main.py

import tkinter  
import customtkinter  
from yt_dlp import YoutubeDL 
from yt_dlp.utils import DownloadError 
import re 

def update_progress(percentage):
    """Update the progress bar and percentage label."""
    progressBar.set(percentage / 100)  
    pPercentage.configure(text=f"{percentage}%")  

def on_progress(d):
    """Callback function to display download progress."""
    if d['status'] == 'downloading':  
        percentage_str = d.get('_percent_str', '')  
        if percentage_str:

            match = re.search(r'(\d+(\.\d+)?)%', percentage_str)  
            if match:
                percentage = match.group(1)  
                try:
                    percent_value = float(percentage)  
                    app.after(0, update_progress, percent_value) 
                except ValueError:
                    print(f"Error converting percentage: {percentage_str}")  
            else:
                print(f"Could not extract percentage from: {percentage_str}")  

def is_valid_youtube_url(url):
    """Check if the URL is a valid YouTube URL."""
    youtube_regex = re.compile(  
        r'(https?://)?(www\.)?(youtube\.com/watch\?v=|youtu\.be/)[\w-]{11}', re.IGNORECASE)
    return re.match(youtube_regex, url) is not None  

def normalize_youtube_url(url):
    """Normalize different YouTube URL formats to a standard format."""
    if 'youtu.be/' in url: 
        video_id = url.split('youtu.be/')[1].split('?')[0]  
        return f'https://www.youtube.com/watch?v={video_id}'  
    elif 'youtube.com/watch?v=' in url:  
        return url.split('&')[0]  
    return url  

def Download():
    """Handles the download process for the YouTube video."""
    try:

        yt_link = link.get().strip() 

        # Validate the URL
        if not is_valid_youtube_url(yt_link): 
            finishLabel.configure(text="Invalid YouTube URL.", text_color="red") 
            return  


        yt_link = normalize_youtube_url(yt_link) 


        if yt_link.startswith('http://'):  
            yt_link = yt_link.replace('http://', 'https://') 

        # yt-dlp options
        ydl_opts = {  # Sets options for yt-dlp
            'format': 'best',  # Specifies to download the best quality available.
            # Available format options:
            # 'worst' - Downloads the lowest quality available.
            # 'bestvideo' - Downloads the best video quality only.
            # 'bestaudio' - Downloads the best audio quality only.
            # 'bestvideo[height<=720]' - Best video under or equal to 720p.
            # 'bestaudio[abr<=192]' - Best audio with an average bitrate of 192 kbps or lower.
            # 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/best' - Best video in MP4 and best audio in M4A.
            # Combinations like 'bestvideo[height<=1080]+bestaudio/best' for quality under 1080p.
            
            'outtmpl': '%(title)s.%(ext)s', 
            'progress_hooks': [on_progress], 
        }

        finishLabel.configure(text="") 
        progressBar.set(0) 
        pPercentage.configure(text="0%")  


        with YoutubeDL(ydl_opts) as ydl:  
            info_dict = ydl.extract_info(yt_link, download=False)  
            ytObject = info_dict  


            title.configure(text=ytObject['title'], text_color="white")  


            ydl.download([yt_link])  

        finishLabel.configure(text="Download Complete!", text_color="green")  

    except DownloadError:
        finishLabel.configure(text="Error: Could not retrieve video information.", text_color="red")  
    except Exception as e:
        finishLabel.configure(text=f"Error occurred: {e}", text_color="red")  

"""
GUI CONFIG IS BELOW THIS LINE, CUSTOMIZE THE FEEL OF THE APP BELOW
"""


customtkinter.set_appearance_mode("dark")  
customtkinter.set_default_color_theme("blue")  


app = customtkinter.CTk()  
app.geometry("720x480")  
app.title("YouTube Downloader") 

# Disable maximize by making the window non-resizable
app.resizable(False, False)  

# Title label
title = customtkinter.CTkLabel(app, 
                               text="YouTube Downloader", 
                               font=("Helvetica", 20, "bold"),  
                               text_color="#00BFFF")  
title.pack(pady=(20, 10))  

# Instruction label
instructionLabel = customtkinter.CTkLabel(app, 
                                           text="Please insert the YouTube video link below:", 
                                           font=("Helvetica", 14),
                                           text_color="#FFFFFF")  
instructionLabel.pack(pady=(0, 10))  

# Entry field for URL input
url_var = tkinter.StringVar()
link = customtkinter.CTkEntry(app, 
                               width=350, 
                               height=40, 
                               textvariable=url_var, 
                               placeholder_text="Enter YouTube URL", 
                               fg_color="#333333", 
                               text_color="white", 
                               border_color="#00BFFF")
link.pack(pady=(0, 20))

# Label to display finish messages
finishLabel = customtkinter.CTkLabel(app, text="", font=("Helvetica", 12))
finishLabel.pack()

# Percentage label for download progress
pPercentage = customtkinter.CTkLabel(app, text="0%", font=("Helvetica", 12))
pPercentage.pack(pady=(10, 0))

# Progress bar for download status
progressBar = customtkinter.CTkProgressBar(app, width=400, progress_color="#00BFFF")
progressBar.set(0)
progressBar.pack(pady=(0, 20))

# Button to initiate the download
download_button = customtkinter.CTkButton(app, 
                                           text="Download", 
                                           command=Download, 
                                           fg_color="#00BFFF", 
                                           hover_color="#0080FF")
download_button.pack(pady=20)

# Run the app loop
app.mainloop()