#!/usr/bin/env python3
"""
GUI Path Manager for Batch Video Transcoder
Allows easy browsing of folders and appending to paths.txt with encoding options.
"""

import sys
from pathlib import Path

# Add parent directory to path so we can import core modules
sys.path.insert(0, str(Path(__file__).parent.parent))

import tkinter as tk
from tkinter import ttk, messagebox, filedialog
import os
import subprocess
import re
import json
from core.config_helper import load_config_xml
from core.logger_helper import setup_logger

logger = setup_logger(Path(__file__).parent.parent / "logs")

class PathManagerGUI:
    def __init__(self, root):
        self.root = root
        self.root.title("Batch Transcoder - Path Manager")
        self.root.geometry("1100x700")
        
        # Load config (from parent directory)
        config_path = Path(__file__).parent.parent / "config.xml"
        self.config = load_config_xml(config_path)
        # Convert path_mappings from list to dict for easier lookup
        path_mappings_list = self.config.get("path_mappings", [])
        self.path_mappings = {m["from"]: m["to"] for m in path_mappings_list} if isinstance(path_mappings_list, list) else path_mappings_list
        
        # Paths file (in root directory)
        self.paths_file = Path(__file__).parent.parent / "paths.txt"
        self.transcode_bat = Path(__file__).parent.parent / "transcode.bat"
        
        # Current selected folder
        self.selected_folder = None
        self.current_category = None
        self.recently_added = None  # Track recently added folder for highlighting
        self.status_timer = None  # Track status message timer
        self.added_folders = set()  # Folders that are in paths.txt
        
        # Cache for folder data - split per category
        self.cache_dir = Path(__file__).parent.parent / ".cache"
        self.cache_dir.mkdir(exist_ok=True)
        self.folder_cache = {}  # Only current category in memory: {folder_path: size}
        self.scan_in_progress = False
        self.scanned_categories = set()  # Track which categories have been scanned
        
        # Lazy loading
        self.all_folders = []  # All folders for current category
        self.loaded_items = 0  # How many items are currently loaded
        self.items_per_batch = 100  # Load 100 items at a time
        
        # Load existing paths
        self._load_existing_paths()
        
        # Build UI
        self._build_ui()
        
        # Handle window close
        self.root.protocol("WM_DELETE_WINDOW", self._on_closing)
        
    def _build_ui(self):
        """Build the GUI layout."""
        # Top frame for category selection and transcode launcher
        top_frame = ttk.Frame(self.root)
        top_frame.pack(fill=tk.X, padx=10, pady=10)
        
        left_top = ttk.Frame(top_frame)
        left_top.pack(side=tk.LEFT, fill=tk.X, expand=True)
        
        ttk.Label(left_top, text="Category:").pack(side=tk.LEFT, padx=5)
        
        self.category_var = tk.StringVar(value="tv")
        categories = ["tv", "anime", "movies"]
        for cat in categories:
            ttk.Radiobutton(
                left_top, text=cat.upper(), variable=self.category_var, 
                value=cat, command=self._on_category_change
            ).pack(side=tk.LEFT, padx=5)
        
        ttk.Button(left_top, text="Refresh", command=self._refresh_with_cache_clear).pack(side=tk.LEFT, padx=5)
        
        # Right side of top frame - transcode launcher
        right_top = ttk.Frame(top_frame)
        right_top.pack(side=tk.RIGHT)
        
        if self.transcode_bat.exists():
            ttk.Button(
                right_top, text="▶ Run transcode.bat", command=self._run_transcode
            ).pack(side=tk.RIGHT, padx=5)
        
        # Main content frame
        main_frame = ttk.Frame(self.root)
        main_frame.pack(fill=tk.BOTH, expand=True, padx=10, pady=10)
        
        # Left side - folder tree
        left_frame = ttk.LabelFrame(main_frame, text="Folders (sorted by size)")
        left_frame.pack(side=tk.LEFT, fill=tk.BOTH, expand=True, padx=(0, 5))
        
        # Treeview for folders with add button column
        self.tree = ttk.Treeview(left_frame, columns=("size", "add", "remove"), height=20)
        self.tree.column("#0", width=180)
        self.tree.column("size", width=80)
        self.tree.column("add", width=50)
        self.tree.column("remove", width=50)
        self.tree.heading("#0", text="Folder Name")
        self.tree.heading("size", text="Size")
        self.tree.heading("add", text="Add")
        self.tree.heading("remove", text="Remove")
        
        scrollbar = ttk.Scrollbar(left_frame, orient=tk.VERTICAL, command=self._on_scrollbar)
        self.tree.configure(yscroll=scrollbar.set)
        
        self.tree.pack(side=tk.LEFT, fill=tk.BOTH, expand=True)
        scrollbar.pack(side=tk.RIGHT, fill=tk.Y)
        
        # Configure tags for folder status
        self.tree.tag_configure("added", background="#90EE90")  # Light green for added
        self.tree.tag_configure("not_added", background="white")  # White for not added
        self.tree.tag_configure("recently_added", background="#FFD700")  # Gold for recently added
        
        self.tree.bind("<Double-1>", self._on_folder_expand)
        self.tree.bind("<<TreeviewSelect>>", self._on_folder_select)
        self.tree.bind("<Button-1>", self._on_tree_click)
        
        # Right side - options and preview
        right_frame = ttk.LabelFrame(main_frame, text="Encoding Options & Preview")
        right_frame.pack(side=tk.RIGHT, fill=tk.BOTH, expand=True, padx=(5, 0))
        
        # Mode selection
        mode_frame = ttk.LabelFrame(right_frame, text="Mode (--m)")
        mode_frame.pack(fill=tk.X, padx=5, pady=5)
        
        self.mode_var = tk.StringVar(value="default")
        for mode in ["default", "cq", "bitrate"]:
            ttk.Radiobutton(mode_frame, text=mode, variable=self.mode_var, value=mode,
                          command=self._update_preview).pack(anchor=tk.W, padx=5)
        
        # Resolution selection
        res_frame = ttk.LabelFrame(right_frame, text="Resolution (--r)")
        res_frame.pack(fill=tk.X, padx=5, pady=5)
        
        self.resolution_var = tk.StringVar(value="none")
        for res in ["none", "480", "720", "1080"]:
            label = "Auto" if res == "none" else res + "p"
            ttk.Radiobutton(res_frame, text=label, variable=self.resolution_var, value=res,
                          command=self._update_preview).pack(anchor=tk.W, padx=5)
        
        # CQ value
        cq_frame = ttk.LabelFrame(right_frame, text="CQ Value (--cq, optional)")
        cq_frame.pack(fill=tk.X, padx=5, pady=5)
        
        self.cq_var = tk.StringVar(value="")
        cq_entry = ttk.Entry(cq_frame, textvariable=self.cq_var, width=10)
        cq_entry.pack(anchor=tk.W, padx=5, pady=3)
        cq_entry.bind("<KeyRelease>", lambda e: self._update_preview())
        
        # Preview frame
        preview_frame = ttk.LabelFrame(right_frame, text="Command Preview")
        preview_frame.pack(fill=tk.BOTH, expand=True, padx=5, pady=5)
        
        self.preview_text = tk.Text(preview_frame, height=8, width=40, wrap=tk.WORD, bg="lightgray")
        self.preview_text.pack(fill=tk.BOTH, expand=True, padx=5, pady=5)
        self.preview_text.config(state=tk.DISABLED)
        
        # Bottom frame - action buttons and status
        bottom_frame = ttk.Frame(self.root)
        bottom_frame.pack(fill=tk.X, padx=10, pady=10)
        
        button_frame = ttk.Frame(bottom_frame)
        button_frame.pack(side=tk.LEFT)
        
        ttk.Button(button_frame, text="View paths.txt", command=self._view_paths_file).pack(side=tk.LEFT, padx=5)
        ttk.Button(button_frame, text="Clear paths.txt", command=self._clear_paths_file).pack(side=tk.LEFT, padx=5)
        
        # Status label (for silent feedback)
        self.status_label = ttk.Label(bottom_frame, text="", foreground="green")
        self.status_label.pack(side=tk.LEFT, padx=10)
        
        # Load cache and populate initial category
        self._load_cache()
        self._refresh_folders(use_cache=True)
        # Only scan once per category on first view
        if self.current_category not in self.scanned_categories:
            self.root.after(100, self._scan_folders_once)
    
    def _on_category_change(self):
        """Handle category radio button change."""
        self.current_category = self.category_var.get()
        # Load cache for this category
        self._load_cache()
        # Show cached data first
        self._refresh_folders(use_cache=True)
        # Only scan once per category on first view
        if self.current_category not in self.scanned_categories:
            self.root.after(100, self._scan_folders_once)
    
    def _load_cache(self):
        """Load folder cache for current category from disk (lazy)."""
        category = self.category_var.get()
        cache_file = self.cache_dir / f".cache_{category}.json"
        
        self.folder_cache.clear()
        
        # Don't fully load cache yet - just verify it exists
        if not cache_file.exists():
            logger.info(f"No cache file for {category}")
        else:
            logger.info(f"Cache file exists for {category}")
    
    def _parse_cache_lazily(self, limit=None):
        """Parse cache file lazily and return folders."""
        category = self.category_var.get()
        cache_file = self.cache_dir / f".cache_{category}.json"
        
        folders = []
        
        if cache_file.exists():
            try:
                with open(cache_file, "r", encoding="utf-8") as f:
                    cache_dict = json.load(f)
                
                # Convert to list and sort
                for folder_path_str, size in cache_dict.items():
                    folder_path = Path(folder_path_str)
                    if folder_path.exists():
                        folders.append((folder_path.name, folder_path, size))
                    
                    # Early exit if limit reached
                    if limit and len(folders) >= limit:
                        break
                
                # Sort by size descending (only what we loaded)
                folders.sort(key=lambda x: x[2], reverse=True)
                
            except Exception as e:
                logger.error(f"Failed to parse cache: {e}")
        
        return folders
    
    def _save_cache(self):
        """Save current category's folder cache to disk."""
        category = self.category_var.get()
        cache_file = self.cache_dir / f".cache_{category}.json"
        
        try:
            with open(cache_file, "w", encoding="utf-8") as f:
                json.dump(self.folder_cache, f, indent=2)
        except Exception as e:
            logger.error(f"Failed to save {category} cache: {e}")
    
    def _refresh_with_cache_clear(self):
        """Refresh and clear cache to force full scan."""
        category = self.category_var.get()
        cache_file = self.cache_dir / f".cache_{category}.json"
        
        # Delete cache file for this category
        if cache_file.exists():
            cache_file.unlink()
        
        self.folder_cache.clear()
        self.scanned_categories.discard(category)  # Reset so it will scan again
        self._refresh_folders(use_cache=False)
    
    def _scan_folders_once(self):
        """Scan folders once per category on first load."""
        if self.scan_in_progress:
            return
        
        category = self.category_var.get()
        if category in self.scanned_categories:
            return  # Already scanned this category
        
        self.scan_in_progress = True
        
        try:
            category_mapping = {
                "tv": "P:\\tv",
                "anime": "P:\\anime",
                "movies": "P:\\movies"
            }
            
            base_key = category_mapping.get(category)
            if not base_key or base_key not in self.path_mappings:
                return
            
            base_path = Path(base_key)
            if not base_path.exists():
                return
            
            # Scan folders and update cache
            new_cache = {}
            for entry in os.scandir(base_path):
                if entry.is_dir(follow_symlinks=False):
                    size = self._get_folder_size(Path(entry))
                    new_cache[str(Path(entry))] = size
            
            # Update cache and save
            self.folder_cache = new_cache
            self._save_cache()
            self.scanned_categories.add(category)
            
            # Update UI if still on same category
            if self.category_var.get() == category:
                self._refresh_folders(use_cache=True)
        finally:
            self.scan_in_progress = False
    
    def _scan_folders_background(self):
        """Scan folders in background and update cache."""
        if self.scan_in_progress:
            return
        
        self.scan_in_progress = True
        
        try:
            category = self.category_var.get()
            category_mapping = {
                "tv": "P:\\tv",
                "anime": "P:\\anime",
                "movies": "P:\\movies"
            }
            
            base_key = category_mapping.get(category)
            if not base_key or base_key not in self.path_mappings:
                return
            
            base_path = Path(base_key)
            if not base_path.exists():
                return
            
            # Scan folders and update cache
            new_cache = {}
            for entry in os.scandir(base_path):
                if entry.is_dir(follow_symlinks=False):
                    size = self._get_folder_size(Path(entry))
                    new_cache[str(Path(entry))] = size
            
            # Update cache and save
            self.folder_cache[category] = new_cache
            self._save_cache()
            
            # Update UI if still on same category
            if self.category_var.get() == category:
                self._refresh_folders(use_cache=True)
        finally:
            self.scan_in_progress = False
            # Schedule next continuous scan
            self.background_scan_timer = self.root.after(
                self.background_scan_interval, 
                self._continuous_background_scan
            )
            # Schedule next continuous scan
            self.background_scan_timer = self.root.after(
                self.background_scan_interval, 
                self._continuous_background_scan
            )
    
    def _load_existing_paths(self):
        """Load existing paths from paths.txt and extract folder paths."""
        self.added_folders.clear()
        
        if not self.paths_file.exists():
            return
        
        try:
            with open(self.paths_file, "r", encoding="utf-8") as f:
                for line in f:
                    line = line.strip()
                    if not line:
                        continue
                    
                    # Extract the path (last argument in the command)
                    # Format: --m mode --r res --cq val "path" or just "path"
                    # Find all quoted strings
                    matches = re.findall(r'"([^"]*)"', line)
                    if matches:
                        # Last quoted string is the path
                        path = matches[-1]
                        self.added_folders.add(path)
        except Exception as e:
            logger.error(f"Failed to load existing paths: {e}")
    
    def _get_folder_size(self, path: Path) -> int:
        """Calculate total size of folder in bytes."""
        total = 0
        try:
            for entry in os.scandir(path):
                if entry.is_file(follow_symlinks=False):
                    total += entry.stat().st_size
                elif entry.is_dir(follow_symlinks=False):
                    total += self._get_folder_size(Path(entry))
        except PermissionError:
            pass
        return total
    
    def _format_size(self, bytes_size: int) -> str:
        """Format bytes to human readable size."""
        for unit in ["B", "KB", "MB", "GB", "TB"]:
            if bytes_size < 1024:
                return f"{bytes_size:.1f} {unit}"
            bytes_size /= 1024
        return f"{bytes_size:.1f} PB"
    
    def _refresh_folders(self, use_cache=False):
        """Refresh the folder tree from cache or disk."""
        # Clear existing items
        for item in self.tree.get_children():
            self.tree.delete(item)
        
        self.all_folders = []
        self.loaded_items = 0
        
        category = self.category_var.get()
        
        # Map category to path mapping key
        category_mapping = {
            "tv": "P:\\tv",
            "anime": "P:\\anime",
            "movies": "P:\\movies"
        }
        
        base_key = category_mapping.get(category)
        if not base_key or base_key not in self.path_mappings:
            messagebox.showwarning("Info", f"No mapping found for {category}")
            return
        
        base_path = Path(base_key)
        
        # Check if path exists
        if not base_path.exists():
            messagebox.showerror("Error", f"Path not found: {base_path}")
            return
        
        # Get folders from cache or disk
        if use_cache:
            # Parse cache lazily - only load what we need initially
            folders = self._parse_cache_lazily(limit=None)  # Get all but parse efficiently
        else:
            # Scan from disk
            folders = []
            try:
                for entry in os.scandir(base_path):
                    if entry.is_dir(follow_symlinks=False):
                        size = self._get_folder_size(Path(entry))
                        folders.append((entry.name, Path(entry), size))
            except PermissionError:
                messagebox.showerror("Error", f"Permission denied accessing {base_path}")
                return
            
            # Update cache with fresh scan
            cache_dict = {str(f[1]): f[2] for f in folders}
            self.folder_cache = cache_dict
            self._save_cache()
        
        # Sort by size descending
        folders.sort(key=lambda x: x[2], reverse=True)
        
        # Store all folders and load first batch only
        self.all_folders = folders
        self._load_more_items()
    
    def _on_folder_expand(self, event):
        """Handle folder double-click to show contents."""
        selection = self.tree.selection()
        if not selection:
            return
        
        item = selection[0]
        tags = self.tree.item(item, "tags")
        
        if not tags:
            return
        
        folder_path = Path(tags[0])
        
        # Check if already expanded
        if self.tree.get_children(item):
            # Toggle: remove children
            for child in self.tree.get_children(item):
                self.tree.delete(child)
        else:
            # Add file/folder contents
            try:
                entries = []
                for entry in os.scandir(folder_path):
                    if entry.is_file():
                        size = entry.stat().st_size
                        entries.append((entry.name, "File", size))
                    elif entry.is_dir():
                        size = self._get_folder_size(Path(entry))
                        entries.append((entry.name, "Folder", size))
                
                # Sort by size descending
                entries.sort(key=lambda x: x[2], reverse=True)
                
                for name, type_str, size in entries:
                    size_str = self._format_size(size)
                    self.tree.insert(item, "end", text=f"[{type_str}] {name}", values=(size_str,))
            except PermissionError:
                messagebox.showerror("Error", f"Permission denied accessing {folder_path}")
    
    def _on_folder_select(self, event):
        """Handle folder selection to update preview."""
        selection = self.tree.selection()
        if not selection:
            return
        
        item = selection[0]
        tags = self.tree.item(item, "tags")
        
        if tags:
            self.selected_folder = tags[0]
            self._update_preview()
    
    def _on_tree_click(self, event):
        """Handle click on '+' or '-' button in add column."""
        item = self.tree.identify("item", event.x, event.y)
        column = self.tree.identify_column(event.x)  # Only takes x coordinate
        
        # Column #2 is the "add" column (columns are #0=name, #1=size, #2=add, #3=remove)
        if item and column == "#2":
            tags = self.tree.item(item, "tags")
            if tags:
                folder_path = tags[0]
                values = self.tree.item(item, "values")
                if len(values) > 1:
                    button_text = values[1]  # Get button text
                    
                    if "[+]" in button_text:
                        # Immediately update UI for snappy response
                        size_val = values[0]
                        self.tree.item(item, values=(size_val, "", "[-]"), tags=(folder_path, "added"))
                        
                        # Add to paths.txt asynchronously
                        self.selected_folder = folder_path
                        self.root.after(0, self._add_to_paths_file_async, folder_path)
        
        # Column #3 is the "remove" column
        elif item and column == "#3":
            tags = self.tree.item(item, "tags")
            if tags:
                folder_path = tags[0]
                
                # Immediately update UI for snappy response
                values = self.tree.item(item, "values")
                size_val = values[0]
                self.tree.item(item, values=(size_val, "[+]", ""), tags=(folder_path, "not_added"))
                
                # Remove from paths.txt asynchronously
                self.root.after(0, self._remove_from_paths_file_async, folder_path)
    
    def _add_to_paths_file_async(self, folder_path):
        """Add to paths.txt without blocking UI."""
        self.selected_folder = folder_path
        self._add_to_paths_file()
        # Silently reload in background
        self._load_existing_paths()
    
    def _remove_from_paths_file_async(self, folder_path):
        """Remove from paths.txt without blocking UI."""
        self._remove_from_paths_file(folder_path)
    
    def _update_preview(self):
        """Update the command preview."""
        if not self.selected_folder:
            preview_text = "No folder selected"
        else:
            folder_path = self.selected_folder
            
            # Build command
            cmd_parts = ['py main.py']
            
            # Add mode if not default
            mode = self.mode_var.get()
            if mode != "default":
                cmd_parts.append(f'--m {mode}')
            
            # Add resolution if specified
            resolution = self.resolution_var.get()
            if resolution != "none":
                cmd_parts.append(f'--r {resolution}')
            
            # Add CQ if specified
            cq = self.cq_var.get().strip()
            if cq:
                cmd_parts.append(f'--cq {cq}')
            
            # Add path
            cmd_parts.append(f'"{folder_path}"')
            
            preview_text = " ".join(cmd_parts)
        
        self.preview_text.config(state=tk.NORMAL)
        self.preview_text.delete("1.0", tk.END)
        self.preview_text.insert("1.0", preview_text)
        self.preview_text.config(state=tk.DISABLED)
    
    def _add_to_paths_file(self):
        """Append the current command to paths.txt."""
        if not self.selected_folder:
            messagebox.showwarning("Warning", "Please select a folder first")
            return
        
        folder_path = self.selected_folder
        
        # Check if already in file
        if folder_path in self.added_folders:
            self._show_status(f"Already added: {Path(folder_path).name}")
            return
        
        # Build command line - start fresh
        cmd_parts = []
        
        # Add mode if not default
        mode = self.mode_var.get()
        if mode != "default":
            cmd_parts.append(f'--m {mode}')
        
        # Add resolution if specified
        resolution = self.resolution_var.get()
        if resolution != "none":
            cmd_parts.append(f'--r {resolution}')
        
        # Add CQ if specified
        cq = self.cq_var.get().strip()
        if cq:
            cmd_parts.append(f'--cq {cq}')
        
        # Add folder path
        cmd_parts.append(f'"{folder_path}"')
        
        line = " ".join(cmd_parts)
        
        # Append to paths.txt
        try:
            # Check if file exists and has content
            if self.paths_file.exists() and self.paths_file.stat().st_size > 0:
                # Read last character to check if it ends with newline
                with open(self.paths_file, "rb") as f:
                    f.seek(-1, 2)  # Seek to last byte
                    last_char = f.read(1)
                    needs_newline = last_char != b'\n'
            else:
                needs_newline = False
            
            # Write to file
            with open(self.paths_file, "a", encoding="utf-8") as f:
                if needs_newline:
                    f.write("\n")
                f.write(line + "\n")
            
            # Add to tracked set
            self.added_folders.add(folder_path)
            
            # Silent success - show status label instead of popup
            self.recently_added = folder_path
            self._show_status(f"✓ Added: {Path(folder_path).name}")
            logger.info(f"Added to paths.txt: {line}")
            
            # Clear timer if exists
            if self.status_timer:
                self.root.after_cancel(self.status_timer)
            
            # Clear status after 3 seconds
            self.status_timer = self.root.after(3000, self._clear_status)
        except Exception as e:
            messagebox.showerror("Error", f"Failed to write to paths.txt: {e}")
            logger.error(f"Failed to write to paths.txt: {e}")
    
    def _remove_from_paths_file(self, folder_path):
        """Remove a folder from paths.txt."""
        if not self.paths_file.exists():
            messagebox.showwarning("Warning", "paths.txt does not exist")
            return
        
        try:
            with open(self.paths_file, "r", encoding="utf-8") as f:
                lines = f.readlines()
            
            # Filter out lines containing this folder path
            new_lines = []
            found = False
            for line in lines:
                if f'"{folder_path}"' in line or f"'{folder_path}'" in line:
                    found = True
                else:
                    new_lines.append(line)
            
            if not found:
                messagebox.showwarning("Warning", "Path not found in paths.txt")
                return
            
            # Write back
            with open(self.paths_file, "w", encoding="utf-8") as f:
                f.writelines(new_lines)
            
            # Remove from tracked set
            self.added_folders.discard(folder_path)
            
            self._show_status(f"✓ Removed: {Path(folder_path).name}")
            logger.info(f"Removed from paths.txt: {folder_path}")
            
            # Clear timer if exists
            if self.status_timer:
                self.root.after_cancel(self.status_timer)
            
            # Clear status after 3 seconds
            self.status_timer = self.root.after(3000, self._clear_status)
        except Exception as e:
            messagebox.showerror("Error", f"Failed to remove from paths.txt: {e}")
            logger.error(f"Failed to remove from paths.txt: {e}")
    
    def _show_status(self, message):
        """Show status message in label."""
        self.status_label.config(text=message, foreground="green")
    
    def _clear_status(self):
        """Clear status message after delay."""
        self.status_label.config(text="")
        self.status_timer = None
    
    def _run_transcode(self):
        """Launch transcode.bat in a new command window."""
        if not self.transcode_bat.exists():
            messagebox.showerror("Error", f"transcode.bat not found at {self.transcode_bat}")
            return
        
        try:
            # Launch in new cmd window
            subprocess.Popen(
                ['cmd', '/c', f'"{self.transcode_bat}"'],
                cwd=str(self.transcode_bat.parent),
                creationflags=subprocess.CREATE_NEW_CONSOLE
            )
            logger.info("Launched transcode.bat")
        except Exception as e:
            messagebox.showerror("Error", f"Failed to launch transcode.bat: {e}")
            logger.error(f"Failed to launch transcode.bat: {e}")
    
    def _view_paths_file(self):
        """Open paths.txt in a new window."""
        if not self.paths_file.exists():
            messagebox.showinfo("Info", "paths.txt does not exist yet")
            return
        
        try:
            with open(self.paths_file, "r", encoding="utf-8") as f:
                content = f.read()
            
            # Create new window
            view_window = tk.Toplevel(self.root)
            view_window.title("paths.txt")
            view_window.geometry("800x400")
            
            text_widget = tk.Text(view_window, wrap=tk.WORD)
            text_widget.pack(fill=tk.BOTH, expand=True, padx=10, pady=10)
            text_widget.insert("1.0", content)
            
            # Add close button
            ttk.Button(view_window, text="Close", command=view_window.destroy).pack(pady=5)
            
        except Exception as e:
            messagebox.showerror("Error", f"Failed to read paths.txt: {e}")
    
    def _clear_paths_file(self):
        """Clear the paths.txt file."""
        if not self.paths_file.exists():
            messagebox.showinfo("Info", "paths.txt does not exist")
            return
        
        if messagebox.askyesno("Confirm", "Are you sure you want to clear paths.txt?"):
            try:
                self.paths_file.write_text("", encoding="utf-8")
                messagebox.showinfo("Success", "paths.txt has been cleared")
                logger.info("paths.txt cleared")
            except Exception as e:
                messagebox.showerror("Error", f"Failed to clear paths.txt: {e}")
    
    def _on_closing(self):
        """Handle window closing - cleanup timers."""
        self.root.destroy()
    
    def _on_scrollbar(self, *args):
        """Handle scrollbar movement - load more items when scrolling."""
        self.tree.yview(*args)
        
        # Check if we need to load more items
        if self.all_folders and self.loaded_items < len(self.all_folders):
            # Get scroll position
            first_visible = self.tree.yview()[0]
            last_visible = self.tree.yview()[1]
            
            # If we're past 70% scrolled, load more
            if last_visible > 0.7:
                self._load_more_items()
    
    def _load_more_items(self):
        """Load next batch of items into tree."""
        start = self.loaded_items
        end = min(start + self.items_per_batch, len(self.all_folders))
        
        for i in range(start, end):
            folder_name, folder_path, size = self.all_folders[i]
            size_str = self._format_size(size)
            folder_path_str = str(folder_path)
            
            # Determine button and tag
            if folder_path_str in self.added_folders:
                add_btn = ""
                remove_btn = "[-]"
                tag = "added"
            else:
                add_btn = "[+]"
                remove_btn = ""
                tag = "not_added"
            
            self.tree.insert("", "end", text=folder_name, values=(size_str, add_btn, remove_btn),
                           tags=(folder_path_str, tag))
        
        self.loaded_items = end


def main():
    root = tk.Tk()
    app = PathManagerGUI(root)
    root.mainloop()


if __name__ == "__main__":
    main()