"""
SOCKS5 → HTTP/HTTPS прокси туннель с поддержкой CONNECT метода.
"""

import asyncio
import socket
import logging
from typing import Optional, Dict
import traceback

from aiohttp import ClientSession, ClientTimeout
from aiohttp_socks import ProxyConnector

logger = logging.getLogger(__name__)


class Socks5ToHttpProxy:
    """
    Локальный HTTP/HTTPS → SOCKS5 прокси с поддержкой CONNECT.
    """
    
    def __init__(
        self,
        socks5_host: str,
        socks5_port: int,
        username: Optional[str] = None,
        password: Optional[str] = None
    ):
        self.socks5_host = socks5_host
        self.socks5_port = int(socks5_port)
        self.username = username
        self.password = password
        
        self._session: Optional[ClientSession] = None
        self._server = None
        self._port: Optional[int] = None
        self._active_connections = 0
        self._lock = asyncio.Lock()
    
    @property
    def local_url(self) -> str:
        return f"http://127.0.0.1:{self._port}"
    
    @property
    def proxy_config_for_browser(self) -> dict:
        return {'server': self.local_url}
    
    async def start(self) -> str:
        """Запускает прокси сервер."""
        self._port = self._find_free_port()
        
        socks_url = self._build_socks5_url()
        connector = ProxyConnector.from_url(socks_url)
        timeout = ClientTimeout(total=30, connect=15)
        self._session = ClientSession(connector=connector, timeout=timeout)
        
        self._server = await asyncio.start_server(
            self._handle_client,
            '127.0.0.1',
            self._port
        )
        
        logger.info(f"🟢 SOCKS5: {self.local_url}")
        return self.local_url
    
    async def stop(self):
        """Останавливает прокси с таймаутом."""
        logger.debug(f"Stopping proxy 127.0.0.1:{self._port}")
        
        # Закрываем сервер (не принимать новые соединения)
        if self._server:
            self._server.close()
        
        # Ждем завершения активных соединений с таймаутом
        try:
            async with asyncio.timeout(5):  # Максимум 5 секунд на завершение
                while self._active_connections > 0:
                    await asyncio.sleep(0.1)
        except asyncio.TimeoutError:
            logger.warning(f"Force stopping proxy with {self._active_connections} active connections")
        
        # Закрываем сервер принудительно
        if self._server:
            try:
                await asyncio.wait_for(self._server.wait_closed(), timeout=3)
            except asyncio.TimeoutError:
                logger.warning("Server close timeout")
            self._server = None
        
        # Закрываем сессию
        if self._session:
            try:
                await asyncio.wait_for(self._session.close(), timeout=3)
            except asyncio.TimeoutError:
                pass
            self._session = None
        
        logger.debug(f"Proxy stopped: 127.0.0.1:{self._port}")
    
    def _find_free_port(self) -> int:
        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
            s.bind(('127.0.0.1', 0))
            return s.getsockname()[1]
    
    def _build_socks5_url(self) -> str:
        if self.username and self.password:
            return f"socks5://{self.username}:{self.password}@{self.socks5_host}:{self.socks5_port}"
        return f"socks5://{self.socks5_host}:{self.socks5_port}"
    
    async def _handle_client(
        self, 
        reader: asyncio.StreamReader, 
        writer: asyncio.StreamWriter
    ):
        """Обрабатывает входящее подключение."""
        async with self._lock:
            self._active_connections += 1
        
        try:
            # Таймаут на чтение первого запроса
            request_line = await asyncio.wait_for(
                reader.readline(), 
                timeout=10
            )
            
            if not request_line:
                return
            
            request_text = request_line.decode('utf-8', errors='ignore').strip()
            
            if request_text.upper().startswith('CONNECT'):
                await self._handle_connect(request_text, reader, writer)
            else:
                await self._handle_http(request_line, reader, writer)
                
        except asyncio.TimeoutError:
            logger.debug("Client timeout")
        except ConnectionResetError:
            logger.debug("Connection reset by client")
        except Exception as e:
            if "Server disconnected" not in str(e):
                logger.error(f"Client error: {e}")
        finally:
            async with self._lock:
                self._active_connections -= 1
            
            try:
                writer.close()
            except Exception:
                pass
    
    async def _handle_connect(
        self,
        request_line: str,
        reader: asyncio.StreamReader,
        writer: asyncio.StreamWriter
    ):
        """Обрабатывает CONNECT запрос."""
        import socks
        remote_socket = None
        
        try:
            parts = request_line.split()
            if len(parts) < 2:
                writer.write(b'HTTP/1.1 400 Bad Request\r\n\r\n')
                return
            
            target = parts[1]
            if ':' in target:
                host, port = target.rsplit(':', 1)
                port = int(port)
            else:
                host = target
                port = 443
            
            # Пропускаем заголовки (с таймаутом)
            while True:
                line = await asyncio.wait_for(reader.readline(), timeout=5)
                if not line or line in [b'\r\n', b'\n']:
                    break
            
            # Создаем SOCKS5 соединение
            remote_socket = socks.socksocket()
            remote_socket.settimeout(15)

            if self.username:
                logger.debug(f"SOCKS5 connect {host}:{port} via {self.socks5_host} auth=yes user={self.username[:4]}***")
                remote_socket.set_proxy(
                    socks.SOCKS5, self.socks5_host, self.socks5_port,
                    username=self.username, password=self.password
                )
            else:
                logger.warning(f"SOCKS5 connect {host}:{port} via {self.socks5_host} auth=NO — credentials missing!")
                remote_socket.set_proxy(
                    socks.SOCKS5, self.socks5_host, self.socks5_port
                )
            
            # Подключаемся (в отдельном потоке чтобы не блокировать)
            loop = asyncio.get_running_loop()
            await loop.run_in_executor(None, remote_socket.connect, (host, port))
            
            # Отвечаем клиенту
            writer.write(b'HTTP/1.1 200 Connection Established\r\n\r\n')
            await writer.drain()
            
            # Пересылка данных с таймаутом
            await asyncio.wait_for(
                self._relay(reader, writer, remote_socket),
                timeout=60
            )
            
        except asyncio.TimeoutError:
            logger.debug("CONNECT timeout")
        except Exception as e:
            logger.debug(f"CONNECT error: {e}")
        finally:
            if remote_socket:
                try:
                    remote_socket.close()
                except Exception:
                    pass
    
    async def _relay(
        self,
        client_reader: asyncio.StreamReader,
        client_writer: asyncio.StreamWriter,
        remote_socket
    ):
        """Двунаправленная пересылка данных."""
        loop = asyncio.get_running_loop()
        running = True
        
        async def client_to_remote():
            try:
                while running:
                    data = await asyncio.wait_for(client_reader.read(8192), timeout=30)
                    if not data:
                        break
                    await loop.sock_sendall(remote_socket, data)
            except Exception:
                pass
        
        async def remote_to_client():
            try:
                while running:
                    data = await loop.sock_recv(remote_socket, 8192)
                    if not data:
                        break
                    client_writer.write(data)
                    await client_writer.drain()
            except Exception:
                pass
        
        try:
            await asyncio.gather(client_to_remote(), remote_to_client())
        except Exception:
            pass
        finally:
            running = False
    
    async def _handle_http(
        self,
        request_line: bytes,
        reader: asyncio.StreamReader,
        writer: asyncio.StreamWriter
    ):
        """Обрабатывает HTTP запрос."""
        try:
            first_line = request_line.decode('utf-8', errors='ignore').strip()
            parts = first_line.split()
            
            if len(parts) < 2:
                return
            
            method = parts[0]
            path = parts[1]
            
            # Читаем заголовки
            headers = {}
            while True:
                line = await asyncio.wait_for(reader.readline(), timeout=5)
                if not line or line in [b'\r\n', b'\n']:
                    break
                
                decoded = line.decode('utf-8', errors='ignore').strip()
                if ':' in decoded:
                    key, value = decoded.split(':', 1)
                    headers[key.strip()] = value.strip()
            
            # Тело запроса
            body = b''
            content_length = int(headers.get('Content-Length', 0))
            if content_length > 0:
                body = await reader.readexactly(content_length)
            
            host = headers.get('Host', 'localhost')
            url = f"http://{host}{path}"
            
            headers.pop('Proxy-Connection', None)
            
            # Проксируем
            async with self._session.request(
                method=method, url=url,
                headers=headers, data=body if body else None,
                allow_redirects=True
            ) as response:
                
                response_body = await response.read()
                
                status_line = f"HTTP/1.1 {response.status} {response.reason}\r\n"
                response_text = status_line
                
                for key, value in response.headers.items():
                    if key.lower() != 'transfer-encoding':
                        response_text += f"{key}: {value}\r\n"
                response_text += f"Content-Length: {len(response_body)}\r\n\r\n"
                
                writer.write(response_text.encode() + response_body)
                await writer.drain()
                
        except asyncio.TimeoutError:
            pass
        except Exception as e:
            if "Server disconnected" not in str(e):
                logger.debug(f"HTTP error: {e}")
                
class Socks5ProxyPool:
    """Пул SOCKS5→HTTP прокси."""
    
    def __init__(self, idle_timeout: int = 300):
        self._proxies: Dict[str, Socks5ToHttpProxy] = {}
        self._last_used: Dict[str, float] = {}
        self._lock = asyncio.Lock()
        self._idle_timeout = idle_timeout
        self._cleanup_task: Optional[asyncio.Task] = None
    
    async def get_proxy_config(self, socks5_proxy) -> dict:
        """Получает или создает конфигурацию HTTP прокси для SOCKS5."""
        key = socks5_proxy.id
        
        async with self._lock:
            if key not in self._proxies:
                proxy = Socks5ToHttpProxy(
                    socks5_host=socks5_proxy.ip,
                    socks5_port=int(socks5_proxy.port),
                    username=socks5_proxy.login,
                    password=socks5_proxy.password
                )
                await proxy.start()
                self._proxies[key] = proxy
            
            loop = asyncio.get_running_loop()
            self._last_used[key] = loop.time()
            return self._proxies[key].proxy_config_for_browser
    
    async def release(self, socks5_proxy):
        """Помечает прокси как неиспользуемый."""
        key = socks5_proxy.id
        async with self._lock:
            if key in self._last_used:
                self._last_used[key] = 0
    
    async def stop_all(self):
        """Останавливает все прокси с таймаутом."""
        if self._cleanup_task:
            self._cleanup_task.cancel()
        
        async with self._lock:
            proxies = list(self._proxies.values())
            self._proxies.clear()
            self._last_used.clear()
        
        for proxy in proxies:
            try:
                await asyncio.wait_for(proxy.stop(), timeout=3)
            except (asyncio.TimeoutError, Exception):
                pass
        
        logger.info("All SOCKS5 proxies stopped")
    
    @property
    def active_count(self) -> int:
        return len(self._proxies)