Rename some filers and folder for clarity

src/backend/errors.py

@@ -0,0 +1,89 @@
+from dataclasses import dataclass, field
+
+import nio
+
+
+# Matrix Errors
+
+@dataclass
+class MatrixError(Exception):
+    http_code: int = 400
+    m_code:    str = "M_UNKNOWN"
+
+    @classmethod
+    def from_nio(cls, response: nio.ErrorResponse) -> "MatrixError":
+        # Check for the M_CODE first: some errors for an API share the same
+        # http code, but have different M_CODEs (e.g. POST /login 403).
+        for subcls in cls.__subclasses__():
+            if subcls.m_code == response.status_code:
+                return subcls()
+
+        for subcls in cls.__subclasses__():
+            if subcls.http_code == response.transport_response.status:
+                return subcls()
+
+        return cls(response.transport_response.status, response.status_code)
+
+
+@dataclass
+class MatrixForbidden(MatrixError):
+    http_code: int = 403
+    m_code:    str = "M_FORBIDDEN"
+
+
+@dataclass
+class MatrixBadJson(MatrixError):
+    http_code: int = 403
+    m_code:    str = "M_BAD_JSON"
+
+
+@dataclass
+class MatrixNotJson(MatrixError):
+    http_code: int = 403
+    m_code:    str = "M_NOT_JSON"
+
+
+@dataclass
+class MatrixUserDeactivated(MatrixError):
+    http_code: int = 403
+    m_code:    str = "M_USER_DEACTIVATED"
+
+
+@dataclass
+class MatrixNotFound(MatrixError):
+    http_code: int = 404
+    m_code:    str = "M_NOT_FOUND"
+
+
+@dataclass
+class MatrixTooLarge(MatrixError):
+    http_code: int = 413
+    m_code:    str = "M_TOO_LARGE"
+
+
+# Client errors
+
+@dataclass
+class UserNotFound(Exception):
+    user_id: str = field()
+
+
+@dataclass
+class InvalidUserId(Exception):
+    user_id: str = field()
+
+
+@dataclass
+class InvalidUserInContext(Exception):
+    user_id: str = field()
+
+
+@dataclass
+class UneededThumbnail(Exception):
+    pass
+
+
+@dataclass
+class BadMimeType(Exception):
+    wanted: str = field()
+    got:    str = field()