Add message info plugin

stdplugins/info.py

@@ -0,0 +1,98 @@
+# 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/.
+
+import string
+
+from telethon import events
+from telethon.utils import add_surrogate
+from telethon.tl.types import MessageEntityPre
+from telethon.tl.tlobject import TLObject
+import datetime
+
+PRINTABLE_SET = set(bytes(string.printable, 'ascii'))
+STR_LEN_MAX = 256
+BYTE_LEN_MAX = 64
+
+
+def parse_pre(text):
+    text = text.strip()
+    return (
+        text,
+        [MessageEntityPre(offset=0, length=len(add_surrogate(text)), language='potato')]
+    )
+
+
+def yaml_format(obj, indent=0):
+    """
+    Pretty formats the given object as a YAML string which is returned.
+    (based on TLObject.pretty_format)
+    """
+    result = []
+    if isinstance(obj, TLObject):
+        obj = obj.to_dict()
+
+    if isinstance(obj, dict):
+        result.append(obj.get('_', 'dict') + ':')
+        if obj:
+            items = obj.items()
+            has_multiple_items = len(items) > 2
+            if has_multiple_items:
+                result.append('\n')
+            indent += 2
+            for k, v in items:
+                if k == '_' or v is None:
+                    continue
+                formatted = yaml_format(v, indent)
+                if not formatted.strip():
+                    continue
+                result.append(' ' * (indent if has_multiple_items else 1))
+                result.append(f'{k}: {formatted}')
+                result.append('\n')
+            result.pop()
+            indent -= 2
+            result.append(' ' * indent)
+    elif isinstance(obj, str):
+        # truncate long strings and display elipsis
+        result.append(repr(obj[:STR_LEN_MAX]))
+        if len(obj) > STR_LEN_MAX:
+            result.append('…')
+    elif isinstance(obj, bytes):
+        # repr() bytes if it's printable, hex like "FF EE BB" otherwise
+        if all(c in PRINTABLE_SET for c in obj):
+            result.append(repr(obj))
+        else:
+            if len(obj) > BYTE_LEN_MAX:
+                result.append('<…>')
+            else:
+                result.append(' '.join(f'{b:02X}' for b in obj))
+    elif isinstance(obj, datetime.datetime):
+        # ISO-8601 without timezone offset (telethon dates are always UTC)
+        result.append(obj.strftime('%Y-%m-%d %H:%M:%S'))
+    elif hasattr(obj, '__iter__'):
+        # display iterables one after another at the base indentation level
+        result.append('\n')
+        indent += 2
+        for x in obj:
+            result.append(' ' * indent)
+            result.append(yaml_format(x, indent))
+            result.append('\n')
+        result.pop()
+        indent -= 2
+        result.append(' ' * indent)
+    else:
+        result.append(repr(obj))
+
+    return ''.join(result)
+
+
+@borg.on(events.NewMessage(pattern=r"\.info", outgoing=True))
+async def _(event):
+    if not event.message.is_reply:
+        return
+    msg = await event.message.get_reply_message()
+    yaml_text = yaml_format(msg)
+    await event.edit(
+        yaml_text,
+        parse_mode=parse_pre
+    )