feat(chat): support public channel chat

app/dependencies/param.py

@@ -0,0 +1,39 @@
+from __future__ import annotations
+
+from typing import Any
+
+from fastapi import Request
+from fastapi.exceptions import RequestValidationError
+from pydantic import BaseModel, ValidationError
+
+
+def BodyOrForm[T: BaseModel](model: type[T]):
+    async def dependency(
+        request: Request,
+    ) -> T:
+        content_type = request.headers.get("content-type", "")
+
+        data: dict[str, Any] = {}
+        if "application/json" in content_type:
+            try:
+                data = await request.json()
+            except Exception:
+                raise RequestValidationError(
+                    [
+                        {
+                            "loc": ("body",),
+                            "msg": "Invalid JSON body",
+                            "type": "value_error",
+                        }
+                    ]
+                )
+        else:
+            form = await request.form()
+            data = dict(form)
+
+        try:
+            return model(**data)
+        except ValidationError as e:
+            raise RequestValidationError(e.errors())
+
+    return dependency