chat.py

"""
Chat Blueprint
Handles chat interface and conversation management
"""

from flask import Blueprint, render_template, request, jsonify, send_file
from flask_login import login_required, current_user
from models import db, Conversation, Message
from gtts import gTTS
import logging
import os
import tempfile
import hashlib

logger = logging.getLogger(__name__)

chat_bp = Blueprint('chat', __name__)


@chat_bp.route('/')
@login_required
def chat_interface():
    """Main chat interface page."""
    #
    # --- MODIFICA CHIAVE DI DEBUG ---
    #
    # Se vediamo questo log, significa che il login e il redirect
    # hanno funzionato. Se NON lo vediamo, il problema è nel user_loader.
    #
    logger.info(f"--- CHAT INTERFACE: Accesso riuscito! L'utente {current_user.username} è sulla pagina della chat.")
    #
    # --- FINE MODIFICA DI DEBUG ---
    #

    # Get user's conversations
    conversations = Conversation.query.filter_by(user_id=current_user.id).order_by(Conversation.updated_at.desc()).all()

    # Get current conversation (most recent) or create new one
    current_conversation = None
    if conversations:
        current_conversation = conversations[0]
    else:
        # Create first conversation
        current_conversation = Conversation(
            user_id=current_user.id,
            title='Welcome Chat'
        )
        db.session.add(current_conversation)
        db.session.commit() 
        conversations = [current_conversation]

    return render_template(
        'chat.html',
        conversations=conversations,
        current_conversation=current_conversation
    )


@chat_bp.route('/api/send', methods=['POST'])
@login_required
def send_message():
    """
    API endpoint to send a message and get a response.

    Expected JSON:
    {
        "message": "user message",
        "conversation_id": 123 (optional)
    }

    Returns JSON:
    {
        "success": true,
        "user_message": {...},
        "assistant_message": {...},
        "conversation_id": 123
    }
    """
    try:
        data = request.get_json()
        user_message_text = data.get('message', '').strip()
        conversation_id = data.get('conversation_id')

        if not user_message_text:
            return jsonify({'success': False, 'error': 'Message cannot be empty'}), 400

        # Get or create conversation
        if conversation_id:
            conversation = Conversation.query.filter_by(
                id=conversation_id,
                user_id=current_user.id
            ).first()

            if not conversation:
                return jsonify({'success': False, 'error': 'Conversation not found'}), 404
        else:
            # Create new conversation
            conversation = Conversation(
                user_id=current_user.id,
                title=user_message_text[:50] + ('...' if len(user_message_text) > 50 else '')
            )
            db.session.add(conversation)
            db.session.commit()

        # Save user message
        user_message = Message(
            conversation_id=conversation.id,
            role='user',
            content=user_message_text
        )
        db.session.add(user_message)
        db.session.commit()

        # Get conversation history (excluding the current message for now)
        history = conversation.get_message_history()[:-1]  # Exclude the message we just added

        # Generate response using thread-safe model access
        # Import here to avoid circular import
        from app import generate_response_threadsafe

        logger.info(f"Generating response for user {current_user.username}")
        assistant_response_text = generate_response_threadsafe(
            prompt=user_message_text,
            conversation_history=history
        )

        # Save assistant message
        assistant_message = Message(
            conversation_id=conversation.id,
            role='assistant',
            content=assistant_response_text
        )
        db.session.add(assistant_message)
        db.session.commit()

        logger.info(f"Response generated successfully for user {current_user.username}")

        return jsonify({
            'success': True,
            'user_message': user_message.to_dict(),
            'assistant_message': assistant_message.to_dict(),
            'conversation_id': conversation.id
        })

    except Exception as e:
        logger.error(f"Error in send_message: {e}", exc_info=True)
        return jsonify({
            'success': False,
            'error': 'An error occurred while processing your message'
        }), 500


@chat_bp.route('/api/conversations')
@login_required
def get_conversations():
    """Get all conversations for the current user."""
    conversations = Conversation.query.filter_by(user_id=current_user.id).order_by(Conversation.updated_at.desc()).all()

    return jsonify({
        'success': True,
        'conversations': [
            {
                'id': c.id,
                'title': c.title,
                'created_at': c.created_at.isoformat(),
                'updated_at': c.updated_at.isoformat(),
                'message_count': len(c.messages)
            }
            for c in conversations
        ]
    })


@chat_bp.route('/api/conversation/<int:conversation_id>')
@login_required
def get_conversation(conversation_id):
    """Get a specific conversation with all messages."""
    conversation = Conversation.query.filter_by(
        id=conversation_id,
        user_id=current_user.id
    ).first()

    if not conversation:
        return jsonify({'success': False, 'error': 'Conversation not found'}), 404

    return jsonify({
        'success': True,
        'conversation': {
            'id': conversation.id,
            'title': conversation.title,
            'created_at': conversation.created_at.isoformat(),
            'updated_at': conversation.updated_at.isoformat(),
            'messages': [msg.to_dict() for msg in conversation.messages]
        }
    })


@chat_bp.route('/api/conversation/new', methods=['POST'])
@login_required
def new_conversation():
    """Create a new conversation."""
    try:
        conversation = Conversation(
            user_id=current_user.id,
            title='New Conversation'
        )
        db.session.add(conversation)
        db.session.commit()

        return jsonify({
            'success': True,
            'conversation': {
                'id': conversation.id,
                'title': conversation.title,
                'created_at': conversation.created_at.isoformat(),
                'updated_at': conversation.updated_at.isoformat()
            }
        })

    except Exception as e:
        logger.error(f"Error creating new conversation: {e}")
        return jsonify({'success': False, 'error': 'Failed to create conversation'}), 500


@chat_bp.route('/api/conversation/<int:conversation_id>/delete', methods=['POST'])
@login_required
def delete_conversation(conversation_id):
    """Delete a conversation."""
    try:
        conversation = Conversation.query.filter_by(
            id=conversation_id,
            user_id=current_user.id
        ).first()

        if not conversation:
            return jsonify({'success': False, 'error': 'Conversation not found'}), 404

        db.session.delete(conversation)
        db.session.commit()

        return jsonify({'success': True})

    except Exception as e:
        logger.error(f"Error deleting conversation: {e}")
        return jsonify({'success': False, 'error': 'Failed to delete conversation'}), 500


@chat_bp.route('/api/tts/generate', methods=['POST'])
@login_required
def generate_tts():
    """
    Generate text-to-speech audio from text.

    Expected JSON:
    {
        "text": "text to convert to speech"
    }

    Returns:
    Audio file (MP3) for client-side playback
    """
    try:
        data = request.get_json()
        text = data.get('text', '').strip()

        if not text:
            return jsonify({'success': False, 'error': 'Text cannot be empty'}), 400

        # Create a unique filename based on text hash (for caching)
        text_hash = hashlib.md5(text.encode()).hexdigest()

        # Create audio directory if it doesn't exist
        audio_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'static', 'audio')
        os.makedirs(audio_dir, exist_ok=True)

        # Path for cached audio file
        audio_filename = f"tts_{text_hash}.mp3"
        audio_path = os.path.join(audio_dir, audio_filename)

        # Generate TTS if not already cached
        if not os.path.exists(audio_path):
            logger.info(f"Generating TTS for text (hash: {text_hash})")

            # Generate speech using Google TTS
            # lang='en' for English, slow=False for normal speed
            tts = gTTS(text=text, lang='en', slow=False)

            # Save to file
            tts.save(audio_path)
            logger.info(f"TTS saved to: {audio_path}")
        else:
            logger.info(f"Using cached TTS (hash: {text_hash})")

        # Return the audio file URL
        return jsonify({
            'success': True,
            'audio_url': f'/static/audio/{audio_filename}'
        })

    except Exception as e:
        logger.error(f"Error generating TTS: {e}", exc_info=True)
        return jsonify({
            'success': False,
            'error': 'Failed to generate speech'
        }), 500