""
        def _close():
            try:
                self.dialog.grab_release()
                self.dialog.destroy()
            except:
                pass
        
        # Schedule on main thread
        if threading.current_thread() == threading.main_thread():
            _close()
        else:
            self.dialog.after(0, _close)
    
    def is_cancelled(self):
        """Check if user cancelled the operation."""
        return self.cancelled