Python: Implement state callbacks using decorators

1 files changed, 59 insertions, 8 deletions

diff --git a/wrappers/python/eduvpncommon/main.py b/wrappers/python/eduvpncommon/main.py
index ac13344..9a4931f 100644
--- a/wrappers/python/eduvpncommon/main.py
+++ b/wrappers/python/eduvpncommon/main.py
@@ -1,21 +1,72 @@
-from . import lib, VPNStateChange, GetDataError
+from . import lib, VPNStateChange, GetDataError, GetPtrString
 from ctypes import *
+from enum import Enum
+import functools
 
-@VPNStateChange
-def state_change(old, new, data):
-    print(f"Python: State change {old.decode()} {new.decode()} DATA {data.decode()}")
+class StateType(Enum):
+    Enter = 1
+    Leave = 2
 
 # Registers the python app with the Go code
 # name: The name of the app to be registered
 # url: The url of the server to connect to, FIXME: To be removed
 # state_callback: The callback to trigger whenever a state is changed, FIXME: Remove whenever this wrapper has implemented callbacks using function decorations
 def Register(name, config_directory, state_callback):
-    name_bytes = name.encode('utf-8')
-    dir_bytes = config_directory.encode('utf-8')
-    lib.Register(name_bytes, dir_bytes, state_callback)
+    name_bytes = name.encode("utf-8")
+    dir_bytes = config_directory.encode("utf-8")
+    ptr_err = lib.Register(name_bytes, dir_bytes, state_callback)
+    err_string = GetPtrString(ptr_err)
+    return err_string
+
+
+class EduVPN(object):
+    def __init__(self, name, config_directory):
+        self.event_handler = EventHandler()
+        self.name = name
+        self.config_directory = config_directory
+
+    def register(self) -> bool:
+        closure = VPNStateChange(
+            lambda old_state, new_state, data: self.callback(
+                old_state.decode(), new_state.decode(), data.decode()
+            )
+        )
+        return Register(self.name, self.config_directory, closure) == ""
+
+    @property
+    def event(self):
+        return self.event_handler
+
+    def callback(self, old_state, new_state, data):
+        self.event.run(old_state, new_state, data)
+
+
+class EventHandler(object):
+    def __init__(self):
+        self.handlers = {}
+
+    def on(self, state, state_type):
+        def wrapped_f(func):
+            if (state, state_type) not in self.handlers:
+                self.handlers[(state, state_type)] = []
+            self.handlers[(state, state_type)].append(func)
+            return func
+        return wrapped_f
+
+    def run_state(self, state, state_type, data):
+        if (state, state_type) not in self.handlers:
+            return
+        for func in self.handlers[(state, state_type)]:
+            func(data)
+
+    def run(self, old_state, new_state, data):
+        if old_state == new_state:
+            return
+        self.run_state(old_state, StateType.Leave, data)
+        self.run_state(new_state, StateType.Enter, data)
+
 
 def GetDiscoServers():
     servers, serversErr = GetDataError(lib.GetServersList())
     organizations, organizationsErr = GetDataError(lib.GetOrganizationsList())
     return servers, serversErr, organizations, organizationsErr
-