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, Timer
import re

app = Flask(__name__)

class CustomFormatter(logging.Formatter):
    def format(self, record):
        log_data = {
            "timestamp": self.formatTime(record, self.datefmt),
            "level": record.levelname,
            "message": self.remove_ansi_escape(record.getMessage()),
        }
        if hasattr(record, 'event_type'):
            log_data['event_type'] = record.event_type
        if hasattr(record, 'data'):
            log_data['data'] = record.data
        return json.dumps(log_data, ensure_ascii=False, indent=2)

    def remove_ansi_escape(self, text):
        ansi_escape = re.compile(r'\x1B(?:[@-Z\\-_]|\[[0-?]*[ -/]*[@-~])')
        return ansi_escape.sub('', text)

def setup_logging():
    logger = logging.getLogger()
    logger.setLevel(logging.INFO)
    handler = logging.StreamHandler()
    handler.setFormatter(CustomFormatter())
    logger.addHandler(handler)

logger = logging.getLogger(__name__)

API_KEY = os.environ.get('PPLX_KEY')
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=False, engineio_logger=False)

connect_opts = {
    'transports': ['websocket', 'polling'],
}

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()
    logger.info(f"Request logged", extra={
        'event_type': 'request_log',
        'data': {
            'ip': ip,
            'route': route,
            'status': status,
            'timestamp': timestamp
        }
    })

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):
    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):
    if re.search(r'[^\x00-\x7F]', text):
        return len(text)
    else:
        tokens = text.split()
        return len(tokens)

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

def calculate_timeout(input_tokens):
    base_timeout = 30
    additional_time = min(max(input_tokens // 100 * 5, 0), 270)
    return base_timeout + additional_time

@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 (optional, defaults to false)",
                    "model": "Model to be used (optional, defaults to claude-3-5-sonnet-20240620)"
                }
            }
        }
    })

@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-3-5-sonnet-20240620')
        stream = json_body.get('stream', False)

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

        msg_id = str(uuid.uuid4())
        response_event = Event()
        timeout_event = Event()
        response_text = []
        total_output_tokens = 0

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

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

        def generate():
            nonlocal total_output_tokens

            def send_event(event_type, data):
                event = create_event(event_type, data)
                logger.info(f"Sending {event_type} event", extra={
                    'event_type': event_type,
                    'data': {'content': event}
                })
                yield event

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

            def on_query_progress(data):
                nonlocal total_output_tokens, 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)
                        chunk_tokens = calculate_tokens(chunk)
                        total_output_tokens += chunk_tokens
                        logger.info("Received chunk", extra={
                            'event_type': 'chunk_received',
                            'data': {
                                'chunk': chunk,
                                'tokens': chunk_tokens,
                                'total_tokens': total_output_tokens
                            }
                        })

                if data.get('final', False):
                    logger.info("Final response received", extra={
                        'event_type': 'response_complete',
                        'data': {
                            'total_tokens': total_output_tokens
                        }
                    })
                    response_event.set()

            def on_connect():
                logger.info("Connected to Perplexity AI", extra={'event_type': 'connection_established'})
                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))
                logger.info("Sent query to Perplexity AI", extra={
                    'event_type': 'query_sent',
                    'data': {
                        'message': previous_messages[:100] + '...' if len(previous_messages) > 100 else previous_messages
                    }
                })

            sio.on('connect', on_connect)
            sio.on('query_progress', on_query_progress)

            def timeout_handler():
                logger.warning("Request timed out", extra={
                    'event_type': 'request_timeout',
                    'data': {
                        'input_tokens': input_tokens,
                        'timeout': timeout
                    }
                })
                timeout_event.set()
                response_event.set()

            timer = Timer(timeout, timeout_handler)
            timer.start()

            try:
                sio.connect('wss://www.perplexity.ai/', **connect_opts, headers=sio_opts['extraHeaders'])
                
                while not response_event.is_set() and not timeout_event.is_set():
                    sio.sleep(0.1)
                    while response_text:
                        chunk = response_text.pop(0)
                        yield from send_event("content_block_delta", {
                            "type": "content_block_delta",
                            "index": 0,
                            "delta": {"type": "text_delta", "text": chunk},
                        })
                
                if timeout_event.is_set():
                    yield from send_event("content_block_delta", {
                        "type": "content_block_delta",
                        "index": 0,
                        "delta": {"type": "text_delta", "text": "Request timed out"},
                    })
                
            except Exception as e:
                logger.error(f"Error during socket connection: {str(e)}", exc_info=True)
                yield from send_event("content_block_delta", {
                    "type": "content_block_delta",
                    "index": 0,
                    "delta": {"type": "text_delta", "text": f"Error during socket connection: {str(e)}"},
                })
            finally:
                timer.cancel()
                if sio.connected:
                    sio.disconnect()

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

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

    except Exception as e:
        logger.error(f"Request error: {str(e)}", exc_info=True)
        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, timeout):
    try:
        response_event = Event()
        response_text = []
        total_output_tokens = 0

        def on_query_progress(data):
            nonlocal total_output_tokens, 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)
                    chunk_tokens = calculate_tokens(chunk)
                    total_output_tokens += chunk_tokens

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

        def on_connect():
            logger.info("Connected to Perplexity AI (non-stream)", extra={'event_type': 'connection_established_non_stream'})
            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))

        sio.on('connect', on_connect)
        sio.on('query_progress', on_query_progress)

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

        if not response_text:
            logger.warning("No response received (non-stream)", extra={
                'event_type': 'no_response_non_stream',
                'data': {
                    'input_tokens': input_tokens,
                    'timeout': timeout
                }
            })
            return jsonify({"error": "No response received"}), 504

        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": total_output_tokens,
            },
        }
        logger.info("Sending non-stream response", extra={
            'event_type': 'non_stream_response',
            'data': {'content': full_response}
        })
        return Response(json.dumps(full_response, ensure_ascii=False), content_type='application/json')

    except Exception as e:
        logger.error(f"Error during non-stream socket connection: {str(e)}", exc_info=True)
        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):
    logger.error(f"Server error: {str(error)}", exc_info=True)
    log_request(request.remote_addr, request.path, 500)
    return "Something broke!", 500

if __name__ == '__main__':
    setup_logging()
    port = int(os.environ.get('PORT', 8081))
    logger.info(f"Perplexity proxy starting", extra={
        'event_type': 'server_start',
        'data': {'port': port}
    })
    if not API_KEY:
        logger.warning("PPLX_KEY environment variable is not set", extra={'event_type': 'config_warning'})
    app.run(host='0.0.0.0', port=port)