Reorganize Python stuff and add command to create packs

Fixes #11

sticker/lib/util.py

@@ -0,0 +1,67 @@
+# Copyright (c) 2020 Tulir Asokan
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+from io import BytesIO
+import os.path
+import json
+
+from PIL import Image
+
+from . import matrix
+
+
+def convert_image(data: bytes) -> (bytes, int, int):
+    image: Image.Image = Image.open(BytesIO(data)).convert("RGBA")
+    new_file = BytesIO()
+    image.save(new_file, "png")
+    w, h = image.size
+    if w > 256 or h > 256:
+        # Set the width and height to lower values so clients wouldn't show them as huge images
+        if w > h:
+            h = int(h / (w / 256))
+            w = 256
+        else:
+            w = int(w / (h / 256))
+            h = 256
+    return new_file.getvalue(), w, h
+
+
+def add_to_index(name: str, output_dir: str) -> None:
+    index_path = os.path.join(output_dir, "index.json")
+    try:
+        with open(index_path) as index_file:
+            index_data = json.load(index_file)
+    except (FileNotFoundError, json.JSONDecodeError):
+        index_data = {"packs": []}
+    if "homeserver_url" not in index_data and matrix.homeserver_url:
+        index_data["homeserver_url"] = matrix.homeserver_url
+    if name not in index_data["packs"]:
+        index_data["packs"].append(name)
+        with open(index_path, "w") as index_file:
+            json.dump(index_data, index_file, indent="  ")
+        print(f"Added {name} to {index_path}")
+
+
+def make_sticker(mxc: str, width: int, height: int, size: int,
+                 body: str = "") -> matrix.StickerInfo:
+    return {
+        "body": body,
+        "url": mxc,
+        "info": {
+            "w": width,
+            "h": height,
+            "size": size,
+            "mimetype": "image/png",
+
+            # Element iOS compatibility hack
+            "thumbnail_url": mxc,
+            "thumbnail_info": {
+                "w": width,
+                "h": height,
+                "size": size,
+                "mimetype": "image/png",
+            },
+        },
+    }