app.py

import os
import asyncio
import wave
import tempfile
import logging
import json
import time
from flask import Flask, render_template, request, jsonify, send_file, stream_with_context, Response
from google import genai
import aiohttp
from pydub import AudioSegment

# Configure logging
logging.basicConfig(level=logging.DEBUG)
logger = logging.getLogger(__name__)

app = Flask(__name__)
app.secret_key = os.environ.get("SESSION_SECRET", "default-secret-key")

# Configure Gemini API
api_key = os.environ.get("GEMINI_API_KEY")
if not api_key:
    logger.warning("GEMINI_API_KEY not found in environment variables. Using default value for development.")
    api_key = "YOUR_API_KEY"  # This will be replaced with env var in production

# Define available voices
AVAILABLE_VOICES = [
    "Puck", "Charon", "Kore", "Fenrir", 
    "Aoede", "Leda", "Orus", "Zephyr"
]
language_code="fr-FR"

# Global variable to track generation progress
generation_progress = {
    "status": "idle",
    "current": 0,
    "total": 0,
    "message": ""
}

def update_progress(current, total, message):
    """Update the global progress tracker."""
    global generation_progress
    generation_progress = {
        "status": "in_progress" if current < total else "complete",
        "current": current,
        "total": total,
        "message": message
    }
def create_async_enumerate(async_iterator):
    """Create an async enumerate function since it's not built-in."""
    i = 0
    async def async_iter():
        nonlocal i
        async for item in async_iterator:
            yield i, item
            i += 1
    return async_iter()

async def generate_speech(text, selected_voice):
    """Generate speech from text using Gemini AI."""
    try:
        client = genai.Client(api_key=api_key)
        model = "gemini-2.0-flash-live-001"
        
        # Configure the voice settings
        speech_config = genai.types.SpeechConfig(
            language_code=language_code,
            voice_config=genai.types.VoiceConfig(
                prebuilt_voice_config=genai.types.PrebuiltVoiceConfig(
                    voice_name=selected_voice
                )
            )
        )
        
        config = genai.types.LiveConnectConfig(
            response_modalities=["AUDIO"],
            speech_config=speech_config
        )
        
        # Create a temporary file to store the audio
        with tempfile.NamedTemporaryFile(suffix=".wav", delete=False) as tmp_file:
            temp_filename = tmp_file.name
            
            async with client.aio.live.connect(model=model, config=config) as session:
                # Open the WAV file for writing
                wf = wave.open(temp_filename, "wb")
                wf.setnchannels(1)
                wf.setsampwidth(2)
                wf.setframerate(24000)
                
                # Send the text to Gemini
                await session.send_client_content(
                    turns={"role": "user", "parts": [{"text": text}]}, 
                    turn_complete=True
                )
                
                # Receive the audio data and write it to the file
                async for idx, response in create_async_enumerate(session.receive()):
                    if response.data is not None:
                        wf.writeframes(response.data)
                
                wf.close()
            
            return temp_filename
    
    except Exception as e:
        logger.error(f"Error generating speech: {str(e)}")
        raise e

@app.route('/')
def index():
    """Render the main page."""
    return render_template('index.html', voices=AVAILABLE_VOICES)

@app.route('/generate', methods=['POST'])
async def generate():
    """Generate speech from text."""
    try:
        data = request.json
        text = data.get('text', '')
        voice = data.get('voice', 'Kore')  # Default voice
        
        if not text:
            return jsonify({"error": "Text is required"}), 400
        
        if voice not in AVAILABLE_VOICES:
            return jsonify({"error": "Invalid voice selection"}), 400
        
        # Generate the speech
        audio_file = await generate_speech(text, voice)
        
        return jsonify({
            "status": "success",
            "message": "Audio generated successfully",
            "audioUrl": f"/audio/{os.path.basename(audio_file)}"
        })
    
    except Exception as e:
        logger.error(f"Error in generate endpoint: {str(e)}")
        return jsonify({"error": str(e)}), 500

@app.route('/audio/<filename>')
def get_audio(filename):
    """Serve the generated audio file."""
    try:
        temp_dir = tempfile.gettempdir()
        file_path = os.path.join(temp_dir, filename)
        
        if not os.path.exists(file_path):
            return jsonify({"error": "Audio file not found"}), 404
        
        return send_file(file_path, mimetype="audio/wav", as_attachment=False)
    
    except Exception as e:
        logger.error(f"Error serving audio file: {str(e)}")
        return jsonify({"error": str(e)}), 500

@app.route('/generate-podcast', methods=['POST'])
async def generate_podcast_route():
    """Generate a podcast from a scenario."""
    try:
        scenario = request.json
        
        # Reset progress tracker
        global generation_progress
        generation_progress = {
            "status": "in_progress",
            "current": 0,
            "total": len(scenario.get('characters', [])),
            "message": "Démarrage de la génération..."
        }
        
        # Start the background task for podcast generation
        # We'll return immediately and let the client poll for progress
        asyncio.create_task(generate_podcast_background(scenario))
        
        return jsonify({
            "status": "started",
            "message": "Génération du podcast commencée. Suivez la progression sur l'interface."
        })
    
    except Exception as e:
        logger.error(f"Error in generate-podcast endpoint: {str(e)}")
        update_progress(0, 0, f"Erreur: {str(e)}")
        return jsonify({"error": str(e)}), 500

async def generate_podcast_background(scenario):
    """Generate a podcast in the background."""
    try:
        # Generate audio for each character
        characters = scenario.get('characters', [])
        total_characters = len(characters)
        update_progress(0, total_characters, f"Préparation du podcast avec {total_characters} personnages...")
        
        audio_segments = []
        podcast_filename = None
        
        for idx, character in enumerate(characters):
            character_name = character.get('name', 'Unknown')
            voice = character.get('voice', 'Kore')
            text = character.get('text', '')
            
            update_progress(idx, total_characters, f"Génération de l'audio pour {character_name} ({idx+1}/{total_characters})...")
            
            if voice not in AVAILABLE_VOICES:
                logger.warning(f"Voice {voice} not available. Using default voice Kore for {character_name}.")
                voice = 'Kore'
            
            # Generate speech for this character
            try:
                audio_file = await generate_speech(text, voice)
                audio_segments.append(audio_file)
            except Exception as e:
                logger.error(f"Error generating speech for {character_name}: {str(e)}")
                update_progress(0, 0, f"Erreur lors de la génération pour {character_name}: {str(e)}")
                return
        
        update_progress(total_characters, total_characters, "Assemblage des segments audio...")
        
        # Combine all audio segments into one file
        combined = AudioSegment.empty()
        
        for audio_file in audio_segments:
            segment = AudioSegment.from_wav(audio_file)
            combined += segment
            # Add a short silence between segments (500ms)
            combined += AudioSegment.silent(duration=500)
        
        # Export the combined audio
        with tempfile.NamedTemporaryFile(suffix=".wav", delete=False) as output_file:
            podcast_filename = output_file.name
            combined.export(podcast_filename, format="wav")
        
        update_progress(total_characters + 1, total_characters + 1, f"Podcast généré avec succès! audio:{os.path.basename(podcast_filename)}")
        
    except Exception as e:
        logger.error(f"Error in podcast background task: {str(e)}")
        update_progress(0, 0, f"Erreur: {str(e)}")

@app.route('/podcast-status')
def podcast_status():
    """Get the current status of the podcast generation."""
    global generation_progress
    
    # If status is complete and contains an audioUrl in the message, extract it
    if generation_progress["status"] == "complete" and "audio:" in generation_progress["message"]:
        message_parts = generation_progress["message"].split("audio:")
        if len(message_parts) > 1:
            audio_filename = message_parts[1].strip()
            return jsonify({
                "status": "complete",
                "message": message_parts[0].strip(),
                "audioUrl": f"/audio/{audio_filename}"
            })
    
    # Otherwise just return the current progress
    return jsonify(generation_progress)

@app.route('/generation-progress')
def get_generation_progress():
    """Get the current progress of podcast generation."""
    return jsonify(generation_progress)

@app.route('/download/<filename>')
def download_audio(filename):
    """Download the generated audio file."""
    try:
        temp_dir = tempfile.gettempdir()
        file_path = os.path.join(temp_dir, filename)
        
        if not os.path.exists(file_path):
            return jsonify({"error": "Audio file not found"}), 404
        
        # Check if this is a podcast or simple speech
        download_name = "gemini_podcast.wav"
        
        return send_file(file_path, mimetype="audio/wav", as_attachment=True, 
                         download_name=download_name)
    
    except Exception as e:
        logger.error(f"Error downloading audio file: {str(e)}")
        return jsonify({"error": str(e)}), 500