translate: simplify the stupid ass mechanism

Now you either specify source/dest languages or nothing, way better.

edmond/bot.py

@@ -14,6 +14,7 @@ from edmond.plugin import Plugin
 
 
 class Bot(irc.client.SimpleIRCClient, Logger):
+    """Main class for the IRC bot: handles connection and manages available plugins."""
 
     CHANNELS_RUNTIME_KEY = "_channels"
 

edmond/plugins/translate.py

@@ -9,6 +9,15 @@ from edmond.plugin import Plugin
 
 
 class TranslatePlugin(Plugin):
+    """Translate text using the `translate` package.
+
+    The translate package can use a bunch of translation interfaces but the default is
+    MyMemory which is fine for our purposes. There are two ways to ask for a
+    translation:
+    - Without any additional params, the source language is autodetected and the target
+      language is specified in the config file;
+    - With BOTH source and target languages.
+    """
 
     REQUIRED_CONFIGS = [
         "commands",
@@ -42,19 +51,12 @@ class TranslatePlugin(Plugin):
 
     def parse_words(self, words):
         """Parse given words for parameters and return (from, to, text)."""
-        from_lang = "autodetect"
-        to_lang = self.config["default_dest"]
-        num_param_found = 0
-        for word in words:
-            if not word.startswith("!"):
-                break
-            num_param_found += 1
-            param_word = word.lstrip("!")
-            if not ":" in param_word:
-                continue
-            param_name, param_value = param_word.split(":")
-            if param_name == self.config["param_source"]:
-                from_lang = param_value
-            elif param_name == self.config["param_dest"]:
-                to_lang = param_value
-        return from_lang, to_lang, " ".join(words[num_param_found:])
+        # If no language specification is found, use default params.
+        if (
+            len(words) < 5
+            or words[0] != self.config["param_source"]
+            or words[2] != self.config["param_dest"]
+        ):
+            return "autodetect", self.config["default_dest"], " ".join(words)
+        # Else use the parameters provided.
+        return words[1], words[3], " ".join(words[4:])