from flask import Flask, request, jsonify, send_file
import requests
import os
import uuid
from pathlib import Path
import threading
import time

from pydub import AudioSegment

def audio_overlay(audio1, audio2, save_filename):
    audio_raw1 = AudioSegment.from_file(audio1)
    audio_raw2 = AudioSegment.from_file(audio2)

    min_length = min(len(audio_raw1), len(audio_raw2))
    audio_raw1 = audio_raw1[:min_length]
    audio_raw2 = audio_raw2[:min_length]

    overlayed_audio = audio_raw1.overlay(audio_raw2)
    save_path = os.path.join("/tmp", save_filename)
    overlayed_audio.export(save_path, format="mp3")

# 任务队列和状态存储
tasks = {}
running_threads = 0
condition = threading.Condition()

def process_audio_overlay(task_id, audio_url1, audio_url2):
    global running_threads
    with condition:
        while running_threads >= 1:
            tasks[task_id] = {"status": "queue"}
            condition.wait()
        running_threads += 1
    tasks[task_id] = {"status": "processing"}
    try:
        # 下载音频文件到本地
        response1 = requests.get(audio_url1)
        if response1.status_code != 200:
            raise Exception("无效的 URL")
        audio_filename1 = audio_url1.split('/')[-1]
        with open("/tmp/" + audio_filename1, 'wb') as f:
            f.write(response1.content)
        response2 = requests.get(audio_url2)
        if response2.status_code != 200:
            raise Exception("无效的 URL")
        audio_filename2 = audio_url2.split('/')[-1]
        with open("/tmp/" + audio_filename2, 'wb') as f:
            f.write(response2.content)

        # 执行音频合并操作
        audio = audio_overlay("/tmp/" + audio_filename1, "/tmp/" + audio_filename2, os.path.join("/tmp", audio_filename1 + "_with_" + audio_filename2 + "_overlayed.mp3"))

        # 提供文件的永久直链
        result_audio_url = "/download/" + audio_filename1 + "_with_" + audio_filename2 + "_overlayed.mp3"

        # 更新任务状态
        tasks[task_id] = {
            "status": "completed",
            "result_url": result_audio_url
        }
    except Exception as e:
        tasks[task_id] = {
            "status": "error",
            "message": str(e)
        }
    with condition:
            running_threads -= 1
            condition.notify_all()

app = Flask(__name__)

@app.route('/', methods=['GET'])
def hello():
    return "Hello! This is an api server, and it is running successfully. For usage, please contact the person who hosted this api server."

@app.route('/api/audio_overlay', methods=['GET'])
def audio_separation():
    audio_url1 = request.args.get('url1')
    if not audio_url1:
        return jsonify({"error": "URL1 parameter is required"}), 400
    audio_url2 = request.args.get('url2')
    if not audio_url2:
        return jsonify({"error": "URL2 parameter is required"}), 400

    task_id = str(uuid.uuid4())
    tasks[task_id] = {"status": "processing"}

    # 异步执行任务
    threading.Thread(target=process_audio_overlay, args=(task_id, audio_url1, audio_url2)).start()

    return jsonify({"task_id": task_id}), 202

@app.route('/api/tasks/<task_id>', methods=['GET'])
def get_task_status(task_id):
    task = tasks.get(task_id)
    if task:
        return jsonify(task)
    else:
        return jsonify({"error": "Task not found"}), 404

@app.route('/download/<filename>', methods=['GET'])
def download(filename):
    return send_file("/tmp/" + filename, as_attachment=True)

if __name__ == '__main__':
    app.run(debug=False)