app.py

import os
import json
import uuid
from datetime import datetime
from flask import Flask, request, Response, jsonify
import socketio
import requests
import logging
from threading import Event
import re

# 创建 Flask 应用
app = Flask(__name__)

# 自定义日志格式
log_format = "%(asctime)s - %(levelname)s - %(name)s - %(message)s"
logging.basicConfig(level=logging.INFO, format=log_format)

# 创建不同的日志记录器
app_logger = logging.getLogger('app')
sio_logger = logging.getLogger('socketio.client')
engineio_logger = logging.getLogger('engineio.client')

# 调整日志级别，隐藏过多的调试信息
sio_logger.setLevel(logging.WARNING)
engineio_logger.setLevel(logging.WARNING)

# 从环境变量中获取 API 密钥
API_KEY = os.environ.get('PPLX_KEY')

# 代理设置
proxy_url = os.environ.get('PROXY_URL')
if proxy_url:
    proxies = {
        'http': proxy_url,
        'https': proxy_url
    }
    transport = requests.Session()
    transport.proxies.update(proxies)
else:
    transport = None

sio = socketio.Client(http_session=transport, logger=sio_logger, engineio_logger=engineio_logger)

# 连接选项
connect_opts = {
    'transports': ['websocket', 'polling'],  # 允许回退到轮询
}

# 其他选项
sio_opts = {
    'extraHeaders': {
        'Cookie': os.environ.get('PPLX_COOKIE'),
        'User-Agent': os.environ.get('USER_AGENT'),
        'Accept': '*/*',
        'priority': 'u=1, i',
        'Referer': 'https://www.perplexity.ai/',
    }
}

def log_request(ip, route, status):
    timestamp = datetime.now().isoformat()
    app_logger.info(f"{timestamp} - {ip} - {route} - {status}")

def validate_api_key():
    api_key = request.headers.get('x-api-key')
    if api_key != API_KEY:
        log_request(request.remote_addr, request.path, 401)
        return jsonify({"error": "Invalid API key"}), 401
    return None

def normalize_content(content):
    """
    递归处理 msg['content']，确保其为字符串。
    如果 content 是字典或列表，将其转换为字符串。
    """
    if isinstance(content, str):
        return content
    elif isinstance(content, dict):
        return json.dumps(content, ensure_ascii=False)
    elif isinstance(content, list):
        return " ".join([normalize_content(item) for item in content])
    else:
        return ""

def calculate_tokens(text):
    """
    改进的 token 计算方法。
    - 对于英文和有空格的文本，使用空格分词。
    - 对于中文等没有空格的文本，使用字符级分词。
    """
    if re.search(r'[^\x00-\x7F]', text):
        return len(text)
    else:
        tokens = text.split()
        return len(tokens)

@app.route('/')
def root():
    log_request(request.remote_addr, request.path, 200)
    return jsonify({
        "message": "Welcome to the Perplexity AI Proxy API",
        "endpoints": {
            "/ai/v1/messages": {
                "method": "POST",
                "description": "Send a message to the AI",
                "headers": {
                    "x-api-key": "Your API key (required)",
                    "Content-Type": "application/json"
                },
                "body": {
                    "messages": "Array of message objects",
                    "stream": "Boolean (true for streaming response)",
                    "model": "Model to be used (optional, defaults to claude-3-opus-20240229)"
                }
            }
        }
    })

@app.route('/ai/v1/messages', methods=['POST'])
def messages():
    auth_error = validate_api_key()
    if auth_error:
        return auth_error

    try:
        json_body = request.json
        model = json_body.get('model', 'claude-3-opus-20240229')
        stream = json_body.get('stream', True)

        previous_messages = "\n\n".join([normalize_content(msg['content']) for msg in json_body['messages']])
        input_tokens = calculate_tokens(previous_messages)

        msg_id = str(uuid.uuid4())
        response_event = Event()
        response_text = []

        if not stream:
            return handle_non_stream(previous_messages, msg_id, model, input_tokens)

        log_request(request.remote_addr, request.path, 200)

        def generate():
            yield create_event("message_start", {
                "type": "message_start",
                "message": {
                    "id": msg_id,
                    "type": "message",
                    "role": "assistant",
                    "content": [],
                    "model": model,
                    "stop_reason": None,
                    "stop_sequence": None,
                    "usage": {"input_tokens": input_tokens, "output_tokens": 1},
                },
            })
            yield create_event("content_block_start", {"type": "content_block_start", "index": 0, "content_block": {"type": "text", "text": ""}})
            yield create_event("ping", {"type": "ping"})

            def on_connect():
                app_logger.info("Connected to Perplexity AI")
                emit_data = {
                    "version": "2.9",
                    "source": "default",
                    "attachments": [],
                    "language": "en-GB",
                    "timezone": "Europe/London",
                    "mode": "concise",
                    "is_related_query": False,
                    "is_default_related_query": False,
                    "visitor_id": str(uuid.uuid4()),
                    "frontend_context_uuid": str(uuid.uuid4()),
                    "prompt_source": "user",
                    "query_source": "home"
                }
                sio.emit('perplexity_ask', (previous_messages, emit_data))

            def on_query_progress(data):
                nonlocal response_text
                if 'text' in data:
                    text = json.loads(data['text'])
                    chunk = text['chunks'][-1] if text['chunks'] else None
                    if chunk:
                        response_text.append(chunk)

                if data.get('final', False):
                    response_event.set()

            def on_disconnect():
                app_logger.info("Disconnected from Perplexity AI")
                response_event.set()

            def on_connect_error(data):
                app_logger.error(f"Connection error: {data}")
                response_text.append(f"Error connecting to Perplexity AI: {data}")
                response_event.set()

            sio.on('connect', on_connect)
            sio.on('query_progress', on_query_progress)
            sio.on('disconnect', on_disconnect)
            sio.on('connect_error', on_connect_error)

            try:
                sio.connect('wss://www.perplexity.ai/', **connect_opts, headers=sio_opts['extraHeaders'])
                
                while not response_event.is_set():
                    sio.sleep(0.1)
                    while response_text:
                        chunk = response_text.pop(0)
                        # 记录每一块返回的内容
                        app_logger.info(f"Returning chunk to client: {chunk}")
                        yield create_event("content_block_delta", {
                            "type": "content_block_delta",
                            "index": 0,
                            "delta": {"type": "text_delta", "text": chunk},
                        })
                
            except Exception as e:
                app_logger.error(f"Error during socket connection: {str(e)}")
                yield create_event("content_block_delta", {
                    "type": "content_block_delta",
                    "index": 0,
                    "delta": {"type": "text_delta", "text": f"Error during socket connection: {str(e)}"},
                })
            finally:
                if sio.connected:
                    sio.disconnect()

            output_tokens = calculate_tokens(''.join(response_text))

            yield create_event("content_block_stop", {"type": "content_block_stop", "index": 0})
            yield create_event("message_delta", {
                "type": "message_delta",
                "delta": {"stop_reason": "end_turn", "stop_sequence": None},
                "usage": {"input_tokens": input_tokens, "output_tokens": output_tokens},
            })
            yield create_event("message_stop", {"type": "message_stop"})

        return Response(generate(), content_type='text/event-stream')

    except Exception as e:
        app_logger.error(f"Request error: {str(e)}")
        log_request(request.remote_addr, request.path, 400)
        return jsonify({"error": str(e)}), 400

def handle_non_stream(previous_messages, msg_id, model, input_tokens):
    try:
        response_event = Event()
        response_text = []

        def on_connect():
            app_logger.info("Connected to Perplexity AI")
            emit_data = {
                "version": "2.9",
                "source": "default",
                "attachments": [],
                "language": "en-GB",
                "timezone": "Europe/London",
                "mode": "concise",
                "is_related_query": False,
                "is_default_related_query": False,
                "visitor_id": str(uuid.uuid4()),
                "frontend_context_uuid": str(uuid.uuid4()),
                "prompt_source": "user",
                "query_source": "home"
            }
            sio.emit('perplexity_ask', (previous_messages, emit_data))

        def on_query_progress(data):
            nonlocal response_text
            if 'text' in data:
                text = json.loads(data['text'])
                chunk = text['chunks'][-1] if text['chunks'] else None
                if chunk:
                    response_text.append(chunk)

            if data.get('final', False):
                response_event.set()

        def on_disconnect():
            app_logger.info("Disconnected from Perplexity AI")
            response_event.set()

        def on_connect_error(data):
            app_logger.error(f"Connection error: {data}")
            response_text.append(f"Error connecting to Perplexity AI: {data}")
            response_event.set()

        sio.on('connect', on_connect)
        sio.on('query_progress', on_query_progress)
        sio.on('disconnect', on_disconnect)
        sio.on('connect_error', on_connect_error)

        sio.connect('wss://www.perplexity.ai/', **connect_opts, headers=sio_opts['extraHeaders'])
        
        response_event.wait(timeout=30)
        output_tokens = calculate_tokens(''.join(response_text))

        full_response = {
            "content": [{"text": ''.join(response_text), "type": "text"}],
            "id": msg_id,
            "model": model,
            "role": "assistant",
            "stop_reason": "end_turn",
            "stop_sequence": None,
            "type": "message",
            "usage": {
                "input_tokens": input_tokens,
                "output_tokens": output_tokens,
            },
        }
        
        # 记录完整的响应内容
        app_logger.info(f"Returning full response to client: {full_response}")
        return Response(json.dumps(full_response, ensure_ascii=False), content_type='application/json')

    except Exception as e:
        app_logger.error(f"Error during socket connection: {str(e)}")
        return jsonify({"error": str(e)}), 500
    finally:
        if sio.connected:
            sio.disconnect()

@app.errorhandler(404)
def not_found(error):
    log_request(request.remote_addr, request.path, 404)
    return "Not Found", 404

@app.errorhandler(500)
def server_error(error):
    app_logger.error(f"Server error: {str(error)}")
    log_request(request.remote_addr, request.path, 500)
    return "Something broke!", 500

def create_event(event, data):
    if isinstance(data, dict):
        data = json.dumps(data, ensure_ascii=False)
    return f"event: {event}\ndata: {data}\n\n"

if __name__ == '__main__':
    port = int(os.environ.get('PORT', 8081))
    app_logger.info(f"Perplexity proxy listening on port {port}")
    if not API_KEY:
        app_logger.warning("Warning: PPLX_KEY environment variable is not set. API key validation will fail.")
    app.run(host='0.0.0.0', port=port)