from flask import Flask, request, send_file
from pydub import AudioSegment
from io import BytesIO
import requests
import zipfile

app = Flask(__name__)

def process_audio(segments):
    track_1 = AudioSegment.empty()
    track_2 = AudioSegment.empty()
    full_mix = AudioSegment.empty()
    crossfade = 100
    cursor = 0

    print(f"Traitement de {len(segments)} segments...")

    for i, seg in enumerate(segments):
        try:
            r = requests.get(seg['url'])
            audio_data = BytesIO(r.content)
            chunk = AudioSegment.from_file(audio_data, format="mp3")
        except Exception as e:
            print(f"Erreur téléchargement segment {i}: {e}")
            continue

        duration = len(chunk)

        if i > 0: cursor -= crossfade

        # Track 1
        gap_1 = cursor - len(track_1)
        if gap_1 > 0: track_1 += AudioSegment.silent(duration=gap_1)
        if str(seg['person']) == "1": track_1 += chunk

        # Track 2
        gap_2 = cursor - len(track_2)
        if gap_2 > 0: track_2 += AudioSegment.silent(duration=gap_2)
        if str(seg['person']) == "2": track_2 += chunk

        # Mix
        if i == 0: full_mix += chunk
        else: full_mix = full_mix.append(chunk, crossfade=crossfade)

        cursor += duration

    final_len = len(full_mix)
    if len(track_1) < final_len: track_1 += AudioSegment.silent(duration=final_len - len(track_1))
    if len(track_2) < final_len: track_2 += AudioSegment.silent(duration=final_len - len(track_2))

    memory_file = BytesIO()
    with zipfile.ZipFile(memory_file, 'w') as zf:
        for name, audio in [("speaker_1.mp3", track_1), ("speaker_2.mp3", track_2), ("mix.mp3", full_mix)]:
            buf = BytesIO()
            audio.export(buf, format="mp3")
            zf.writestr(name, buf.getvalue())
    
    memory_file.seek(0)
    return memory_file

@app.route('/')
def home():
    return "PodGen API is running! Send POST requests to /generate"

@app.route('/generate', methods=['POST'])
def generate():
    data = request.json
    segments = data.get('segments', [])
    if not segments: return {"error": "No segments provided"}, 400
    try:
        zip_buffer = process_audio(segments)
        return send_file(zip_buffer, mimetype='application/zip', as_attachment=True, download_name='podcast_pack.zip')
    except Exception as e:
        return {"error": str(e)}, 500

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=7860)