app.py

import os
import numpy as np
from flask import Flask, request, jsonify, send_file, send_from_directory
import google.generativeai as genai
from gtts import gTTS, lang
import tempfile
import soundfile as sf
from kokoro import KPipeline
from werkzeug.utils import secure_filename
from flask_cors import CORS

app = Flask(__name__, static_folder='static')
CORS(app)
app.config['MAX_CONTENT_LENGTH'] = 100 * 1024 * 1024  # 100MB limit

# Configure Gemini API
GEMINI_API_KEY = os.getenv("GEMINI_API_KEY")
if not GEMINI_API_KEY:
    raise ValueError("GEMINI_API_KEY environment variable not set")
genai.configure(api_key=GEMINI_API_KEY)

# Language configurations
KOKORO_LANGUAGES = {
    "American English": "a",
    "British English": "b",
    "Mandarin Chinese": "z",
    "Spanish": "e",
    "French": "f",
    "Hindi": "h",
    "Italian": "i",
    "Brazilian Portuguese": "p"
}

GTTS_LANGUAGES = lang.tts_langs()
GTTS_LANGUAGES['ja'] = 'Japanese'

SUPPORTED_LANGUAGES = sorted(
    list(set(list(KOKORO_LANGUAGES.keys()) + list(GTTS_LANGUAGES.values()))
)

MAX_FILE_SIZE = 50 * 1024 * 1024  # 50MB Gemini limit
CHUNK_SIZE = 20 * 1024 * 1024  # 20MB chunks

def process_large_audio(file_path):
    """Process large audio files in chunks"""
    try:
        file_size = os.path.getsize(file_path)
        if file_size <= MAX_FILE_SIZE:
            # Process small files normally
            uploaded_file = genai.upload_file(file_path)
            return [uploaded_file]
        
        # Split large files into chunks
        chunks = []
        with open(file_path, 'rb') as f:
            chunk_num = 0
            while chunk_data := f.read(CHUNK_SIZE):
                chunk_path = f"{file_path}_chunk_{chunk_num}"
                with open(chunk_path, 'wb') as chunk_file:
                    chunk_file.write(chunk_data)
                chunks.append(genai.upload_file(chunk_path))
                chunk_num += 1
        return chunks
    except Exception as e:
        raise RuntimeError(f"File processing failed: {str(e)}")

def cleanup_files(file_path, chunks):
    """Cleanup temporary files and uploaded chunks"""
    try:
        if os.path.exists(file_path):
            os.remove(file_path)
        for chunk in chunks:
            if os.path.exists(chunk.name):
                os.remove(chunk.name)
            chunk.delete()
    except Exception as e:
        app.logger.error(f"Cleanup error: {str(e)}")

@app.route('/translate', methods=['POST'])
def translate_audio():
    temp_path = None
    uploaded_chunks = []
    
    try:
        if 'audio' not in request.files:
            return jsonify({'error': 'No audio file uploaded'}), 400

        audio_file = request.files['audio']
        target_language = request.form.get('language', 'English')

        if not audio_file or audio_file.filename == '':
            return jsonify({'error': 'Invalid audio file'}), 400

        # Save to temp file
        temp_path = os.path.join(tempfile.gettempdir(), secure_filename(audio_file.filename))
        audio_file.save(temp_path)

        # Process file in chunks if needed
        uploaded_chunks = process_large_audio(temp_path)
        
        # Transcribe chunks
        model = genai.GenerativeModel("gemini-2.0-flash")
        transcripts = []
        
        for chunk in uploaded_chunks:
            response = model.generate_content(
                ["Transcribe this audio chunk verbatim. Respond only with the transcription:", chunk]
            )
            transcripts.append(response.text.strip())
            chunk.delete()

        transcription = " ".join(transcripts)

        # Translation
        prompt = f"Translate to {target_language} preserving meaning:\n\n{transcription}"
        response = model.generate_content(prompt)
        translated_text = response.text.strip()

        # TTS Generation
        if target_language in KOKORO_LANGUAGES:
            # Kokoro processing
            lang_code = KOKORO_LANGUAGES[target_language]
            pipeline = KPipeline(lang_code=lang_code)
            generator = pipeline(translated_text, voice="af_heart", speed=1)
            
            audio_segments = []
            for _, _, audio in generator:
                if audio is not None:
                    audio_segments.append(audio)
            
            if not audio_segments:
                raise ValueError("No audio generated by Kokoro")
            
            audio_data = np.concatenate(audio_segments)
            _, output_path = tempfile.mkstemp(suffix=".wav")
            sf.write(output_path, audio_data, 24000)
        else:
            # gTTS processing
            lang_code = next((k for k, v in GTTS_LANGUAGES.items() if v == target_language), 'en')
            tts = gTTS(translated_text, lang=lang_code)
            _, output_path = tempfile.mkstemp(suffix=".mp3")
            tts.save(output_path)

        return jsonify({
            'transcription': transcription,
            'translation': translated_text,
            'audio_url': f'/download/{os.path.basename(output_path)}'
        })

    except Exception as e:
        app.logger.error(f"Processing error: {str(e)}")
        return jsonify({'error': str(e)}), 500
    finally:
        cleanup_files(temp_path, uploaded_chunks)

@app.route('/download/<filename>')
def download_file(filename):
    try:
        return send_file(
            os.path.join(tempfile.gettempdir(), filename),
            mimetype="audio/mpeg",
            as_attachment=True,
            download_name=f"translated_{filename}"
        )
    except Exception as e:
        return jsonify({'error': str(e)}), 404

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000, debug=True)