cthulhu/src/cthulhu/plugins/self_voice/plugin.py

#!/usr/bin/env python3
#
# Copyright (c) 2024 Stormux
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., Franklin Street, Fifth Floor,
# Boston MA  02110-1301 USA.
#

"""Self Voice plugin for Cthulhu screen reader."""

import os
import socket
import select
import logging
import threading
from threading import Thread, Lock
from cthulhu.plugin import Plugin, cthulhu_hookimpl

logger = logging.getLogger(__name__)

# Special codes for message handling
APPEND_CODE = '<#APPEND#>'
PERSISTENT_CODE = '<#PERSISTENT#>'

class SelfVoice(Plugin):
    """Plugin that provides a socket interface for external applications to send text to Cthulhu."""
    
    def __init__(self):
        """Initialize the plugin."""
        super().__init__()
        self.lock = Lock()
        self.active = False
        self.voiceThread = Thread(target=self.voiceWorker)
        self.voiceThread.daemon = True  # Make thread exit when main thread exits
    
    @cthulhu_hookimpl
    def activate(self):
        """Activate the self-voice plugin."""
        super().activate()
        logger.info("Activating Self Voice Plugin")
        self.activateWorker()
    
    @cthulhu_hookimpl
    def deactivate(self):
        """Deactivate the self-voice plugin."""
        logger.info("Deactivating Self Voice Plugin")
        self.deactivateWorker()
        super().deactivate()
    
    def activateWorker(self):
        """Start the voice worker thread."""
        with self.lock:
            self.active = True
        
        # Only start if not already running
        if not self.voiceThread.is_alive():
            self.voiceThread = Thread(target=self.voiceWorker)
            self.voiceThread.daemon = True
            self.voiceThread.start()
    
    def deactivateWorker(self):
        """Stop the voice worker thread."""
        with self.lock:
            self.active = False
        
        # Try to join the thread if it's alive, with a timeout
        if self.voiceThread.is_alive():
            try:
                self.voiceThread.join(timeout=2.0)
            except Exception as e:
                logger.warning(f"Error stopping voice worker thread: {e}")
    
    def isActive(self):
        """Check if the worker is active."""
        with self.lock:
            return self.active
    
    def outputMessage(self, message):
        """Output a message through Cthulhu's speech and braille systems.
        
        Args:
            message: The message to output. May include special codes.
        """
        # Process special codes
        append = message.startswith(APPEND_CODE)
        if append:
            message = message[len(APPEND_CODE):]
        
        persistent = False
        if message.endswith(PERSISTENT_CODE):
            message = message[:len(message)-len(PERSISTENT_CODE)]
            persistent = True
        
        # Output through appropriate channel
        if persistent:
            # Use the APIHelper for persistent messages
            self.app.getAPIHelper().outputMessage(message, not append)
        else:
            # Use the script manager for standard messages
            script_manager = self.app.getDynamicApiManager().getAPI('ScriptManager')
            scriptManager = script_manager.getManager()
            scriptManager.getDefaultScript().presentMessage(message, resetStyles=False)
    
    def voiceWorker(self):
        """Worker thread that listens on a socket for messages to speak."""
        socketFile = '/tmp/cthulhu.sock'
        # For testing purposes
        # socketFile = '/tmp/cthulhu-plugin.sock'
        
        # Clean up any existing socket file
        if os.path.exists(socketFile):
            try:
                os.unlink(socketFile)
            except Exception as e:
                logger.error(f"Error removing existing socket file: {e}")
                return
        
        try:
            # Create and set up the socket
            cthulhu_sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
            cthulhu_sock.bind(socketFile)
            os.chmod(socketFile, 0o222)  # Write-only for everyone
            cthulhu_sock.listen(1)
            
            logger.info(f"Self Voice plugin listening on {socketFile}")
            
            # Main loop - listen for connections
            while self.isActive():
                # Check if data is available with a timeout
                try:
                    r, _, _ = select.select([cthulhu_sock], [], [], 0.8)
                except select.error as e:
                    logger.error(f"Select error: {e}")
                    break
                
                if not r:  # No data available
                    continue
                
                # Accept connection
                if cthulhu_sock in r:
                    try:
                        client_sock, _ = cthulhu_sock.accept()
                        client_sock.settimeout(0.5)  # Set a timeout for receiving data
                        
                        try:
                            # Receive and process data
                            raw_data = client_sock.recv(8192)
                            if raw_data:
                                data = raw_data.decode("utf-8").strip()
                                if data:
                                    self.outputMessage(data)
                        except socket.timeout:
                            pass
                        except Exception as e:
                            logger.error(f"Error receiving data: {e}")
                        finally:
                            client_sock.close()
                    except Exception as e:
                        logger.error(f"Error accepting connection: {e}")
            
        except Exception as e:
            logger.error(f"Socket error: {e}")
        finally:
            # Clean up
            if 'cthulhu_sock' in locals():
                try:
                    cthulhu_sock.close()
                except Exception:
                    pass
            
            if os.path.exists(socketFile):
                try:
                    os.unlink(socketFile)
                except Exception as e:
                    logger.error(f"Error removing socket file: {e}")
            
            logger.info("Self Voice plugin socket closed")