import streamlit as st
import yt_dlp
import os
from pathlib import Path

# Set page config
st.set_page_config(page_title="YouTube Video Downloader", page_icon="📺")

# Set the title of the app
st.title("YouTube Video Downloader 📺")

# Create output directory if it doesn't exist
output_dir = Path("downloads")
output_dir.mkdir(exist_ok=True)

# Input field for YouTube video URL
video_url = st.text_input("Enter YouTube Video URL:", placeholder="https://www.youtube.com/watch?v=...")

# Format selection
format_option = st.selectbox(
    "Select Format:",
    options=[
        "Best Quality (Video + Audio)",
        "Audio Only (Best Quality)",
        "720p",
        "480p",
        "360p"
    ]
)

def get_format_options(selection):
    if selection == "Best Quality (Video + Audio)":
        return {
            'format': 'best',  # Changed from bestvideo+bestaudio to best
            'merge_output_format': 'mp4'
        }
    elif selection == "Audio Only (Best Quality)":
        return {
            'format': 'bestaudio/best',
            'postprocessors': [{
                'key': 'FFmpegExtractAudio',
                'preferredcodec': 'mp3',
            }]
        }
    elif selection == "720p":
        return {
            'format': 'best[height<=720]',  # Simplified format selection
            'merge_output_format': 'mp4'
        }
    elif selection == "480p":
        return {
            'format': 'best[height<=480]',
            'merge_output_format': 'mp4'
        }
    elif selection == "360p":
        return {
            'format': 'best[height<=360]',
            'merge_output_format': 'mp4'
        }

def download_video(url, format_selection):
    try:
        format_opts = get_format_options(format_selection)
        
        ydl_opts = {
            'outtmpl': str(output_dir / '%(title)s.%(ext)s'),
            'quiet': True,
            'no_warnings': True,
            # Enhanced options to bypass restrictions
            'nocheckcertificate': True,
            'ignoreerrors': True,
            'no_color': True,
            'noprogress': True,
            'user_agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
            'referer': 'https://www.youtube.com/',
            'http-chunk-size': '10485760',  # 10MB chunks for better reliability
        }
        
        # Update options with format-specific settings
        ydl_opts.update(format_opts)

        # Progress placeholder
        progress_bar = st.progress(0)
        status_text = st.empty()
        
        def progress_hook(d):
            if d['status'] == 'downloading':
                try:
                    progress = d['downloaded_bytes'] / d['total_bytes']
                    progress_bar.progress(progress)
                    status_text.text(f"Downloading: {progress:.1%}")
                except:
                    status_text.text("Downloading... (size unknown)")
            elif d['status'] == 'finished':
                progress_bar.progress(1.0)
                status_text.text("Processing...")

        ydl_opts['progress_hooks'] = [progress_hook]
        
        with yt_dlp.YoutubeDL(ydl_opts) as ydl:
            info = ydl.extract_info(url, download=False)
            filename = ydl.prepare_filename(info)
            ydl.download([url])
            
            return filename

    except Exception as e:
        st.error(f"An error occurred: {str(e)}")
        return None

# Download button
if st.button("Download"):
    if video_url:
        try:
            with st.spinner("Preparing download..."):
                downloaded_file_path = download_video(video_url, format_option)
                
            if downloaded_file_path and os.path.exists(downloaded_file_path):
                with open(downloaded_file_path, 'rb') as file:
                    st.download_button(
                        label="Click here to download",
                        data=file,
                        file_name=os.path.basename(downloaded_file_path),
                        mime="application/octet-stream"
                    )
                st.success("✅ Download ready!")
            else:
                st.error("❌ Download failed. Please try again.")
        except Exception as e:
            st.error(f"❌ An error occurred: {str(e)}")
    else:
        st.warning("⚠️ Please enter a valid YouTube URL.")

# Add help section
with st.expander("ℹ️ Help"):
    st.markdown("""
    **How to use:**
    1. Paste a YouTube video URL in the input field
    2. Select your preferred format
    3. Click the Download button
    4. Wait for the download to complete
    5. Click the download button that appears
    
    **Note:** Some videos might be restricted due to YouTube's policies.
    """)