# -*- coding: utf-8 -*-
"""
    proxy.py
    ~~~~~~~~
    ⚡⚡⚡ Fast, Lightweight, Pluggable, TLS interception capable proxy server focused on
    Network monitoring, controls & Application development, testing, debugging.

    :copyright: (c) 2013-present by Abhinav Singh and contributors.
    :license: BSD, see LICENSE for more details.
"""
import time
from typing import Any, Optional

from proxy.proxy import Proxy
from proxy.common.utils import build_http_response
from proxy.http.codes import httpStatusCodes
from proxy.http.parser import httpParserStates
from proxy.http.methods import httpMethods
from proxy.core.acceptor import AcceptorPool
from proxy.core.base import BaseTcpTunnelHandler


class HttpsConnectTunnelHandler(BaseTcpTunnelHandler):
    """A https CONNECT tunnel."""

    PROXY_TUNNEL_ESTABLISHED_RESPONSE_PKT = memoryview(build_http_response(
        httpStatusCodes.OK,
        reason=b'Connection established'
    ))

    PROXY_TUNNEL_UNSUPPORTED_SCHEME = memoryview(build_http_response(
        httpStatusCodes.BAD_REQUEST,
        headers={b'Connection': b'close'},
        reason=b'Unsupported protocol scheme'
    ))

    def __init__(self, *args: Any, **kwargs: Any) -> None:
        super().__init__(*args, **kwargs)

    def handle_data(self, data: memoryview) -> Optional[bool]:
        # Queue for upstream if connection has been established
        if self.upstream and self.upstream._conn is not None:
            self.upstream.queue(data)
            return None

        # Parse client request
        self.request.parse(data)

        # Drop the request if not a CONNECT request
        if self.request.method != httpMethods.CONNECT:
            self.client.queue(
                HttpsConnectTunnelHandler.PROXY_TUNNEL_UNSUPPORTED_SCHEME)
            return True

        # CONNECT requests are short and we need not worry about
        # receiving partial request bodies here.
        assert self.request.state == httpParserStates.COMPLETE

        # Establish connection with upstream
        self.connect_upstream()

        # Queue tunnel established response to client
        self.client.queue(
            HttpsConnectTunnelHandler.PROXY_TUNNEL_ESTABLISHED_RESPONSE_PKT)

        return None


def main() -> None:
    # This example requires `threadless=True`
    pool = AcceptorPool(
        flags=Proxy.initialize(port=12345, num_workers=1, threadless=True),
        work_klass=HttpsConnectTunnelHandler)
    try:
        pool.setup()
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        pass
    finally:
        pool.shutdown()


if __name__ == '__main__':
    main()