1 files changed, 135 insertions, 0 deletions
diff --git a/robots/server.py b/robots/server.py
new file mode 100644
index 0000000..759766c
--- /dev/null
+++ b/robots/server.py
@@ -0,0 +1,135 @@
+from functools import wraps
+import json
+import os
+import uuid
+
+import logbook
+
+import network
+
+log = logbook.Logger(__name__)
+
+def bad_request(msg):
+    return {'status': 400, 'message': msg}
+
+def not_found(msg):
+    return {'status': 404, 'message': msg}
+
+def server_error(msg):
+    return {'status': 500, 'message': msg}
+
+def success(**kwargs):
+    rv = {'status': 200}
+    rv.update(kwargs)
+    return rv
+
+def json_handler(handle):
+    SERVER_ERROR = json.dumps(server_error('Unexpected server error.')).encode('utf-8')
+
+    @wraps(handle)
+    def handler(data):
+        try:
+            request = json.loads(data.decode('utf-8'))
+        except ValueError:
+            log.exception('Bad JSON data: {!r}', request)
+        try:
+            response = handle(request)
+            data = json.dumps(response).encode('utf-8')
+        except Exception:
+            log.exception('Exception in handler.')
+            data = SERVER_ERROR
+        return data
+
+    return handler
+
+def get_options(fn):
+    arguments = fn.__code__.co_varnames
+    defaults = fn.__defaults__
+
+    required = arguments[:-len(defaults)]
+    optional = list(zip(defaults, arguments[-len(defaults):]))
+    return (required, optional)
+
+class Server(object):
+    SERVER_NAME = os.getenv('NAME')
+    SERVER_KIND = 'robots'
+
+    def __init__(self):
+        # Maps bot names to a function which will return the bot callable.
+        # (or, you know, a class)
+        self.bots = {}
+
+        # Maps instance ids to a bot callable.
+        self.instances = {}
+
+    def add_bot(self, fn, name=None):
+        if name is None:
+            name = fn.__name__
+        self.bots[name] = fn
+
+    def add_simple_bot(self, fn, name=None):
+        if name is None:
+            name = fn.__name__
+        return self.add_bot(lambda: fn, name)
+
+    def list_bots(self):
+        bots = {
+            name: None and get_options(fn)
+            for name, fn in self.bots.items()
+        }
+        return success(bots=bots)
+
+    def create(self, name, options):
+        try:
+            bot_class = self.bots[name]
+        except KeyError:
+            message = 'Could not find bot %s' % (name,)
+            log.warning(message)
+            return not_found(message)
+
+        try:
+            instance = bot_class(**options)
+        except Exception:
+            message = 'Could not create bot %s' % (name,)
+            log.exception(message)
+            return server_error(message)
+
+        instance_id = str(uuid.uuid4())
+        self.instances[instance_id] = instance
+        log.debug('Created new bot instance %s' % instance_id)
+        return success(instance_id=instance_id)
+
+    def handle(self, request):
+        try:
+            action = request['action']
+
+            if action == 'list':
+                return self.list_bots()
+
+            elif action == 'create':
+                name = request['name']
+                options = request['options']
+                return self.create(name, options)
+
+            elif action == 'process':
+                instance_id = request['instance_id']
+                state = request['state']
+                return self.next_move(instance_id, state)
+
+            elif action == 'destroy':
+                instance_id = request['instance_id']
+                return self.destroy(instance_id)
+
+            else:
+                return bad_request('Unrecognised action %s' % (action,))
+
+        except KeyError as e:
+            return bad_request('No %s specified' % e.args)
+
+    def run(self):
+        server = network.Server(
+            self.SERVER_NAME,
+            self.SERVER_KIND,
+            handler=json_handler(self.handle),
+        )
+        server.run()