Change things

maubot/plugin_server.py

@@ -0,0 +1,87 @@
+# maubot - A plugin-based Matrix bot system.
+# Copyright (C) 2018 Tulir Asokan
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+from typing import List, Callable, Awaitable
+from functools import partial
+
+from aiohttp import web, hdrs
+from yarl import URL
+
+Handler = Callable[[web.Request], Awaitable[web.Response]]
+Middleware = Callable[[web.Request, Handler], Awaitable[web.Response]]
+
+
+class PluginWebApp(web.UrlDispatcher):
+    def __init__(self):
+        super().__init__()
+        self._middleware: List[Middleware] = []
+
+    def add_middleware(self, middleware: Middleware) -> None:
+        self._middleware.append(middleware)
+
+    def remove_middleware(self, middleware: Middleware) -> None:
+        self._middleware.remove(middleware)
+
+    def clear(self) -> None:
+        self._resources = []
+        self._named_resources = {}
+        self._middleware = []
+
+    async def handle(self, request: web.Request) -> web.Response:
+        match_info = await self.resolve(request)
+        match_info.freeze()
+        resp = None
+        request._match_info = match_info
+        expect = request.headers.get(hdrs.EXPECT)
+        if expect:
+            resp = await match_info.expect_handler(request)
+            await request.writer.drain()
+        if resp is None:
+            handler = match_info.handler
+            for middleware in self._middleware:
+                handler = partial(middleware, handler=handler)
+            resp = await handler(request)
+        return resp
+
+
+class PrefixResource(web.Resource):
+    def __init__(self, prefix, *, name=None):
+        assert not prefix or prefix.startswith('/'), prefix
+        assert prefix in ('', '/') or not prefix.endswith('/'), prefix
+        super().__init__(name=name)
+        self._prefix = URL.build(path=prefix).raw_path
+
+    @property
+    def canonical(self):
+        return self._prefix
+
+    def get_info(self):
+        return {'path': self._prefix}
+
+    def url_for(self):
+        return URL.build(path=self._prefix, encoded=True)
+
+    def add_prefix(self, prefix):
+        assert prefix.startswith('/')
+        assert not prefix.endswith('/')
+        assert len(prefix) > 1
+        self._prefix = prefix + self._prefix
+
+    def _match(self, path: str) -> dict:
+        return {} if self.raw_match(path) else None
+
+    def raw_match(self, path: str) -> bool:
+        return path and path.startswith(self._prefix)
+