# Licensed under a 3-clause BSD style license - see LICENSE.rst


import sys
import traceback
import warnings
import socketserver
import xmlrpc.client as xmlrpc
from xmlrpc.server import SimpleXMLRPCRequestHandler, SimpleXMLRPCServer

from .constants import SAMP_ICON
from .errors import SAMPWarning

__all__ = []


class SAMPSimpleXMLRPCRequestHandler(SimpleXMLRPCRequestHandler):
    """
    XMLRPC handler of Standard Profile requests.
    """

    def do_GET(self):

        if self.path == '/samp/icon':
            self.send_response(200, 'OK')
            self.send_header('Content-Type', 'image/png')
            self.end_headers()
            self.wfile.write(SAMP_ICON)

    def do_POST(self):
        """
        Handles the HTTP POST request.

        Attempts to interpret all HTTP POST requests as XML-RPC calls,
        which are forwarded to the server's ``_dispatch`` method for
        handling.
        """

        # Check that the path is legal
        if not self.is_rpc_path_valid():
            self.report_404()
            return

        try:
            # Get arguments by reading body of request.
            # We read this in chunks to avoid straining
            # socket.read(); around the 10 or 15Mb mark, some platforms
            # begin to have problems (bug #792570).
            max_chunk_size = 10 * 1024 * 1024
            size_remaining = int(self.headers["content-length"])
            L = []
            while size_remaining:
                chunk_size = min(size_remaining, max_chunk_size)
                L.append(self.rfile.read(chunk_size))
                size_remaining -= len(L[-1])
            data = b''.join(L)

            params, method = xmlrpc.loads(data)

            if method == "samp.webhub.register":
                params = list(params)
                params.append(self.client_address)
                if 'Origin' in self.headers:
                    params.append(self.headers.get('Origin'))
                else:
                    params.append('unknown')
                params = tuple(params)
                data = xmlrpc.dumps(params, methodname=method)

            elif method in ('samp.hub.notify', 'samp.hub.notifyAll',
                            'samp.hub.call', 'samp.hub.callAll',
                            'samp.hub.callAndWait'):

                user = "unknown"

                if method == 'samp.hub.callAndWait':
                    params[2]["host"] = self.address_string()
                    params[2]["user"] = user
                else:
                    params[-1]["host"] = self.address_string()
                    params[-1]["user"] = user

                data = xmlrpc.dumps(params, methodname=method)

            data = self.decode_request_content(data)
            if data is None:
                return  # response has been sent

            # In previous versions of SimpleXMLRPCServer, _dispatch
            # could be overridden in this class, instead of in
            # SimpleXMLRPCDispatcher. To maintain backwards compatibility,
            # check to see if a subclass implements _dispatch and dispatch
            # using that method if present.
            response = self.server._marshaled_dispatch(
                data, getattr(self, '_dispatch', None), self.path
            )
        except Exception as e:
            # This should only happen if the module is buggy
            # internal error, report as HTTP server error
            self.send_response(500)

            # Send information about the exception if requested
            if hasattr(self.server, '_send_traceback_header') and \
               self.server._send_traceback_header:
                self.send_header("X-exception", str(e))
                trace = traceback.format_exc()
                trace = str(trace.encode('ASCII', 'backslashreplace'), 'ASCII')
                self.send_header("X-traceback", trace)

            self.send_header("Content-length", "0")
            self.end_headers()
        else:
            # got a valid XML RPC response
            self.send_response(200)
            self.send_header("Content-type", "text/xml")
            if self.encode_threshold is not None:
                if len(response) > self.encode_threshold:
                    q = self.accept_encodings().get("gzip", 0)
                    if q:
                        try:
                            response = xmlrpc.gzip_encode(response)
                            self.send_header("Content-Encoding", "gzip")
                        except NotImplementedError:
                            pass
            self.send_header("Content-length", str(len(response)))
            self.end_headers()
            self.wfile.write(response)


class ThreadingXMLRPCServer(socketserver.ThreadingMixIn, SimpleXMLRPCServer):
    """
    Asynchronous multithreaded XMLRPC server.
    """

    def __init__(self, addr, log=None,
                 requestHandler=SAMPSimpleXMLRPCRequestHandler,
                 logRequests=True, allow_none=True, encoding=None):
        self.log = log
        SimpleXMLRPCServer.__init__(self, addr, requestHandler,
                                    logRequests, allow_none, encoding)

    def handle_error(self, request, client_address):
        if self.log is None:
            socketserver.BaseServer.handle_error(self, request, client_address)
        else:
            warnings.warn("Exception happened during processing of request "
                          "from {}: {}".format(client_address, sys.exc_info()[1]),
                          SAMPWarning)
