Added Downloader cog (#786)

cogs/downloader/json_mixins.py

@@ -0,0 +1,37 @@
+import json
+from pathlib import Path
+
+
+class RepoJSONMixin:
+    INFO_FILE_NAME = "info.json"
+
+    def __init__(self, repo_folder: Path):
+        self._repo_folder = repo_folder
+
+        self.author = None
+        self.install_msg = None
+        self.short = None
+        self.description = None
+
+        self._info_file = repo_folder / self.INFO_FILE_NAME
+        if self._info_file.exists():
+            self._read_info_file()
+
+        self._info = {}
+
+    def _read_info_file(self):
+        if not (self._info_file.exists() or self._info_file.is_file()):
+            return
+
+        try:
+            with self._info_file.open(encoding='utf-8') as f:
+                info = json.load(f)
+        except json.JSONDecodeError:
+            return
+        else:
+            self._info = info
+
+        self.author = info.get("author")
+        self.install_msg = info.get("install_msg")
+        self.short = info.get("short")
+        self.description = info.get("description")