Add podgrab featureset

README_DATABASE_FIX_V2.md

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+# Fix for "unable to open database file" Error - Version 2
+
+## Problem
+
+The application was encountering the following error when starting up:
+
+```
+Error during database initialization: (sqlite3.OperationalError) unable to open database file
+```
+
+Despite previous fixes to ensure the instance directory exists and is writable, the application was still unable to create or access the database file.
+
+## Root Cause
+
+The issue could be caused by several factors:
+
+1. The database file path might be incorrect or inaccessible
+2. There might be permission issues with the database file
+3. The database directory might not be writable
+4. There might be a locking issue with the database file
+5. SQLAlchemy might be having issues connecting to the database
+
+## Solution
+
+The solution involved several enhancements to the database initialization process:
+
+### 1. Using Absolute Paths for Database File
+
+Modified the database connection string to use an absolute path to the database file:
+
+```python
+SQLALCHEMY_DATABASE_URI=os.environ.get('DATABASE_URI', f'sqlite:///{os.path.abspath(os.path.join(os.path.dirname(__file__), "instance", "podcastrr.db"))}')
+```
+
+This ensures that SQLite can find the database file regardless of the current working directory.
+
+### 2. Enhanced Database File Checks
+
+Added more comprehensive checks for the database file:
+
+- Check if the database file exists
+- Check if the database file is readable and writable
+- Attempt to fix permissions if there are issues
+- Create the database file if it doesn't exist
+- Set appropriate permissions on the newly created file
+
+### 3. Retry Mechanism for Database Connection
+
+Added a retry mechanism for database connection:
+
+```python
+# Try to create the database tables with retries
+max_retries = 3
+retry_count = 0
+while retry_count < max_retries:
+    try:
+        # Test the database connection first
+        with db.engine.connect() as conn:
+            app.logger.info("Database connection successful")
+        
+        # Create the tables
+        db.create_all()
+        break
+    except Exception as e:
+        retry_count += 1
+        app.logger.error(f"Error creating database tables (attempt {retry_count}/{max_retries}): {str(e)}")
+        if retry_count >= max_retries:
+            app.logger.error("Maximum retry attempts reached. Could not create database tables.")
+            raise
+        import time
+        time.sleep(1)  # Wait a second before retrying
+```
+
+This helps with transient connection issues by attempting to connect multiple times before giving up.
+
+### 4. Fallback to In-Memory Database
+
+Added a fallback mechanism that uses an in-memory SQLite database if all attempts to use a file-based database fail:
+
+```python
+# If we've tried multiple times and still failing, try a fallback approach
+if retry_count >= max_retries and not fallback_used:
+    app.logger.warning("Maximum retry attempts reached. Trying fallback approach...")
+    
+    try:
+        # Create a fallback database in memory
+        app.logger.info("Attempting to use in-memory SQLite database as fallback")
+        app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///:memory:'
+        
+        # Reinitialize the database with the new connection string
+        db.init_app(app)
+        
+        # Reset retry counter and set fallback flag
+        retry_count = 0
+        fallback_used = True
+        
+        # Add a warning message that will be displayed in the application
+        app.config['DB_FALLBACK_WARNING'] = True
+        app.logger.warning("WARNING: Using in-memory database as fallback. Data will not be persisted between application restarts!")
+        
+        continue
+    except Exception as fallback_error:
+        app.logger.error(f"Error setting up fallback database: {str(fallback_error)}")
+```
+
+This provides a last resort option if all other attempts to create the database fail. The in-memory database won't persist data between application restarts, but it will at least allow the application to start and function temporarily.
+
+### 5. User-Visible Warning for Fallback Database
+
+Added a warning message that is displayed in the application if the fallback database is being used:
+
+```python
+# Add a context processor to make the fallback warning available to all templates
+@app.context_processor
+def inject_db_fallback_warning():
+    """Inject the database fallback warning into all templates."""
+    return {
+        'db_fallback_warning': app.config.get('DB_FALLBACK_WARNING', False)
+    }
+```
+
+And in the base.html template:
+
+```html
+<!-- Database Fallback Warning -->
+{% if db_fallback_warning %}
+    <div class="flash-messages">
+        <div class="flash-message error" style="background-color: #f85149; color: white; font-weight: bold;">
+            WARNING: Using in-memory database as fallback. Data will not be persisted between application restarts!
+            <br>
+            <span style="font-size: 0.9em;">Please check the application logs for details on how to fix this issue.</span>
+        </div>
+    </div>
+{% endif %}
+```
+
+This helps users understand the implications of using the fallback database and encourages them to fix the underlying issue.
+
+## How to Verify the Solution
+
+1. Run the application:
+   ```
+   python main.py
+   ```
+
+2. Verify that the application starts without any database-related errors.
+
+3. If the application is using the fallback database, you should see a warning message at the top of the page.
+
+4. Check the logs for any error messages related to database initialization.
+
+## Preventing Similar Issues in the Future
+
+To prevent similar issues in the future:
+
+1. Always ensure that directories exist before trying to create files in them.
+2. Use absolute paths for database files to avoid issues with relative paths.
+3. Test if directories and files are writable before attempting operations on them.
+4. Add proper error handling and logging to help diagnose issues.
+5. Implement retry mechanisms for database connections to handle transient issues.
+6. Provide fallback options for critical components to ensure the application can still function.
+7. Add user-visible warnings for fallback modes to encourage fixing the underlying issues.