Add channel URL lookup and auto-detection

- Accept YouTube URLs in any format (@handle, /c/, /user/, /channel/)
- Auto-extract channel ID from URLs using yt-dlp
- Auto-detect channel name from URL (optional field)
- Support direct channel ID input (backwards compatible)
- Prevent duplicate channels
- Updated UI with better instructions and examples
- Improved user experience - just paste channel URL

app.py

@@ -7,8 +7,10 @@ Provides a web UI for managing YouTube channel downloads
 import os
 import subprocess
 import json
+import re
 from datetime import datetime
 from pathlib import Path
+from urllib.parse import urlparse, parse_qs
 from flask import Flask, render_template, request, jsonify, redirect, url_for, flash
 
 app = Flask(__name__)
@@ -45,6 +47,51 @@ def save_settings(settings):
     with open(SETTINGS_FILE, 'w') as f:
         json.dump(settings, f, indent=2)
 
+def extract_channel_id(url_or_id):
+    """
+    Extract channel ID from various YouTube URL formats or validate direct ID
+    Returns tuple: (channel_id, channel_name_hint or None)
+    """
+    # If it looks like a channel ID already (24 characters starting with UC)
+    if re.match(r'^UC[\w-]{22}$', url_or_id.strip()):
+        return url_or_id.strip(), None
+
+    # Parse as URL
+    try:
+        parsed = urlparse(url_or_id)
+
+        # Format: youtube.com/channel/CHANNEL_ID
+        if '/channel/' in parsed.path:
+            channel_id = parsed.path.split('/channel/')[-1].split('/')[0]
+            if channel_id:
+                return channel_id, None
+
+        # Format: youtube.com/@handle or youtube.com/c/name or youtube.com/user/name
+        # These require fetching the page to get the actual channel ID
+        if parsed.netloc in ['youtube.com', 'www.youtube.com', 'm.youtube.com']:
+            # Use yt-dlp to extract channel ID from URL
+            try:
+                result = subprocess.run(
+                    ['yt-dlp', '--dump-json', '--playlist-items', '0', url_or_id],
+                    capture_output=True,
+                    text=True,
+                    timeout=10
+                )
+
+                if result.returncode == 0 and result.stdout:
+                    data = json.loads(result.stdout.split('\n')[0])
+                    channel_id = data.get('channel_id')
+                    channel_name = data.get('channel')
+
+                    if channel_id:
+                        return channel_id, channel_name
+            except:
+                pass
+    except:
+        pass
+
+    return None, None
+
 def get_channels():
     """Read channels from channels.txt"""
     channels = []
@@ -166,18 +213,38 @@ def channels():
 @app.route('/channels/add', methods=['POST'])
 def add_channel():
     """Add a new channel"""
-    channel_id = request.form.get('channel_id', '').strip()
+    channel_input = request.form.get('channel_id', '').strip()
     channel_name = request.form.get('channel_name', '').strip()
 
-    if not channel_id or not channel_name:
+    if not channel_input:
-        flash('Channel ID and Name are required', 'error')
+        flash('Channel ID or URL is required', 'error')
         return redirect(url_for('channels'))
 
+    # Extract channel ID from URL or validate direct ID
+    channel_id, auto_name = extract_channel_id(channel_input)
+
+    if not channel_id:
+        flash('Invalid channel ID or URL. Please check and try again.', 'error')
+        return redirect(url_for('channels'))
+
+    # Use auto-detected name if no name was provided
+    if not channel_name and auto_name:
+        channel_name = auto_name
+    elif not channel_name:
+        flash('Channel name is required (could not auto-detect from URL)', 'error')
+        return redirect(url_for('channels'))
+
+    # Check for duplicates
     channels = get_channels()
+    for existing in channels:
+        if existing['id'] == channel_id:
+            flash(f'Channel already exists: {existing["name"]}', 'error')
+            return redirect(url_for('channels'))
+
     channels.append({'id': channel_id, 'name': channel_name})
     save_channels(channels)
 
-    flash(f'Added channel: {channel_name}', 'success')
+    flash(f'Added channel: {channel_name} ({channel_id})', 'success')
     return redirect(url_for('channels'))
 
 @app.route('/channels/delete/<int:index>')

templates/channels.html

@@ -11,17 +11,20 @@
     <h3>Add New Channel</h3>
     <form method="POST" action="{{ url_for('add_channel') }}" class="form">
         <div class="form-group">
-            <label for="channel_id">Channel ID <span class="required">*</span></label>
+            <label for="channel_id">Channel URL or ID <span class="required">*</span></label>
             <input type="text" id="channel_id" name="channel_id" required
-                   placeholder="UCfDNi1aEljAQ17mUrfUjkvg" class="form-control">
+                   placeholder="https://www.youtube.com/@AltonBrown or UCfDNi1aEljAQ17mUrfUjkvg" class="form-control">
-            <small class="form-help">Find this in the channel URL or page source</small>
+            <small class="form-help">
+                Paste any YouTube channel URL or enter the channel ID directly<br>
+                <strong>Supported formats:</strong> youtube.com/@handle, youtube.com/channel/ID, youtube.com/c/name, youtube.com/user/name
+            </small>
         </div>
 
         <div class="form-group">
-            <label for="channel_name">Channel Name <span class="required">*</span></label>
+            <label for="channel_name">Channel Name</label>
-            <input type="text" id="channel_name" name="channel_name" required
+            <input type="text" id="channel_name" name="channel_name"
-                   placeholder="Alton Brown" class="form-control">
+                   placeholder="Alton Brown (optional - auto-detected from URL)" class="form-control">
-            <small class="form-help">Display name for the channel folder</small>
+            <small class="form-help">Display name for the channel folder. Leave blank to auto-detect from URL.</small>
         </div>
 
         <button type="submit" class="btn btn-primary">Add Channel</button>
@@ -65,14 +68,26 @@
 </div>
 
 <div class="card info-card">
-    <h3>How to Find Channel IDs</h3>
+    <h3>How to Add Channels</h3>
+
+    <h4>Option 1: Paste the Channel URL (Easiest)</h4>
     <ol>
-        <li>Go to the YouTube channel page</li>
+        <li>Go to the YouTube channel you want to sync</li>
-        <li>Right-click and select "View Page Source" (or press Ctrl+U / Cmd+U)</li>
+        <li>Copy the URL from your browser address bar</li>
-        <li>Search for "channelId" (Ctrl+F / Cmd+F)</li>
+        <li>Paste it into the "Channel URL or ID" field above</li>
-        <li>Copy the value that looks like: <code>UCfDNi1aEljAQ17mUrfUjkvg</code></li>
+        <li>Click "Add Channel" - the name will be detected automatically!</li>
     </ol>
-    <p><strong>Alternative:</strong> Some channel URLs include the ID directly:<br>
+
-    <code>youtube.com/channel/<strong>CHANNEL_ID_HERE</strong>/videos</code></p>
+    <h4>Option 2: Enter Channel ID Directly</h4>
+    <p>If you have the channel ID (starts with "UC" and is 24 characters long), just paste it directly.</p>
+    <p><strong>Example:</strong> <code>UCfDNi1aEljAQ17mUrfUjkvg</code></p>
+
+    <h4>Supported URL Formats</h4>
+    <ul>
+        <li><code>https://www.youtube.com/@AltonBrown</code> - Modern @ handle format</li>
+        <li><code>https://www.youtube.com/channel/UCfDNi1aEljAQ17mUrfUjkvg</code> - Channel ID format</li>
+        <li><code>https://www.youtube.com/c/AltonBrown</code> - Custom URL format</li>
+        <li><code>https://www.youtube.com/user/altonbrown</code> - Legacy user format</li>
+    </ul>
 </div>
 {% endblock %}